Investigation of a mpox outbreak in Central African Republic, 2021-2022.

Human monkeypox virus is spreading globally, and more information is required about its epidemiological and clinical disease characteristics in endemic countries. We report the investigation of an outbreak in November 2021 in Central African Republic (CAR). The primary case, a hunter, fell ill after contact with a non-human primate at the frontier between forest and savannah. The ensuing investigation in a small nearby town concerned two families and four waves of inter-human transmission, with 14 confirmed cases, 11 suspected cases and 17 non-infected contacts, and a secondary attack rate of 59.5% (25/42). Complications were observed in 12 of the 19 (63.2%) confirmed and suspected cases with available clinical follow-up data: eight cases of bronchopneumonia, two of severe dehydration, one corneal ulcer, one abscess, two cutaneous superinfections, and six cutaneous sequelae (cheloid scars, or depigmentation). There was one death, giving a case fatality ratio of 1/25 (4.0%) for confirmed and suspected cases. This outbreak, with the largest number of confirmed cases ever described in CAR, confirms the potential severity of the disease associated with clade I monkeypox viruses, and highlights the need for rapid control over virus circulation to prevent the further national and international spread of infection.

New introduction and spread of rabies among dog population in Bangui.

Rabies is endemic in the Central African Republic (CAR) and a neglected enzootic disease which represents a serious public health problem. Before April 2009, rabies was not a notifiable disease in CAR. Vaccination of animals is expensive and not commonly done. In 2005, none rabies case was recorded in Bangui. To understand how rabies was introduced and propagated in the city of Bangui from 2006 to 2008, we analyzed samplings of dog brain as well as reviewed the records of dog owners. A total of 86 out of 101 samples (84.8%) tested positive for rabies virus during this period. Previous phylogenetic analysis of some strains circulating in Bangui between 2006 and 2008 indicated that virus of cosmopolitan and Africa 2 clade are found. Given the time frame and location of these samples, one possible explanation for this alarming result may be that two different strains of rabies virus were introduced at different times in Bangui. Stray dogs are solely responsible for the spread of the epidemic.

Serological surveillance of brucellosis and Q fever in cattle in the Central African Republic.

No data are available concerning the seroprevalence of brucellosis in Central African Republic (CAR) and the last report concerning the seroprevalence of Q fever in CAR is from 1995. The aim of our study was to determine the prevalence of these diseases in CAR, especially in Zebu cattle. We used the Rose Bengal Plate Test to test 2032 bovine serum samples for antibodies to Brucella spp. and an indirect immunofluorescence assay to test 784 bovine serum samples for antibodies to Coxiella burnetii (the species responsible for Q fever). The mean seroprevalences of antibodies to Brucella and Coxiella were 3.3 and 14.3%, respectively. Significant differences were found between regions and herds for both diseases. However, relation with differences of climate or vegetation were not evident. Therefore, further data are necessary to better understand the epidemiology of these diseases in CAR and evaluate losses to the farmers.

[Microbiological surveillance: viral hemorrhagic fever in Central African Republic: current serological data in man]. / Veille microbiologique: les fièvres hémorragiques virales en République centrafricaine; données sérologiques actualisées chez l'homme.

An investigation was conducted between 1994 and 1997 in forested areas of the Central African Republic (CAR) to determine the seroprevalence of IgG antibodies against several haemorrhagic fever viruses present in the region. Sera were obtained from 1762 individuals in two groups (Pygmy and Bantu locuted populations) living in 4 forested areas in the south of the country. Sera were tested for IgG antibodies against Ebola, Marburg, Rift Valley fever (RVF), Yellow fever (YF) and Hantaviruses by enzyme immunoassay (EIA), and against Lassa virus by immunofluorescent assay. The prevalence of IgG antibodies was 5.9% for Ebola, 2% for Marburg, 6.9% pour RVF, 6.5% for YF, 2% for Hantaan. No antibodies were detected against Lassa, Seoul, Puumala and Thottapalayam viruses. No IgM antibodies were detected against RVF and YF viruses. The distribution of antibodies appears to be related to tropical rain forest areas. This study indicates that several haemorrhagic fever viruses are endemic in forested areas of the CAR and could emerge due to environmental modification.

Identification of Ebola virus sequences present as RNA or DNA in organs of terrestrial small mammals of the Central African Republic.

The life cycle of the Ebola (EBO) virus remains enigmatic. We tested for EBO virus in the organs of 242 small mammals captured during ecological studies in the Central African Republic. EBO virus glycoprotein or polymerase gene sequences were detected by reverse transcription PCR in RNA extracts of the organs of seven animals and by PCR in DNA extract of one animal. Neither live virus nor virus antigen was detected in any organ sample. Direct sequencing of amplicons identified the virus as being of the Zaire/Gabon subtype. Virus-like nucleocapsids were observed by electron microscopy in the cytoplasm of the spleen cells of one animal. The animals belonged to two genera of rodents (Muridae; Mus setulosus, Praomys sp1 and P. sp2) and one species of shrew (Soricidae; Sylvisorex ollula). These preliminary results provide evidence that common terrestrial small mammals living in peripheral forest areas have been in contact with the EBO virus and demonstrate the persistence of EBO virus RNA and DNA in the organs of the animals. Our findings should lead to better targeting of research into the life cycle of the EBO virus.

[Toxoplasmosis at the Pasteur Institute of Bangui, Central African Republic (1996-1998): serological data]. / La toxoplasmose à l'Institut Pasteur de Bangui, République centrafricaine (1996-1998): données sérologiques.

A serological study of toxoplasmosis was conducted between 1996 and 1998 on 1953 patients of the Medical Analysis Laboratory of the Institut Pasteur de Bangui. The mean age of patients was 28 years. Among sera tested by ELISA, seropositivity to IgG antibodies was observed in 50.6%, and 2.6% sera were found positive for IgM antitoxoplasma antibodies (immuno-capture). The seroprevalence did not vary significantly according to sex or age. The results showed 40.8% sera had IgG antibodies titered 400 Ul/ml and more. The proportion of high level (> 400 Ul) IgG was more important in males than in females. High level IgG antibodies were statistically significant more frequently in the sera of females aged 10-29 years. Of the procreative women, 49.1% were at risk of contacting toxoplasmosis. The diagnosis of recently acquired infection, based on the coexistence of IgM antibodies and high level IgG antibodies, was noted in 1.6% among sera of procreative women. In the Central African Republic, serologic survey during pregnancy is not systematic and HIV seroprevalence is high (15%). Risks of acute infections during pregnancy and of opportunistic infections in HIV-infection patients are high. A control of toxoplasmosis is justifiable (screening during pregnancy, sanitary education) in CAR.