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

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