Molecular characterization of dengue virus serotype 1 infections in French travelers from Africa between 2013 and 2019

Laboratory-confirmed dengue virus (DENV) infections in Africa are rarely reported. In this study, we report 18 DENV serotype 1 (DENV-1) infections, diagnosed by the French National Reference Center for Arboviruses, in patients who had histories of recent travel in Africa. Our analyses revealed two cases, one from Niger in 2018 and one from the Republic of the Congo in 2016, where dengue fever had not been previously reported, and one case from Mauritania in 2015, where DENV-1 had not been previously reported. These cases support the reported spread of DENV outside its well-established tropical and subtropical environment toward the arid deserts of the Sahel. Phylogenetic analyses suggest that a single monophyletic DENV-1 lineage is currently in circulation in West Africa, having spread from East Africa after its original importation from Asia. Our study provides an improved understanding of DENV dynamics in Africa and underlines the importance of surveillance of travel-acquired infections

Concurrent Chikungunya and Dengue Virus Infections during Simultaneous Outbreaks, Gabon, 2007

An outbreak of febrile illness occurred in Gabon in 2007, with 20,000 suspected cases. Chikungunya or dengue-2 virus infections were identified in 321 patients; 8 patients had documented co-infections. Aedes albopictus was identified as the principal vector for the transmission of both viruses

Marburg Virus Infection Detected in a Common African Bat

Marburg and Ebola viruses can cause large hemorrhagic fever (HF) outbreaks with high case fatality (80–90%) in human and great apes. Identification of the natural reservoir of these viruses is one of the most important topics in this field and a fundamental key to understanding their natural history. Despite the discovery of this virus family almost 40 years ago, the search for the natural reservoir of these lethal pathogens remains an enigma despite numerous ecological studies. Here, we report the discovery of Marburg virus in a common species of fruit bat (Rousettus aegyptiacus) in Gabon as shown by finding virus-specific RNA and IgG antibody in individual bats. These Marburg virus positive bats represent the first naturally infected non-primate animals identified. Furthermore, this is the first report of Marburg virus being present in this area of Africa, thus extending the known range of the virus. These data imply that more areas are at risk for MHF outbreaks than previously realized and correspond well with a recently published report in which three species of fruit bats were demonstrated to be likely reservoirs for Ebola virus

Clinical Forms of Chikungunya in Gabon, 2010

Chikungunya fever (CHIK) is a disease caused by a virus transmitted to humans by infected mosquitos. The virus is responsible for multiple outbreaks in tropical and temperate areas worldwide, and is now a global concern. Clinical and biological features of the disease are poorly described, especially in Africa, where the disease is neglected because it is considered benign. During a recent CHIK outbreak that occurred in southeast Gabon, we prospectively studied clinical and biological features of 270 virologically confirmed cases. Fever and arthralgias were the predominant symptoms. Furthermore, variable and distinct clinical pictures including pure febrile, pure arthralgic and unusual forms (neither fever nor arthralgias) were detected. No severe forms or deaths were reported. These findings suggest that, during CHIK epidemics, some patients may not have classical symptoms (fever and arthralgias). Local surveillance is needed to detect any changes in the pathogenicity of this virus

Positive SARS‐CoV‐2 RT‐qPCR of a nasal swab spot after 30 days of conservation on filter paper at room temperature

International audienceAbstract We tested the use of nasal swabs spotted onto filter paper (Whatman 3M) for the molecular diagnosis of SARS‐CoV‐2 infection. Spots of a positive nasal swab in conservation medium (B.1.177 strain, 21Ct) were still positive (duo E‐gene/IP4) after 10, 20, and 30 days of conservation at room temperature, with Ct values of 28, 27, and 26, respectively. Direct spotting of the swab at bedside (omicron strain) still gave a positive result after 10 days in two RT‐qPCR systems: 33.7 Ct using duo E‐gene/IP4, and 34.8 using a specific Omicron system. Spotting of a dilution range of media spiked with the Delta (strain 2021/FR/0610, lineage B 1.617.2) and Omicron strains (strain UVE/SARS‐CoV‐2/2021/FR/1514) showed a threshold of 0.04 TCID 50 after 10 days of conservation. We show, for the first time, that this simple and low‐cost conservation method can be used to store samples for RT‐qPCR against SARS‐CoV‐2 for up to at least 1 month