Predicting the extinction of HIV-2 in rural Guinea-Bissau.
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ABSTRACT:
SUBMITTER: Fryer HR
PROVIDER: S-EPMC4645958 | biostudies-literature | 2015 Nov
REPOSITORIES: biostudies-literature
Publications
Predicting the extinction of HIV-2 in rural Guinea-Bissau.
Fryer Helen R HR Van Tienen Carla C Van Der Loeff Maarten Schim MS Aaby Peter P Da Silva Zacarias J ZJ Whittle Hilton H Rowland-Jones Sarah L SL de Silva Thushan I TI
AIDS (London, England) 20151101 18
<h4>Objective</h4>This article predicts the future epidemiology of HIV-2 in Caió, a rural region of Guinea Bissau; and investigates whether HIV-2, which has halved in prevalence between 1990 and 2007 and is now almost absent in young adults in Caió, can persist as an infection of the elderly.<h4>Design</h4>A mathematical model of the spread of HIV-2 was tailored to the epidemic in Caió, a village in Guinea-Bissau.<h4>Methods</h4>An age-stratified difference equation model of HIV-2 transmission w ...[more]
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Project description:ObjectivesIn many African countries, child mortality is higher in the rainy season than in the dry season. We investigated the effect of season on child mortality by time periods, sex and age in rural Guinea-Bissau.MethodsBandim health project follows children under-five in a health and demographic surveillance system in rural Guinea-Bissau. We compared the mortality in the rainy season (June to November) between 1990 and 2013 with the mortality in the dry season (December to May) in Cox proportional hazards models providing rainy vs. dry season mortality rate ratios (r/d-mrr). Seasonal effects were estimated in strata defined by time periods with different frequency of vaccination campaigns, sex and age (<1 month, 1-11 months, 12-59 months). Verbal autopsies were interpreted using InterVa-4 software.ResultsFrom 1990 to 2013, overall mortality was declined by almost two-thirds among 81 292 children (10 588 deaths). Mortality was 51% (95% ci: 45-58%) higher in the rainy season than in the dry season throughout the study period. The seasonal difference increased significantly with age, the r/d-mrr being 0.94 (0.86-1.03) among neonates, 1.57 (1.46-1.69) in post-neonatal infants and 1.83 (1.72-1.95) in under-five children (P for same effect <0.001). According to the InterVa, malaria deaths were the main reason for the seasonal mortality difference, causing 50% of all deaths in the rainy season, but only if the InterVa included season of death, making the argument self-confirmatory.ConclusionThe mortality declined throughout the study, yet rainy season continued to be associated with 51% higher overall mortality.
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Project description:BackgroundHTLV-1 is endemic in Guinea-Bissau, and the highest prevalence in the adult population (5.2%) was observed in a rural area, Caió, in 1990. HIV-1 and HIV-2 are both prevalent in this area as well. Cross-sectional associations have been reported for HTLV-1 with HIV infection, but the trends in prevalence of HTLV-1 and HIV associations are largely unknown, especially in Sub Saharan Africa. In the current study, data from three cross-sectional community surveys performed in 1990, 1997 and 2007, were used to assess changes in HTLV-1 prevalence, incidence and its associations with HIV-1 and HIV-2 and potential risk factors.ResultsHTLV-1 prevalence was 5.2% in 1990, 5.9% in 1997 and 4.6% in 2007. Prevalence was higher among women than men in all 3 surveys and increased with age. The Odds Ratio (OR) of being infected with HTLV-1 was significantly higher for HIV positive subjects in all surveys after adjustment for potential confounding factors. The risk of HTLV-1 infection was higher in subjects with an HTLV-1 positive mother versus an uninfected mother (OR 4.6, CI 2.6-8.0). The HTLV-1 incidence was stable between 1990-1997 (Incidence Rate (IR) 1.8/1,000 pyo) and 1997-2007 (IR 1.6/1,000 pyo) (Incidence Rate Ratio (IRR) 0.9, CI 0.4-1.7). The incidence of HTLV-1 among HIV-positive individuals was higher compared to HIV negative individuals (IRR 2.5, CI 1.0-6.2), while the HIV incidence did not differ by HTLV-1 status (IRR 1.2, CI 0.5-2.7).ConclusionsTo our knowledge, this is the largest community based study that has reported on HTLV-1 prevalence and associations with HIV. HTLV-1 is endemic in this rural community in West Africa with a stable incidence and a high prevalence. The prevalence increases with age and is higher in women than men. HTLV-1 infection is associated with HIV infection, and longitudinal data indicate HIV infection may be a risk factor for acquiring HTLV-1, but not vice versa. Mother to child transmission is likely to contribute to the epidemic.
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Project description:BACKGROUND:With increased access to antiretroviral treatment (ART) in sub-Saharan Africa emergence of HIV-1 pretreatment drug resistance constitutes a serious risk. This may lead to rapid virological failure in subjects initiating ART, and mother-to-child transmission despite prophylaxis. METHODS:Treatment-naïve pregnant women from four antenatal care clinics in Bissau, Guinea-Bissau, were enrolled from October 2016 to November 2017. Genotypic resistance testing and phylogenetic subtype analysis was performed on 48 specimens. RESULTS:Forty eight women met the survey inclusion criteria. All specimens were successfully amplified and genotyped. Specimens from five women were associated with HIV-1 drug resistance mutations. Four carried mutations exclusively linked to non-nucleoside reverse transcriptase inhibitors (NNRTIs) (K103N, K103N/S) and one carried mutations to both NNRTIs (G190S, K101E) and nucleoside reverse transcriptase inhibitors (NRTIs) (M184V). These results corresponded to 10.4% (95% CI: 4.5-22.2%), 2.1% (95% CI: 0.4-10.9%) and 0% (95% CI: 0.0-7.4%) drug resistance mutations to NNRTIs, NRTIs and protease inhibitors, respectively. HIV-1 circulating recombinant form 02AG was most commonly found, followed by HIV-1 sub-subtype A3. Subtype/CRF was not associated with drug resistance mutations. CONCLUSION:Our study reports a 10.4% prevalence of pretreatment drug resistance to NNRTIs in HIV-1-infected pregnant women in the capital Bissau, Guinea Bissau. Since NNRTIs are part of first-line ART in the country, baseline resistance screenings or adjustment of national treatment guidelines should be considered as antiretroviral treatment programs are scaled up.
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Project description:ObjectiveThe WHO aims for 90% coverage of the Expanded Program on Immunization (EPI), which in Guinea-Bissau included BCG vaccine at birth, three doses of diphtheria-tetanus-pertussis vaccine (DTP) and oral polio vaccine (OPV) at 6, 10 and 14 weeks and measles vaccine (MV) at 9 months when this study was conducted. The WHO assesses coverage by 12 months of age. The sequence of vaccines may have an effect on child mortality, but is not considered in official statistics or assessments of programme performance. We assessed vaccination coverage and frequency of out-of-sequence vaccinations by 12 and 24 months of age.DesignObservational cohort study.Setting and participantsThe Bandim Health Project's (BHP) rural Health and Demographic Surveillance site covers 258 randomly selected villages in all regions of Guinea-Bissau. Villages are visited biannually and vaccination cards inspected to ascertain vaccination status. Between 2003 and 2009 vaccination status by 12 months of age was assessed for 5806 children aged 12-23 months; vaccination status by 24 months of age was assessed for 3792 children aged 24-35 months.Outcome measuresCoverage of EPI vaccinations and frequency of out-of-sequence vaccinations.ResultsHalf of 12-month-old children and 65% of 24-month-old children had completed all EPI vaccinations. Many children received vaccines out of sequence: by 12 months of age 54% of BCG-vaccinated children had received DTP with or before BCG and 28% of measles-vaccinated children had received DTP with or after MV. By 24 months of age the proportion of out-of-sequence vaccinations was 58% and 35%, respectively, for BCG and MV.ConclusionsIn rural Guinea-Bissau vaccination coverage by 12 months of age was low, but continued to increase beyond 12 months of age. More than half of all children received vaccinations out of sequence. This highlights the need to improve vaccination services.
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Project description:The HIV-1 epidemic in West Africa has been dominated by subtype A and the recombinant form CRF02_AG. Little is known about the origins and the evolutionary history of HIV-1 in this region. We employed Maximum likelihood and Bayesian methods in combination with temporal and spatial information to reconstruct the HIV-1 subtype distribution, demographic history and migration patterns over time in Guinea-Bissau, West Africa. We found that CRF02_AG and subsubtype A3 were the dominant forms of HIV-1 in Guinea-Bissau and that they were introduced into the country on at least six different occasions between 1976 and 1981. These estimates also corresponded well with the first reported HIV-1 cases in Guinea-Bissau. Migration analyses suggested that (1) the HIV-1 epidemic started in the capital Bissau and then dispersed into more rural areas, and (2) the epidemic in Guinea-Bissau was connected to both Cameroon and Mali. This is the first study that describes the HIV-1 molecular epidemiology in a West African country by combining the results of subtype distribution with analyses of epidemic origin and epidemiological linkage between locations. The multiple introductions of HIV-1 into Guinea-Bissau, during a short time-period of five years, coincided with and were likely influenced by the major immigration wave into the country that followed the end of the independence war (1963-1974).
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Project description:BACKGROUND:Bacillus Calmette-Guérin (BCG) vaccination may have beneficial non-specific effects on child survival, the effects being stronger for children developing a scar. In a prospective cohort study, we examined determinants for not developing a BCG scar within 6 months of vaccination. METHODS:Bandim Health Project (BHP) runs a Health and Demographic Surveillance System site in rural Guinea-Bissau. BHP provides BCG at monthly visits. We studied determinants for not developing a BCG scar using binomial regression models to obtain relative risks (RR). RESULTS:From May 2012 until October 2014, BHP nurses vaccinated 2415 infants with BCG. We assessed BCG scar between 6 and 12 months of age for 2156 (89%) of these children and 2115 (98%) had developed a scar. In comparison, among 785 children BCG vaccinated elsewhere, 622 (79%) had a scar, the RR of not having a scar being 10.91 (7.52-15.85) compared with children vaccinated by BHP. Among children vaccinated by BHP, those receiving the Russian BCG strain were more likely not to develop a scar (RR = 2.98 (1.52-5.81)) compared with children receiving Danish BCG strain. Children with no post-injection wheal or a wheal <3 mm were more likely to not develop a scar (RR = 9.05 (3.69-22.20) and RR = 4.74 (1.96-11.45), respectively). Nutritional status and socioeconomic status were not associated with scarification. CONCLUSION:Vaccination technique and vaccine strain were associated with BCG scar development while nutritional status and socioeconomic status were not. Scarring rate may therefore be a better indicator of vaccination programme performance than coverage.
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Project description:BackgroundWorldwide, governments have implemented restrictions on movement and gatherings to contain the COVID-19 pandemic. In the spirit of the Convention on the Rights of the Child, children have a right to express their opinion on matters of concern to them. The study aimed to describe and analyse how adolescents in the capital Bissau understood the unfolding COVID-19 pandemic and their lived experiences during the first 3 months of the pandemic.MethodsCollaborators identified participants in five urban areas in Bissau in June 2020. Semistructured, open-ended interviews were conducted with 30 adolescents aged 15-17 years, attending private and public schools or out-of-school. The interviews were conducted in Kriol, recorded, transcribed, translated and analysed.ResultsAll the participants were heavily affected by the confinement measures during a state of emergency. Almost all believed in the realness of coronavirus while there were some doubts about its arrival in the country. The consequences were staying at home, enforced with increased police violence. At the same time, other violence on the streets or between neighbours had decreased. A few participants said they liked staying at home because they appreciated spending more time with their families. Most participants claimed that they and their family members tried to follow preventive measures. Almost all participants voiced concerns about the worsening financial situation at home, leading to food scarcity. Nearly all the adolescents were tired of the lockdown and worried about the pandemic's implications on their future opportunities.ConclusionsStudy participants, here adolescents in Bissau, have a clear notion of their existence and the current situation's potential negative impact on their future. Their voices need to be heard and acted on, which may soften the lockdown's negative impact on adolescents in Guinea-Bissau, as elsewhere.
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