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Plasmodium falciparum is the most prevalent and lethal of the malaria parasites infecting humans, yet the origin and evolutionary history of this important pathogen remain controversial. Here we develop a single-genome amplification strategy to identify and characterize Plasmodium spp. DNA sequences in faecal samples from wild-living apes. Among nearly 3,000 specimens collected from field sites throughout central Africa, we found Plasmodium infection in chimpanzees (Pan troglodytes) and western gorillas (Gorilla gorilla), but not in eastern gorillas (Gorilla beringei) or bonobos (Pan paniscus). Ape plasmodial infections were highly prevalent, widely distributed and almost always made up of mixed parasite species. Analysis of more than 1,100 mitochondrial, apicoplast and nuclear gene sequences from chimpanzees and gorillas revealed that 99% grouped within one of six host-specific lineages representing distinct Plasmodium species within the subgenus Laverania. One of these from western gorillas comprised parasites that were nearly identical to P. falciparum. In phylogenetic analyses of full-length mitochondrial sequences, human P. falciparum formed a monophyletic lineage within the gorilla parasite radiation. These findings indicate that P. falciparum is of gorilla origin and not of chimpanzee, bonobo or ancient human origin. [ABSTRACT FROM AUTHOR]

Occasionally, the heinousness of a crime, the seeming certainty of the same result if the case is remanded, and the delay occasioned by remand tempt one to wink at procedural defects. Nevertheless, the cornerstone of any civilized system of justice is that the rules are applied evenly to everyone, no matter how despicable the crime [ABSTRACT FROM AUTHOR]

Background: Ebola (EBOV) and Sudan (SUDV) orthoebolaviruses are responsible for lethal hemorrhagic fever outbreaks in humans in Central and West Africa, and in apes that can be at the source of human outbreaks for EBOV., Methods: To assess the risk of exposure to orthoebolaviruses through contact with nonhuman primates (NHP), we tested the presence of antibodies against different viral proteins with a microsphere-based multiplex immunoassay in a case-control study on bites from NHPs in forest areas from Cameroon (n = 795) and in cross-sectional surveys from other rural populations (n = 622) of the same country., Results: Seroreactivities against at least 2 viral proteins were detected in 13% and 12% of the samples for EBOV and SUDV, respectively. Probability of seroreactivity was not associated with history of NHP bites, but was 3 times higher in Pygmies compared to Bantus. Although no neutralizing antibodies to EBOV and SUDV were detected in a selected series of highly reactive samples, avidity results indicate strong affinity to SUDV antigens., Conclusions: The detection of high level of seroreactivities against orthoebolaviruses in rural Cameroon, where no outbreaks have been reported, raises the possibilities of silent circulation of orthoebolaviruses, or of other not yet documented filoviruses, in these forested regions., Article's Main Point: Our study found high seroreactivities to Ebola and Sudan orthoebolavirus antigens in rural Cameroonian populations, especially among Pygmies, despite no reported outbreaks. This suggests potential silent circulation of orthoebolaviruses or unknown filoviruses, highlighting the need for further surveillance and research., Competing Interests: Potential conflicts of interest. The authors: No reported conflicts of interest. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed., (© The Author(s) 2024. Published by Oxford University Press on behalf of Infectious Diseases Society of America.)

Introduction: While the global COVID-19 pandemic is slowly coming under control, current efforts are focused on understanding the epidemiology of endemic SARS-CoV-2. The tool of choice for doing so remains serological tests that detect SARS-CoV-2 induced antibodies. However, the performance of these tests should be evaluated to ensure they comply with the specific performance criteria desired by each country that they are used in., Methods: Here, we use pre-COVID-19 plasma and plasma from SARS-CoV-2-infected individuals collected in 2020, 2021 and 2022 to evaluate the performance of two commercial Rapid Lateral Flow (RLF) tests (the PANBIO™ COVID-19 IgG/IgM rapid test and the LABNOVATION™ COVID-19 (SARS-CoV-2) IgG/IgM rapid test) and one commercial ELISA test (the PLATELIA™ SARS-CoV-2 total Ab)., Results: We find that whereas the specificity of the two RLF tests is ≥ 95%, it was 91% for the ELISA tests. However, at 14 days post-COVID-19 date of diagnosis (DoD), only the ELISA test constantly achieved a sensitivity of ≥80% over all the three years. In addition, the rate of detection of the two RLF tests varied across the years with a sensitivity ranging from <80% in 2021 to >80% in 2022. More importantly the capacity of these two RLF tests to detect IgG antibodies decreased with time. On the contrary, the sensitivity of the ELISA test was still above 80% more than six months post DoD., Conclusion: We recommend that sero-epidemiological surveys focused on testing antibodies should not rely on performances reported by the assay manufacturers. They should include a formal evaluation of the selected assays to ensure its limitations and strengths conform with the data-accuracy requirements of the surveys., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

The seroprevalence to orthoebolaviruses was studied in 9594 bats (5972 frugivorous and 3622 insectivorous) from Cameroon, the Democratic Republic of Congo (DRC) and Guinea, with a Luminex-based serological assay including recombinant antigens of four orthoebolavirus species. Seroprevalence is expressed as a range according to different cut-off calculations. Between 6.1% and 18.9% bat samples reacted with at least one orthoebolavirus antigen; the highest reactivity was seen with Glycoprotein (GP) antigens. Seroprevalence varied per species and was higher in frugivorous than insectivorous bats; 9.1-27.5% versus 1.3-4.6%, respectively. Seroprevalence in male (13.5%) and female (14.4%) bats was only slightly different and was higher in adults (14.9%) versus juveniles (9.4%) ( p < 0.001). Moreover, seroprevalence was highest in subadults (45.4%) when compared to mature adults (19.2%), ( p < 0.001). Our data suggest orthoebolavirus circulation is highest in young bats. More long-term studies are needed to identify birthing pulses for the different bat species in diverse geographic regions and to increase the chances of detecting viral RNA in order to document the genetic diversity of filoviruses in bats and their pathogenic potential for humans. Frugivorous bats seem more likely to be reservoirs of orthoebolaviruses, but the role of insectivorous bats has also to be further examined.

Background: Emergence of mosquito-borne arboviruses has caused significant public health burden. The life cycle of arboviruses comprises sylvatic and urban cycles, including a wildlife reservoir, a human host, and an arthropod vector. However, many questions remain on the sylvatic cycles of arboviruses. In this study, we investigate the prevalence of IgG antibodies to arboviruses of public health importance in African bats. Material and Methods: We collected dried blood spots from bats in Cameroon, Guinea, and the Democratic Republic of the Congo (DRC). To detect IgG antibodies to 10 antigens of 6 arboviruses (Dengue, Zika, West Nile, Usutu, Chikungunya, and O'nyong nyong viruses), we adapted a previously validated multiplex detection assay based on the Luminex technology. Results: We tested samples from 2579 bats, representing 1917 frugivorous and 641 insectivorous bats distributed in 7 families and 21 species. Overall, 218/2579 (8.45%) bat samples reacted with at least 1 of the 10 antigens tested. The highest prevalence was observed against Usutu virus with 2.3% (59/2579), followed by 1.9% (49/2579) and 1.35% (35/2579) for the Dengue virus serotypes 4 and 3, respectively. The global seroprevalence varied by country and collection site: 11% (151/1376) in Cameroon, 3.5% (20/565) in DRC, and 7.3% (47/638) in Guinea. The highest rates were observed in Hypsignathus monstrosus (17.9%), Rousettus aegyptiacus (16.4%), and Eidolon helvum (10.7%), and in species from the insectivorous Molossidae family (7.8-8.9%). Finally, we observed changes in seroprevalence over the year in E. helvum and H. monstrosus colonies, which could be related to population structure. Conclusion: On more than 2500 bat samples tested, we showed variable IgG seroprevalences against multiple arboviruses. Overall, the prevalence of IgG antibodies of 8.45% against arboviruses found in bats suggest that they could play a role in arboviruses cycles in the wild, in addition to other animal species.

Background: Population-based studies to estimate viral load (VL) suppression and rate of acquired HIV drug resistance (ADR) are essential in sub-Saharan Africa. We conducted the first nationally representative study estimating VL suppression and ADR in Cameroon., Methods: Eligible participants were patients on antiretroviral therapy (ART) for 12 to 24 months (ART 12-24) or 48 to 60 months (ART 48-60). ART 12-24 participants were recruited from 24 randomly selected clinics in both urban and rural regions. ART 48-60 participants were recruited from 7 urban clinics. Recruitment occurred from February to August 2015. Dried blood spots (DBSs) and plasma specimens were collected and tested for HIV-1 RNA level and presence of drug resistance mutations (DRM) when VL ≥ 1000 copies/ml., Results: Overall, 1064 ART 12-24 and 388 ART 48-60 participants were recruited. Viral suppression in the ART 12-24 group was 72.1% (95% CI: 66.3-77.2) overall, 75.0% (65.2-82.7) in urban sites, and 67.7% (58.3-75.8) in rural sites. In the ART 48-60 group, viral suppression was 67.7% (55.8-77.7). Overall, HIV drug resistance (HIVDR) was 17.7% (15.1-20.6) and 28.3% (17.4-42.5) in the ART 12-24 and ART 48-60 groups, respectively. However, among patients with VL ≥ 1000 copies/ml, HIVDR was identified in 63.3% (52.0-73.3) of ART 12-24 patients, and in 87.7% (67.4-96.1) of ART 48-60 patients., Conclusions: Results of this first nationwide study indicate alarming levels of virological failure and ADR in Cameroon. Better ART management is urgently needed and should focus on improving ART adherence, availability of VL monitoring, and more timely switches to second-line ART.

HIV-1, the cause of AIDS, is composed of four phylogenetic lineages, groups M, N, O, and P, each of which resulted from an independent cross-species transmission event of simian immunodeficiency viruses (SIVs) infecting African apes. Although groups M and N have been traced to geographically distinct chimpanzee communities in southern Cameroon, the reservoirs of groups O and P remain unknown. Here, we screened fecal samples from western lowland (n = 2,611), eastern lowland (n = 103), and mountain (n = 218) gorillas for gorilla SIV (SIVgor) antibodies and nucleic acids. Despite testing wild troops throughout southern Cameroon (n = 14), northern Gabon (n = 16), the Democratic Republic of Congo (n = 2), and Uganda (n = 1), SIVgor was identified at only four sites in southern Cameroon, with prevalences ranging from 0.8-22%. Amplification of partial and full-length SIVgor sequences revealed extensive genetic diversity, but all SIVgor strains were derived from a single lineage within the chimpanzee SIV (SIVcpz) radiation. Two fully sequenced gorilla viruses from southwestern Cameroon were very closely related to, and likely represent the source population of, HIV-1 group P. Most of the genome of a third SIVgor strain, from central Cameroon, was very closely related to HIV-1 group O, again pointing to gorillas as the immediate source. Functional analyses identified the cytidine deaminase APOBEC3G as a barrier for chimpanzee-to-gorilla, but not gorilla-to-human, virus transmission. These data indicate that HIV-1 group O, which spreads epidemically in west central Africa and is estimated to have infected around 100,000 people, originated by cross-species transmission from western lowland gorillas.

Background: In resource-limited countries, estimating CD4-specific incidence rates of mortality and morbidity among patients receiving antiretroviral therapy (ART) may help assess the effectiveness of care and treatment programmes, identify program weaknesses, and inform decisions., Methods: We pooled data from 13 research cohorts in 5 sub-Saharan African (Benin, Burkina Faso, Cameroon, Cote d'Ivoire, and Senegal) and 2 Asian (Cambodia and Laos) countries. HIV-infected adults (18 years and older) who received ART in 1998-2008 and had at least one CD4 count available were eligible. Changes in CD4 counts over time were estimated by a linear mixed regression. CD4-specific incidence rates were estimated as the number of first events occurring in a given CD4 stratum divided by the time spent within the stratum., Results: Overall 3917 adults (62% women) on ART were followed up during 10,154 person-years. In the ≤ 50, 51-100, 101-200, 201-350, 351-500, 501-650, and >650 cells/mm CD4 cells strata, death rates were 20.6, 11.8, 6.7, 3.3, 1.8, 0.9, and 0.3 per 100 person-years; AIDS rates were 50.5, 32.9, 11.5, 4.8, 2.8, 2.2, and 2.2 per 100 person-years; and loss-to-follow-up rates were 4.9, 6.1, 3.5, 3.1, 2.9, 1.7, and 1.2 per 100 person-years, respectively. Mortality and morbidity were higher during the first year after ART initiation., Conclusions: In these resource-limited settings, death and AIDS rates remained substantial after ART initiation, even in individuals with high CD4 cell counts. Ensuring earlier ART initiation and optimizing case finding and treatment for AIDS-defining diseases should be seen as priorities.

We studied neutralization of CRF02&#95;AG HIV-1-infected plasma samples. In contrast to previous reports, these samples neutralized CRF02&#95;AG viruses better than other viruses. This included six of eight CRF02&#95;AG viruses previously designated resistant (tier 2/3 or 3). Only viruses 253-11 and 278-50 remained highly resistant, but they were sensitive to membrane-proximal external region (MPER)-specific monoclonal antibodies, suggesting neutralization targets for even these viruses. We propose using high-neutralizing-within-subtype samples for evaluation of neutralization resistance of viruses.

In this study, HIV strains circulating among military personnel were characterized, in Malabo, the capital city of Equatorial Guinea. One sample was found to be HIV-2 group A while a high degree of genetic diversity was recorded in the pol region of 41 HIV-1-positive samples. CRF02&#95;AG accounted for 53.7% of the strains, and 11 different variants were obtained in the remaining 19 samples: subtype G (n = 3), A3 (n = 2), C (n = 2), CRF26&#95;A5U (n = 2), F2 (n = 1), CRF06 (n = 1), CRF09 (n = 1), CRF11 (n = 1), CRF22 (n = 1), and divergent subtype A (n = 1) and F (n = 1). One strain could not be classified and three were unique recombinants. Analysis of antiretroviral drug resistance mutations revealed two patients each harboring one major mutation, M46I in protease and D67N in reverse transcriptase sequences, respectively. The high genetic diversity and emerging ARV resistance mutations call for frequent surveys and appropriate monitoring of ARV considering the increasing access to ARV in the country.

De Brazza's monkeys (Cercopithecus neglectus) are non-human primates (NHP) living in Equatorial Africa from South Cameroon through the Congo-Basin to Uganda. As most of the NHP living in sub-Saharan Africa, they are naturally infected with their own simian lentivirus, SIVdeb. Previous studies confirmed this infection for De Brazza's from East Cameroon and Uganda. In this report, we studied the genetic diversity of SIVdeb in De Brazza's monkeys from different geographical areas in South Cameroon and from the Democratic Republic of Congo (DRC). SIVdeb strains from east, central and western equatorial Africa form a species-specific monophyletic lineage. Phylogeographic clustering was observed among SIVdeb strains from Cameroon, the DRC and Uganda, but also among primates from distinct areas in Cameroon. These observations suggest a longstanding virus-host co-evolution. SIVdeb prevalence is high in wild De Brazza's populations and thus represents a current risk for humans exposed to these primates in central Africa.

It is now well established that the clade of simian immunodeficiency viruses (SIVs) infecting west central African chimpanzees (Pan troglodytes troglodytes) and western gorillas (Gorilla gorilla gorilla) comprises the progenitors of human immunodeficiency virus type 1 (HIV-1). In this study, we have greatly expanded our previous molecular epidemiological survey of SIVcpz in wild chimpanzees in Cameroon. The new results confirm a wide but uneven distribution of SIVcpzPtt in P. t. troglodytes throughout southern Cameroon and indicate the absence of SIVcpz infection in Pan troglodytes vellerosus. Analyzing 725 fecal samples from 15 field sites, we obtained partial nucleotide sequences from 16 new SIVcpzPtt strains and determined full-length sequences for two of these. Phylogenetic analyses of these new viruses confirmed the previously reported phylogeographic clustering of SIVcpzPtt lineages, with viruses related to the ancestors of HIV-1 groups M and N circulating exclusively in southeastern and south central P. t. troglodytes communities, respectively. Importantly, the SIVcpzPtt strains from the southeastern corner of Cameroon represent a relatively isolated clade indicating a defined geographic origin of the chimpanzee precursor of HIV-1 group M. Since contacts between humans and apes continue, the possibility of ongoing transmissions of SIV from chimpanzees (or gorillas) to humans has to be considered. In this context, our finding of distinct SIVcpzPtt envelope V3 sequence clades suggests that these peptides may be useful for the serological differentiation of SIVcpzPtt and HIV-1 infections, and thus the diagnosis of new cross-species transmissions if they occurred.