Trafficking Women for Sexual Exploitation: A Systematic Review

Abstract

Human trafficking is a complex global problem that demands current and scientifically grounded knowledge capable of coordinating interventions among various sectors of society. To address this issue, a systematic collection of scientific articles was conducted in two databases (Web of Science and Scielo) using keywords in both English and Portuguese. After screening 267 articles based on title, abstract, and full text, an 11-article sample was analyzed for quality. The results revealed that conceptual inconsistency is a challenge in signaling human trafficking, particularly in cases of sexual exploitation of women where it may be associated with prostitution, pimping, or migration—all of which are activities tied to financial gain. Addressing human trafficking requires action from concept to practice, including strengthened policies for sanctions and necessary support for victims.

1. Introduction

Trafficking in human beings (THB) is a global political, social, and public health challenge. Sexual exploitation has an unequivocal gender dimension, since the victims are primarily female, of any age [1]. A study on human trafficking in the European Union indicated that the vast majority of registered victims were female (65% women and 23% girls), with the main purpose being sexual exploitation (92% of victims). According to the same source, in 2017–2018, 58% of trafficked females were registered as victims of trafficking for the purpose of sexual exploitation [2].

In Portugal, the crime of “Trafficking in Persons” is defined in Article 160 of the Penal Code [3] as the act of offering, delivering, enticing, accepting, transporting, accommodating, or welcoming a person for the purposes of sexual exploitation, work, begging, slavery, organ harvesting, or other criminal activities. The crime can be committed through violence, kidnapping or serious threats, ruses or fraudulent maneuvers, abuse of authority, taking advantage of the psychological incapacity or special vulnerability of the victim, or obtaining the consent of the person who controls the victim. A crime of THB involves three steps: recruitment, transportation, and exploitation.

The numbers of migrants and refugees on the move have been rising, affecting border enforcement, which is crucial for identifying victims of trafficking and developing effective responses [4]. The difficulty of identification is compounded by the misuse of the term “trafficking in human beings” to refer to the entire movement of people across the Mediterranean, rendering THB victims invisible as migrants or refugees [5].

It is essential to identify THB victims, and there are some signs that may help professionals in this, according to the Portuguese Association for Victim Support [6]. These signs include difficulty expressing themselves in the destination country’s language, aggression, deprivation of basic necessities, sexual abuse, lack of contact with family and friends, social isolation, and lack of control over identity documents. Sometimes, THB victims do not want to be identified for fear of retaliation or the label of victimhood, making rescue, assistance, and investigation challenging. Tackling THB requires identifying and addressing the root causes of exploitation and strengthening border enforcement, victim identification, protection, and investigation. Education and raising social awareness and involvement are crucial in preventing and combating THB.

According to the National Referral System for Victims of Human Trafficking, the majority of identified victims of human trafficking for sexual exploitation are women [7]. Women are more likely than men to be subjected to forced labor, sexual exploitation, prostitution, and other forms of violence [8]. Ref. [9] argues that women often struggle to recognize that they have been trafficked, taking responsibility for the problems they have faced and making it more difficult for them to seek help.

One of the most important challenges facing these victims is integration into society, which depends on proper support and follow-up from the beginning of the process. Health professionals can improve care for female victims of trafficking by understanding their specific needs and developing tailored programs to serve them in a more personalized way [10]. In cases of trafficking for sexual exploitation, it is crucial to consider the risk of sexually transmitted diseases such as HIV, underscoring the need for monitoring of female victims [10].

To provide a more organized overview of the state of the art on the subject of human trafficking for sexual exploitation, we conducted a systematic review focused on identifying, signaling, and integrating women victims of THB.

2. Materials and Methods

For this review, a systematic collection of scientific articles was conducted by searching different databases for research on human and women trafficking with keywords related to the topic under study. The collected articles were extensively analyzed based on predefined inclusion and exclusion criteria to extract relevant information in line with the research objectives.

2.1. Search Procedure

The search was conducted in electronic databases, such as Web of Science and Scielo, using keywords (human trafficking OR women trafficking AND sexual exploitation) in English and Portuguese, between May and July 2022.

2.1.1. Inclusion and Exclusion Criteria

In order to obtain relevant results and guide the research process, the study established a set of inclusion criteria, which were as follows: (a) only studies written in English, Portuguese, or Spanish for ease of linguistic understanding; (b) studies carried out between 2014 and 2022, in order to include the last two action plans for preventing and combating human trafficking in Portugal; (c) studies that focused solely on female victims aged 18 years or over; (d) sample studies that addressed sexual exploitation; and (e) open access studies.

The exclusion criteria consisted of (a) studies written in languages other than those mentioned in the inclusion criteria; (b) studies carried out outside the specified time frame; (c) samples with male victims; (d) studies that included the sexual exploitation of children; (e) samples with participants under the age of 18; (f) studies that addressed other types of human trafficking; and (g) unpublished or non-peer-reviewed material, such as doctoral theses or master’s dissertations.

2.1.2. Selection of Articles

A total of 267 results were identified, with 47 from Scielo and 220 from the Web of Science (as shown in Figure 1). The identified results were subjected to a first screening process based on the predetermined inclusion and exclusion criteria, resulting in the exclusion of 88 articles, 82 of which were repeated in the databases, and 6 due to access restrictions. The remaining 179 articles were analyzed based on their titles, and 60 of them were excluded. Subsequently, the abstract content was analyzed leading to the exclusion of an additional 47 articles. Six articles were also excluded due to a lack of access to the abstract. Ultimately, 72 articles met the inclusion criteria and were subjected to full analysis. Out of the 72 articles, 61 were excluded for various reasons, such as being conducted outside the specified time frame (n = 13), including other types of human trafficking (n = 19), not just focusing on female victims (n = 4), the sample representing participants under the age of 18 (n = 12), or not being in line with the research theme (n = 23). In the end, 11 empirical articles were identified for analysis, which are marked in the list of references with an asterisk.

2.1.3. Quality Analysis of the Articles

The quality analysis of the articles was conducted using Prisma Checklist 2020, adapted for the purposes of this study, which examined the robustness of the articles through evaluating consistency and title clarity, abstract synthesis, state of the art, objectives and/or hypotheses, and method analysis for future research [11]. The checklist was modified to include 13 topics ((1) title; (2) abstract; (3) rationale; (4) objectives; (5) protocol; (6) eligibility criteria; (7) information sources; (8) inclusion/exclusion criteria; (9) data collection process; (10) study design; (11) main measures; (12) summary of main results; (13) conclusion and study limitations) deemed significant to the study’s objectives, with articles classified on a Likert scale from 0 (not reported/not specified) to 2 (adequately done).

This table categorizes the articles into a Likert scale encompassing 0 (not reported/not specified), 1 (unclear/reported to some extent), and 2 (adequately done). A score of zero indicates that the study lacks information on the topic in question, while a score of one suggests that the researchers briefly mentioned the issue without providing detailed explanations. A score of two shows that the researchers thoroughly discussed the topic and explained the methodology used in a clear and understandable manner. Two researchers independently analyzed each article using the same grid, and items with dissimilar scores were assessed jointly to attain the final values presented in

Table 1. Analysis of the quality of selected articles.

Articles	1	2	3	4	5	6	7	8	9	10	11	12	13	Total
Barbuzano et al. (2020) [12]	2	2	2	2	2	2	2	2	2	2	2	2	2	26 High
Barrio Alvarez (2018) [13]	1	2	2	2	2	2	2	2	2	2	2	2	2	25 High
Brunovskis and Surtees (2019) [5]	1	2	2	2	2	2	2	1	2	2	2	1	2	24 High
da Silva and Sathiyaseelan (2019) [14]	1	2	2	2	2	2	2	2	2	2	2	2	2	25 High
de Perez (2015) [15]	2	2	2	2	2	2	2	2	2	2	2	2	2	26 High
Falcón (2016) [16]	1	2	2	2	1	1	2	1	2	1	1	1	2	19 Average
Jiménez-Lasserrotte et al. (2020) [10]	1	2	2	2	2	2	2	2	2	2	2	2	2	25 High
Norfolk and Hallgrimsdottir (2019) [4]	1	2	2	2	2	2	2	1	1	1	1	1	2	20 Average
Palacios et al. (2019) [17]	1	2	2	2	2	2	2	2	2	1	1	0	1	20 Average
Sambo and Spies (2020) [18]	1	2	2	2	2	2	2	2	2	2	2	2	2	25 High
Sousa (2016) [9]	2	2	2	2	2	2	2	2	2	1	2	2	2	25 High

Grades: 0—not reported/not specified; 1—unclear/reported to some extent; 2—adequately done.

. The degree of agreement between the researchers was 95%.

It was not possible to complete the N sample for two studies [9,12], and there were difficulties in understanding the collection of certain sample elements, such as specifically used documents (e.g., [13,14]), which were marked as something less positive (cf.

Table 2. Summary of articles under analysis.

Authors/Year	Objectives	Study Location/Sample	Design/Instruments	Conclusion
Barbuzano et al. (2020) [12]	Locate, systematize, and facilitate the knowledge of victims of trafficking	Spain n = 3 women; n = 21 people from organizations; n = 1-way guide	Qualitative Literature review; semi-structured interviews	Women are no longer categorized just as victims, deciding to take part in building knowledge about the phenomenon.
Barrio Alvarez (2018) [13]	To analyze the potential of a model of increased life satisfaction in groups of survivors of sexual exploitation who carry out sex work	Spain n = 30 women ≥ 26; n = 30 aged ≥40	Quantitative CD-RISC; PGTI; Life Satisfaction Scale.	The results of the study indicate that self-efficacy levels seem to be predictors of increased life satisfaction in the over-40 age group.
Brunovskis and Surtees (2019) [5]	Identifying and assisting victims of human trafficking on the front lines of the “refugee crisis”	Serbia n = 32 migrant/refugee cases; n= 9 frontline professionals	Qualitative Semi-structured interviews	During the refugee crisis in the Balkans, it was challenging to operationalize the anti-trafficking framework both conceptually and practically, to ensure individual protections and rights and to gather information in order to increase effective response capacity.
da Silva and Sathiyaseelan (2019) [14]	To understand the emotional needs of post-rescue sex trafficking survivors living in nursing homes in India and analyze post-rescue survivors’ suggestions to various entities	India n = 10 survivors of sex trafficking	Qualitative General Health Questionnaire (GHQ-28)	Survivors have improved their lives after rescue and need respect, understanding, acceptance, and trust from the people around them.
de Pérez (2015) [15]	Analyze the position of Brazil, Spain, and Portugal, taking into account the concept of “trafficking victims”, with a focus on legislation	Spain legislative documents	Qualitative Case study	It demonstrates how the incompatible definitions used compromise genuine actions to combat trafficking. This may be an indicator that ending trafficking may not be the main concern of these governments’ policies.
Falcón (2016) [16]	Offer an overview of the trafficking of women for the purpose of sexual exploitation that combines a gender perspective and human rights	Mexico THB documents	Qualitative Documentary research	The conclusions emphasize the patriarchal consensus that supports and perpetuates this serious social scourge.
Jiménez-Lasserrotte et al. (2020) [10]	Describe and understand violence against women in the context of irregular migration arriving in small boats to Spain	Spain n = 26 women	Qualitative Semi-structured interviews	Irregular migrant women arriving in Europe on small boats have a history of violence: rape, prostitution, forced pregnancy, and human trafficking. Gynecological examinations should be included in order to detect sexual violence and human trafficking in hospital emergency care as part of health protocols.
Norfolk and Hallgrimsdottir (2019) [4]	Determine whether the frontier is an effective instrument or tool for the identification of victims and intervention in human trafficking for sex work.	British Columbia 80 documents	Qualitative Documentary research	Current mechanisms fail to address and combat the issue of cross-border sex trafficking for several reasons: lack of uniform definitions of sex trafficking; sex work, leading to misidentification at the border; and emphasis in border security measures on victim support.
Palacios et al. (2019) [17]	Give visibility to all areas that make up THB for the purpose of sexual exploitation and have a political and social impact, influencing future plans to prevent and fight against the most appropriate THB, in a way that guarantees people’s human rights.	Morocco n = 6 health professionals; NGO officials; n = 1 psychologist; n = 1 health center director; n = 1 physician; n = 1 social worker	Qualitative Semi-structured interviews; field journal	Trafficking in human beings for the purpose of sexual exploitation is directly related to extreme gender inequalities, gender roles associated with sex, and concepts such as prostitution, and in the city of Melilla there is no plan against trafficking.
Sambo and Spies (2020) [18]	Describe the consequences of human trafficking that women survivors experienced and explore the perception of women who survived despite the consequences.	South Africa n = 12 surviving women	Qualitative Semi-structured interviews	Women survivors of human trafficking suffer intense and indescribable physical, sexual, psychological, economic, and social traumatic experiences.
Sousa (2016) [9]	Reflect on the role of the state in the face of the dynamics of trafficking in women for sexual exploitation	Brazil Professionals working in NETP/CE	Qualitative Semi-structured interviews; comments; documentary research	The problem lies beyond the structural and social issues of class divisions, or the political and cultural aspects that permeate the universe of human trafficking

). However, these studies were included because they were deemed important for characterizing and framing the data in this study [11].

3. Results

The 11 empirical studies under review were selected because they focus on women trafficking and sexual exploitation. Table 2 summarizes the main results, including the authors, year of publication, objective, country, participants, and instruments utilized.

3.1. Main Characteristics of the Studies

The articles’ publication dates range from 2015 (e.g., [15]) to 2020 (e.g., [10,15,16]). The year with the most publications was 2019 (n = 4), followed by 2020 (n = 3), 2016 (n = 2), 2018 (n = 1), and 2015 (n = 1).

3.1.1. Design and Instruments

Of the ten qualitative studies, three utilized semi-structured interviews [5,10,16], one, a case study [15], the General Health Questionnaire-28 (GHQ) [14]), documentary research [16], semi-structured interviews and a field diary [17], semi-structured interviews and a literature review [12], and semi-structured interviews, observations, and documentary research [4,9].

The quantitative study [13] utilized the Connor–Davidson Resilience Scale (CD-RISC), the Posttraumatic Growth Inventory (PGTI), and the Satisfaction with Life Scale (SWLS).

3.1.2. Countries Where the Studies Were Conducted

These studies come from Spain (n = 4) [10,13,15,18], Serbia (n = 1) [5], India (n = 1) [14], Brazil (n = 1), Morocco [17], Mexico (n = 1) [16], British Columbia (n = 1) [4], and South Africa (n = 1) [18].

3.1.3. Sample Type and Gender

Barbuzano et al. [12] used a research sample consisting of 3 women, 21 people from organizations, and 1 guide on the way. Barrio Alvaréz [13] had a sample composed of 30 women survivors of human trafficking who performed sex work and were aged 26 years or older, as well as another sample of women aged 40 years or older (n = 30). Brunovskis and Surtees [5] had a sample of 32 migrant women and 9 frontline professionals.

Da Silva and Sathiyaseelan [14] conducted a study with a sample consisting of 10 female survivors of sex trafficking who were aged between 18 and 24 years. De Pérez’s [15] sample was based on legislative documents referring to Brazil, Spain, and Portugal alluding to the concept of victims of trafficking for sexual exploitation. Falcón’s [16] study was a documentary analysis of female gender perspectives and human rights regarding sexual exploitation.

Jiménez-Lasserrotte et al. [10] had a sample of 26 women who had crossed the Mediterranean Sea in the last five years. Lara Palacios et al. [17] conducted interviews with people in charge of all the non-governmental organizations (NGOs) present in the cities of Nador and Melilla that work with immigration (the sample is unknown), with the head of the Central Unit of Networks of Illegal Immigration and False Documentation (UCRIF) (n = 1), with the Melilla social welfare adviser (n = 1), with the directors of the hospital in Melilla and the hospital in Hassani de Nador, with the director of the Center for the Temporary Stay of Immigrants (CETI) (n = 1), with the responsible physician (n = 1), social worker (n = 1), psychologist (n = 1), and the Director of Health and Hygiene in Nador (n = 1).

Norfolk and Hallgrimsdottir [4] conducted a review of 80 documents related to sex trafficking over an 8-month period. Sambo and Spies [18] had a sample of 12 female survivors, and Sousa [9] studied professionals working in institutions to combat THB (N not mentioned), specifically in the Nucleus for Combating Trafficking in Persons in the State of Ceará (Núcleo de Enfrentamento ao Tráfico de Pessoas do Estado do Ceará, NETP/CE).

4. Results and Discussion

This systematic review aimed to collect data on preventing women trafficking, and identifying and integrating women who are victims of human trafficking, particularly for sexual exploitation. The analysis revealed that there is still a lack of consistency regarding the definition of trafficking in human beings as countries have differing conceptualizations on this issue [15] and the implications that this crime entails. Moreover, it is challenging to prove human trafficking as it requires three stages, and the place of displacement is irrelevant as it can occur within the same or different countries [12].

In different countries, prostitution is sometimes regarded as a voluntary activity, but many women in this employment find themselves exploited under the guise of prostitution. There is a difference between forced and voluntary work which makes it difficult to recognize such cases, especially when women who profess to be working voluntarily do not consider themselves as victims [4].

Prostitution yields significant financial gains, making it a simple business to manage with high demand and profit margins, which entices individuals who wish to profit from this activity criminally. Consequently, prostitution is often linked with crimes such as pimping. Although prostitution, pimping, and sexual exploitation are distinct concepts, they can be confused. It is noteworthy that not all individuals in prostitution networks are involved against their will [19].

In Portugal, prostitution is not permissible as a profession, and anyone who promotes, facilitates, or favors the practice of prostitution by another is criminally punished for pimping [20]. Although prostitution, pimping, and sexual exploitation can be different, they can be easily confused, so it is important to differentiate these concepts. There are differences and there is no direct link between these crimes. Prostitution does not always imply pimping just as pimping does not always imply human trafficking. Trafficking is not always intended for prostitution and for sexual exploitation. Trafficking requires action, means, and finality.

One of the reasons people link human trafficking to pimping is the lucrative nature of pimping as a business, which tempts traffickers into engaging in such activities. It is also necessary to reinforce the idea that not all people who are part of prostitution networks are involved against their will, and may find themselves in these same networks of their own free will [19].

The current control system for identifying and dealing with victims of human trafficking comprises three phases: flagging, identifying, and integrating. There are several challenges within this system as border security authorities often lack the necessary tools to identify and verify human trafficking victims [4]. With regard to identification, different countries use different definitions and terminologies, which can lead to inaccurate signaling. It is possible that a Brazilian migrant sex worker could be labeled as a potential victim of trafficking in Spain without being labeled as such in Portugal [15]. Finally, in terms of integration, ongoing support is critical to ensure these victims do not feel displaced, disrespected, disoriented, or lack trust in the space or people around them, but feel understood, protected, and safe [14].

It is vitally important to consider the risk of victimization and the context of poverty, which may contribute to vulnerability to human trafficking. In view of the need for an improvement in the quality of life, migration is sometimes carried out with the consent of the migrant person, who is unaware of the true purpose of the assistance provided, which can result in a situation of THB. In this condition, the victim may have greater difficulty recognizing that she is in a situation of trafficking due to the self-responsibility she experiences, and the belief in the possibility of work or improvement in the quality of life [9].

When women are in the process of migrating, they face many dangers from the mafias that try to exploit them. Unfortunately, these dangers often include rape and human trafficking. Some women are even deceived by false promises of work and a better life in their own country, only to end up trapped in trafficking networks [17].

NGOs have found it difficult to determine which migrant victims are victims of trafficking, as they are often incredibly vulnerable [5]. Most women come from countries with economic and social inequality, with few resources to survive, and this situation makes it almost impossible to access education and escape poverty or social exclusion. In addition to violence and gender discrimination, imagining an idealized life in Europe with equal opportunities can lead to a high-risk migration journey [10].

In the study by Sambo et al. [18] 12 interviews were conducted with women victims of trafficking who showed how much the experiences of trafficking affected their self-esteem and their confidence. They felt worthless and sometimes could not understand themselves after the experience. They expressed how the experience of trafficking destroyed their confidence both in themselves and in others, including criminal police bodies, health professionals, or even their families after the trafficking experience.

Exposure to situations of trafficking and sexual exploitation inevitably has consequences at the physical and psychological level as well as in the interpersonal relationships of the victims. In addition to the impact of exposure on these victims, it is also important to note that the risk of revictimization is often not taken into account, due to factors such as a delay in the trial, retelling the story several times to different professionals, or the difficulty of providing support in terms of housing and health.

5. Final Considerations

As mentioned, there is difficulty in identifying victims because the definition of THB falls short of the reality of the phenomenon. It is necessary to find a terminology for THB that is common worldwide, along with all issues related to THB, in order to adequately identify these women. Therefore, identifying risk factors that could potentiate human trafficking would lead to earlier and more realistic detection. Differentiating trafficking from other phenomena such as prostitution is essential.

It is extremely important to also mention the need for psychological follow-up, as some of these victims go through traumatic experiences contributing to psychological issues that may eventually be somatized. There are also social issues, as they arrive in countries devoid of any goods, and medical issues, in terms of how to control sexually transmitted diseases or even prevent them with adequate information, as many of these victims come from countries where there is insufficient information on topics such as this.

With regard to combat and prevention policies, there is an investment in offering responses to THB; however, although there are plans at the European and world level, it is important that the terminology is the same for everyone. The definition of THB should be the same for everyone so that there is no room for doubt as to the signs not being followed up because an activity is not considered trafficking in human beings under the law of the country.

Therefore, we reiterate the importance of conceptual uniformity, which significantly influences the legal definitions of the subject matter and can assist in the prevention and detection of human trafficking at various levels (primary, secondary, and tertiary). Addressing this global issue greatly benefits from close coordination between academia and professional practice, with the quality of knowledge produced being based on empirical evidence that promotes technical training for effective and efficient crime prevention.

One of the limitations of this systematic review was the fact that sexual exploitation is a topic that encompasses several issues, and despite striving to be exhaustive and systematic, using strict criteria, some studies are not accessible or not available and were not included in this review. The second limitation was the lack of Portuguese studies in the databases covered by this study. It is suggested that future studies on the same specific topic of this article may extend the research to other relevant databases such as PsychINFO, MEDLINE, Scopus, Criminology collection, or EBSCOhost, in order to broaden the scope of article selection according to established criteria.

The aim of this study was to reflect on the importance of all stages of referral. Not only is it essential to flag cases of trafficking in women for the purpose of sexual exploitation, but it is also equally important to support them so as not to jeopardize the future of these women and to be able to successfully reintegrate them into society.

It is expected that there will be an investment in research on this subject as it is a crime that has many contours and needs to be updated regarding the forms of trafficking, such as the presence of social networks and the current war situation.