J. Peter Figueroa

Epidemiology in Latin America and the Caribbean: current situation and challenges

Background This article analyses the epidemiological research developments in Latin America and the Caribbean (LAC). It integrates the series commissioned by the International Epidemiological Association to all WHO Regions to identify global opportunities to promote the development of epidemiology. Methods Health situations of the regions were analysed based on published data on selected mortality, morbidity and risk factors. Epidemiological publication output by country was estimated by Medline bibliometrics. Internet and literature searches and data provided by key informants were used to describe perspectives on epidemiological training, research and funding. Findings Despite important advances in recent decades, LAC remains the worlds most unequal region. In 2010, 10% of the LACs people still lived in conditions of multidimensional poverty, with huge variation among countries. The region has experienced fast and complex epidemiological changes in past decades, combining increasing rates of non-communicable diseases and injuries, and keeping uncontrolled many existing endemic and emerging diseases. Overall, epidemiological publications per year increased from 160 articles between 1961 and 1970 to 2492 between 2001 and 2010. The increase in papers per million inhabitants in the past three decades varied from 57% in Panama to 1339% in Paraguay. Universities are the main epidemiological training providers. There are at least 34 universities and other institutions in the region that offer postgraduate programmes at the master’s and doctoral levels in epidemiology or public health. Most LAC countries rely largely on external funding and donors to initiate and sustain long-term research efforts. Despite the limited resources, the critical mass of LAC researchers has produced significant scientific contributions. Future needs The health research panorama of the region shows enormous regional discrepancies, but great prospects. Improving research and human resources capacity in the region will require establishing research partnerships within and outside the region, between rich and poor countries, promoting collaborations between LAC research institutions and universities to boost postgraduate programmes and aligning research investments and outputs with the current burden of disease.

A Phase IIA Randomized Clinical Trial of a Multiclade HIV-1 DNA Prime Followed by a Multiclade rAd5 HIV-1 Vaccine Boost in Healthy Adults (HVTN204)

Background The safety and immunogenicity of a vaccine regimen consisting of a 6-plasmid HIV-1 DNA prime (envA, envB, envC, gagB, polB, nefB) boosted by a recombinant adenovirus serotype-5 (rAd5) HIV-1 with matching inserts was evaluated in HIV-seronegative participants from South Africa, United States, Latin America and the Caribbean. Methods 480 participants were evenly randomized to receive either: DNA (4 mg IM by Biojector) at 0, 1 and 2 months, followed by rAd5 (1010 PU IM by needle/syringe) at 6 months; or placebo. Participants were monitored for reactogenicity and adverse events throughout the 12-month study. Peak and duration of HIV-specific humoral and cellular immune responses were evaluated after the prime and boost. Results The vaccine was well tolerated and safe. T-cell responses, detected by interferon-γ (IFN-γ) ELISpot to global potential T-cell epitopes (PTEs) were observed in 70.8% (136/192) of vaccine recipients overall, most frequently to Gag (54.7%) and to Env (54.2%). In U.S. vaccine recipients T-cell responses were less frequent in Ad5 sero-positive versus sero-negative vaccine recipients (62.5% versus 85.7% respectively, p = 0.035). The frequency of HIV-specific CD4+ and CD8+ T-cell responses detected by intracellular cytokine staining were similar (41.8% and 47.2% respectively) and most secreted ≥2 cytokines. The vaccine induced a high frequency (83.7%–94.6%) of binding antibody responses to consensus Group M, and Clades A, B and C gp140 Env oligomers. Antibody responses to Gag were elicited in 46% of vaccine recipients. Conclusion The vaccine regimen was well-tolerated and induced polyfunctional CD4+ and CD8+ T-cells and multi-clade anti-Env binding antibodies. Trial Registration: ClinicalTrials.gov NCT00125970

SPONTANEOUS LYMPHOCYTE PROLIFERATION IN SYMPTOM-FREE HTLV-I POSITIVE JAMAICANS

Spontaneous lymphocyte proliferation was studied in HTLV-1-infected but symptom-free individuals to see if factors such as demographics or socioeconomics influence spontaneous proliferation in Jamaicans. Among the 30 healthy Jamaicans the only demographic feature (age sex socioeconomic status) associated with high lymphoproliferation was low income. However logistic regression analysis revealed that HTLV-1 seropositivity was a stronger risk factor for high lymphoproliferation (odds ratios (OR) = 17.2 95% confidence intervals (CI) 1.8-164.7) than was low income (OR = 8.5 95% CI 0.9-81.6). Besides adult T-cell leukemia/lymphoma (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) HTLV-1 infection has been associated with immunodeficiency and in-vitro immunological effects including perturbations in T-cell subsets. The data suggest that increased spontaneous lymphoproliferation is associated with HTLV-1 exposure per se. HTLV-1-negative black Jamaicans had significantly higher lymphoproliferation than US white controls. The reason for this finding is unclear. Genetic factors may account for the difference. However it is also possible that spontaneous proliferation is influenced by exposure to antigens and pathogens; and multiple infections are more common in Jamaica than in the US.

HPV 16 antibody prevalence in Jamaica and the United States reflects differences in cervical cancer rates

Human papillomavirus (HPV) is widely accepted as the primary etiologic agent in the development of cervical cancer. DNA of a particular HPV type, HPV 16, is found in about half of tumors tested. Inconsistent with this causal relationship, however, population‐based studies of HPV DNA prevalence have often failed to find high rates of anogenital HPV infection in countries with high cervical cancer rates. To examine this issue, we used serology to compare HPV 16 exposure in healthy volunteer blood donors in the United States (n = 278) and similar subjects from a country with 3‐fold higher cervical cancer rates, Jamaica (n = 257). Jamaican sexually transmitted disease (STD) patients (n = 831) were also studied to examine in detail the relation of HPV 16 antibodies with sexual history. Serology was conducted using an ELISA employing HPV 16 virus‐like particles (VLPs). Age‐adjusted seroprevalence rates were greatest among male (29%) and female (42%) STD patients, intermediate in male (19%) and female (24%) Jamaican blood donors and lowest among male (3%) and female (12%) U.S. blood donors. The higher seroprevalence in women was significant, and prevalence tended to increase with age. In multivariate logistic regression, controlling for age and gender, Jamaican blood donors were 4.2‐fold (95% CI 2.4–7.2) and STD patients 8.1‐fold (95% CI 5.0–13.2) more likely to have HPV 16 VLP antibodies than U.S. blood donors. Among STD patients, HPV 16 antibodies were associated with lifetime number of sex partners and years of sexual activity, as well as other factors. Our data suggest that HPV 16 VLP antibodies are strongly associated with sexual behavior. Moreover, exposure to HPV 16 appears to be much greater in Jamaica than in the United States, consistent with the high rate of cervical cancer in Jamaica. Int. J. Cancer 80:339–344, 1999. Published 1999 Wiley‐Liss, Inc.

Self-reported condom use is associated with reduced risk of Chlamydia, Gonorrhea, and Trichomoniasis

Objectives: To evaluate the association between self-reported condom use and prevalent and incident chlamydia, gonorrhea, and trichomoniasis. Study Design: Prospective study of 414 males attending a sexually transmitted infection (STI) clinic in Jamaica. Condom use and STI status were assessed at enrollment and at 4 follow-up visits. Results: The analyses on condom use and prevalent STI included data from 414 men, while those on incident STI were based on 1111 intervals from 355 men. We diagnosed prevalent STI (chlamydia, gonorrhea, and/or trichomoniasis) in 54.6% (n = 226) of the participants at enrollment. About 14% (n = 51) of participants had at least 1 of the study STIs during follow-up. Follow-up visits in which participants reported consistent condom use (100% of acts) for the past 7 days had less incident STI (adjusted OR, 0.4; 95% CI, 0.2–0.9) compared with visits where no condom use was reported. Self-reported condom use was more closely correlated with incident than prevalent STI. For example, the adjusted OR for prevalent infection for participants reporting consistent versus no condom use in past 7 days was 0.7 (95% CI, 0.4–1.2). Classifications based on the number of unprotected acts yielded findings similar to those based on the proportion of acts protected. Conclusions: Consistent condom use was associated with reduced risk of incident urethral STI. Research on condom effectiveness should focus on incident STI outcomes, where the temporal relationship between condom use and infection is clearer.

HIV coping self-efficacy: a key to understanding stigma and HIV test acceptance among incarcerated men in Jamaica.

Abstract Although prisons have been noted as important venues for HIV testing, few studies have explored the factors within this context that may influence HIV test acceptance. Moreover, there is a dearth of research related to HIV and incarcerated populations in middle and low-income countries, where both the burden of HIV and the number of people incarcerated is higher compared to high-income countries. This study explores the relationship between HIV coping self-efficacy, HIV-related stigma, and HIV test acceptance in the largest prisons in Jamaica. A random sample of inmates (n=298) recruited from an HIV testing demonstration project were asked to complete a cross-sectional quantitative survey. Participants who reported high HIV coping self-efficacy (adjusted odds ratio (AOR) 1.86: 95% confidence interval CI 1.24–2.78, p-value=0.003), some perceived risk of HIV (AOR 2.51: 95% (CI) 1.57–4.01, p-value=0.000), and low HIV testing stigma (AOR 1.71: 95% CI 1.05–2.79, p-value=0.032) were more likely to test for HIV. Correlates of HIV coping self-efficacy included external and internal HIV stigma (AOR 1.28: 95% CI 1.25–1.32, p-value=0.000 and AOR 1.76: 95% CI 1.34–2.30, p-value=0.000, respectively), social support (AOR 2.09: 95% CI 1.19–3.68, p-value=0.010), and HIV knowledge (AOR 2.33: 95% CI 1.04–5.22, p-value=0.040). Policy and programs should focus on the interrelationships of these constructs to increase participation in HIV testing in prison.

Understanding the High Prevalence of HIV and Other Sexually Transmitted Infections among Socio-Economically Vulnerable Men Who Have Sex with Men in Jamaica

Objectives This study estimates HIV prevalence among men who have sex with men (MSM) in Jamaica and explores social determinants of HIV infection among MSM. Design An island-wide cross-sectional survey of MSM recruited by peer referral and outreach was conducted in 2011. A structured questionnaire was administered and HIV/STI tests done. We compared three groups: MSM who accepted cash for sex within the past 3 months (MSM SW), MSM who did not accept cash for sex (MSM non-SW), and MSM with adverse life events (ever raped, jailed, homeless, victim of violence or low literacy). Results HIV prevalence among 449 MSM was 31.4%, MSM SW 41.1%, MSM with adverse life events 38.5%, 17 transgender MSM (52.9%), and MSM non-SW without adverse events 21.0%. HIV prevalence increased with age and number of adverse life events (test for trend P < 0.001), as did STI prevalence (P = 0.03). HIV incidence was 6.7 cases/100 person-years (95% CI: 3.74, 12.19). HIV prevalence was highest among MSM reporting high-risk sex; MSM SW who had been raped (65.0%), had a STI (61.2%) and who self identified as female (55.6%). Significant risk factors for HIV infection common to all 3 subgroups were participation in both receptive and insertive anal intercourse, high-risk sex, and history of a STI. Perception of no or little risk, always using a condom, and being bisexual were protective. Conclusion HIV prevalence was high among MSM SW and MSM with adverse life events. Given the characteristics of the sample, HIV prevalence among MSM in Jamaica is probably in the range of 20%. The study illustrates the importance of social vulnerability in driving the HIV epidemic. Programs to empower young MSM, reduce social vulnerability and other structural barriers including stigma and discrimination against MSM are critical to reduce HIV transmission.

Homophobia, stigma and HIV in Jamaican prisons

Success in addressing HIV and AIDS among men who have sex with men, a key population in the global epidemic, is impeded by homophobia. Homophobia as a barrier to HIV prevention and AIDS treatment is a particularly acute problem in the prison setting. In this qualitative study, we explore HIV and AIDS, stigma and homosexuality in the largest all male prison in Jamaica by conducting iterative in-depth interviews with 25 inmates. Participant narratives unveil a purposeful manipulation of beliefs related to homosexuality that impedes an effective response to HIV and AIDS both in prison and wider society. Findings indicate that homophobia is both a social construction and a tangible tool used to leverage power and a sense of solidarity in a larger political and economic landscape. This use of homophobia may not be unique to Jamaica and is an important issue to address in other low- and middle-income post-colonialist societies.

Success in controlling a major outbreak of malaria because of Plasmodium falciparum in Jamaica

In 2006, after 44 years of eradication of malaria, Jamaica had an outbreak of Plasmodium falciparum: 406 confirmed cases between September 2006 and December 2009 with a peak of the epidemic in December 2006. In response to the outbreak, the Ministry of Health launched an emergency response through early detection and prompt treatment of cases, vector control, public education and intersectoral collaboration. Ninety percent (361) of cases were residents of Kingston, and 63.6% were identified through house to house surveillance visits. For 56% of the confirmed cases, treatment with chloroquine was initiated within a week of onset of symptoms. Only one (0.3%) of 358 cases who had a post‐treatment smear on day 7 had a persistent asexual parasitaemia, while none of the 149 persons who had a follow‐up smear on day 28 was positive. The outbreak highlighted the need for increased institutional capacity for surveillance, confirmation and treatment of malaria as well as effective prevention and control of outbreaks which can occur after elimination. Jamaica appears to have successfully eliminated malaria after its reintroduction.

The challenge of promoting safe sex at sites where persons meet new sex partners in Jamaica: results of the Kingston PLACE randomized controlled trial

Objective  To determine whether a site‐based Priorities for Local AIDS Control Efforts (PLACE) HIV prevention intervention in Kingston, Jamaica increased condom use among persons with new or multiple sex partners.