Search

Background Women in sub-Saharan Africa are disproportionately affected by the HIV epidemic. Young women are twice as likely to be living with HIV as men of the same age and account for 64% of new HIV infections among young people. Many studies suggest that financial needs, alongside biological susceptibility, are a leading cause of the gender disparity in HIV acquisition. New robust evidence suggests women adopt risky sexual behaviours to cope with economic shocks, the sudden decreases in household's income or consumption power, enhancing our understanding of the link between poverty and HIV. We investigated if health insurance protects against economic shocks, reducing the need for vulnerable women to engage in risky sexual behaviours and reducing HIV and sexually transmitted infection (STI) incidence. Method and findings We conducted a randomised controlled trial to test the effectiveness of a formal shock coping strategy to prevent HIV among women at high risk of HIV (registration number: ISRCTN 22516548). Between June and August 2021, we recruited 1,508 adolescent girls and women over age 15 years who were involved in transactional sex (n = 753) or commercial sex (n = 755), using snowball sampling. Participants were randomly assigned (1:1) to receive free health insurance for themselves and their economic dependents for 12 months either at the beginning of the study (intervention; n = 579; commercial sex n = 289, transactional sex n = 290) from November 2021 or at the end of the study 12 months later (control; n = 568; commercial sex n = 290, transactional sex n = 278). We collected data on socioeconomic characteristics of participants. Primary outcomes included incidence of HIV and STIs and were measured at baseline, 6 months after randomisation, and 12 months after randomisation. We found that study participants who engaged in transactional sex and were assigned to the intervention group were less likely to become infected with HIV post-intervention (combined result of 6 months post-intervention or 12 months post-intervention, depending on the follow-up data available; odds ratio (OR) = 0.109 (95% confidence interval (CI) [0.014, 0.870]); p = 0.036). There was no evidence of a reduction in HIV incidence among women and girls involved in commercial sex. There was also no effect on STI acquisition among both strata of high-risk sexual activity. The main limitations of this study were the challenges of collecting reliable STI incidence data and the low incidence of HIV in women and girls involved in commercial sex, which might have prevented detection of study effects. Conclusion The study provides to our knowledge the first evidence of the effectiveness of a formal shock coping strategy for HIV prevention among women who engage in transactional sex in Africa, reinforcing the importance of structural interventions to prevent HIV. Trial registration The trial was registered with the ISRCTN Registry: ISRCTN 22516548. Registered on 31 July 2021., Author(s): Aurélia Lépine 1,*, Sandie Szawlowski 1, Emile Nitcheu 2, Henry Cust 1, Eric Defo Tamgno 2, Julienne Noo 2, Fanny Procureur 1, Illiasou Mfochive 2, Serge Billong 3, Ubald [...]

Zoonotic spillover of animal viruses into human populations is a continuous and increasing public health risk. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) highlights the global impact of emergence. Considering the history and diversity of coronaviruses (CoVs), especially in bats, SARS-CoV-2 will likely not be the last to spillover from animals into human populations. We sampled and tested wildlife in the Central African country Cameroon to determine which CoVs are circulating and how they relate to previously detected human and animal CoVs. We collected animal and ecological data at sampling locations and used family-level consensus PCR combined with amplicon sequencing for virus detection. Between 2003 and 2018, samples were collected from 6,580 animals of several different orders. CoV RNA was detected in 175 bats, a civet, and a shrew. The CoV RNAs detected in the bats represented 17 different genetic clusters, coinciding with alpha (n = 8) and beta (n = 9) CoVs. Sequences resembling human CoV-229E (HCoV-229E) were found in 40 Hipposideridae bats. Phylogenetic analyses place the human-derived HCoV-229E isolates closest to those from camels in terms of the S and N genes but closest to isolates from bats for the envelope, membrane, and RNA-dependent RNA polymerase genes. The CoV RNA positivity rate in bats varied significantly (P

Host-virus associations have co-evolved under ecological and evolutionary selection pressures that shape cross-species transmission and spillover to humans. Observed virus-host associations provide relevant context for newly discovered wildlife viruses to assess knowledge gaps in host-range and estimate pathways for potential human infection. Using models to predict virus-host networks, we predicted the likelihood of humans as hosts for 513 newly discovered viruses detected by large-scale wildlife surveillance at high-risk animal-human interfaces in Africa, Asia, and Latin America. Predictions indicated that novel coronaviruses are likely to infect a greater number of host species than viruses from other families. Our models further characterize novel viruses through prioritization scores and directly inform surveillance targets to identify host ranges for newly discovered viruses.

Adenoviruses (AdVs) are diverse pathogens of humans and animals, with several dozen bat AdVs already identified. Considering that over 100 human AdVs are known, and the huge diversity of bat species, many bat AdVs likely remain undiscovered. To learn more about AdV prevalence, diversity and evolution, we sampled and tested bats in Cameroon using several PCR assays for viral and host DNA. AdV DNA was detected in 14 % of the 671 sampled animals belonging to 37 different bat species. There was a correlation between species roosting in larger groups and AdV DNA detection. The detected AdV DNA belonged to between 28 and 44 different, mostly previously unknown, mastadenovirus species. The novel isolates are phylogenetically diverse and while some cluster with known viruses, others appear to form divergent new clusters. The phylogenetic tree of novel and previously known bat AdVs does not mirror that of the various host species, but does contain structures consistent with a degree of virus-host co-evolution. Given that closely related isolates were found in different host species, it seems likely that at least some bat AdVs have jumped species barriers, probably in the more recent past; however, the tree is also consistent with such events having taken place throughout bat AdV evolution. AdV diversity was highest in bat species roosting in large groups. The study significantly increased the diversity of AdVs known to be harboured by bats, and suggests that host behaviours, such as roosting size, may be what limits some AdVs to one species rather than an inability of AdVs to infect other related hosts.

Background: Influenza and severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) are both respiratory viruses with similar clinical manifestations and modes of transmission. This study describes influenza data before and during the coronavirus disease pandemic (COVID‐19) in Cameroon and SARS‐CoV‐2 data during the pandemic period. Methods: The study ran from 2017 to 2022, and data were divided into two periods: before (2017–2019) and during (2020–2022) the COVID‐19 pandemic. Nasopharyngeal samples collected from persons with respiratory illness were tested for influenza using the Centers for Disease Control and Prevention (CDC) typing and subtyping assays. During the COVID‐19 pandemic, the respiratory specimens were simultaneously tested for SARS‐CoV‐2 using the DaAn gene protocol or the Abbott real‐time SARS‐CoV‐2 assay. The WHO average curve method was used to compare influenza virus seasonality before and during the pandemic. Results: A total of 6246 samples were tested. Influenza virus detection rates were significantly higher in the pre‐pandemic period compared to the pandemic period (30.8% vs. 15.5%; p < 0.001). Meanwhile, the SARS‐CoV‐2 detection rate was 2.5%. A change in the seasonality of influenza viruses was observed from a bi‐annual peak before the pandemic to no clear seasonal pattern during the pandemic. The age groups 2–4 and 5–14 years were significantly associated with higher influenza positivity rates in both pre‐pandemic and pandemic periods. For SARS‐CoV‐2, all age groups above 15 years were the most affected population. Conclusion: The COVID‐19 pandemic had a significant impact on the seasonal influenza by changing the seasonality of the virus and reducing its detection rates. [ABSTRACT FROM AUTHOR]

Abstract Background Zoonotic transmission of simian retroviruses in Central Africa is ongoing and can result in pandemic human infection. While simian foamy virus (SFV) infection was reported in primate hunters in Cameroon and Gabon, little is known about the distribution of SFV in Africa and whether human-to-human transmission and disease occur. We screened 3,334 plasmas from persons living in rural villages in central Democratic Republic of Congo (DRC) using SFV-specific EIA and Western blot (WB) tests. PCR amplification of SFV polymerase sequences from DNA extracted from buffy coats was used to measure proviral loads. Phylogenetic analysis was used to define the NHP species origin of SFV. Participants completed questionnaires to capture NHP exposure information. Results Sixteen (0.5%) samples were WB-positive; 12 of 16 were from women (75%, 95% confidence limits 47.6%, 92.7%). Sequence analysis detected SFV in three women originating from Angolan colobus or red-tailed monkeys; both monkeys are hunted frequently in DRC. NHP exposure varied and infected women lived in distant villages suggesting a wide and potentially diverse distribution of SFV infections across DRC. Plasmas from 22 contacts of 8 WB-positive participants were all WB negative suggesting no secondary viral transmission. Proviral loads in the three women ranged from 14 – 1,755 copies/105 cells. Conclusions Our study documents SFV infection in rural DRC for the first time and identifies infections with novel SFV variants from Colobus and red-tailed monkeys. Unlike previous studies, women were not at lower risk for SFV infection in our population, providing opportunities for spread of SFV both horizontally and vertically. However, limited testing of close contacts of WB-positive persons did not identify human-to-human transmission. Combined with the broad behavioral risk and distribution of NHPs across DRC, our results suggest that SFV infection may have a wider geographic distribution within DRC. These results also reinforce the potential for an increased SFV prevalence throughout the forested regions of Africa where humans and simians co-exist. Our finding of endemic foci of SFV infection in DRC will facilitate longitudinal studies to determine the potential for person-to-person transmissibility and pathogenicity of these zoonotic retroviral infections.

Human parvovirus 4 infections are primarily associated with parenteral exposure in western countries. By ELISA, we demonstrate frequent seropositivity for antibody to parvovirus 4 viral protein 2 among adult populations throughout sub-Saharan Africa (Burkina Faso, 37%; Cameroon, 25%; Democratic Republic of the Congo, 35%; South Africa, 20%), which implies existence of alternative transmission routes.

Human parvovirus 4 infections are primarily associated with parenteral exposure in western countries. By ELISA, we demonstrate frequent seropositivity for antibody to parvovirus 4 viral protein 2 among adult populations throughout sub-Saharan Africa (Burkina Faso, 37%; Cameroon, 25%; Democratic Republic of the Congo, 35%; South Africa, 20%), which implies existence of alternative transmission routes.

Despite the fact that most emerging diseases stem from the transmission of pathogenic agents from animals to humans, the factors that mediate this process are still ill defined. What is known, however, is that the interface between humans and animals is of paramount importance in the process. This review will discuss the importance of the human-animal interface to the disease emergence process. We also provide an overview of factors that are believed to contribute to the origin and global spread of emerging infectious diseases and offer suggestions that may serve as future prevention strategies, such as social mobilization, public health education, behavioral change, and communication strategies. Because there exists no comprehensive global surveillance system to monitor zoonotic disease emergence, the intervention measures discussed herein may prove effective temporary alternatives.

Despite the fact that most emerging diseases stem from the transmission of pathogenic agents from animals to humans, the factors that mediate this process are still ill defined. What is known, however, is that the interface between humans and animals is of paramount importance in the process. This review will discuss the importance of the human-animal interface to the disease emergence process. We also provide an overview of factors that are believed to contribute to the origin and global spread of emerging infectious diseases and offer suggestions that may serve as future prevention strategies, such as social mobilization, public health education, behavioral change, and communication strategies. Because there exists no comprehensive global surveillance system to monitor zoonotic disease emergence, the intervention measures discussed herein may prove effective temporary alternatives.

HIV-1 is an immunosuppressive pathogen. Our behavioral data for 191 HIV-1-infected rural Cameroonians show frequent exposure to nonhuman primates through activities such as hunting and butchering. Immunosuppression among persons exposed to body fluids of wild nonhuman primates could favor the process of adaptation and subsequent emergence of zoonotic pathogens.

Enteroviruses (EVs) form a diverse genus in the virus family Picornaviridae. EVs that infect humans are divided genetically into 4 species (EV A-D), and each contains numerous antigenically distinct serotypes [...]

Cross-species transmission of retroviruses is common in Cameroon. To determine risk for simian T-cell lymphotropic virus (STLV) transmission from nonhuman primates to hunters, we examined 170 hunter-collected dried blood spots [...]

Exposure to nonhuman primates has led to the emergence of important diseases, including Ebola hemorrhagic fever, AIDS, and adult T-cell leukemia. To determine the extent of exposure to nonhuman primates, [...]

A vaginal gel containing the spermicide nonoxynol-9 does not appear to protect women from gonorrhea and chlamydia infection. This was the conclusion of a study of 1,251 women who used a condom or a condom plus nonoxynol-9., Context Nonoxynol-9 has been suggested as a vaginal microbicide to protect against common sexually transmitted infections. Objective To compare nonoxynol-9 gel and condom use (gel group) vs condom use alone (condom group) for the prevention of male-to-female transmission of urogenital gonococcal and chlamydial infection. Design and Setting Randomized controlled trial conducted at 10 community clinics and 10 pharmacies in Yaounde, Cameroon, between October 1998 and September 2000, with 6 months of follow-up. Participants High-risk population of 1251 women (excluding sex workers) being treated for or who had symptoms of sexually transmitted infections. Three were excluded from the gel group (0.5%) and 7 from the condom group (1 %) because of no follow-up data. Interventions Nonoxynol-9 gel (100 mg) and condoms or condoms only. Main Outcome Measure A positive test result for gonococcal or chlamydial infection by the ligase chain reaction assay; secondary outcome measure was a positive test result for human immunodeficiency virus (HIV). Results The rate ratio (RR) for new urogenital infections was 1.2 for the gel group vs condom group (95% confidence interval [CI], 0.9-1.6; P=.21). The gel group had 116 diagnosed gonococcal infections, chlamydial infections, or both for a rate of 43.6 per 100 person-years, and the condom group had 100 infections for a rate of 36.6 per 100 person-years. The RR for gonococcal infection in the gel group vs the condom group was 1.5 (95% Cl, 1.0-2.3) and for chlamydial infection was 1.0 (95% Cl, 0.7-1.4). There were 5 new cases of HIV infections in the gel group and 4 in the condom group. Three women in each group became pregnant during the study. Conclusion Nonoxynol-9 gel did not protect against urogenital gonococcal or chlamydial infection.