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Investigation of rodent reservoirs of emerging pathogens in Côte d’Ivoire, West Africa

 

*1,2Meite, S., 1,2Koffi, K. S., 1Kouassi, K. S., 1Coulibaly, K. J., 1Koffi, K. E., 1Sylla, A., 1Sylla, Y., 1,2Faye-Ketté, H., and 1,2Dosso, M.

 

1Molecular Biology Platform and Environnement and Health Department, Pasteur Institute, Cote d’Ivoire 2Medical Sciences, Microbiology department, Felix Houphouet Boigny University, Cocody, Abidjan *Correspondence to: meitesynd@yahoo.fr

Abstract:

Background: One of the main health problems in West Africa remains upsurge of emerging pathogens. Ebola virus disease outbreak occurred in 2014 in Liberia, Guinea and Sierra Leone, Monkeypox virus in Nigeria in 2017 and most recently Lassa virus in Nigeria, Togo and Benin in 2018. These pathogens have animal reservoirs as vectors for transmission. Proper investigation of the pathogens in their rodent vectors could help reduce and manage their emergence and spread. Continue reading “Investigation of rodent reservoirs of emerging pathogens in Côte d’Ivoire, West Africa”

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Molecular diagnostics by PCR of poxviruses (Orthopoxvirus (OPV) and Molluscum contagiosum virus (MCV)) in Cote d’Ivoire West Africa

S Meite, N.D. Coulibaly, C Boni-Cissé, K.S. Koffi, A Sylla, K.S. Kouassi, A.P. Mlan, S.M. Kouame, F.S. Zaba, K.S. Ngazoa, H Faye-Ketté, M Dosso

 

Abstract

The Orthopoxvirus (OPV) and the Molluscum contagiosum virus (MCV) are Poxviruses involved in viruses skin lesions in humans. OPV infects many vertebrates and MCV mainly infects humans. A diagnostic confusion is often observed between the clinical lesions due to the different Poxviruses firstly and secondly with other viruses like the virus of the chickenpox. In Côte d’Ivoire, the diagnosis of MCV remains essentially clinical and that of OPV is non-existent despite the risk of circulation of the virus. This study aims to implementthe molecular detection of the OPV and the MVC in Côte d’Ivoire. Material and method: Cowpoxvirus DNA and 21 DNA extracts from suspicious cutaneous lesions of the MCV were analyzed by conventional PCR. The consensus primers (EACP1, EACP2) designed from the surface hemagglutin gene were used for the detection of the OPVs and the primers (MCV1, MCV2) targeting the K fragment of the MCV were used for the MCV’s detection . A growing dilution series of the Cowpoxvirus DNA and the MCV allowed the study of the method’s sensitivity used. The DNAs of S.aureus, M. ulcerans, VZV, HSV, the Measles virus and Varicella virus were used for the specificity tests. Results: The detection of the OPV from the Cowpoxvirus viral strain was positive with a positivity threshold at 10-1 dilution. That of the MCV DNA from the suspected MCV’s lesion was positive with a positivity threshold of up to 10 -6 dilution. No non-specific amplification was observed with the DNAs of the other pathogens responsible for lesions Cutaneous. The clinical diagnosis of the MCV was confirmed by PCR in 18 out of the 21 patients, ie 85.71%. On the 3 patients with a negative MCV PCR, 2 were positive for the OPV PCR , reflecting the risk of confusion between clinical lesions due to Poxviruses.

Keyvords: Molecular diagnostic, Poxviruses, West Africa

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Molecular diagnostics by PCR of poxviruses (Orthopoxvirus (OPV) and Molluscum contagiosum virus (MCV)) in Cote d’Ivoire West Africa

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Review of Lassa fever, an emerging old world haemorrhagic viral disease in sub-Saharan Africa

O Azeez-Akande

 

Abstract

Lassa fever is an acute immunosuppressive illness of increasing public health concern causing severe morbidity and significant mortality (Case fatality rate (CFR) ≥ 50%) especially in epidemic cases. Although Lassa fever has emerged (following its first detection (1969) in Lassa town, Nigeria) as one of the most prevalent and debilitating viral haemorrhagic fevers endemic in West Africa region (Nigeria inclusive), yet, the control/prevention of the regular outbreak of the disease has become an herculean task in the areas affected; there is inadequate healthcare facility (including Laboratory/diagnostic and care centres), poor socioeconomic environment, lack of awareness among the populace and presence of favourable ecologic niche for the survival and propagation of the natural host and reservoir mouse (Mastomys natalensis) of Lassa virus . Lassa fever is mainly transmitted by contact with excretions and secretions of infected rats via foods and water as well as exposure to other contaminated items. Lassa virus is a member of an Old World Arenariruses, of family Arenaviridae. It is an enveloped, single-stranded (SS) bisegmented RNA virus with ability to replicate very rapidly. It consists of 4 lineages; 3 members are identified as ancenstral strains found in Nigeria, while the fourth is domiciled in other West Africa Countries. Lassa virus infects almost every tissue in human body resulting in multisystemic dysfunction. The incubation period is generally between 6 to 21 days resulting in 3 stages of clinical manifestation viz: Acute phase characterized by flu-like, non-specific illness; haemorrhagic phase accompanied with gastrointestinal symptoms and cardiovascular/neurologic complications. Currently, there is no clinically certified Lassa fever vaccine thus complicating deterrent or preventive measures. Hence, there is need for intensification of educational programs for the populace on the useful control measures against Lassa fever. The stakeholders need to prioritize intervention and support program and also speed up the processes leading to the production of effective vaccine to limit the menace of Lassa fever outbreak and associated morbidity, fatality and high socio-economic cost.

Keywords: Lassa fever, endemic, epidemic, reservoir rodent, West Africa

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Review of Lassa fever, an emerging old world haemorrhagic viral disease in sub-Saharan Africa