Nicolas Berthet

Ebola in West Africa: the outbreak able to change many things.

1) Centre International de Recherches Medicales, Franceville, Gabon, 2) Institut de Recherche pour le Developpement, UMR MIVEGEC 224 ‘MaladiesInfectieuses et Vecteurs: Ecologie, Genetique Evolution et Contr^ole, Montpellier and 3) Centre National de la Recherche Scientifique, UMR3569, Paris, FranceE-mail: eric.leroy@ird.frArticle published online: 26 September 2014

High Prevalence and Diversity of Hepatitis Viruses in Suspected Cases of Yellow Fever in the Democratic Republic of Congo

ABSTRACT The majority of patients with acute febrile jaundice (>95%) identified through a yellow fever surveillance program in the Democratic Republic of Congo (DRC) test negative for antibodies against yellow fever virus. However, no etiological investigation has ever been carried out on these patients. Here, we tested for hepatitis A (HAV), hepatitis B (HBV), hepatitis C (HCV), hepatitis D (HDV), and hepatitis E (HEV) viruses, all of which can cause acute febrile jaundice, in patients included in the yellow fever surveillance program in the DRC. On a total of 498 serum samples collected from suspected cases of yellow fever from January 2003 to January 2012, enzyme-linked immunosorbent assay (ELISA) techniques were used to screen for antibodies against HAV (IgM) and HEV (IgM) and for antigens and antibodies against HBV (HBsAg and anti-hepatitis B core protein [HBc] IgM, respectively), HCV, and HDV. Viral loads and genotypes were determined for HBV and HVD. Viral hepatitis serological markers were diagnosed in 218 (43.7%) patients. The seroprevalences were 16.7% for HAV, 24.6% for HBV, 2.3% for HCV, and 10.4% for HEV, and 26.1% of HBV-positive patients were also infected with HDV. Median viral loads were 4.19 × 105 IU/ml for HBV (range, 769 to 9.82 × 109 IU/ml) and 1.4 × 106 IU/ml for HDV (range, 3.1 × 102 to 2.9 × 108 IU/ml). Genotypes A, E, and D of HBV and genotype 1 of HDV were detected. These high hepatitis prevalence rates highlight the necessity to include screening for hepatitis viruses in the yellow fever surveillance program in the DRC.

Characterization of a Genogroup I Sapovirus Isolated from Chimpanzees in the Republic of Congo

ABSTRACT Sapoviruses, which are members of the Caliciviridae family, are small nonenveloped viruses known to infect a large spectrum of mammalian hosts. We report here the first complete genome sequences of two genogroup I sapoviruses isolated from fecal samples from chimpanzees living in the Tchimpounga sanctuary, Republic of Congo.

First detection of an enterovirus C99 in a captive chimpanzee with acute flaccid paralysis, from the Tchimpounga chimpanzee rehabilitation center, Republic of Congo

Enteroviruses, members of the Picornaviridae family, are ubiquitous viruses responsible for mild to severe infections in human populations around the world. In 2010 Pointe-Noire, Republic of Congo recorded an outbreak of acute flaccid paralysis (AFP) in the humans, caused by wild poliovirus type 1 (WPV1). One month later, in the Tchimpounga sanctuary near Pointe-Noire, a chimpanzee developed signs similar to AFP, with paralysis of the lower limbs. In the present work, we sought to identify the pathogen, including viral and bacterial agents, responsible for this illness. In order to identify the causative agent, we evaluated a fecal specimen by PCR and sequencing. A Human enterovirus C, specifically of the EV-C99 type was potentially responsible for the illness in this chimpanzee. To rule out other possible causative agents, we also investigated the bacteriome and the virome using next generation sequencing. The majority of bacterial reads obtained belonged to commensal bacteria (95%), and the mammalian virus reads matched mainly with viruses of the Picornaviridae family (99%), in which enteroviruses were the most abundant (99.6%). This study thus reports the first identification of a chimpanzee presenting AFP most likely caused by an enterovirus and demonstrates once again the cross-species transmission of a human pathogen to an ape.

A vanG-type locus in Clostridium argentinense

OBJECTIVES The objective was to study a new vanG-type locus in Clostridium argentinense vanGCar and to determine its impact on glycopeptide susceptibility of the host. METHODS The whole genome of C. argentinense NCIB 10714 was sequenced using Illumina single-reads sequencing technology. The presence of vanGCar in seven C. argentinense strains was tested by PCR and its expression was tested by quantitative RT-PCR (qRT-PCR). Glycopeptide susceptibility was determined by the Etest procedure. RESULTS The vanGCar locus contained four genes encoding a carboxypeptidase, a d-alanine:d-serine ligase, a serine transporter and a serine racemase, and was present in the seven C. argentinense studied. An AraC-type transcriptional regulator was found upstream from the genes. C. argentinense NCIB 10714 was susceptible to vancomycin and to teicoplanin. qRT-PCR experiments revealed that vanGCar was not expressed without or with induction by a subinhibitory concentration of vancomycin. CONCLUSIONS The new vanGCar locus was cryptic in C. argentinense and intrinsic to this species. Emergence of vancomycin resistance in C. argentinense due to decryptification of the vanGCar gene cluster could occur.

Impact of human papillomavirus on head and neck squamous cell cancers in Gabon.

Head and neck squamous cell cancers are among the most aggressive. Their incidence and mortality rates are relatively lower in Middle Africa than worldwide, but in Gabon, these rates tend to be 2–3 fold higher than in neighboring countries. The main risk factors are alcohol and tobacco consumption. However, in the last decades, there was cumulated evidence that human papillomaviruses were a significant risk factor, particularly for oropharyngeal squamous cell cancer. In Gabon, as elsewhere in Africa, assessment of these 3 risk factors need to be improved to determine their respective role in the development of head and neck squamous cell cancers. The potential differences in alcohol/tobacco consumption habits as well as in infectious ecology between developing and developed countries can make it difficult to transpose current data on this issue. Determining the respective role of alcohol/tobacco consumption and human papillomaviruses in the development of head and neck squamous cell cancers is crucial for the management of these cancers that could become a serious public health issue in Gabon. Human papillomaviruses are not only a risk factor but also a biomarker with promising clinical potential for the follow-up of head and neck squamous cell cancers potentially able to select an adequate treatment. Then, assessing the epidemiological impact of human papillomaviruses in Gabon and in all of Africa would prove useful for the clinical follow-up of head and neck squamous cell cancers, and would also provide essential data to plan a global prevention strategy against head and neck squamous cell cancers due to human papillomaviruses.Head and neck squamous cell cancers are among the most aggressive. Their incidence and mortality rates are relatively lower in Middle Africa than worldwide, but in Gabon, these rates tend to be 2–3 fold higher than in neighboring countries. The main risk factors are alcohol and tobacco consumption. However, in the last decades, there was cumulated evidence that human papillomaviruses were a significant risk factor, particularly for oropharyngeal squamous cell cancer. In Gabon, as elsewhere in Africa, assessment of these 3 risk factors need to be improved to determine their respective role in the development of head and neck squamous cell cancers. The potential differences in alcohol/tobacco consumption habits as well as in infectious ecology between developing and developed countries can make it difficult to transpose current data on this issue. Determining the respective role of alcohol/tobacco consumption and human papillomaviruses in the development of head and neck squamous cell cancers is crucial for the management of these cancers that could become a serious public health issue in Gabon. Human papillomaviruses are not only a risk factor but also a biomarker with promising clinical potential for the follow-up of head and neck squamous cell cancers potentially able to select an adequate treatment. Then, assessing the epidemiological impact of human papillomaviruses in Gabon and in all of Africa would prove useful for the clinical follow-up of head and neck squamous cell cancers, and would also provide essential data to plan a global prevention strategy against head and neck squamous cell cancers due to human papillomaviruses.

A Nosocomial Outbreak of Human Monkeypox in the Central African Republic

Abstract An outbreak of familial monkeypox occurred in the Central African Republic in 2015/2016 by 3 transmission modes: familial, health care–related, and transport-related. Ten people (3 children and 7 adults) were infected. Most presented with cutaneous lesions and fever, and 2 children died. The viral strain responsible was a Zaire genotype strain.

Exploring the diversity of blood-sucking Diptera in caves of Central Africa

Caves house pathogenic microorganisms, some of which are transmitted by blood-sucking arthropods. In Africa, previous studies identified mosquitoes, sand flies and biting midges as the main potential vectors of cave-dwelling pathogens. However, to understand their involvement in pathogen spillover, it is crucial to characterize their diversity, community composition and dynamics. Using CDC light traps, we collected hematophagous Diptera in six caves of Gabon during one-shot or longitudinal sampling, and investigated their species diversity and dynamics in relation with external rainfall. Overall, we identified 68 species of mosquitoes, sand flies and biting midges, including 45 new records for Gabon. The dominant species were: Uranotaenia nigromaculata, Anopheles smithii s.l., Culex. rima group and Culex quasiguiarti for mosquitoes, Spelaeophlebotomus gigas and Spelaeomyia emilii for sand flies and the Culicoides trifasciellus group and Culicoides fulvithorax for biting midges. The survey revealed that species assemblages were cave-specific and included mainly troglophilous and trogloxenous species. Both diversity and abundance varied according to the cave and sampling time, and were significantly associated with rainfall. These associations were modulated by the cave specific environmental conditions. Moreover, the presence of trogloxenous and troglophilous species could be of high significance for pathogen transfers between cave and epigeous hosts, including humans.

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

ABSTRACT 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.

Erratum to: Impact of human papillomavirus on head and neck squamous cell cancers in Gabon.

[This corrects the article DOI: 10.1186/s13027-015-0036-7.].