Objectives The use of a mobile van (MV) for screening for HIV and other sexually transmitted infections (STIs) is effective at reaching at-risk populations. The aim of this study was to compare behaviour characteristics and HIV and syphilis prevalence between subjects tested at a MV offering voluntary counselling and testing and those tested at three STI clinics in Guatemala.
Methods Over 28 months, female sex workers (FSWs), men who have sex with men/transgenders (MSM/TG), and people not reporting being a member of a risk group (NR) were offered HIV and syphilis rapid tests and interviewed about their sociodemographic and risk behaviour.
Results 2874 subjects were tested (MV, 1336 (46%); clinics, 1538 (54%)). The MV screened 73% of FSWs and 73% of the MSM/TG, and detected 19% of HIV and 69% of syphilis cases. HIV prevalence was significantly higher (p<0.001) at the STI clinics than at the MV for both NR and MSM/TG groups (NR, 7% vs 1%; MSM/TG, 8% vs 1%, respectively). A significantly higher proportion of MSM/TG screened at the STI clinic reported having had a prior HIV test (MV, 21%; clinics, 41%; p<0.001), whereas more FSWs tested in the MV reported having multiple partners and using condoms during their last sexual intercourse.
Conclusions The higher prevalence of HIV and syphilis at the STI clinics suggests that they successfully identified high-risk subjects. In particular, the NR group showed higher than expected HIV and syphilis prevalence. Innovative approaches such as the use of a MV helped to increase access to other hard-to-reach groups such as MSM/TG and FSWs.
- Mobile van
- rapid tests
- outreach services
- STD clinic
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Early identification of HIV and sexually transmitted infections (STIs) not only results in earlier treatment initiation and reduced morbidity, but also decreases further infection transmission. Most voluntary counselling and testing (VCT) services are offered by traditional publicly funded HIV/STI clinics and community-based services. However, outreach programmes such as mobile van (MV) clinics for HIV/STI screening have proven to be an effective service for reaching at-risk populations, including female sex workers (FSWs), men who have sex with men (MSM), and injection drug users (IDUs),1–3 offering them VCT in convenient locations. In addition, the uptake of HIV testing increases fourfold when VCT is provided in community-based settings, highlighting the potential to reduce testing barriers such as stigma.4–6 Furthermore, recent evidence has shown that the use of rapid tests might enhance the effectiveness of MV clinics, increasing significantly the proportion of patients receiving their results and post-counselling.7–10
Several studies have found differences in demographic, behavioural and clinical characteristics between clients seen in traditional HIV/STI clinics and those seen at a MV HIV/STI clinic.1–3 Studies conducted in urban populations of the USA have observed that mobile clinic clients were more likely to receive a diagnosis of HIV2 and that ‘high-risk’ clients (including MSM and IDUs) were more likely to seek care in non-traditional outreach settings.1 Reisner et al observed that MSM accessing MV services in Massachusetts, USA had higher HIV-related risk behaviours.3 However, there is little information on the effectiveness of MV HIV/STI clinics in identifying HIV and STIs among at-risk populations in developing countries, in particular in Central America.
Guatemala currently has a concentrated HIV epidemic, with a prevalence of <1% in people who do not report a risk behaviour and high HIV prevalence in at-risk groups.11 In the past few years, efforts have been made to expand VCT services across the country, with the number of facilities providing HIV counselling and testing increasing from 41 in 2007 to 183 at the end of 2008.12 Despite this, HIV testing is still conducted largely in client-initiated testing sites, and outreach programmes are still scarce,13 resulting in missed HIV/STI prevention opportunities, especially for hard-to-reach populations such as FSWs and MSM who might not seek care at traditional VCT clinics. A study on reproductive healthcare perceptions and needs among FSWs in Guatemala found that most were reluctant to attend public healthcare centres because of the stigmatising nature of service provision and the discriminatory attitudes of the health personnel.14
To address the effectiveness of MV services in identifying cases of HIV and STIs and contributing to infection control efforts, we aimed to compare HIV and syphilis prevalence and risk behaviour characteristics between subjects tested at the MV and those tested at the traditional VCT service offered at three STI clinics in Escuintla, Guatemala.
Study setting and population
In 2005, the Fundació Sida i Societat, a non-profit organisation that specialises in providing STI and HIV prevention and care services in resource-constrained settings, in collaboration with the Ministry of Health of Guatemala, implemented the UALE Project (UALE means ‘be in health’ in Latin), a multilevel intervention with the overall aim of preventing and controlling HIV/STI, particularly among vulnerable groups in Guatemala.15 The UALE Project includes three STI clinics located within the community healthcare centres of three municipalities of the Escuintla province (Escuintla provincial capital, Santa Lucia Cotzumalguapa, and Puerto de San José), which has one of the highest HIV prevalences of the Guatemalan provinces.16 This may be related to greater population mobility through the Pacific Road, the trafficking of irregular migrants and illegal drugs, as well as the widespread sex work. All three clinics offer HIV and syphilis counselling and testing on a voluntary and anonymous basis from 8:30 to 16:00, uninterrupted.
In 2006, a community-based MV offering a VCT service with HIV and syphilis rapid tests was implemented to target hard-to-reach populations in the municipalities where the STI clinics were located and in 10 other municipalities characterised by a high number of commercial sex venues. To establish the operational frame of the MV, we used the community mapping of commercial sex venues and sites frequented by MSM and transgenders (TG) already completed by the UALE Project in each municipality. Experienced health educators visited bars, brothels, MSM hair salons, and streets where sex workers met clients to obtain the permission of their owners/managers. None refused the MV service provision. The MV offered the VCT service once every 2 weeks in a different site of each municipality.
Subjects were recruited from February 2006 to May 2009. We defined FSWs as women who reported having sex in exchange for money during the preceding 12 months. The MSM/TG group was defined as men who self-identified as homosexuals or who reported having sex with penetration with a same-sex partner during the last 12 months, including male sex workers (MSWs). Those who did not meet any of the previous criteria were considered people who do not report being a member of a risk group, from now on referred to as the ‘not-reporting’ (NR) group.
Counselling and testing
The procedures were similar in both settings. After obtaining written informed consent from participants, trained health educators conducted pretest HIV counselling and collected data on sociodemographic characteristics, personal risk behaviours, HIV testing history, and reasons for testing, by means of a structured questionnaire. Educational material on HIV/STI and condoms was available in both settings.
Samples were collected by a practitioner nurse, who also performed both the HIV and syphilis testing by finger prick. HIV testing was performed using the Determine HIV-1/2 rapid test (Abbott Laboratories, Tokyo, Japan), and participants received their results within 15 min. Venepuncture blood was drawn from participants with a reactive HIV rapid test result; they were post-test counselled as preliminary positive, and were asked to return to the STI clinic or to the MV testing place after 7 days to receive their confirmatory test result and counselling by the same health educator. All reactive samples were confirmed by ELISA using Bioelisa HIV-1+2 (Biokit, Lliçà d'Amunt, Spain). Those participants with a positive Determine HIV-1/2 rapid test who did not return for their results were actively traced. Subjects with a positive confirmatory test were referred, and accompanied by a community health worker, to the HIV referral hospital for enrolment in the care and treatment programme.
Syphilis testing was performed using the Determine Syphilis rapid test (Abbott Laboratories). Participants with a reactive syphilis rapid test were referred to the STI clinic for confirmatory testing using the Treponema pallidum haemagglutination test (Immutrep TPHA; Omega Diagnostics Ltd, Alva, UK) and the Venereal Infections Research Laboratory test (VDRL; Murex Biotech Limited, Dartford, UK). Because of the high probability of syphilis reinfection, treatment was administered when the rapid treponema test was reactive in order to minimise loss of follow-up as well as to stop the transmission chain.
The analysis was restricted to participants who were at least 15 years old and to the baseline visit, regardless of the testing site. Data were analysed using Stata V10.0 and described using frequencies, medians and interquartile ranges (IQRs). Sociodemographic and behavioural characteristics and HIV/syphilis prevalence of each subpopulation between the STI clinics and the MV were compared using the χ2 test or Fisher exact test for categorical variables, and the Wilcoxon rank-sum test for continuous variables. Within each subgroup, the prevalence of HIV over time was determined using the Mantel-Haenszel test for trend.
This analysis was included in the general IRB of the UALE Project, which was approved by the Hospital Germans Trias i Pujol ethics review committee, and had the support of the Guatemalan Ministry of Health and the Escuintla Department of Health.
From February 2006 to May 2009, 2874 subjects (≥15 years old) were tested for HIV and syphilis (MV, 1336 (46%); STI clinics, 1538 (54%)). Only 125 (4%) had more than one visit, and subsequent visits were excluded from the analysis. A mean of 80 subjects received VCT each month (37 people at the MV and 43 at the clinics).
The sociodemographic characteristics of subjects included in the analysis are described in table 1. The median age of the NR group tested at the MV was slightly older than those tested in the traditional clinics (29.6 vs 28.3 years, p=0.007), and the proportion of females tested in the MV was also significantly higher than in the clinics (62% vs 55%, respectively; p=0.005). The MSM/TG group included 28 (5%) transgenders and 123 (23%) MSWs (which included nine transgenders). Among the NR group, subjects tested in the MV were significantly more likely to report that they took the test to know their health status (MV, 98% vs STI clinics, 94%; p<0.001), although less likely to report that their partner asked them to take the test (MV, 1% vs STI clinics, 3%; p=0.001). Overall, 1136 (40%) subjects had previously been tested for HIV. MSM/TG (including MSWs) seen at the MV clinic were significantly less likely to have had a prior HIV test than those seen at the STI clinics (21% vs 42%; p<0.001). Almost 24% of FSWs were from a country other than Guatemala (mainly from El Salvador and Honduras), and this proportion was similar in both settings.
HIV and syphilis prevalence
The MV screened 29% (513/1746) of the NR group, 73% (385/529) of the MSM/TG, and 73% (438/599) of the FSWs, and detected 19% (27/140) of HIV and 69% (25/36) of syphilis cases (table 2). HIV prevalence was significantly higher at the STI clinics for NR (1% vs 7%; p<0.001) and MSM/TG (1% vs 8%; p<0.001). Among the MSM/TG group, HIV prevalence was similar in the three subgroups (MSM, 3%; TG, 4%; MSW, 3%) (data not shown). Syphilis prevalence was similar between the MV and clinics for NR and MSM/TG. The two cases of syphilis in the MSM/TG group were MSM who were neither TG nor MSW. Although not significant, syphilis rates among FSWs tested at the MV tended to be slightly higher (MV, 5% vs STI clinics, 1%; p=0.128). Five participants were coinfected with HIV and syphilis. The proportion of patients with a reactive HIV rapid test who returned for their confirmatory results was lower in the MV than in the STI clinics (42% vs 65%, respectively; p<0.001). Nevertheless, all of them were post-counselled as preliminary positive on the day they undertook the rapid HIV test, and those who did not come back for their confirmatory result were actively traced.
From 2006 to 2008, HIV prevalence at the clinics decreased significantly for NR and MSM/TG (NR, 18% vs 6%; p<0.001, test for linear trend; MSM/TG, 25% vs 5%, p=0.06, test for linear trend), while no statistically significant difference was observed across time in the MV (data not shown).
HIV-related risk behaviours are displayed in table 2. NR tested at the MV were less likely to report having had sex with a FSW (MV, 11% vs clinics, 17%; p=0.009) or with multiple partners (MV, 5% vs clinics 12%, p<0.001). MSM/TG tested at the MV were more likely to report having had sex with a bisexual partner (MV, 53% vs clinics, 34%; p<0.001), although the proportion reporting other risk behaviours were similar in both groups. A substantial proportion of MSM/TG reported having had sex in exchange for money or drugs in the past 12 months (MV, 25% vs clinics, 19%; p=0.134), although the HIV and syphilis prevalence of this subgroup were similar to the overall MSM/TG group (data not shown). Finally, FSWs tested at the MV were more likely to report having had sex with multiple partners (MV, 47% vs clinics, 33%; p=0.003), as well as more likely to have used a condom at their last sexual intercourse (MV, 78% vs clinics, 68%; p=0.021).
Our findings confirm significant differences in HIV and syphilis prevalence and risk behaviour characteristics between mobile clinic users and traditional STI clinic users in Escuintla, Guatemala. Contrary to our initial hypothesis, HIV prevalence was statistically significantly higher in the STI clinics for both the NR and MSM/TG group, suggesting that the traditional VCT effectively identified high-risk subjects. Nonetheless, the MV was successful in diagnosing new cases of HIV and syphilis and increasing access to at-risk populations such as MSM/TG and FSWs. Our results are contrary to those of Ellen et al2 in Baltimore, USA, although the context of our study was very different, and they did not stratify by population group. In fact, their MV group had a higher percentage of at-risk subjects (FSWs and IDUs), which may explain the higher prevalence of HIV in this group.
The higher HIV rates observed in the STI clinics among people who do not report being a member of a risk group may be explained in part by high-risk subjects seeking HIV screening earlier than others, as suggests the higher proportion of men attending the clinics who have sex with sex workers and who had multiple sexual partners during the last 12 months. Because seeking HIV testing is a voluntary decision, data from the VCT service located in the STI clinic is particularly prone to participation bias, and therefore HIV prevalence in the STI clinic will result in an overestimation of the prevalence in this group. Although Escuintla province has one of the highest HIV prevalences in Guatemala,16 the overall HIV prevalence in people who do not report any risk behaviours is much higher than expected (5% compared with the national estimate of 0.8%17).
With regard to the MSM/TG group, our findings are consistent with those observed by Bailey et al,18 where HIV prevalence was higher at the STI clinics. Despite the low level of risk behaviours reported by MSM tested in the STI clinics, they showed higher HIV rates, reported lower condom use, and were twice as likely to have had a prior HIV test than those tested in the MV, which suggests they might perceive themselves at risk of infection. Moreover, a major proportion of MSM/TG in our study performed sex work, but their HIV and syphilis prevalence was similar to that of those who did not. The overall HIV prevalence for MSM was 5.5%, much lower than the 12% that Soto et al found in Guatemala City.19 The MV provided HIV testing and counselling services to a group of MSM/TG who continue to face obstacles in accessing essential HIV prevention, treatment, and care services, as 80% of those seen at the MV were being tested for HIV for the first time. In fact, most of the MSM/TG group were tested at the MV, indicating that the MV does indeed increase access and choice for this population seeking testing for HIV and syphilis as previously described.18
No significant differences in HIV prevalence were observed among FSWs, and the overall 4% prevalence was similar to what has been described elsewhere.17 19 FSWs tested in the MV reported higher HIV-related risk behaviour, but a significantly higher proportion of condom use during the last sexual intercourse. Overall, condom use for FSWs was very high (68%). Whether the high condom use among FSWs in this study is related to the UALE Project needs further evaluation, but the project has shown a significant reduction in STI and HIV incidence among FSWs attending the STI clinic, as well as an increase in condom use with clients.15
In Latin American and Caribbean countries, the proportion of FSWs and MSM who know their HIV status from a recent test is 66% and 34%, respectively,12 which is similar to the percentage observed in our study. In the three populations, the main reason for testing was to know their health status, while the proportion that had the test because they perceived themselves to be at risk of HIV/STI was low. Taking into account the low proportion of subjects who used a condom during their last sexual intercourse (especially NR and MSM/TG), the low risk perception reported in this study provides evidence of one of the main barriers to behavioural change that would lead to safer conduct and lower HIV/STI prevalence.
A unique aspect of the MV is that it allows HIV/STI control programmes to be spatially and temporally targeted. The MV service identified more than two-thirds of the new syphilis cases (mostly in FSWs), suggesting the potential of this innovative service. The high prevalence of syphilis in the FSW group tested in the MV may be due to a higher proportion of street-based FSWs using the MV than the traditional clinic. In contrast with off-street FSWs, street-based FSWs are not required to visit the health clinic periodically to obtain a health stamp on their health card (which includes a medical examination and HIV/STI testing),15 and are more reluctant to attend the health centre for examination for STIs.14
One of the limitations of this study is possible misclassification of high-risk subjects, which may have led to inclusion of MSM who do not self-identify as homosexuals or did not disclose their sexual orientation in the NR group. To minimise this bias, the health workers had extensive experience working with vulnerable groups and ensured high levels of confidentiality. A second limitation was the need to confirm the reactive rapid tests, which may have led to loss of follow-up. In fact, one of the limitations of outreach programmes is the difficulty of ensuring that HIV-positive patients actually access the health system. In our study, all patients with a reactive HIV rapid test were post-counselled as preliminary positive, and an active case-finding programme was implemented for those confirmed HIV-positive patients who did not return for their results. Finally, the cost of the MV was reasonable and affordable for resource-constraint budgets, but studies on cost-effectiveness are scarce.20
The high HIV prevalence observed in the three groups combined with reported low condom use and low perception risk highlight the need to expand current HIV prevention and treatment programmes in the country. Our findings provide evidence of the success of STI clinics in identifying new cases of HIV among at-risk populations, as well as emphasising the benefits of using innovative approaches such as the MV to increase access to hard-to-reach groups.
HIV prevalence was statistically significantly higher in the sexually transmitted infection clinics than at the mobile van for both people not reporting being a member of a risk group and men who have sex with men and transgenders (MSM/TG), suggesting that traditional voluntary counselling and testing did effectively identify high-risk subjects.
The mobile van was successful in diagnosing new cases of HIV and syphilis and increasing access to at-risk populations such as MSM/TG and female sex workers.
People who did not report being a member of a risk group had higher than expected HIV prevalence
We thank Asamblea de Cooperación por la Paz, the Centro de Medicina Tropical del Instituto de Salud Carlos III and the Centre d'Estudis Epidemiològics sobre les ITS/HIV/SIDA de Catalunya (CEEISCAT), Institut Català d'Oncologia/Departament de Salut, Generalitat de Catalunya. This project was funded by the Agència Catalana de Cooperació al Desenvolupament, the Agencia Española de Cooperación Internacional al Desarrollo, and the Global Fund to Fight AIDS, Tuberculosis and Malaria.
The UALE Project includes the following: director: Jordi Casabona; executive director: Jaume Font; Ministry of Health in Guatemala: Bianca Rosa Guevara, María Isabel Pedroza, Laura Figueroa; local coordinators: Victor Hugo Fernández, José Ernesto Monzón; medical doctors: Rudy Ortiz, Otoniel Barrios; nurses: Elva Orellana, Irma Mazariegos, Isabel Barrientos, and Leticia Roldan; health educators: Estuardo Cabrera, Kristian Villavicencio, Miguel Meléndez; psychologist: Karla Guzman; microbiologists: Gabriela Hernández, Olga Gálvez, Cristina Cu, Samuel Churuc, Amelia Gerónimo, Xavier Vallès, Victoria González, Christian Alvarez; statisticians: Federica Giardina; IT: Mikhail Nikiforov; epidemiologists: Meritxell Sabidó; National AIDS Programme: Mariel Castro; primary healthcare centre: Maribel Godoy (Santa Lucía Cotzumalguapa), Lucía Gallardo (Puerto de San José), Karina Sazo (Escuintla); data entry: Alba Cajas, Hugo Felipe; technical support: Fabiola Llanos, Chus Sanz, Mirian Guadalupe Brañas.
The full list involved in the UALE project are listed in the Appendix at the end of this paper.
Funding The project was supported by the Catalan Agency for Cooperation Development, the Spanish Agency for International Development Cooperation, the Global Fund to Fight AIDS, Tuberculosis and Malaria, and Fundació Sida i Societat. The funding agency had no role in the design, conduct, or performance of the study, the analysis or reporting of the data, or the preparation, review, or acceptance of the article.
Competing interests None.
Ethics approval This study was included in the general IRB of the UALE project, which was approved by the Hospital Germans Trias i Pujol ethics review committee, and had the support of the Guatemalan Ministry of Health and the Escuintla Department of Health.
Provenance and peer review Not commissioned; externally peer reviewed.
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