Ecological distribution of Chikungunya haemagglutination inhibition antibodies in human and domestic animals in Nigeria.

A serological survey to detect presence of antibodies to Chikungunya virus in 477 human sera randomly sampled from four ecological zones of Nigeria was carried out employing a haemagglutination inhibition (HI) test. Similarly 220 animal sera collected mostly from the northern parts of Nigeria were screened for HI antibody to Chikungunya virus. Of the 477 human sera tested a total of 68 or 14.3% were found to possess Chikungunya HI antibodies made up of 10% in swampy forest, 20% in the rain forest, 14% in the derived savannah and 6.7% in the guinea savannah. Such sera positive for Chikungunya HI antibodies were further screened against other circulating alphaviruses of which 17 or 25% were positive to Igbo-Ora virus, 6 or 38.1% to Semliki forest virus and 36 or 52.6% were positive to Sindbis virus. Five or 2.3% of the 220 animal sera screened were found to possess Chikungunya HI antibodies.