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Single-nucleotide polymorphism in APOBEC3C (resulting in a serine to isoleucine in position 188) is present in approximately 10% of African populations and greatly enhances restriction against human immunodeficiency virus-1 and simian immunodeficiency virus by improving dimerization and DNA processivity of the enzyme. In this study, we demonstrated in culture and in infected patients that hepatitis B virus (HBV) could be edited by APOBEC3CS188I. Using next-generation sequencing, we demonstrated that APOBEC3CS188I led to enhanced editing activity in 5ʹTpCpA→5ʹTpTpA context. This constitutes a new hallmark of this enzyme, which could be used to determine its impact on HBV or nuclear DNA.

International audience; Yellow fever remains a public-health threat in remote regions of Africa. Here, we report the identification and genetic characterisation of one yellow-fever case observed during the investigation of a cluster of nine suspected haemorrhagic fever cases in a village in the Central African Republic. Samples were tested using real-time RT-PCR targeting the main African haemorrhagic fever viruses. Following negative results, we attempted virus isolation on VERO E6 cells and newborn mice and rescreened the samples using rRT-PCR. The whole viral genome was sequenced using an Illumina NovaSeq 6000 sequencer. Yellow-fever virus (YFV) was isolated from one woman who reported farming activities in a forest setting several days before disease onset. Phylogenetic analysis shows that this strain belongs to the East-Central African YFV genotype, with an estimated emergence some 63 years ago. Finally, five unique amino-acid changes are present in the capsid, envelop, NS1A, NS3, and NS4B proteins. More efforts are required to control yellow-fever re-emergence in resource-limited settings.

Introduction: Very little is known about the impact of vision impairment (VI) on physical health in late-life in sub-Saharan Africa populations, whereas many older people experience it. We investigated the association between self-reported VI and frailty in Central African older people with low cognitive performance. Methods: It was cross-sectional analysis of data from the Epidemiology of Dementia in Central Africa (EPIDEMCA) population-based study. After screening for cognitive impairment, older people with low cognitive performance were selected. Frailty was assessed using the Study of Osteoporotic Fracture index. Participants who met one of the 3 parameters assessed (unintentional weight loss, inability to do 5 chair stands, and low energy level) were considered as pre-frail, and those who met 2 or more parameters were considered as frail. VI was self-reported. Associations were investigated using multinomial logistic regression models. Results: Out of 2,002 older people enrolled in EPIDEMCA, 775 (38.7%) had low cognitive performance on the screening test. Of them, 514 participants (sex ratio: 0.25) had available data on VI and frailty and were included in the analyses. In total, 360 (70%) self-reported VI. Prevalence of frailty was estimated at 64.9% [95% confidence interval: 60.9%–69.1%] and 23.7% [95% CI: 20.1%–27.4%] for pre-frailty. After full adjustment, self-reported VI was associated with frailty (adjusted odds ratio = 2.2; 95% CI: 1.1–4.3) but not with pre-frailty (adjusted odds ratio = 1.8; 95% CI: 0.9–3.7). Conclusion: In Central African older people with low cognitive performance, those who self-reported VI were more likely to experience frailty. Our findings suggest that greater attention should be devoted to VI among this vulnerable population in order to identify early frailty onset and provide adequate care management.

International audience; OBJECTIVE: The main objective of the MACOMBA (Maternity and Control of Malaria-HIV co-infection in Bangui) trial was to show that cotrimoxazole (CTX) is more effective than Sulphadoxine-Pyremethamine-IPTp (IPTp-SP) to prevent placental malaria infection (primary endpoint) among HIV-positive pregnant women with a CD4+ count ≥350 cells/mm(3) in Bangui, CAR.METHODS: MACOMBA is a multicenter, open-label randomized trial conducted in four maternity hospitals in Bangui. Between 2013 and 2017, 193 women were randomized and 112 (59 and 53 in CTX and IPTp-SP arms, respectively) were assessed for placental infection defined by microscopic parasitemia or PCR.RESULTS: Thirteen women had a placental infection: 5 in the CTX arm (1 by microscopic placental parasitemia and 4 by PCR) and 8 by PCR in the SP-IPTp (8.5% vs 15.1%, p = 0.28). The percentage of newborns with low birthweight (< 2500 g) did not differ statistically between the two arms. Self-reported compliance to CTX prophylaxis was good. There was a low overall rate of adverse events in both arms.CONCLUSION: Although our results do not allow us to conclude that CTX is more effective, drug safety and good compliance among women with this treatment favour its widespread use among HIV-infected pregnant women, as currently recommended by WHO.

Background Visual impairment (VI) and determinants of poor cardiovascular health are very common in Sub-Saharan Africa. However, we do not know whether these determinants are associated with VI among older adults in this region. This study aimed at investigating the association between the determinants of poor cardiovascular health and near VI among older adults living in Congo. Methods Participants were Congolese adults aged 65 or older included in Epidemiology of Dementia in Central Africa—Follow-up population-based cohort. Near VI was defined as visual acuity less than 20/40 measured at 30 cm. Associations between determinants of poor cardiovascular health collected at baseline and near visual acuity measured at first follow-up were investigated using multivariable logistic regression models. Results Among the 549 participants included, 378 (68.8%; 95% confidence interval [CI]: 64.9%–72.7%]) had near VI. Of the determinants of poor cardiovascular health explored, we found that having high body mass index of at least 25 kg/m2 (odds ratio [OR] = 2.15; 95% CI: 1.25–3.68), diabetes (OR = 2.12; 95% CI: 1.06–4.25) and hypertension (OR = 1.65; 95% CI: 1.02–2.64) were independently associated with near VI. Conclusions Several determinants of poor cardiovascular health were associated with near VI in this population. This study suggests that promoting good cardiovascular health could represent a target for VI prevention among older adults.

International audience; Introduction: Depression and anxiety are two very common psychiatric disorders in late-life. They are markers of poor quality of life and are strongly associated with death among older people. Yet, few studies on these comorbidities have been conducted in the African population. This study aims to present the epidemiology of depression and anxiety among older people in Central Africa.Method: A cross-sectional population-based study was carried out in Republic of Congo (ROC) and Central African Republic (CAR) between 2011 - 2012 among older people aged ≥ 65 years (EPIDEMCA study). Data were collected using a standardized questionnaire and participants underwent a brief physical examination. Depression and anxiety symptoms were ascertained using a community version of the Geriatric Mental State (GMS-B3) and the Automated Geriatric Examination for Computer Assisted Taxonomy diagnostic system (AGECAT), probable cases were defined as having a GMS-AGECAT level of 3 or more. Logistic regression models were used to investigate the association between potential risk factors collected and each symptom.Results: Overall 2002 participants were included in the EPIDEMCA study (500 in Brazzaville and 529 in Gamboma in ROC, 500 in Bangui and 473 in Nola (473) in CAR). Median age of the participants was 72 years [interquartile range: 68 – 78 years] and females were mostly represented (61.8%). Prevalence was 38.1% (95% Confidence Interval: 35.9% - 40.2%) for depression, 7.7% (95% CI: 6.5% - 8.9%) for anxiety and 5.7% (95% CI: 4.6% - 6.7%) for the co-occurrence of both disorders. For all three outcomes, prevalence was significantly higher among females and in rural areas. Only depression increased with age. Preliminary analyses showed that female sex, living in a rural area, and living without a partner were associated with the three outcomes (Odds Ratios from 1.59 to 3.27; p

Background Onchocerciasis is a serious problem in tropical areas. The role of the parasite as a factor associated with neurological diseases needs to be addressed because it might involve a reduction of the risk via elimination strategies. We performed a systematic scoping review to identify available studies on this association and put into perspective the different methodological approaches for interpreting the evidence. Methodology A literature search was conducted using MEDLINE (Pubmed) through October 1, 2020. We included all the studies evaluating the association between onchocerciasis and four neurological diseases (epilepsy, nodding syndrome, Nakalanga syndrome, and encephalitis) in tropical countries. A descriptive and critical summary of the results was conducted to provide an overview of the findings. Results Overall, 161 articles were identified in the literature search. After full-length examination, we included twelve articles for epilepsy and three for nodding syndrome. Two meta-analyses of case-control studies found a modest strength of the association between O. volvulus and epilepsy. Recent meta-analyses and original studies support a significant association. Epidemiological studies suggest an association between onchocerciasis and nodding syndrome, however, the level of evidence from case-control studies was relatively low. No measure of association was reported for Nakalanga syndrome. There was no specific study on the association between O. volvulus and encephalitis. Conclusion The association between onchocerciasis and epilepsy seems increasingly likely. However, there are still many unanswered questions about the different clinical presentations of this epilepsy. Strong international collaboration is essential to improve our understanding of risk factors and physiopathological mechanisms of these intriguing conditions.

International audience; Hepatocellular carcinoma (HCC) is still a major killing malignancy in sub-Saharan Africa. Lifelong intoxication with aflatoxin B1 is considered as one of the primary causes of this situation. The role of aflatoxin in HCC from a given population is commonly estimated through the prevalence of R249S mutation of TP53, a hallmark for previous exposure to the mycotoxin. However, the role of AFB1 is barely known in large part of Africa. We conducted a survey on circulating cell-free DNA from 149 patients with HCC and 213 control subjects with and without liver diseases from Cameroon and Central African Republic using droplet digital PCR technique. We observed a mutation prevalence of 24.8% (n = 37/149) in patients with tumor and 5.6% (n = 12/213) in controls (P = 2.2E-07). Patients with mutations usually displayed significantly increased circulating alpha-fetoprotein (AFP) values, high hepatitis B virus (HBV) DNA loads as well as worsened values of blood cells count. Interestingly, the fraction of droplets positive for R249S was significantly larger in patients with liver cancer (15.3 ± 3.7%) than in controls (0.5 ± 0.3%, P = 7.1E-04). Our survey indicates that AFB1 is instrumental for HCC development in Middle Africa and that droplet digital PCR might be used in the region both to diagnose HCC and to conduct public health surveys on populations at risk of chronic aflatoxin intoxication.