THE PREVALENCE AND IDENTIFICATION OF INFLUENZA VIRUS SUBTYPES IN OLIVE BABOONS FROM SELECTED AREAS IN KENYA

Abstract

Worldwide, infections with influenza A viruses are associated with substantial illness and death among mammals and birds ,in humans it accounts for 250,000 -500,000 deaths per year its continuous mutation in different hosts poses a threat that can result in the emergence of a novel virus with an ability to cause a widespread pandemic. Surveillance of Influenza A viral genome from diverse hosts and subtyping is critical in understanding of the antigenic shift and drift of the influenza virus especially in hosts that are closely related to human beings like the Non-Human Primates (NHPs),pigs and birds. This study therefore identified the influenza subtypes circulating in Papio anubis (Olive baboons) at the interface of human and NHPs in Kenya. Fifty nasal swabs samples were collected from baboons from the colony at the Institute of Primate Research (IPR), these animals were originally collected from Olorbototo, Yatta, Aberdares, Movoloni and Laikipia. The nasal swabs were collected in viral transport media using sterile dacron swabs and stored at −80°C. In this study, samples were screened initially using real time RT-PCR- CDC protocol for influenza A virus detection that targets the matrix gene and twenty five were found to be positive. The proportion positive were as follows , Olorbototo (75%), Ngurumani (44%) Aberdares (43%), Mavoloni (37.5%), Yatta (14%), and Laikipia (9%) . These samples were taken through conventional PCR to amplify the haemagglutinin, neuraminidase and the matrix genes and eight samples were successfully amplified and later sequenced through 24- capillaries ABI 3500 XL Genetic Analyzer. Upon BLAST of these sequences, influenza subtypes H1N1 and H3N2 were detected. It was observed that the subtypes in baboons were as follows Olorbototo H1N1,Yatta H3N2, Aberdares H3N2, Mavoloni H1N1, Ngurumani H1N1 and Laikipia H1N1. Upon further analysis, the influenza positive Olive baboons were found to have been reared in the colony at at IPR colony for between 1-2 years and were in close contact with personnel. Given the presence of H1N1 and H3N2 subtypes in baboons suggests that baboons can be naturally infected with seasonal endemic human influenza viruses , avian emerging pandemic or pandemic swine flu origin .