Concurrent Clade I and Clade II Monkeypox Virus Circulation, Cameroon, 1979-2022.

During 1979-2022, Cameroon recorded 32 laboratory-confirmed mpox cases among 137 suspected mpox cases identified by the national surveillance network. The highest positivity rate occurred in 2022, indicating potential mpox re-emergence in Cameroon. Both clade I (n = 12) and clade II (n = 18) monkeypox virus (MPXV) were reported, a unique feature of mpox in Cameroon. The overall case-fatality ratio of 2.2% was associated with clade II. We found mpox occurred only in the forested southern part of the country, and MPXV phylogeographic structure revealed a clear geographic separation among concurrent circulating clades. Clade I originated from eastern regions close to neighboring mpox-endemic countries in Central Africa; clade II was prevalent in western regions close to West Africa. Our findings suggest that MPXV re-emerged after a 30-year lapse and might arise from different viral reservoirs unique to ecosystems in eastern and western rainforests of Cameroon.

Interactions between vector competence to chikungunya virus and resistance to deltamethrin in Aedes aegypti laboratory lines?

The urban mosquito species Aedes aegypti is the main vector of arboviruses worldwide. Mosquito control with insecticides is the most prevalent method for preventing transmission in the absence of effective vaccines and available treatments; however, the extensive use of insecticides has led to the development of resistance in mosquito populations throughout the world, and the number of epidemics caused by arboviruses has increased. Three mosquito lines with different resistance profiles to deltamethrin were isolated in French Guiana, including one with the I1016 knock-down resistant allele. Significant differences were observed in the cumulative proportion of mosquitoes with a disseminated chikungunya virus infection over time across these lines. In addition, some genes related to resistance (CYP6BB2, CYP6N12, GST2, trypsin) were variably overexpressed in the midgut at 7 days after an infectious bloodmeal in these three lines. Our work shows that vector competence for chikungunya virus varied between Ae. aegypti laboratory lines with different deltamethrin resistance profiles. More accurate verification of the functional association between insecticide resistance and vector competence remains to be demonstrated.

Cotrimoxazole versus sulfadoxine-pyrimethamine for intermittent preventive treatment of malaria in HIV-infected pregnant women in Bangui, Central African Republic: A pragmatic randomised controlled trial.

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 end point) among HIV-positive pregnant women with a CD4+ count ≥350 cells/mm3 in Bangui, CAR. METHODS: MACOMBA is a multicentre, open-label randomised trial conducted in four maternity hospitals in Bangui. Between 2013 and 2017, 193 women were randomised and 112 (59 and 53 in CTX and IPTp-SP arms, respectively) were assessed for placental infection defined by microscopic parasitaemia or PCR. RESULTS: Thirteen women had a placental infection: five in the CTX arm (one by microscopic placental parasitaemia and four by PCR) and eight 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.

Genomic history of human monkey pox infections in the Central African Republic between 2001 and 2018.

Monkeypox is an emerging infectious disease, which has a clinical presentation similar to smallpox. In the two past decades, Central Africa has seen an increase in the frequency of cases, with many monkeypox virus (MPXV) isolates detected in the Democratic Republic of Congo (DRC) and the Central African Republic (CAR). To date, no complete MPXV viral genome has been published from the human cases identified in the CAR. The objective of this study was to sequence the full genome of 10 MPXV isolates collected during the CAR epidemics between 2001 and 2018 in order to determine their phylogenetic relationships among MPXV lineages previously described in Central Africa and West Africa. Our phylogenetic results indicate that the 10 CAR isolates belong to three lineages closely related to those found in DRC. The phylogenetic pattern shows that all of them emerged in the rainforest block of the Congo Basin. Since most human index cases in CAR occurred at the northern edge of western and eastern rainforests, transmissions from wild animals living in the rainforest is the most probable hypothesis. In addition, molecular dating estimates suggest that periods of intense political instability resulting in population movements within the country often associated also with increased poverty may have led to more frequent contact with host wild animals. The CAR socio-economic situation, armed conflicts and ecological disturbances will likely incite populations to interact more and more with wild animals and thus increase the risk of zoonotic spillover.

Fatal Outcome in a Hepatitis E Virus/Human Immunodeficiency Virus Co-Infected Malnourished Child in the Central African Republic.

Hepatitis E virus (HEV) infection is responsible for major endemic outbreaks in developing countries. Human immunodeficiency virus (HIV) and HEV are widespread in the Central African Republic. We report the first documented case of an HEV infection in a 36-month-old child already suffering from HIV and severe acute malnutrition (SAM). The HIV patient was hospitalized for SAM with persistent diarrhea and prolonged fever. The presence of IgG anti-HEV antibodies was noted. Sequencing of the amplified HEV RNA revealed the presence of genotype 3c. The alanine aminotransferase level was slightly above average. The patient died despite being treated by antiretroviral therapy accompanied by probabilistic antibiotic therapy and nutritional rehabilitation. HEV/HIV co-infection in a malnourished patient can accelerate a fatal outcome. In the presence of biological abnormalities in a severe acutely malnourished HIV-infected patient, HEV RNA detection should be added to the standard medical assessment in sub-Saharan African countries.

Hepatitis E virus outbreak associated with rainfall in the Central African Republic in 2008-2009.

BACKGROUND: Infection by hepatitis E virus (HEV) can cause a high burden of morbidity and mortality in countries with poor access to clean water and sanitation. Our study aimed to investigate the situation of HEV infections in the Central African Republic (CAR). METHODS: A retrospective analysis of the blood samples and notification forms collected through the national yellow fever (YF) surveillance program, but for which a diagnosis of YF was discarded, was carried out using an anti-HEV IgM ELISA and a HEV-specific RT-PCR. RESULTS: Of 2883 YF-negative samples collected between January 2008 and December 2012, 745 (~ 26%) tested positive by at least either of the 2 tests used to confirm HEV cases. The results revealed that the CAR was hit by a large HEV outbreak in 2008 and 2009. The results also showed a clear seasonal pattern with correlation between HEV incidence and rainfall in Bangui. A phylogenetic analysis showed that the circulating strains belonged to genotypes 1e and 2b. CONCLUSIONS: Overall, this study provides further evidences that HEV can be a significant cause of acute febrile jaundice, particularly among adults during rainy season or flood, in a country from Sub-Saharan Africa.

Complete Genome Sequences of Igbo-Ora and Babanki Alphavirus Strains Isolated in the Central African Republic in the 1960s and 1970s.

Vector-borne viruses are becoming increasingly important from a public health standpoint with the emergence or reemergence of viruses and extension of the areas at risk. Here, we report the whole-genome sequences of two alphaviruses, namely, one Igbo-Ora virus and one Babanki virus, that were isolated several decades ago in Africa from human serum.

Impact of Zika Virus Emergence in French Guiana: A Large General Population Seroprevalence Survey.

BACKGROUND: Since the identification of Zika virus (ZIKV) in Brazil in May 2015, the virus has spread throughout the Americas. However, ZIKV burden in the general population in affected countries remains unknown. METHODS: We conducted a general population survey in the different communities of French Guiana through individual interviews and serologic survey during June-October 2017. All serum samples were tested for anti-ZIKV immunoglobulin G antibodies using a recombinant antigen-based SGERPAxMap microsphere immunoassay, and some of them were further evaluated through anti-ZIKV microneutralization tests. RESULTS: The overall seroprevalence was estimated at 23.3% (95% confidence interval [CI], 20.9%-25.9%) among 2697 participants, varying from 0% to 45.6% according to municipalities. ZIKV circulated in a large majority of French Guiana but not in the most isolated forest areas. The proportion of reported symptomatic Zika infection was estimated at 25.5% (95% CI, 20.3%-31.4%) in individuals who tested positive for ZIKV. CONCLUSIONS: This study described a large-scale representative ZIKV seroprevalence study in South America from the recent 2015-2016 Zika epidemic. Our findings reveal that the majority of the population remains susceptible to ZIKV, which could potentially allow future reintroductions of the virus.

Vaccination coverage in the context of the emerging Yellow Fever threat in French Guiana.

BACKGROUND: French Guiana, a French overseas department located in South America between Brazil and Surinam, is the only European territory geographically located in the Amazonian forest complex and is considered endemic for yellow fever (YF). In the context of the emergent threat of YF in Latin America, we conducted a large household cross-sectional survey from June to October 2017 to estimate vaccination coverage in the population and to determine associations with sociodemographic and geographical characteristics. METHODOLOGY/PRINCIPAL FINDINGS: In total, 1,415 households and 2,697 individuals were included from the 22 municipalities of French Guiana. YF vaccination coverage was estimated at 95.0% (95% CI: 93.4-96.2) in the entire territory but was spatially heterogeneous, with the lowest levels estimated in the western part of the territory along the Surinamese cross-border region, particularly in children under 16 years who were not enrolled in school, immigrant adults and disadvantaged populations with low socioeconomic indexes. CONCLUSIONS/SIGNIFICANCE: Despite the good vaccination coverage against YF in the general population of French Guiana resulting from the compulsory nature of YF vaccination for residents and travelers, there is an urgent need to improve vaccination coverage in vulnerable populations living in the northwestern part of the territory to limit the risk of transmission in the context of the emerging YF threat in South America. Despite the relative rarity of YF and the significant number of infectious and tropical diseases in French Guiana, clinicians should adopt a high index of suspicion for YF, particularly in vulnerable and at-risk populations.

Complete Genome Sequence of the Tataguine Virus, Isolated in the Central African Republic in 1972 from a Human with an Acute Febrile Syndrome.

Tataguine virus (TATV) is an orthobunyavirus that causes febrile illnesses in Africa. Here, we report the complete genome sequences of TATV strain HB72P583, isolated in the Central African Republic in 1972. Several genetic variations were detected in the small (S), medium (M), and large (L) segments relative to a TATV strain isolated in Nigeria in 1966.

Revisiting human T-cell lymphotropic virus types 1 and 2 infections among rural population in Gabon, central Africa thirty years after the first analysis.

HTLV-1 infection is considered as highly endemic in central Africa. Thirty years ago, a first epidemiological study was performed in Gabon, central Africa, and revealed that the prevalence varied from 5.0 to 10.5%. To evaluate current distribution of HTLVs in Gabon, 4.381 samples were collected from rural population living in 220 villages distributed within the 9 provinces of country. HTLVs prevalence was determined using two ELISA tests and positive results were confirmed by Western Blot. The overall HTLV-1 seroprevalence was of 7.3% among the rural Gabonese population; with 5.4% for men and 9.0% for women. Prevalence of HTLV-1 differed by province, ranging from 2.3% to 12.5% into the rain forest. Being a woman older than 51 years represented a high risk for HTLV-1 acquisition. Hospitalization, operation/surgery, transfusion and medical abortion or fever, arthritis and abdominal pain are also significant risk factors. In addition, 0.1% of samples were found as HTLV-2 positive, while 12.0% had an indeterminate HTLV serological pattern. HTLV-3 and HTLV-4 were not found. Phylogenetic analysis was performed on 87 samples and demonstrated that HTLV-1 present in Gabon belongs mostly to subtype B, however the rare subtype D was also found. Altogether, our results demonstrate that almost thirty years after the first epidemiological study prevention of HTLVs infection is still an issue in Gabon.

Current challenges and implications for dengue, chikungunya and Zika seroprevalence studies worldwide: A scoping review.

BACKGROUND: Arboviral infections are a public health concern and an escalating problem worldwide. Estimating the burden of these diseases represents a major challenge that is complicated by the large number of unapparent infections, especially those of dengue fever. Serological surveys are thus required to identify the distribution of these diseases and measure their impact. Therefore, we undertook a scoping review of the literature to describe and summarize epidemiological practices, findings and insights related to seroprevalence studies of dengue, chikungunya and Zika virus, which have rapidly expanded across the globe in recent years. METHODOLOGY/PRINCIPAL FINDINGS: Relevant studies were retrieved through a literature search of MEDLINE, WHOLIS, Lilacs, SciELO and Scopus (2000 to 2018). In total, 1389 publications were identified. Studies addressing the seroprevalence of dengue, chikungunya and/or Zika written in English or French and meeting the inclusion and exclusion criteria were included. In total, 147 studies were included, from which 185 data points were retrieved, as some studies used several different samples. Most of the studies were exclusively conducted on dengue (66.5%), but 16% were exclusively conducted on chikungunya, and 7 were exclusively conducted on Zika; the remainder were conducted on multiple arboviruses. A wide range of designs were applied, but most studies were conducted in the general population (39%) and in households (41%). Although several assays were used, enzyme-linked immunosorbent assays (ELISAs) were the predominant test used (77%). The temporal distribution of chikungunya studies followed the virus during its rapid expansion since 2004. The results revealed heterogeneity of arboviruses seroprevalence between continents and within a given country for dengue, chikungunya and Zika viruses, ranging from 0 to 100%, 76% and 73% respectively. CONCLUSIONS/SIGNIFICANCE: Serological surveys provide the most direct measurement for defining the immunity landscape for infectious diseases, but the methodology remains difficult to implement. Overall, dengue, chikungunya and Zika serosurveys followed the expansion of these arboviruses, but there remain gaps in their geographic distribution. This review addresses the challenges for researchers regarding study design biases. Moreover, the development of reliable, rapid and affordable diagnosis tools represents a significant issue concerning the ability of seroprevalence surveys to differentiate infections when multiple viruses co-circulate.

Zika virus outbreak in Suriname, a report based on laboratory surveillance data.

INTRODUCTION: Since the identification of ZIKV in Brazil in May 2015, the virus has spread extensively throughout the Americas. Cases of ZIKV infection have been reported in Suriname since October 2, 2015. METHODS: A laboratory-based surveillance system was quickly implemented according to previous experience with the emergence of chikungunya. General practitioners and public health centers located in different districts of Suriname were asked to send blood samples from suspicious cases to Academic Hospital for molecular diagnosis of Zika virus infection. We investigated Zika-related laboratory data collected during surveillance and response activities to provide the first outbreak report in Suriname in terms of time, location and person. RESULTS: A total of 791 molecularly confirmed cases were reported during a 48-week interval from October 2015 to August 2016. The majority of ZIKV-positive cases involved women between 20 and 39 years of age, reflecting concern about Zika infection during pregnancy. The outbreak peaked in mid-January and gradually spread from the district of Paramaribo to western coastal areas. DISCUSSION: This report provides a simple and comprehensive description of the outbreak in Suriname and demonstrates the utility of laboratory data to highlight the spatiotemporal dynamics of the outbreak in that country.

Emerging trends of Zika apprehension in an epidemic setting.

BACKGROUND: French Guiana is a territory that has a decades-long history of dengue outbreaks and more recently, in 2014, a chikungunya outbreak. Zika virus (ZIKV) emerged in late 2015 and subsequently led to an important outbreak. METHODOLOGY/PRINCIPAL FINDINGS: A cross-sectional phone survey was conducted among the general population during the outbreak in June 2016 with a total of 1,129 individuals interviewed to assess perceptions, knowledge and behaviors regarding zika infection. The population seemed aware of zika, and perceived the infection as a more serious health threat than other common mosquito-borne diseases. Furthermore, both the perceptions and behaviors related to zika and its prevention were found to vary considerably among different social groups, geographic areas and gender; less educated female participants were found to perceive the disease as more worrisome and were less likely to adopt protective behaviors. Moreover, female population has been particularly responsive to awareness campaigns and rapidly understood the extent of risks associated with ZIKV infection. CONCLUSIONS/SIGNIFICANCE: These results revealed that ZIKV appeared at the time of the survey as a new health threat that concerns the public more than chikungunya and dengue fever with differences observed among subgroups of population. These results have implications for the development of multifaceted infection control programs, including strategies for prevention and awareness, helping the population to develop an accurate perception of the threat they are facing and encouraging behavior changes.

The proportion of asymptomatic infections and spectrum of disease among pregnant women infected by Zika virus: systematic monitoring in French Guiana, 2016.

Zika virus (ZIKV) infection has been associated with complications during pregnancy. Although the presence of symptoms might be a risk factor for complication, the proportion of ZIKV-infected pregnant women with symptoms remains unknown. Following the emergence of ZIKV in French Guiana, all pregnancies in the territory were monitored by RT-PCR and/or detection of ZIKV antibodies. Follow-up data collected during pregnancy monitoring interviews were analysed from 1 February to 1 June 2016. We enrolled 3,050 pregnant women aged 14-48 years and 573 (19%) had laboratory-confirmed ZIKV infection. Rash, arthralgia, myalgia and conjunctival hyperaemia were more frequently observed in ZIKV-positive women; 23% of them (95% confidence interval (CI): 20-27) had at least one symptom compatible with ZIKV infection. Women 30 years and older were significantly more likely to have symptoms than younger women (28% vs 20%). The proportion of symptomatic infections varied from 17% in the remote interior to 35% in the urbanised population near the coast (adjusted risk ratio: 1.6; 95% CI: 1.4-1.9.). These estimates put findings on cohorts of symptomatic ZIKV-positive pregnant women into the wider context of an epidemic with mainly asymptomatic infections. The proportion of symptomatic ZIKV infections appears to vary substantially between populations.

Sentinel surveillance of influenza-like illness in the Central African Republic, 2010-2015.

BACKGROUND: Influenza-like illness (ILI) is an important public health problem worldwide. In the Central African Republic, acute infectious diseases are the commonest reason for consultation. The Institut Pasteur of Bangui set up a surveillance network in 2008 to monitor the circulation of influenza viruses. We report the results of use of this surveillance system during the period 2010-2015. METHODS: The first surveillance centre covered Bangui, the capital of the country, and neighbouring areas and epidemiological data on syndromes similar to ILI. Throat and nasopharyngeal swab samples are transmitted weekly to the Institut Pasteur of Bangui, where real-time and multiplex reverse transcription polymerase chain reaction are used to detect and subtype influenza A (H1N1 and H3N2) and B viruses. The demographic characteristics of all patients and of positive cases according to age and the seasonal patterns of influenza virus circulation were analysed. RESULTS: Between January 2010 and December 2015, 5385 throat swabs were collected; 454 (8.4%) of the samples were positive. Of these, 450 yielded at least one influenza virus and four showed co-infections. Children under the age of 5 years were the most frequently infected (257/450, 57.1%), with irregular peaks of ILI. Influenza B predominated (56.2%; n = 201), with 39.0% H3N2 and 16.7%H1N1pdm09. Influenza viruses were detected mainly in the rainy season (July-December). CONCLUSION: The sentinel surveillance site is yielding important information about the seasonality and age pattern of circulating influenza virus. Nationwide distribution of sentinel sites is warranted.

Diagnostic Validation of the RealStar® Zika Virus Reverse Transcription Polymerase Chain Reaction Kit for Detection of Zika Virus RNA in Urine and Serum Specimens.

With the Zika virus outbreak in South America starting in 2015 and its potential to cause malformation of the fetus in infected women, the need for diagnostic methods became obvious. Until now, only limited data are available on the diagnostic performance of commercial kits. Here, we present data comparing the RealStar® Zika Virus RT-PCR Kit 1.0 for detection of Zika virus from 208 serum and urine samples collected in French Guiana with a reference method. Of these, 114 samples tested positive with the RealStar® Kit and 111 with the reference method.

Non-malarial infectious diseases of antenatal care in pregnant women in Franceville, Gabon.

BACKGROUND: In sub-tropical countries, infectious diseases remain one of the main causes of mortality. Because of their lack of active immunity, pregnant women and their unborn children represent the most susceptible people. In Gabon, data on infectious diseases of pregnant women such as syphilis and rubella are either scarce or very old. Few studies have assessed T. gondii infection during pregnancy in the country. Here, we evaluate seroprevalence of HIV, HTVL-1, syphilis and T. gondii and rubella infection during antenatal care among women living in Franceville, Gabon. METHODS: A retrospective study was conducted on data collected from May 2007 to July 2010. After signing an informed written consent form, all pregnant women consulting in two hospitals of Franceville (Gabon) and in offices of maternity and childbirth health centers were included. Demographic and clinical data were collected. Serum samples were collected and analysed using immunological assays relevant for HIV (Genscreen HIV-1 version 2, Bio-Rad®, Marne la Roquette, France).HTLV-1 (Vironostika HTLV-1, Biomérieux®, Marcy l'Etoile, France), T. pallidum (TPHA/VDRL), BIOLABO®SA), rubella virus (Vidas Biomerieux®, Marcy l'Etoile, France) and T. gondii (Vidas Biomerieux®, Marcy l'Etoile, France) diagnoses were performed. Data analysis was done using the Stat view 5.0 software. RESULTS: A total of 973 pregnant women were assessed. The mean age was 25.84 ± 6.9 years, with a minimum age of 14.0 years and a maximum of 45.0 years. Women from 26 to 45 years old and unemployed women were the most prevalent: 41.93% and 77.18%, respectively. The prevalence of studied infectious diseases were 2.50% for syphilis, 2.88% for HTLV-1, 4.00% for HIV with no significant difference between them (p = 0.1). Seropositivity against rubella was higher (87.56%, n = 852) than seropositivity against T. gondii (57.35%, n = 557), (p < 0.0001). Only 5 (0.51%) co-infection cases were found: 2 co-infected with HIVand T. pallidum, 2 co-infected with HIV and HTLV-1, and one co-infected with T. pallidum and HTLV-1. Sixty-two pregnant women were seronegative against toxoplasmosis and rubella (6.37%). CONCLUSION: High levels of seropositivity against T. gondii and the rubella virus were observed. The prevalence of T. pallidum and HTLV-1 were lowest but HIV prevalence in young women was worrying.

Complete Genome Sequences of Two Chikungunya Viruses Isolated in the Central African Republic in the 1970s and 1980s.

Some arboviruses threaten human global health with potentially explosive emergence. Analysis of whole-genome sequences of decades-old isolates might contribute to the understanding of the complex dynamics which drive their circulation and emergence. Here, we report the whole-genome sequences of two Chikungunya viruses isolated in the Central African Republic in the 1970s and 1980s.

Potential of Aedes aegypti and Aedes albopictus populations in the Central African Republic to transmit enzootic chikungunya virus strains.

BACKGROUND: Major chikungunya outbreaks have affected several Central African countries during the past decade. The chikungunya virus (CHIKV) was isolated from humans and sylvan mosquitoes in the Central African Republic (CAR) during the 1970 and 1980s but has not been found recently, despite the presence of Aedes albopictus since 2010. The risk of a massive chikungunya epidemic is therefore potentially high, as the human populations are immunologically naïve and because of the presence of the mosquito vector. In order to estimate the risk of a large outbreak, we assessed the vector competence of local Ae. aegypti and Ae. albopictus populations for ancient local strains of CHIKV in CAR. Mosquitoes were orally infected with the virus, and its presence in mosquito saliva was analysed 7 and 14 days post-infection (dpi) by quantitative reverse transcriptase polymerase chain reaction. RESULTS: The two species had similar infection rates at 7 and 14 days, and the dissemination rate of both vectors was ≥ 80% at 14 dpi. Only females followed up to 14 dpi had CHKV in their saliva. CONCLUSION: These results confirm the risk of transmission of enzootic CHIKV by anthropophilic vectors such as Ae. aegypti and Ae. albopictus.