Virologic and sero-epidemiological studies of Middle East respiratory syndrome coronavirus (MERS-COv) infections in dromedary camels in Nigeria

Abstract

This study was carried out as a pilot study to feasibility in detecting and characterizing Middle East respiratory syndrome coronavirus (MERS-CoV) in dromedary camels in Nigeria. In Nigeria, camel husbandry is mainly carried out by the Fulani people in the North of the country. Their nomadic lifestyle predisposes to the risk of rapid and easy spread of pathogens carried by their animals. The Municipal abattoir in Kano was chosen for this study because this abattoir is one of the largest in the country with the largest number of camels slaughtered every day. Data on the sampled camels was collected using a pre-designed questionnaire. Information on the overall sources, husbandry and trade patterns of the camels slaughtered at the abattoir were gathered by means of interview with the camel marketers, butchers and other abattoir staff. A total of 132 camels were sampled at the abattoir immediately post-slaughter with nasal swab and serum samples being collected from each animal. The specimens were analyzed at The University of Hong Kong. Serology using a validated MERS-spike protein pseudoparticle neutralization test (ppNT) and 126 of 132 (95.45%) of the sera were sero-positive for MERS-CoV, indicating past infection with the virus. Thus, MERS-CoV appears to be a common infection in camels in Nigeria and the adjoining regions. Virus nucleic acid was extracted from the nasal swabs, reverse transcribed to complementary DNA and the PCR technique was employed to detect presence of MERS-CoV. MERS-Virus RNA was detected in 10 (7.6%) of 132 animals sampled indicating high levels of exposure of slaughterhouse workers to the virus. Genetic sequencing of MERS-CoV from one nasal swab revealed that it was genetically divergent from other known MERS-CoV. With the exception of a two virus genetic sequences from Egypt, this is the only other MERS-CoV viral genetic sequence from Africa.