Abstract:

The aim of this review was to describe HIV prevalence in children and youth living on the street and subject to commercial sexual exploitation, and the studies' characteristics in terms of place, time, population, and sample design. This was a systematic review, not a meta-analysis, based on an article search in 10 electronic databases: Science Direct, MEDLINE, OVID, LILACS, Wiley InterScience, MD Consult, Springer Link, Embase, Web of Science, and Ebsco. A complementary search was also performed in the libraries of schools of public health and webpages of U.N. agencies, besides the reference lists from the selected articles. We selected observational studies focused on children and youth living on the street and subject to commercial sexual exploitation, ranging in age from 10 to 20 years, with the results for HIV prevalence rates. A total of 9,829 references were retrieved, of which 15 met the inclusion criteria and comprise this descriptive summary. Of these 15 articles, 12 were conducted in children and youth living on the street and three in children subject to commercial sexual exploitation. All 15 were cross-sectional studies. HIV prevalence in children and youth living on the street ranged from 0% in Dallas, USA and Cochabamba, Bolivia to 37.4% in St. Petersburg, Russia. In children and youth living subject to commercial sexual exploitation, prevalence ranged from 2% in Toronto, Canada to 20% in Kolkata, India. In conclusion, HIV infection is present in children and youth living on the street and subject to commercial sexual exploitation. Measures are needed for prevention, diagnosis, and treatment as a public health priority and an ethical responsibility on the part of governments and society.

Keywords:
Homeless Youth; Sexual Child Abuse; HIV

Introduction

The HIV epidemic continues to be a global public health problem, and the prevention of new infections is a challenge for the world's health systems ¹1. World Health Organization. Consolidated strategic information guidelines for HIV in the health sector. http://www.ncbi.nlm.nih.gov/books/NBK299486/ (accedido el 15/Jul/2015).
http://www.ncbi.nlm.nih.gov/books/NBK299... . According to the Joint United Nations Programme on HIV/AIDS (UNAIDS), 36.9 million persons in the world were living with HIV in the 2014, including 2.3 million cases of new infection, while 1.2 million persons died in the world from AIDS-related causes ²2. Programa Conjunto de las Naciones Unidas sobre el VIH/Sida. ODM 6: 15 años, 15 lecciones de esperanza de la respuesta al sida. Estadísticas mundiales 2014. http://www.unaids.org/es/resources/documents/2015/20150714_factsheet (accedido el 16/Jul/2015).
http://www.unaids.org/es/resources/docum... . Statistics for 2012 showed a prevalence of 0.4% in Latin America, with Guyana and Belize showing the highest prevalence rates (1.3% and 1.4%, respectively). Prevalence in North America was 0.5%, while the world's highest prevalence was in Sub-Saharan Africa (4.7%), reaching 26.5% in Swaziland ³3. Joint United Nations Programme on HIV/AIDS; World Health Organization. Report on the global AIDS epidemic 2013. Geneva: Joint United Nations Programme on HIV/AIDS; 2013..

Since the beginning of the HIV epidemic, children and youth have been considered socially and physically vulnerable to the infection, given the risk of transmission during childbirth when the mother is infected with the virus ⁴4. World Health Organization. Scale up planning guide for prevention of mother-to-child transmission of HIV and paediatric HIV care, treatment and support. http://www.who.int/hiv/pub/mtct/pmtct-scaleup-guide-2007/en/ (accedido el 17/Jul/2015).
http://www.who.int/hiv/pub/mtct/pmtct-sc... , situations of sexual abuse ⁵5. Lindegren ML, Hanson IC, Hammett TA, Beil J, Fleming PL, Ward JW. Sexual abuse of children: intersection with the HIV epidemic. Pediatrics 1998; 102:e46., and limited access to and use of sexual health services, including condom use, due to economic, social, and cultural barriers ⁶6. Regmi PR, van Teijlingen E, Simkhada P, Acharya DR. Barriers to sexual health services for young people in Nepal. J Health Popul Nutr 2010; 28:619-27.. According to global reports for the year 2012, 16% of children born to mothers with HIV acquired the infection during childbirth, a third of new HIV cases occurred in the population 15 to 24 years of age, and only 20% of female adolescents and 29% of male adolescents 15 to 19 years of age showed correct knowledge on HIV transmission and prevention ⁷7. Joint United Nations Programme on HIV/AIDS. The gap report. Geneva: Joint United Nations Programme on HIV/AIDS; 2014..

In addition to the factors mentioned above, other conditions of social vulnerability expose children and youth to increased risk of HIV infection. Such conditions include homelessness or living on the street and commercial sexual exploitation, such as child prostitution and child pornography ⁵5. Lindegren ML, Hanson IC, Hammett TA, Beil J, Fleming PL, Ward JW. Sexual abuse of children: intersection with the HIV epidemic. Pediatrics 1998; 102:e46.^{), (8}8. Kearon WG. Deinstitutionalization, street children, and the coming AIDS epidemic in the adolescent population. Juv Fam Court J 1990; 41:9-18., which additionally restrict the guarantee of their human rights ⁹9. Panter-Brick C. Street children, human rights, and public health: a critique and future directions. Annu Rev Anthropol 2002; 31:147-71.^{), (10}10. Willis BM, Levy BS. Child prostitution: global health burden, research needs, and interventions. Lancet 2002; 359:1417-22..

In 2002, the International Labor Organization (ILO) estimated that 1.8 million children and youth in the world were sexually exploited for commercial purposes. Of these, 750,000 were in Latin America and the Caribbean, the region with the largest number of cases, followed by the Asian Pacific with 590,000 ¹¹11. Statistical Information and Monitoring Programme on Child Labour, International Labour Organization. Every child counts. New global estimates on child labour. Geneva: International Labour Organization; 2002.. The figure increased in 2006, with the United Nations Children's Fund (UNICEF) reporting 3 million children and youth victims of commercial sexual exploitation ¹²12. Fondo para la Infancia de las Naciones Unidas. Estado mundial de la infancia 2006: excluidos e invisibles. New York: Fondo para la Infancia de las Naciones Unidas; 2005.. Estimates by UNICEF in 1996 pointed to 100,000 children and youth living on the street in Latin America ¹³13. Programa de Naciones Unidas para el Desarrollo Humano. Informe sobre desarrollo humano 1996. Madrid: Ediciones Mundi-Prensa; 1996.. In 2002 there were 12,000 children and youth living on the streets in Colombia, one of the Latin American countries with the largest presence of this phenomenon ¹⁴14. Fondo para la Infancia de las Naciones Unidas. La niñez colombiana en cifras. Bogotá: UNICEF Colombia; 2002..

While living on the street or subject to commercial sexual exploitation, children and youth are exposed to physical, mental, and social vulnerability ¹⁵15. Muñoz I, Noreña C, Londoño B, Rojas C. Morbilidad atendida y conductas de riesgo de la niñez y adolescencia en situación de calle de Medellín, 2008. Rev Salud Pública 2011; 13:207-18.^{), (16}16. Gomes R. Prostituição infantil: uma questão de saúde pública. Cad Saúde Pública 1994; 10:58-66.^{), (17}17. Dorsen C. Vulnerability in homeless adolescents: concept analysis. J Adv Nurs 2010; 66:2819-27.^{), (18}18. Tarasuk V, Dachner N, Li J. Homeless youth in Toronto are nutritionally vulnerable. J Nutr 2005; 135:1926-33. due to their backgrounds, circumstances, and contexts in which their daily life unfolds. Under such conditions they often abuse and develop addiction to drugs and alcohol due to the abundant supply in the street scene ¹⁹19. Song JY, Safaeian M, Strathdee SA, Vlahov D, Celentano DD. The prevalence of homelessness among injection drug users with and without HIV infection. J Urban Health 2000; 77:678-87.^{), (20}20. Giraldo A, Forero C, Hurtado MA, Ochoa JA, Suárez L, Valencia A. Un viaje que puede controlarse: consumo de drogas en niños en situación de calle. Rev Fac Nac Salud Pública 2008; 26:11-7.. Survival becomes a daily struggle where delinquent conduct and forced labor are common ²¹21. Aptekar L. Street children in the developing world: a review of their condition. Cross-Cult Res 1994; 28:195-224.. Sexuality is mediated by situations of power and control by pimps or panderers over the children's bodies ²²22. Galeano E, Velez O. La calle como forma de sobrevivencia: gaminismo, prostitución infantil y menor trabajador en el centro de Medellín. Medellín: Cámara de Comercio de Medellín; 1996.^{), (23}23. Save the Children. Abuso sexual infantil y explotación sexual comercial infantil en América Latina y El Caribe. Stockholm: Save the Children; 2006. (Informe Genérico Situacional)., and condom use is uncommon and subject to negotiation ²⁴24. Rueda M. Navegar con rumbo. Cartas de navegación para la prevención y erradicación de la explotación sexual comercial infantil. 3ª Ed. Bogotá: OIT/IPEC Sudamérica; 2005.. Many children and youth also have a history of sexual abuse ²³23. Save the Children. Abuso sexual infantil y explotación sexual comercial infantil en América Latina y El Caribe. Stockholm: Save the Children; 2006. (Informe Genérico Situacional)., which in the street context places them at increased risk of further abuse and commercial sexual exploitation.

In this scenario, one might assume that children and youth living on the street and subject to commercial sexual exploitation would show high HIV prevalence rates. Despite some specific reports on the theme ²⁵25. Hillis SD, Zapata L, Robbins CL, Kissin DM, Skipalska H, Yorick R, et al. HIV seroprevalence among orphaned and homeless youth. AIDS 2012; 26:105-10.^{), (26}26. Kissin DM, Zapata L, Yorick R, Vinogradova EN, Volkova GV, Cherkassova E, et al. HIV seroprevalence in street youth, St Petersburg, Russia. AIDS 2007; 21:2333-40.^{), (27}27. Robbins CL, Zapata L, Kissin DM, Shevchenko N, Yorick R, Skipalska H, et al. Multicity HIV seroprevalence in street youth, Ukraine. Int J STD AIDS 2010; 21:489-96.^{), (28}28. Mejía W. La utilización de niños, niñas y adolescentes en la prostitución en el Departamento de Risaralda. Bogotá: PENTA; 2006., there is no compilation and summary of the scientific evidence to back such a statement. We thus conducted a systematic review with the aim of describing HIV prevalence in children and youth living on the street and subject to prostitution, as well as the studies' characteristics: place, time, population, and sampling design.

Methodology

This study is part of the project: Systematic Review: HIV and Other Sexually Transmitted Infections in Children and Youth Living on the Street and Subject to Commercial Sexual Exploitation. It was conceived as a baseline study on HIV in both populations, with a descriptive scope. The protocol was not registered in the International Prospective Register of Systematic Reviews database (PROSPERO), and the report is presented according to the Preferred Reporting Items for Systematic Reviews (PRISMA) ²⁹29. Liberati A, Altman DG, Tetzlaff J, Mulrow C, Gøtzsche PC, Ioannidis JPA, et al. The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate healthcare interventions: explanation and elaboration. BMJ 2009; 339:b2700.. In addition, the Cochrane manual for systematic literature reviews was consulted throughout the entire study process.

Despite not comparing two interventions in the same population, the PICOS strategy was used to define the study question and outline the study's scope in terms of population, outcome, and design.

P = children and youth living on the street or subject to commercial sexual exploitation;

O = HIV prevalence;

S = observational studies.

Inclusion criteria

A search was conducted for scientific articles that met the following inclusion criteria: (i) observational studies (cross-sectional, cohort, case-control); (ii) with results for HIV prevalence, based on tests applied by the investigators or recorded in the clinical history of the children and youth; (iii) that included a sample of children and adolescents living on the street or subject to commercial sexual exploitation. For this study's purposes, living on the street considered two circumstances: those who were on the street, or who remained on the street for a large share of the time, but who had not broken off their family ties permanently, since they spent the night in their homes or slept in a specific hotel or shelter. The other situation involved children and youth of the street, that is, homeless, who had already broken off their family ties and spent 24 hours a day on the city streets, living and sleeping there ⁹9. Panter-Brick C. Street children, human rights, and public health: a critique and future directions. Annu Rev Anthropol 2002; 31:147-71.. In the case of commercial sexual exploitation, two situations were considered, the open or visible form, appearing on the city streets, and the disguised form, which included children and youth located in closed establishments (bars, canteens, massage parlors, nightclubs) ³⁰30. Tercer Congreso Mundial contra la Explotación Sexual de Niños, Niñas y Adolescentes. Declaración de Río de Janeiro y llamado a la acción para prevenir y detener la explotación sexual de niños, niñas y adolescentes. http://www.ecpat.net/WorldCongressIII/index.php (accedido el 25/Abr/2011).
http://www.ecpat.net/WorldCongressIII/in... ; (iv) with an age range from 10 to 20 years (the minimum age was set at 10 years, because in some countries a sex act with a child under 10 years is considered sexual abuse, a crime, and in no case is it classified as commercial sexual exploitation, and 20 years was set as the maximum age, since various countries adopt 20 as the age of majority); (v) publications in Spanish, English, or Portuguese; (vi) no limitation on the country or year of publication. Exclusion criteria were: lack of important information on the study (sample size, sample design, HIV prevalence or number of positive cases); self-reported HIV prevalence; different publications by the authors using the same sample; or the study population failed to meet the proposed definitions, based on a reading of the full text.

Article search

The article search was conducted in various ways. From September 2012 to February 2013, two investigators independently tracked abstracts and articles in 10 databases: Science Direct, MEDLINE, OVID, LILACS, Wiley InterScience, MD Consult, Springer Link, Embase, Web of Science, and Ebsco, using the combination of terms from Medical Subject Headings (MeSH) described below:

Population: (("homeless youth"[MeSH]) OR "child abuse, sexual")

Result: (((("HIV seroprevalence"[MeSH]) OR "HIV infections") OR "HIV seropositivity") OR "HIV/AIDS")

Study design: "observational study"

Population + Result: ((((((("homeless youth"[MeSH]) OR "child abuse, sexual")) AND (((("HIV seroprevalence") OR "HIV infections") OR "HIV seropositivity") OR "HIV/AIDS")))))

Population + Result + Study design: ((((((("homeless youth"[MeSH]) OR "child abuse, sexual"[MeSH Terms])) AND (((("HIV seroprevalence") OR "HIV infections") OR "HIV seropositivity") OR "HIV/AIDS"))))) Filters: Observational Study.

To prevent loss of relevant information, we also consulted the selected articles' reference lists. A search was conducted in the "gray literature" in the principal webpages of the United Nations agencies working with childhood and adolescence. A search was also conducted in the internal reference catalogues in the libraries of the Mexican School of Public Health and the University of Antioquia, Colombia, since they were the current home institutions of the review's researchers. In the latter cases the search terms were street children, child prostitution, and HIV/AIDS. We also consulted expert researchers on the themes of children and adolescents.

Article selection

Two authors jointly reviewed the articles' titles and abstracts, applying the inclusion criteria. In case of disagreement between the reviewers on a given article, a third author reviewed it. The reasons for excluding articles were recorded.

Data extraction

By duplicate and independently, the three authors read the full text, extracted the data, and conducted a summary, and entered the information on a Microsoft Access capture mask (Microsoft Corp., USA). The principal target outcome was HIV prevalence, including confidence intervals. In case of multicenter studies, the findings were extracted for each center. When the confidence intervals for HIV prevalence rates were not reported, they were calculated assuming a simple random sample, using Stata version 12 (StataCorp LP, College Station, USA). Data were also collected on factors associated with HIV prevalence.

Secondary data were also considered, including: (i) article's descriptive characteristics (Vancouver reference, key words, continent, city, country, and year of study, type of study population: (a) children and youth living on the street and (b) children and youth subject to commercial sexual exploitation, sample size, sex, and age. For age, when a selected study included individuals older than 20 years, whenever possible the sample size was adjusted exclusively to the population 10 to 20 years of age and a new HIV prevalence rate and confidence intervals were calculated, otherwise the study was excluded. (ii) methods (type of study, way of accessing the population, sample design, defined as probabilistic (stratified random sample, time-location, respondent-driven sampling, venue-based); non-probabilistic (snowball, convenience sample); HIV detection test; and ethical aspects. Given this systematic review's descriptive characteristics, the risk of bias in each article was not assessed.

Data analysis

The studies' results were analyzed independently for each population: (i) children and youth living on the street; (ii) children and youth subject to commercial sexual exploitation, presented in tables, with a descriptive figure for HIV prevalence rates in children and youth living on the street using Microsoft Excel (Microsoft Corp., USA). For multicenter studies, the disaggregated results for each center are presented.

Results

Selected articles

A total of 171 relevant references were selected and screened. Forty-eight articles were considered adequate for inclusion. Thirty-three were excluded for the following reasons: duplicates; young adult population (older than 20 years); no data on HIV prevalence; or the children and youth were not living on the street or subject to commercial sexual exploitation. Finally, 15 studies comprised this systematic review (Figure 1). Of these 15 studies, 12 focused on children and youth living on the street and three on children and youth subject to commercial sexual exploitation. The highest percentage was conducted in the Americas, four used probabilistic samples, and the highest percentage of studies were published in the 2000s (Table 1).

Studies on HIV prevalence in children and youth living on the street

Table 2 shows the characteristics of studies on HIV prevalence in children and youth living on the street. Two were multicenter studies in the United States, in five centers for youth living on the street from four cities, and in the Ukraine in three cities. The review thus includes records of 18 HIV prevalence rates in these populations.

Of the 12 studies that were included, six were conducted in North America, with the United States (four) and New York (two) as the country and city with the most studies on the topic. Seven were conducted in the 1990s. The 12 studies included a total population of 8,531 children and youth living on the street, with a median of 383 children and youth and interquartile range (IQR) of 262-569. With regard to sampling design, all the studies with probabilistic samples found positive HIV cases. The study with the highest HIV prevalence used a venue-based sample (Table 2).

HIV prevalence in children and youth living on the street ranges from 0% in cities like Dallas (USA), Cochabamba (Bolivia), and Teheran (Iran) to 37.4% in St. Petersburg (Russia). Prevalence exceeded 10% in two cities in the Ukraine (Odessa and Kiev). Two studies were found in South America, but only in Belo Horizonte (Brazil) was reported positive HIV cases, with 1%. In Asia, specifically in Kolkata (India), prevalence was 1.1%. Figure 2 shows the HIV prevalence rates and confidence intervals in children and youth living on the street according to the continent and city where the study was held.

Studies on children and youth subject to commercial sexual exploitation

Of the three studies, two were done in the Americas, in Bogotá (Colombia) and Toronto (Canada), from 2004 to 2006. They were done exclusively in females, with 336 girls and female adolescents subject to commercial sexual exploitation (median 51, IQR 30-255). With non-probabilistic samples, they found HIV prevalence ranging from 2.0% in Toronto, to 20% in Kolkata (Table 3).

Discussion

The results of this systematic review come from 15 studies, the majority of which in children and youth living on the street, with only three in children and youth subject to commercial sexual exploitation. Few studies in either group used probabilistic samples, and the largest share of studies on the HIV epidemic in these groups was in the 2000s. It is evident that the prevalence of HIV in these populations varies by region of the world: between 0% and 5% on the continent of America, 2% and 37% in Europe and between 0% and 20% in Asia.

With regard to the characteristics of time, place, type of population, and methodological aspects, the current review identified few studies in Latin America and the Caribbean, considering that it is the region of the Americas with the most children and youth living on the street and victims of prostitution ¹¹11. Statistical Information and Monitoring Programme on Child Labour, International Labour Organization. Every child counts. New global estimates on child labour. Geneva: International Labour Organization; 2002.^{), (14}14. Fondo para la Infancia de las Naciones Unidas. La niñez colombiana en cifras. Bogotá: UNICEF Colombia; 2002.^{), (15}15. Muñoz I, Noreña C, Londoño B, Rojas C. Morbilidad atendida y conductas de riesgo de la niñez y adolescencia en situación de calle de Medellín, 2008. Rev Salud Pública 2011; 13:207-18.. This situation reflects the need for future studies in Latin America and the Caribbean to access these populations, drawing on the existing methodologies and experience elsewhere in the world.

Only four studies used probabilistic samples. This shows the persistent challenge of drawing on or generating a sampling framework for hard-to-reach subgroups, partly because their status are considered illegal, stigmatized and criminalized. Likewise, the generation of sampling frameworks is costly and may prove largely unfeasible ³¹31. Kendall C, Kerr LRFS, Gondim RC, Werneck GL, Macena RHM, Pontes MK, et al. An empirical comparison of respondent-driven sampling, time location sampling, and snowball sampling for behavioral surveillance in men who have sex with men, Fortaleza, Brazil. AIDS Behav 2008; 12(4 Suppl):S97-104.^{), (32}32. Magnani R, Sabin K, Saidel T, Heckathorn D. Review of sampling hard-to-reach and hidden populations for HIV surveillance. AIDS 2005; 19 Suppl 2:S67-72.^{), (33}33. Tran HV, Le L-VN, Johnston LG, Nadol P, Van Do A, Tran HTT, et al. Sampling males who inject drugs in Haiphong, Vietnam: comparison of time-location and respondent-driven sampling methods. J Urban Health 2015; 92:744-57..

The use of samples for hidden populations, such as venue-based in St. Petersburg ²⁶26. Kissin DM, Zapata L, Yorick R, Vinogradova EN, Volkova GV, Cherkassova E, et al. HIV seroprevalence in street youth, St Petersburg, Russia. AIDS 2007; 21:2333-40., and time-location in India and the Ukraine ²⁷27. Robbins CL, Zapata L, Kissin DM, Shevchenko N, Yorick R, Skipalska H, et al. Multicity HIV seroprevalence in street youth, Ukraine. Int J STD AIDS 2010; 21:489-96.^{), (34}34. Bal B, Mitra R, Mallick AH, Chakraborti S, Sarkar K. Nontobacco substance use, sexual abuse, HIV, and sexually transmitted infection among street children in Kolkata, India. Subst Use Misuse 2010; 45:1668-82., may partially explain the high prevalence rates found there. The three studies reached sample sizes greater than 200 children and youth and prevalence rates that reached 10%. This situation reflects the samples' capacity to reach the more hidden subgroups and perhaps those at greatest vulnerability, a necessary characteristic to avoid biased estimates ³²32. Magnani R, Sabin K, Saidel T, Heckathorn D. Review of sampling hard-to-reach and hidden populations for HIV surveillance. AIDS 2005; 19 Suppl 2:S67-72..

In addition to the sample design, other possible explanations for the high HIV prevalence rates found in Russia and Ukraine are discussed next. In 2002, Russia estimated 3 million homeless children as the result of economic and social crises in the 1990s ³⁵35. Zaretsky V, Dubrovskaya M, Oslon V, Holmogorova A. Ways to solve the orphanhood problem in Russia. Moscow: Voprosy Psychologii; 2002., and by 2006 it was the country of Eastern Europe with the largest HIV epidemic concentrated in the population between 15 and 30 years of age ³⁶36. Joint United Nations Programme on HIV/AIDS; World Health Organization. AIDS epidemic update, December 2006. Geneva: World Health Organization; 2007.. Meanwhile, in Ukraine there were an estimated 40,000 homeless children and youth in 2006 ³⁷37. Teltschick A. Children and young people living or working on the streets; vie missing face of the HIV epidemic in Ukraine. Kiev: United Nations Children's Fund/AIDS Foundation East-West; 2006., and the country had the highest HIV prevalence in Eastern Europe by 2010 ³⁸38. Joint United Nations Programme on HIV/AIDS; World Health Organization. Report on the global AIDS epidemic 2010. Geneva: Joint United Nations Programme on HIV/AIDS; 2010., with young people the most heavily affected due to injection drug use and needle sharing ³⁹39. United Nations Children's Fund. Experiences from the field: HIV prevention among most at risk adolescents in central and Eastern Europe and the Commonwealth of Independent States. Geneva: United Nations Children's Fund; 2013..

In the studies on HIV prevalence and child prostitution, the highest rate was in India, a country with a combined phenomenon of person trafficking and sexual exploitation of women of all ages. In 2008 there were a reported 150,000 victims of this phenomenon worldwide ⁴⁰40. U.S. State Department. Trafficking in persons report. http://www.state.gov/j/tip/rls/tiprpt/2008/.
http://www.state.gov/j/tip/rls/tiprpt/20... . The three studies on commercial sexual exploitation focused exclusively on females. This indicates that the phenomenon is a form of gender-based violence, since females are the principal victims. A study in five cities of Colombia reported that of all children and youth subject to commercial sexual exploitation and assisted by government services, 91% were females ⁴¹41. Defensoría del Pueblo, Ministerio Público, República de Colombia. Situación de la niñez explotada sexualmente en Colombia. Bogotá: Editorial Presencia; 1995..

In addition to the above, the magnitude of the HIV epidemic in these populations should be analyzed in the context of the conditions of social exclusion and violence faced by children and youth ⁹9. Panter-Brick C. Street children, human rights, and public health: a critique and future directions. Annu Rev Anthropol 2002; 31:147-71.^{), (10}10. Willis BM, Levy BS. Child prostitution: global health burden, research needs, and interventions. Lancet 2002; 359:1417-22., including history of sexual abuse ²³23. Save the Children. Abuso sexual infantil y explotación sexual comercial infantil en América Latina y El Caribe. Stockholm: Save the Children; 2006. (Informe Genérico Situacional).. Condom use is mediated by drug consumption and situations of power exerted over children and youth by pimps and panderers ⁴²42. International Labour Organization. A comparative analysis: girl child labour in agriculture, domesticwork and sexual exploitation. The cases of Ghana, Ecuador and the Philippines. v. 2. Geneva: International Labour Organization; 2004.^{), (43}43. Programa Internacional para la Erradicación del Trabajo Infantil, Organización Internacional del Trabajo. Explotación sexual comercial de niñas, niños y adolescentes: una evaluación rápida. San Salvador: Programa Internacional para la Erradicación del Trabajo Infantil, Organización Internacional del Trabajo; 2002.; during injection use, needles are shared ²⁶26. Kissin DM, Zapata L, Yorick R, Vinogradova EN, Volkova GV, Cherkassova E, et al. HIV seroprevalence in street youth, St Petersburg, Russia. AIDS 2007; 21:2333-40.^{), (44}44. Stricof RL, Kennedy JT, Nattell TC, Weisfuse IB, Novick LF. HIV seroprevalence in a facility for runaway and homeless adolescents. Am J Public Health 1991; 81 Suppl:50-3.^{), (45}45. Roy E, Haley N, Leclerc P, Lemire N, Boivin JF, Frappier JY, et al. Prevalence of HIV infection and risk behaviours among Montreal street youth. Int J STD AIDS 2000; 11:241-7.^{), (46}46. Smereck GA, Hockman EM. Prevalence of HIV infection and HIV risk behaviors associated with living place: on-the-street homeless drug users as a special target population for public health intervention. Am J Drug Alcohol Abuse 1998; 24:299-319.. Other factors include stigma, discrimination, and invariable denial of the provision of social and health services ¹⁵15. Muñoz I, Noreña C, Londoño B, Rojas C. Morbilidad atendida y conductas de riesgo de la niñez y adolescencia en situación de calle de Medellín, 2008. Rev Salud Pública 2011; 13:207-18..

To respond to this HIV/AIDS problem in both populations means developing actions to prevent infection ⁴⁷47. Beijer U, Wolf A, Fazel S. Prevalence of tuberculosis, hepatitis C virus, and HIV in homeless people: a systematic review and meta-analysis. Lancet Infect Dis 2012; 12:859-70.. This involves mobilizing resources for monitoring, surveillance, and treatment through social and health models with comprehensive care, extending beyond individual actions ⁴⁸48. World Health Organization. Rapid HIV tests: guidelines for use in HIV testing and counselling services in resource-constrained settings. Geneva: World Health Organization; 2004.^{), (49}49. Gwadz MV, Cleland CM, Quiles R, Nish D, Welch J, Michaels LS, et al. CDC HIV testing guidelines and the rapid and conventional testing practices of homeless youth. AIDS Educ Prev 2010; 22:312-27.^{), (50}50. Needle RH, Trotter RT, Singer M, Bates C, Page JB, Metzger D, et al. Rapid assessment of the HIV/AIDS crisis in racial and ethnic minority communities: an approach for timely community interventions. Am J Public Health 2003; 93:970-9., where social determinants intervene in combination with the persistent inequities in these population groups ⁴⁷47. Beijer U, Wolf A, Fazel S. Prevalence of tuberculosis, hepatitis C virus, and HIV in homeless people: a systematic review and meta-analysis. Lancet Infect Dis 2012; 12:859-70.^{), (51}51. National Institute for Health and Clinical Excellence. Tuberculosis: hard-to-reach groups (PH37). Manchester: National Institute for Health and Clinical Excellence; 2012.. But it also involves prosecution of sexual abusers and exploiters of children and youth ⁵²52. Muñoz-Echeverri IF, Noreña-Herrera C, Rodríguez-Garzón SA, Ossa-Estrada DA, Bastidas-Lopera DL. Escenarios de explotación sexual comercial de niños, niñas y adolescentes, modalidad abierta, Medellín, 2012. Rev Fac Nac Salud Pública 2016; 34:9-19., drug policies with an emphasis on public health rather than criminalization, such as the creation of needle exchange programs rather than criminalization of consumers ⁵³53. Csete J, Kamarulzaman A, Kazatchkine M, Altice F, Balicki M, Buxton J, et al. Public health and international drug policy. Lancet 2016; 387:1427-80.. Nevertheless, the social and government response to these issues should keep international ethical principles in mind, including the child's greater interest, prevalence of their rights, and comprehensive protection ⁹9. Panter-Brick C. Street children, human rights, and public health: a critique and future directions. Annu Rev Anthropol 2002; 31:147-71.^{), (15}15. Muñoz I, Noreña C, Londoño B, Rojas C. Morbilidad atendida y conductas de riesgo de la niñez y adolescencia en situación de calle de Medellín, 2008. Rev Salud Pública 2011; 13:207-18.^{), (54}54. Convención sobre los Derechos del Niño; Comité de los Derechos del Niño. El VIH/SIDA y los derechos del niño. New York: Naciones Unidas; 2003.^{), (55}55. Rizzini I, Lusk MW. Children in the streets: Latin America's lost generation. Child Youth Serv Rev 1995; 17:391-400.^{), (56}56. Daly GP. Homeless: policies, strategies, and lives on the street. London: Routledge; 1996..

This systematic review shows some gaps between studies on HIV in children and youth living on the street when compared to the limited number of studies on studies in children and youth subject to commercial sexual exploitation. This shows how this criminal activity is clandestine and invisible, and how it violates human rights ⁵⁷57. Declaración de Yokohama, 2001. http://www.ecpat.net/EI/Global_yokohama.asp (accedido el 25/Abr/2011).
http://www.ecpat.net/EI/Global_yokohama.... . In addition, the lack of longitudinal studies in these population groups limits any causal inferences, related to injection drug use during life on the street or sexual exploitation, and the presence of HIV. Another element to consider is the scarce use of probabilistic samples and sampling techniques for hard-to-reach populations such as those included in this review. This may lead to underestimation of the epidemic, due to inability of the no probabilistic samples to capture important foci of infection, which could lead to greater spread of HIV due to the interventions' limited scope of action ³²32. Magnani R, Sabin K, Saidel T, Heckathorn D. Review of sampling hard-to-reach and hidden populations for HIV surveillance. AIDS 2005; 19 Suppl 2:S67-72..

The search for gray literature in only two Public Health School libraries may be a limitation to this systematic review. Universities currently have digital repositories where they store the theses and conferences available online, which could leave out studies conducted in various countries and which might contribute greater evidence for this study's purposes. Calculation of confidence intervals for the studies that did not report them restricts the data's interpretation. According to Salganik ⁵⁸58. Salganik MJ. Variance estimation, design effects, and sample size calculations for respondent-driven sampling. J Urban Health 2006; 83(6 Suppl):i98-112., despite progress with prevalence estimates, less is known about the sample's variability for estimations, which could lead to the calculation of confidence intervals around imprecise estimates. In addition, the lack of an overall estimate of prevalence could be considered another important limitation. Nevertheless, the methodological decisions back this limiting factor: in the first place, the review's descriptive objective, which only intended to provide an overview of the characteristics of studies on HIV in children and youth living on the street and subject to commercial sexual exploitation, and the intent of not conducting a meta-analysis. The latter decision was based on the studies' heterogeneity in terms of the place where the populations were recruited, the sample designs, and different inclusion criteria. These differences could have led to a biased estimate of overall prevalence. However, this aspect can be the object of a future systematic review and meta-analysis on HIV and other sexually transmitted infections in these population groups.

The above limitations notwithstanding, this was the first systematic review of HIV prevalence in these population groups. There are few systematic reviews on groups of children and adolescents in conditions of social vulnerability. Some of the existing reviews have focused on living conditions and the effects of life on the street ²¹21. Aptekar L. Street children in the developing world: a review of their condition. Cross-Cult Res 1994; 28:195-224.. There is a meta-analysis on HIV risk in adolescents and adults with a history of orphanhood ⁵⁹59. Operario D, Underhill K, Chuong C, Cluver L. HIV infection and sexual risk behaviour among youth who have experienced orphanhood: systematic review and meta-analysis. J Int AIDS Soc 2011; 14:25. and another on HIV prevalence in homeless adults ⁴⁷47. Beijer U, Wolf A, Fazel S. Prevalence of tuberculosis, hepatitis C virus, and HIV in homeless people: a systematic review and meta-analysis. Lancet Infect Dis 2012; 12:859-70..

This study thus responded to an internationally relevant question for public health and can become a technical and policy tool for prevention, control, and care in the HIV epidemic, helping guarantee the right to health for children and youth living on the street and subject to sexual exploitation. Such research allows identifying methodological approaches for these populations, which are highly mobile and referred to as hidden and hard to reach ⁶⁰60. Lorraine Y. Journeys to the street: the complex migration geographies of Ugandan street children. Geoforum 2004; 35:471-88.^{), (61}61. Joint United Nations Programme on HIV/AIDS; World Health Organization. Guidelines on estimating the size of populations most at risk to HIV. Geneva: World Health Organization; 2010..

Based on the review's findings, we conclude: HIV is a problem in the lives of children and youth living on the street and subject to commercial sexual exploitation, requiring intervention as a global health priority with comprehensive measures to avoid spread of the epidemic and to guarantee the right to health and dignity for these population groups, with outreach strategies that include appropriate techniques for approaching hidden and hard-to-reach populations.

Acknowledgments

C. Noreña-Herrera wishes to thank the Administrative Department of Science, Technology, and Innovation (Colciencias), Colombia, for granting an internship in the program for young researchers and innovators, under Call for Projects number 525 in 2011. C. A. Rojas acknowledges the Sustainability Strategy 2014-2015 of the Committee for the Development of University Research (CODI), University of Antioquia, Colombia

References

Publication Dates

History