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Research trends on human trafficking: a bibliometric analysis using Scopus database

Globalization and Health201814:106

https://doi.org/10.1186/s12992-018-0427-9

  • Received: 20 June 2018
  • Accepted: 24 October 2018
  • Published:

Abstract

Background

Human trafficking is a crime against humanity. It is also a serious threat to global health and security. Globalization has made human trafficking an easier task for the criminal organizations. No data are available on the volume, research trends, and key players in this field. Therefore, the aim of this study was to assess the research activity and research trends on human trafficking.

Methods

A bibliometric method was adopted. Literature published in academic journals indexed in Scopus database was retrieved. The study period was set from 2000 to 2017.

Results

Two thousand forty-four documents were retrieved. The average number of authors per document was 1.9. Over one third (n = 771; 37.7%) of the retrieved documents were about sex trafficking, 616 (30.1%) were about labor trafficking/forced labor, 199 (9.7%) were about child trafficking, and 138 (6.8%) were about organ trafficking. One third (n = 707; 34.6%) of the documents were in health-related fields while 1526 (74.7%) were in social sciences and humanities. The USA ranked first (n = 735; 36.0%) regarding the number of published documents. Geographic distribution of the retrieved document showed that world regions with a high prevalence of human trafficking had the least research contribution. International research collaboration has a limited contribution to the retrieved literature. The Harvard University (USA) was the most active institution (n = 39; 1.9%). International Migration (n = 35; 1.7%) was the most active journal in publishing documents on HT. Documents published in Transplantation journal received the highest number of citations per document (25.5) and two of the most cited documents were about organ trafficking.

Conclusion

There was an under-representation of health-related literature on human trafficking. Literature on sex trafficking dominated the field of human trafficking. Research networks and research collaboration between the source and destination countries is important. Future research plans need to focus on health issues and on exploited/trafficked laborers.

Keywords

  • Human trafficking
  • Bibliometrics
  • Research analysis
  • Global health

Background

Human trafficking (HT), or modern slavery, is an old problem [1]. However, in the past few decades, HT became a global concern [2, 3]. The most accepted definition of HT is presented by the Trafficking Protocol [4]. Human trafficking was addressed by several international agreements and conferences such as the International Agreement for the Suppression of White Slave Traffic (1904) [5], International Agreement for the Suppression of Traffic in Women and Children (1927) [6], the Trafficking Protocol (2000), and the Protocol against Smuggling of Migrants by Land, Sea, and Air (2000) [4]. The last two protocols recognized HT as a transnational crime rather than just human rights or migration issue [7]. Different countries used the UN Trafficking Protocol to develop criminal codes for HT. As of 2016, over 150 countries had criminal laws for HT [8]. In the USA, the Office to Monitor and Combat Trafficking in Persons releases an annual report (TIP Report) about international efforts to combat trafficking. The European Union adopted the Brussels Declaration on Preventing and Combating Trafficking in Human Beings which aimed to fight HT in Europe [9]. Other non-European and non-American countries developed their own national policies and protocols to criminalize and fight HT [10].

Sex trafficking is one of the most common forms of HT with more than half a million women being trafficked every year [6]. Forced labor, child labor, child soldiers, debt bondage, involuntary domestic servitude, and organ/tissue removal for transplantation are other common forms of HT [11]. Forced prostitution represents the highest percentage of HT victims with the majority being women from Eastern Europe, Central Asia, and North and South America [8, 12, 13]. In contrast, the majority of victims of forced labor are men from Africa, the Middle East, and Asia [8, 12]. International organizations distinguish between HT and smuggling. In smuggling, the actor takes part in the process while HT involves some deception or coercion [14]. Unlike HT, migration and smuggling are less often involved with a criminal organization [14].

Human trafficking has a global dimension despite that trafficking could occur within the same country [8]. Human trafficking affects people of all races, religions, social class, and education. It often results in mental health disorders and life-threatening infections [8, 1520]. For example, a study of 207 trafficked women from 14 countries reported that 95% of women had experienced physical and/or sexual violence [21]. A study on trafficked Nepalese girls and women found that 23% of them tested positive for HIV [22]. Despite its negative social, health, and legal consequences, HT is a growing business for criminal organizations [21, 23]. Poverty, social injustice, disasters, substance abuse, family breakdown, and homelessness are major push factors for victims [2426]. Globalization has created a larger gap between developing and developed countries with poverty and marginalization being major push factors for victims [1].

The International Labor Organization (ILO) reported 12.3 million trafficking victims in 2005, 21 million victims in 2012, and 40.3 million victims in 2016 [27]. The 2016 report of the ILO estimated that 40.3 million people in modern slavery, including 24.9 in forced labor and 15.4 million in the forced marriage [28]. Out of the 24.9 million people trapped in forced labor, 16 million people in the private sector such as domestic work, construction or agriculture; 4.8 million persons in forced sexual exploitation, and 4 million persons in forced labor imposed by state authorities [27]. The ILO considers the Asia-Pacific region to have the largest number of victims of HT followed by Africa and Latin America [28]. It was estimated that over 40% of trafficked victims were detected in their own countries and that 71% of the trafficked victims were women while 28% were children [8].

Bibliometric analysis is a research method used to shed light on research activity [2931]. It differs from systematic reviews, which aim to answer a specific research question based on a selected group of articles [32, 33]. It also differs from scoping reviews, which aim to identify the nature and extent of research evidence [34, 35]. Bibliometric studies were carried out to provide a snapshot of national and international contribution to literature [36] and to advance information and science [37]. Bibliometric indicators assess national and international efforts carried out to achieve a particular goal. Several bibliometric studies on migrants and refugees have been published [3840]. However, none was carried out on HT. Therefore, the aim of this study was to analyze published literature on HT. Such a study will shed light on the global research activity and discussed themes in literature on HT. Bibliometric analysis may be useful for health authorities and UN agencies interested in mapping and identifying research gaps within the HT research landscape, which is important for advancing an evidence-informed research agenda. Findings of a bibliometric analysis are difficult to obtain by other research methods such as systematic or scoping reviews. For example, a recent systematic review of research methods on HT and health concluded that despite the presence of various quantitative and qualitative data collection and analysis methods, the implemented methodological approaches have limitations that affect what is known about HT and health [41]. Most available literature on HT is based on emotional stories rather than on empirical research [42]. Bibliometric analysis would give an accurate quantitative analysis of literature on HT that would serve as a basis for future studies. The findings of a bibliometric study on HT will shed light on the evolution, volume, and scope of research on HT and will help identify countries and regions lagging behind in this field [5]. A bibliometric analysis of literature on HT will also give detailed information on the number of publication on each type of HT and therefore a direct academic and research effort as well as funding towards less-researched types of HT.

Methods

Source of information

In the current study, SciVerse Scopus was selected to accomplish the objectives. Scopus is a bibliographic database created by Elsevier in November 2004 [43]. With 22,800 titles from over 5000 international publishers, Scopus delivers the most comprehensive view of the world’s research output in the fields of science, technology, medicine, social science and arts and humanities [43]. Scopus database includes all MEDLINE journals and allows for citation analysis [44, 45]. Scopus database has several operating functions that facilitate bibliometric analysis. Such operating functions include journal name, type of document, year of publication, authors and their affiliations, the number of citations, and h-index metrics for documents [46, 47].

Study design

A bibliometric method was implemented. The study period was set from 2000 to 2017. The study period was determined based on the assumption that HT has attracted a lot of public attention after the introducing the UN Trafficking Protocol ratified in December 2000.

Search strategy

In bibliometric analysis, selection of keywords is of utmost importance, as these keywords have a direct impact on the findings and results. In the current study, search strategy was based on title or title/abstract search with certain constraints to minimize false-positive results (Table 1). Keywords were obtained from previously published literature on HT [20, 4851]. The search strategy was limited to documents published in academic journals but was not restricted to any language. The online search was performed on June 03, 2018.
Table 1

Research strategy and keywords used to retrieve documents in the field of human trafficking

Search method

Keywords

Constraints

Exclusion

Title search

TITLE(“modern slavery” or “trade in human being” or “human trafficking” OR “trafficking in human” OR “lab*r trafficking” OR “forced lab*r” OR “compulsory lab*r” OR “sex* traffick*” OR “sex* trade*” OR “trafficking in persons” OR “traffick* person*” OR “traffick* wom*” OR “traffick* people” OR “traffick* girl*” OR “wom*n traffick*” OR “child* traffick*” OR “organ traffick*” OR “transplant tourism” OR “trafficking in wom*” OR “traffick* in organ*” OR “forced prostit*” OR “trafficking of child*” OR “trafficking of wom*” OR “sex* slavery” OR “commercial sexual exploitation” OR “lab*r traffick*” OR “organ trade” OR “forced marriage” OR “bonded lab*r” OR “child harvesting” OR “modern slavery” OR “child prostitut*” or “forced prostitut*” or “domestic servitude” or “debt bondage” or “debt slavery” or “bonded lab*r” or “child pornography”)

NONE

AND NOT TITLE-ABSTRACT (insect or droso* OR sexta OR cell OR molecular OR biology OR leukocyte* OR DNA)

OR

 Title search

TITLE (“tissue removal” OR “ova removal” OR slave* OR slavery OR servitude OR “child lab*r” OR “cross border traffick*” OR “child soldier*” OR anti-trafficking OR “human abduction”)

AND ALL (“human trafficking” OR “trafficking in human” OR “forced lab*r” OR “forced sex*” OR “forced prostitution” OR kidnap* or abduct* OR “child sex* or exploitation”)

AND NOT TITLE-ABSTRACT (insect or droso* OR sexta OR cell OR molecular OR biology OR leukocyte* OR DNA)

OR

 Title-Abstract search

TITLE-ABSTRACT (traffick*) AND TITLE-ABSTRACT (“in human” OR “human being*”)

AND ALL (“human trafficking” OR “trafficking in human*”)

AND NOT TITLE-ABS-KEY (phallus OR pgd OR cell OR molecule OR gene OR *cytes OR dna OR nucle* OR droso* OR sexta OR memberane OR “trade-off*” or insect)

AND NOT SRCTITLE (insect OR physiology OR biology OR biochemistry OR cellular OR evolution*)

AND

 Limit

1. Source type = journal

2. Time interval = 2000–2017

Estimation of the number of health- and non-health-related documents

Using the function designated as “subject area”; it was possible to estimate the number of HT documents in health field, defined as documents in the following subject areas: medicine, nursing, psychology, pharmacology, neuroscience, general health, microbiology/immunology, biochemistry, and dentistry. The total number of health and non-health documents was greater than the total number of the retrieved documents because some journals are indexed in both medicine and social sciences; e.g. the Journal of Social Medicine which is categorized in both social science and medicine. Health-related documents were further divided into different domains such as mental health, health policy and systems, maternal and reproductive health, non-communicable diseases, and infectious diseases [38].

Bibliometric indicators, analytics, and mapping

In the current study, bibliometric indicators were presented as ten most active countries, institutions, journals, authors, and ten most cited documents. The choice of number ten as a threshold to list the results was an arbitrary selection that has been used in previously published bibliometric studies [40, 5254].

International collaboration

Research collaboration was assessed using author affiliation. For example, documents with authors having different country affiliations represent international research collaboration while documents with authors having the same country affiliation represent intra-country collaboration. Scopus allows for segregation of documents based on authoraffiliation. Therefore, for each country, the number of documents with international authors was calculated as a percentage of the total number of documents published by that country. Documents with international authors were referred to as multiple country publications (MCP) and represented the extent of international collaboration [5558].

Bibliometric visualization maps

Co-authorship analysis, international collaboration, and keyword analysis were presented as network visualization maps using VOSviewer (Leiden University, Leiden, Netherlands) [59, 60].The Statistical Package for Social Sciences (SPSS) (SPSS, Chicago, Illinois) was used to generate line presentation of the annual growth of publications. ArcGIS 10.1 software (Esri; USA) is a geographic information system used in bibliometric studies to map worldwide research contribution. The GIS map allows for a better understanding of regional contribution to a specific scientific topic.

Results

Growth of publications and typology of documents

In total, 2044 documents were retrieved (Additional file 1). The retrieved documents were of eight different types: research articles (1553; 76.0%), reviews (280; 13.7%); notes (66; 3.2%); editorials (46; 2.3%), letters (30; 1.5%); short surveys (23; 1.1%), conference papers (22; 1.1%), and unclassified (24; 1.2%).

The number of retrieved documents have significantly increased during the study period (linear regression: β = .978, P < .001, R2 = .956; Figure 1). If this trend continues, it was estimated that 293 documents would be published in 2020.
Fig. 1
Fig. 1

Total number of published documents from 2000 to 2017

Mapping the most frequent keywords and typology of trafficking

Most frequent keywords were visualized (Fig. 2). The map showed five clusters: (1) organ trafficking; (2) child trafficking; (3) forced labor; (4) sex trafficking of women, and (5) slavery. Further analysis of the retrieved documents showed that 771 (37.7%) documents were about sex trafficking, 616 (30.1%) were about labor trafficking/forced labor, 199 (9.7%) were about child trafficking, and 138 (6.8%) were about organ trafficking. The remaining documents were general documents or ones that discussed multiple types of trafficking.
Fig. 2
Fig. 2

Mapping 10 most frequent keywords

Research domains

In total, 707 (34.6%) documents were in the health field while 1526 (74.7%) were in social sciences and humanities taking into consideration certain limited overlap between the health and health research domains. Analysis of the retrieved showed that 971 (47.5%) documents were about law and criminology, 238 (11.6%) were about health policy and systems, 200 (9.8%) were about social work, and 183 (9.0%) were about mental health (Fig. 3).
Fig. 3
Fig. 3

Research domains in the retrieved literature

Top 10 active countries

Authors from 91 different countries participated in publishing the retrieved documents. The top 10 active countries participated in publishing 1478 (72.3%) documents (Table 2). The United States ranked first (735; 36.0%) regarding the number of published documents. Five countries in the top 10 active list were in Western Europe, two were in Northern America, one in the Western Pacific region, one in Southeast Asia, and one in Latin America. The geographic distribution of the retrieved document showed that world regions with a high prevalence of HT, such as South East Asia, East Europe, Africa, and Latin America [8], had the least research contribution (Fig. 4).
Table 2

Top 10 active countries and international research collaboration

Rank

Country

Frequency (%) N = 2044

Number of collaborating countries

SCP

MCP

1st

United States

735 (36.0)

43

644 (87.6)

91 (12.4)

2nd

United Kingdom

269 (13.2)

28

222 (82.5)

47 (17.5)

3rd

Canada

111 (5.4)

20

88 (79.3)

23 (20.7)

4th

Australia

84 (4.1)

19

68 (81.0)

16 (19.0)

5th

Germany

75 (3.7)

13

60 (80.0)

15 (20.0)

6th

Netherlands

53 (2.6)

10

45 (84.9)

8 (15.1)

7th

Brazil

43 (2.1)

10

38 (88.4)

5 (11.6)

8th

Italy

38 (1.9)

9

31 (81.6)

7 (18.4)

9th

India

37 (1.8)

15

19 (51.4)

18 (48.6)

10th

France

33 (1.6)

7

25 (75.8)

8 (24.2)

  

1478 (72.3)

 

1240 (83.9)

238 (16.1)

SCP single country collaboration = intra-country collaboration, MCP multiple country collaboration = international collaboration

Fig. 4
Fig. 4

Geographic distribution of publications based on the country affiliation of authors. The following is the color-coding for the map

International collaboration

Analysis of international research collaboration for the top 10 active countries showed that India had the highest percentage of documents (49%) with international research collaboration. In contrast, Brazil had the least percentage of documents (12%) with international research collaboration. For the US, which led in the number of publications, only 12.5% of documents with US authors included authors from other countries. Of the 1478 publications produced by the top 10 active countries, there were only 238 (16.1%) publications with international collaboration.

Top 10 active institutions

Harvard University (USA) (n = 39; 1.9%) was the most active institution in this field followed by University of British Columbia (Canada) and London School of Hygiene & Tropical Medicine (UK) (Table 3). The top 10 active list of institutions included four in the USA, three in Canada, and three in the UK.
Table 3

Top 10 active institutions in the field of human trafficking

Rank

Institution

Frequency (%) N = 2044

Country

1st

Harvard Medical School

39 (1.9)

USA

2nd

The University of British Columbia

26 (1.3)

Canada

3rd

London School of Hygiene & Tropical Medicine

22 (1.1)

UK

4th

Massachusetts General Hospital

20 (1.0)

USA

5th

King’s College London

18 (0.9)

UK

5th

University of Oxford

18 (0.9)

UK

7th

Johns Hopkins University

15 (0.7)

USA

8th

University of Toronto

14 (0.7)

Canada

9th

George Mason University

13 (0.6)

USA

9th

York University

13 (0.6)

Canada

Authorship analysis

In total, 3920 authors participated in publishing the retrieved documents, giving an average of 1.9 authors per document. Approximately 61% (n = 1250) documents were single-authored publications, 20.0% (n = 408) were two-authored publications, while the remaining 18.9% (n = 386) were multi-authored publications (≥ 3 authors per document). Professor Cathy Zimmerman (UK) was the most active author (22; 1.1%). Professor Jay Silverman (USA) ranked second (17; 0.8%) (Table 4).
Table 4

Top 10 active authors in the field of human trafficking

Ranka

Author

Frequency (%) N = 2044

Affiliation

1st

Zimmerman, C.

22 (1.1)

London School of Hygiene & Tropical Medicine, Department of Global Health and Development, London, United Kingdom

2nd

Silverman, J.G.

17 (0.8)

Center on Gender Equity and Health, Division of Global Public Health. University of California, San Diego, San Diego, United States

3rd

Oram, S.

16 (0.8)

Health Service and Population Research, King’s College London, London, United Kingdom

4th

Decker, M.R.

14 (0.7)

Johns Hopkins Bloomberg School of Public Health, Department of Population, Baltimore, United States

5th

Reid, J.A.

13 (0.7)

University of South Florida St. Petersburg, St Petersburg, United States

6th

Raj, A.

12 (0.6)

University of California, San Diego, Department of Medicine, San Diego, United States

7th

Delmonico, F.L.

11 (0.5)

Organisation Mondiale de la Sante, New England Donor Services, Geneve, Switzerland

8th

Howard, L.M.

9 (0.4)

King’s College London, London, United Kingdom

9th

Cho, S.Y.

8 (0.4)

Universitat Marburg, Marburg, Germany

9th

Gupta, J.

8 (0.4)

George Mason University, Department of Global and Community Health, Fairfax, United States

aAuthors with equal research output were given the same rank, and then a gap is left in the ranking numbers

Research networks

Mapping research networks for authors with a minimum research output of five documents showed only two research clusters (Fig. 5). The first cluster (red) included six authors with Zimmerman, C. as a member in this cluster. The second cluster (green) included five authors with Silverman, J as a member of this cluster.
Fig. 5
Fig. 5

Networks of active authors who published at least five publications and exist in a research network with a minimum of five authors

Preferred journals for publishing documents about HT

The retrieved documents were published in 998 different journals. The International Migration was the most active journal in this field. Top 10 active journals belonged to different fields including migration, criminology, medicine, social studies, gynecology, transplantation, violence, and human rights (Table 5). The majority of active journals were based in the USA. Documents published in Transplantation (25.5) journal received the highest number of citations per article followed by those published in International Migration (22.5).
Table 5

Top 10 active journals in the field of human trafficking

Ranka

Journal

Frequency (%) N = 2044

C/Ab

 

Subject area (category)c

1st

International Migration

35 (1.7)

22.5

UK

Social sciences (demography)

2nd

Trends In Organized Crime

25 (1.2)

7.6

USA

Social sciences (Law)

3rd

Crime Law And Social Change

24 (1.2)

7.3

Netherlands

Medicine (Pathology and Forensic Medicine)

4th

Social Inclusion

20 (1.0)

1.7

Portugal

Psychology (social psychology)

5th

Lancet

19 (0.9)

6.3

UK

Medicine

6th

Cadernos Pagu

15 (0.7)

3.1

Brazil

Social Sciences (Gender studies)

6th

International Social Work

15 (0.7)

12.6

USA

Social Sciences (social and political sciences)

8th

Human Rights Review

13 (0.6)

7.3

Netherlands

Social sciences (Law)

8th

Osteuropa

13 (0.6)

1.2

Germany

(social and political sciences)

10th

European Journal Of Criminology

12 (0.6)

9.8

USA

Social sciences (Law)

10th

European Journal On Criminal Policy And Research

12 (0.6)

12.3

Netherlands

Social sciences (Law)

10th

International Journal Of Gynecology And Obstetrics

12 (0.6)

17.8

UK

Medicine (Gynecology And Obstetrics)

10th

Journal Of International Criminal Justice

12 (0.6)

6.2

UK

Social sciences (Law)

10th

Journal Of Interpersonal Violence

12 (0.6)

10.9

USA

Psychology (clinical psychology)

10th

Transplantation

12 (0.6)

25.8

USA

Medicine (Transplantation)

10th

Women And Criminal Justice

12 (0.6)

7.5

USA

Social sciences (Law and Gender studies)

a Journals with equal research output were given the same rank, and then a gap is left in the ranking numbers

bNumber of citations per article

cObtained from Scimago Journal and Country Rank

Citation analysis

The retrieved documents received 15,505 citations giving a mean of 7.6 citations per document. The h-index of the retrieved documents was 48. The document that received the highest number of citations was published in 2007 in Politics and Society. Top ten cited documents discussed topics about organ trafficking, mental health, and HIV infections of HT victims. Table 6 showed the list of top 10 cited documents [22, 6170].
Table 6

Top 10 cited documents in the field of human trafficking

Rankaa

Title

Source title

Number of citations

Document Type

1st

The social construction of sex trafficking: Ideology and institutionalization of a moral crusade

Politics and Society

246

Article

2nd

The state of the international organ trade: A provisional picture based on integration of available information

Bulletin of the World Health Organization

172

Review

3rd

Organ trafficking and transplant tourism: A commentary on the global realities

American Journal of Transplantation

146

Note

4th

The Swedish law that prohibits the purchase of sexual services: Best practices for prevention of prostitution and trafficking in human beings

Violence Against Women

132

Review

5th

The ‘butner study’ redux: A report of the incidence of hands-on child victimization by child pornography offenders

Journal of Family Violence

123

Article

5th

Will the real sex slave please stand up?

Feminist Review

123

Article

7th

(Un)popular strangers and crises (un)bounded: Discourses of sex-trafficking, the European political community and the panicked state of the modern state

European Journal of International Relations

116

Review

8th

HIV prevalence and predictors of infection in sex-trafficked nepalese girls and women

Journal of the American Medical Association

113

Article

8th

The perverse politics of four-letter words: Risk and pity in the securitisation of human trafficking

Millennium: Journal of International Studies

113

Article

10th

Prevalence and risk of violence and the physical, mental, and sexual health problems associated with human trafficking: Systematic review

PLoS Medicine

102

Article

10th

Transplant tourism: Outcomes of United States residents who undergo kidney transplantation overseas

Transplantation

102

Conference Paper

aDocuments with equal number of citations were given the same rank, and then a gap is left in the ranking numbers

Discussion

Volume and growth of publications

The current study aimed to assess and analyze published literature on HT. Quantitative analysis of literature on HT is complicated by the lack of academic and legal consensus on the definition of HT as well as the unclear distinction between trafficked victims, exploited people, and vulnerable migrants [71]. For example, some researchers consider illegal migrants who end up in prostitution as victims of HT [72, 73]. Despite these technical difficulties, the current study was the first to analyze volume, growth, research trends, and research domains of literature on HT published in academic journals.

The findings of the current study showed that the total number of retrieved documents on HT was low when compared to the size of literature on the 21 million people described as refugees [74]. The number of publications on HT could be attributed to the methodological, operational, criminal, and hidden nature of HT [20]. The limited research collaboration, as evident from the mean number of authors per document and the percentage of documents with international authors, is another potential reason for the limited number of publications on HT. The finding regarding international research collaboration is difficult to explain but could be attributed to lack of communications, motivation, funding, or lack of international conferences that could help gather experts in this field [75, 76].

Health versus non-health related research

The current study showed that there was an underrepresentation of health-related research on HT despite the potential threat of HT to national health security [1]. Health is a subject that has been neglected in anti-trafficking work efforts compared to activities in the fields of immigration and law enforcement [77, 78]. Many experts in health and HT agree that the health sector has had limited engagement in trafficking dialogues and research [78] despite that HT is being considered as a threat to global health security [79]. The presence of sexually transmitted diseases and tuberculosis among trafficked victims place the general population at risk [80, 81].

The findings of the current study regarding the under-representation of labor trafficking relative to sex trafficking were in agreement several previously published studies [18, 82]. Promotion and advancement of research on health aspects of HT require intensive involvement of public health experts in the global debate about HT. Public health experts and editors of medical and health journals need to create an international forum to encourage researchers from different parts of the world to get involved in health research about HT. This will benefit global public health agendas by shedding light on aspects related to HT such as labor exploitation and smuggling in Africa, Asia, and the Middle East where labor exploitation might not be considered illegal or a human right violation [83]. Establishing research networks that include scholars from destination and source countries will create a more detailed analysis of health aspects of HT.

The source versus destination countries

The current study showed that the bulk of the retrieved literature and the topics discussed represent the perspective of the destination rather than source countries. It is believed that the source countries are ones with no or minimum level of democracy, high levels of corruption, and poor economic growth, which make engagement in research and academic investigation an unaffordable luxury. The source countries might not have enough public health researchers or experts HT, which influence their contribution to literature in this field. It is recommended that the source countries place migration and trafficking in their national and foreign policy agendas. Healthcare professionals, social care specialists, and experts in global health diplomacy in source countries need to get engaged in developing evidence-based information about methods used by traffickers in recruiting their victims from source countries [84]. Legal and labor experts need to provide detailed information for migrants to increase their awareness of labor exploitation and trafficking [85]. Awareness of being a potential victim to traffickers is important in source countries, particularly those with a humanitarian crisis or armed conflict where young desperate men and women will take a quick decision regarding migration in hope of a better life and better wages [86]. For destination countries, healthcare professionals, and public health experts need to identify working conditions and occupational health hazards of migrant workers who might end up being victims of HT. Policymakers need to develop strict regulation to provide migrants with legal and health protection equivalent to that of domestic workers [87]. Health policymakers need to develop mechanisms to discover victims of HT once they attend a healthcare facility [88] and offer them appropriate health services and social as well as financial support and compensation. Experts in criminology need to develop detailed criminal codes based on international diplomatic cooperation to fight organizations involved in HT [89, 90].

Types of trafficking

In the current study, published literature on sex trafficking dominated the field of HT. The over-representation of sex trafficking suggests that research related to other forms of trafficking, particularly labor trafficking is being under-researched. Trafficked laborers live and work in harsh and mostly unhealthy conditions that might involve confiscation of passports, low wages, sex slavery, and deprivation of basic health need [9194]. Research domain in labor trafficking needs to be strengthened, supported, funded, and encouraged to generate more evidence-based data in this field.

Study limitations

The current study has a few limitations. Using Scopus database to retrieve literature on HT created a certain bias toward countries with a large number of journals indexed in Scopus. Scopus is biased toward academic journals in which documents are published in English. Therefore, documents in HT published in non-English were not retrieved. The current study, like all other bibliometric studies, did not include grey literature. The search strategy used in this study might have led to some false-negative or false-positive results. Therefore, interpretation of the results should take into consideration these limitations.

Conclusion

The current study is the first to assess research activity in the field of HT. The current study showed that health aspects of HT were under-represented compared to criminal, legal, and social aspects of HT. Similarly, research on labor trafficking was under-represented compared to sex trafficking and exploitation. The literature on HT represents the agendas of destination countries with limited contribution of countries in Asia, Latin America, Africa, the Middle East, and Eastern European. Future research plans should shed light on trafficking for non-sexual purposes. Furthermore, research networks need to be strengthened by including scholar from source and destination countries to investigate health conditions of trafficking survivors or exploited migrants. Greater investments in international research collaborations and research networks should be encouraged to help prioritize research on HT in various world regions.

Abbreviations

HT: 

human trafficking

MCP: 

multiple country collaboration = international collaboration

SCP: 

single country collaboration = intra-country collaboration

Declarations

Acknowledgements

The author would like to thank An-Najah National University for facilitating this study. The author would like to thank Professors Adham abut aha and Ansam Sawalha for their language corrections

Funding sources

None.

Availability of data and materials

Data pertaining to this study could be retrieved using Scopus and the search strategy is outlined in Table 1.

Author’s contribution

This was a single-authored publication. The author read and approved the final manuscript.

Ethics approval and consent to participate

The study did not include any human subjects or human materials, and ethical approval of the study was thus not required based on guidance from the institutional review board of An-Najah National University.

Consent for publication

Not applicable.

Competing interests

The author declares that he has no competing interests.

Publisher’s Note

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Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

Authors’ Affiliations

(1)
Department of Physiology, Pharmacology/Toxicology, Division of Biomedical Sciences, College of Medicine and Health Sciences, An-Najah National University, Nablus, Palestine

References

  1. Shelley L. Human trafficking: a global perspective. New York: Cambridge University press; 2010.Google Scholar
  2. Davy D. Anti–human trafficking interventions: how do we know if they are working? Am J Eval. 2016;37(4):486–504.View ArticleGoogle Scholar
  3. Gulati GJ. News frames and story triggers in the Media’s coverage of human trafficking. Hum Rights Rev. 2011;12(3):363–79.View ArticleGoogle Scholar
  4. United Nations (UN): Protocol to Prevent, Suppress and Punish Trafficking in Persons, Especially Women and Children. 2000.Google Scholar
  5. Kangaspunta K. Was trafficking in persons really criminalised? Anti-Trafficking Rev. 2015;4.Google Scholar
  6. Whitman A, Gray DH. Transnational Human Trafficking. Global Secur Stud. 2015;6(3).Google Scholar
  7. Shelley L. 6 human trafficking as a form of transnational crime. In: Human Trafficking. Portland: Willan; 2013. p. 128–49.Google Scholar
  8. United Nations Office on Drugs and Crime (UNODC): Global Report in Trafficking in Persons 2016. 2016.Google Scholar
  9. Laczko F. Data and research on human trafficking. Int Migr. 2005;43(1–2):5–16.View ArticleGoogle Scholar
  10. Amahazion F. Human trafficking: the need for human rights and government effectiveness in enforcing anti-trafficking. Global crime. 2015;16(3):167–96.View ArticleGoogle Scholar
  11. Zimmerman C, Kiss L. Human trafficking and exploitation: a Global Health concern. PLoS Med. 2017;14(11):e1002437.View ArticleGoogle Scholar
  12. Honeyman KL, Stukas AA, Marques MD. Human trafficking: factors that influence willingness to combat the issue. J Appl Soc Psychol. 2016;46(9):529–43.View ArticleGoogle Scholar
  13. Tripp TM, McMahon-Howard J. Perception vs. reality: the relationship between organized crime and human trafficking in metropolitan Atlanta. Am J Crim Justice. 2016;41(4):732–64.View ArticleGoogle Scholar
  14. Aronowitz AA. Smuggling and trafficking in human beings: the phenomenon, the markets that drive it and the Organisations that promote it. European J Crim Policy Res. 2001;9(2):163–95.View ArticleGoogle Scholar
  15. Ottisova L, Smith P, Shetty H, Stahl D, Downs J, Oram S. Psychological consequences of child trafficking: an historical cohort study of trafficked children in contact with secondary mental health services. PLoS One. 2018;13(3):e0192321.View ArticleGoogle Scholar
  16. Charteris A, German C, Hansrani Z, Li E, Merchant J. Health at Risk: Health Implications of Human Trafficking in the Context of Globalization and Migration; 2018.Google Scholar
  17. Henry AML, Grodin MA. Human trafficking: a health and human rights agenda. Ann Intern Med. 2018;168(9):674–5.View ArticleGoogle Scholar
  18. Cockbain E, Bowers K, Dimitrova G. Human trafficking for labour exploitation: the results of a two-phase systematic review mapping the European evidence base and Synthesising key scientific research evidence. J Exp Criminol. 2018:1–42.Google Scholar
  19. Hemmings S, Jakobowitz S, Abas M, Bick D, Howard LM, Stanley N, Zimmerman C, Oram S. Responding to the Health Needs of Survivors of Human Trafficking: A Systematic Review. BMC Health Serv Res. 2016;16(1).Google Scholar
  20. Ottisova L, Hemmings S, Howard LM, Zimmerman C, Oram S. Prevalence and risk of violence and the mental, physical and sexual health problems associated with human trafficking: an updated systematic review. Epidemiol Psychiatr Sci. 2016;25(4):317–41.View ArticleGoogle Scholar
  21. Zimmerman C, Hossain M, Yun K, Roche B, Morison L, Watts C. Stolen smiles: a summary report on the physical and psychological health consequences of women and adolescents trafficked in Europe. Stolen smiles. 2006.Google Scholar
  22. Silverman JG, Decker MR, Gupta J, Maheshwari A, Willis BM, Raj A. Hiv prevalence and predictors of infection in sex-trafficked Nepalese girls and women. Jama. 2007;298(5):536–42.View ArticleGoogle Scholar
  23. Wheaton EM, Schauer EJ, Galli TV. Economics of human trafficking. Int Migr. 2010;48(4):114–41.View ArticleGoogle Scholar
  24. Cho S-Y. Modelling for determinants of human trafficking; 2015.Google Scholar
  25. Okech D, McGarity SV, Hansen N, Burns AC, Howard W. Financial capability and sociodemographic factors among survivors of human trafficking. J Evid informed Soc Work. 2018;15(2):123–36.View ArticleGoogle Scholar
  26. Wolfe D, Greeson J, Wasch S, Treglia D. Human trafficking prevalence and child welfare risk factors among homeless youth a Multi-City study; 2018.Google Scholar
  27. International Labour Organization (ILO); Forced Labour, Modern Slavery and Human Trafficking 2016 [Cited 2018 June 02, 2018].Google Scholar
  28. International Labour Organization (ILO). Global Estimates of Modern Slavery: Forced Labour and Forced Marriage. Geneva: International Labour Organization (ILO); 2017.Google Scholar
  29. Sweileh WM, Al-Jabi SW, AbuTaha AS, Zyoud SH, Anayah FMA, Sawalha AF. Bibliometric analysis of worldwide scientific literature in Mobile - health: 2006-2016. BMC Med Inform Decis Mak. 2017;17(1):72.View ArticleGoogle Scholar
  30. Sweileh WM, AbuTaha AS, Sawalha AF, Al-Khalil S, Al-Jabi SW, Zyoud SH. Bibliometric Analysis of Worldwide Publications on Multi-, Extensively, and Totally Drug - Resistant Tuberculosis (2006-2015). Multidiscip Respir Med. 2016, 11:45.Google Scholar
  31. Sweileh WM, Sawalha AF, Al-Jabi SW, Zyoud SH, Shraim NY, Abu-Taha AS. A bibliometric analysis of literature on malaria vector resistance: (1996 - 2015). Glob Health. 2016;12(1):76.View ArticleGoogle Scholar
  32. Peters MD, Godfrey CM, Khalil H, McInerney P, Parker D, Soares CB. Guidance for conducting systematic scoping reviews. Int J Evid Based Healthc. 2015;13(3):141–6.View ArticleGoogle Scholar
  33. Møller A, Myles P. What makes a good systematic review and meta-analysis? Br J Anaesth. 2016;117(4):428–30.View ArticleGoogle Scholar
  34. Grant MJ, Booth A. A typology of reviews: an analysis of 14 review types and associated methodologies. Health Inf Libr J. 2009;26(2):91–108.View ArticleGoogle Scholar
  35. Levac D, Colquhoun H, O'Brien KK. Scoping studies: advancing the methodology. Implement Sci. 2010;5(1):69.View ArticleGoogle Scholar
  36. Rosas SR, Kagan JM, Schouten JT, Slack PA, Trochim WM. Evaluating research and impact: a bibliometric analysis of research by the Nih/Niaid Hiv/aids clinical trials networks. PLoS One. 2011;6(3):e17428.View ArticleGoogle Scholar
  37. Koskinen J, Isohanni M, Paajala H, Jaaskelainen E, Nieminen P, Koponen H, Tienari P, Miettunen J. How to use bibliometric methods in evaluation of scientific research? An example from Finnish schizophrenia research. Nord J Psychiatry. 2008;62(2):136–43.View ArticleGoogle Scholar
  38. Sweileh WM, Wickramage K, Pottie K, Hui C, Roberts B, Sawalha AF, Zyoud SH. Bibliometric analysis of global migration Health Research in peer-reviewed literature (2000-2016). BMC Public Health. 2018;18(1):777.View ArticleGoogle Scholar
  39. Sweileh WM. Global research output on HIV/AIDS-related medication adherence from 1980 to 2017. BMC Health Serv Res. 2018;18(1):765. https://doi.org/10.1186/s12913-018-3568-x.
  40. Sweileh WM. Global research output in the health of international Arab migrants (1988-2017). BMC Public Health. 2018;18(1):755.View ArticleGoogle Scholar
  41. Cannon AC, Arcara J, Graham LM, Macy RJ. Trafficking and health: a systematic review of research methods. Trauma Violence Abuse. 2018;19(2):159–75.View ArticleGoogle Scholar
  42. Goździak EM. Data Matters: Issues and Challenges for Research on Traffi Cking. In: Global Human Trafficking: Routledge; 2014. p. 37–52.Google Scholar
  43. Elsevier; Scopus [https://www.elsevier.com/solutions/scopus/content]. Accessed 1 Sept 2018.
  44. Falagas ME, Pitsouni EI, Malietzis GA, Pappas G. Comparison of Pubmed, Scopus, web of science, and Google scholar: strengths and weaknesses. FASEB J. 2008;22(2):338–42.View ArticleGoogle Scholar
  45. Kulkarni AV, Aziz B, Shams I, Busse JW. Comparisons of citations in web of science, Scopus, and Google scholar for articles published in general medical journals. JAMA. 2009;302(10):1092–6.View ArticleGoogle Scholar
  46. Hirsch JE. An index to quantify an Individual's scientific research output. Proc Natl Acad Sci U S A. 2005;102(46):16569–72.View ArticleGoogle Scholar
  47. Agarwal A, Durairajanayagam D, Tatagari S, Esteves SC, Harlev A, Henkel R, Roychoudhury S, Homa S, Puchalt NG, Ramasamy R, et al. Bibliometrics: tracking research impact by selecting the appropriate metrics. Asian J Androl. 2016;18(2):296–309.View ArticleGoogle Scholar
  48. Babik JM, Chin-Hong P. Transplant Tourism: Understanding the Risks. Curr Infect Dis Rep. 2015;17(4):473.View ArticleGoogle Scholar
  49. Coverdale J, Beresin EV, Louie AK, Balon R, Roberts LW. Human trafficking and psychiatric education: a call to action. Acad Psychiatry. 2016;40(1):119–23.View ArticleGoogle Scholar
  50. Muraya DN, Fry D. Aftercare Services for Child Victims of sex trafficking: a systematic review of policy and practice. Trauma Violence Abuse. 2015;17(2):204–20.View ArticleGoogle Scholar
  51. Varma S, Gillespie S, McCracken C, Greenbaum VJ. Characteristics of child commercial sexual exploitation and sex trafficking victims presenting for medical Care in the United States. Child Abuse Negl. 2015;44:98–105.View ArticleGoogle Scholar
  52. Sweileh WM. Global research trends of World Health Organization's top eight emerging pathogens. Glob Health. 2017;13(1):9.View ArticleGoogle Scholar
  53. Sweileh WM. Bibliometric analysis of literature in aids-related stigma and discrimination. Transl Behav Med. 2018.Google Scholar
  54. Sweileh WM. Bibliometric analysis of peer-reviewed literature in transgender health (1900 - 2017). BMC Int Health Hum Rights. 2018;18(1):16.View ArticleGoogle Scholar
  55. Sweileh WM, Al-Jabi SW, Sawalha AF. Bibliometric Analysis of Worldwide Publications on Antimalarial Drug Resistance (2006–2015), vol. 2017; 2017. p. 6429410.Google Scholar
  56. Sweileh WM, Al-Jabi SW, Zyoud SH, Sawalha AF. Outdoor air pollution and respiratory health: a bibliometric analysis of publications in peer-reviewed journals (1900 - 2017). Multidiscip Respir Med. 2018;13:15.View ArticleGoogle Scholar
  57. Zyoud SH, Sweileh WM, Awang R, Al-Jabi SW. Global trends in research related to social Media in Psychology: mapping and bibliometric analysis. Int J Ment Health Syst. 2018;12:4.View ArticleGoogle Scholar
  58. Zyoud SH, Waring WS, Al-Jabi SW, Sweileh WM. Global Cocaine Intoxication Research Trends During 1975-2015: A bibliometric analysis of web of Science Publications. Subst Abuse. 2017;12(1):6.Google Scholar
  59. van Eck NJ, Waltman L. Software survey: Vosviewer, a computer program for bibliometric mapping. Scientometrics. 2010;84(2):523–38.View ArticleGoogle Scholar
  60. van Eck NJ, Waltman L: Vosviewer Manual. Manual for VOSviewer version 13 2011.Google Scholar
  61. Aradau C. The perverse politics of four-letter words: risk and pity in the securitisation of human trafficking. Millennium. 2004;33(2):251–77.View ArticleGoogle Scholar
  62. Berman J. (Un)Popular Strangers and Crises (Un)Bounded: Discourses of Sex-Trafficking, the European Political Community and the Panicked State of the Modern State. Eur J Int Rel. 2003;9(1):37–86+165.View ArticleGoogle Scholar
  63. Bourke ML, Hernandez AE. The ‘Butner Study’ redux: a report of the incidence of hands-on child victimization by child pornography offenders. J Fam Violence. 2009;24(3):183–91.View ArticleGoogle Scholar
  64. Budiani-Saberi DA, Delmonico FL. Organ trafficking and transplant tourism: a commentary on the global realities. Am J Transplant. 2008;8(5):925–9.View ArticleGoogle Scholar
  65. Canales MT, Kasiske BL, Rosenberg ME. Transplant tourism: outcomes of United States residents who undergo kidney transplantation overseas. Transplantation. 2006;82(12):1658–61.View ArticleGoogle Scholar
  66. Ekberg G. The Swedish law that prohibits the purchase of sexual services: best practices for prevention of prostitution and trafficking in human beings. Violence Against Women. 2004;10(10):1187–218.View ArticleGoogle Scholar
  67. O'Connell Davidson J. Will the real sex slave please stand up? Fem Rev. 2006;83:4–22.View ArticleGoogle Scholar
  68. Oram S, Stöckl H, Busza J, Howard LM, Zimmerman C. Prevalence and Risk of Violence and the Physical, Mental, and Sexual Health Problems Associated with Human Trafficking: Systematic Review. PLoS Med. 2012;9(5):e1001224.View ArticleGoogle Scholar
  69. Shimazono Y. The state of the international organ trade: a provisional picture based on integration of available information. Bull World Health Organ. 2007;85(12):955–62.View ArticleGoogle Scholar
  70. Weitzer R. The social construction of sex trafficking: ideology and institutionalization of a moral crusade. Polit Soc. 2007;35(3):447–75.View ArticleGoogle Scholar
  71. Oram S, Zimmerman C, Adams B, Busza J. International Law, National Policymaking, and the Health of Trafficked People in the Uk. Health Human Rights. 2011;13(2):E3–16.PubMedGoogle Scholar
  72. Kara S. Sex trafficking: inside the business of modern slavery: Columbia University press; 2009.Google Scholar
  73. Yen I. Of vice and men: a new approach to eradicating sex trafficking by reducing male demand through educational programs and abolitionist legislation. J Crim L Criminol. 2007;98:653.Google Scholar
  74. Sweileh WM. Bibliometric analysis of medicine–related publications on refugees, asylum-seekers, and internally displaced people: 2000–2015. BMC Int Health Hum Rights. 2017;17(1):7.View ArticleGoogle Scholar
  75. Gazni A, Sugimoto CR, Didegah F. Mapping world scientific collaboration: authors, institutions, and countries. J Am Soc Inf Sci Technol. 2012;63(2):323–35.View ArticleGoogle Scholar
  76. Wilsdon J. Knowledge, networks and nations: global scientific collaboration in the 21st century: The Royal Society; 2011.Google Scholar
  77. Morrison J, Director E, Crosland B. The trafficking and smuggling of refugees: the end game in European asylum policy? Geneva: UNHCR; 2000.Google Scholar
  78. Zimmerman C, Hossain M, Watts C. Human trafficking and health: a conceptual model to inform policy, Intervention and Research. Soc Sci Med. 2011;73(2):327–35.View ArticleGoogle Scholar
  79. Moreno MA. Human trafficking: from a Global Health perspective: San Diego State University; 2015.Google Scholar
  80. Tiittala P, Ristola M, Liitsola K, Ollgren J, Koponen P, Surcel HM, Hiltunen-Back E, Davidkin I, Kivelä P. Missed hepatitis b/c or syphilis diagnosis among Kurdish, Russian, and Somali origin migrants in Finland: linking a population-based survey to the national infectious disease register. BMC Infect Dis. 2018;18(1):137.Google Scholar
  81. Decker MR, McCauley HL, Phuengsamran D, Janyam S, Silverman JG. Sex Trafficking, Sexual Risk, Sexually Transmitted Infection and Reproductive Health among Female Sex Workers in Thailand. J Epidemiol Community Health. 2010;65(4):334–9.View ArticleGoogle Scholar
  82. Surtees R. Trafficking in men–cases from Belarus and Ukraine. IOM Migr Res Ser. 2008:17–9.Google Scholar
  83. Kharel U. The global epidemic of occupational injuries: counts, costs, and compensation: The Pardee RAND Graduate School; 2016.Google Scholar
  84. Novotny TE, Kickbusch I. 21st Century Global Health Diplomacy, vol. 3: World Scientific; 2013.Google Scholar
  85. Azad A. Recruitment of migrant Workers in Bangladesh: elements of human trafficking for labor exploitation. J Hum Trafficking. 2018:1–21.Google Scholar
  86. International Labour Organization (ILO). Addressing Human Trafficking and Exploitation in Times of Crisis- Evidence and Recommendations for Further Action to Protect Vulnerable and Mobile Populations I December 2015. Geneva: International Labour Organization (ILO); 2015.Google Scholar
  87. Marks E, Olsen A. Policy and practice: the role of trade unions in reducing migrant workers’ vulnerability to forced labour and human trafficking in the greater Mekong subregion. Anti-Trafficking Rev. 2015;5.Google Scholar
  88. Chang KS, Hayashi AS: The Role of Community Health Centers in Addressing Human Trafficking. In: Human Trafficking Is a Public Health Issue. edn.: Springer; 2017: 347–362.Google Scholar
  89. van der Leun J, Bedrijfsvoering S. Criminal policy, migration policy and human trafficking. Addressing the Dark Figure; 2017.Google Scholar
  90. Stolz BA. Criminal justice policy and transnational crime: the case of anti–human trafficking policy. US Criminal Justice Policy. 2015;337.Google Scholar
  91. Barrick K, Lattimore PK, Pitts WJ, Zhang SX. When farmworkers and advocates see trafficking but law enforcement does not: challenges in identifying labor trafficking in North Carolina. Crime Law Soc Chang. 2014;61(2):205–14.View ArticleGoogle Scholar
  92. Bélanger D. Labor migration and trafficking among Vietnamese migrants in Asia. Ann Am Acad Pol Soc Sci. 2014;653(1):87–106.View ArticleGoogle Scholar
  93. Brennan D. Trafficking, scandal, and abuse of migrant Workers in Argentina and the United States. ANNALS Am Acad Political Soc Sci. 2014;653(1):107–23.View ArticleGoogle Scholar
  94. Joarder MAM, Miller PW. The experiences of migrants trafficked from Bangladesh. Ann Am Acad Political Soc Sci. 2014;653(1):141–61.View ArticleGoogle Scholar

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© The Author(s). 2018

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