Molecular diagnosis of coinfections with Human bocavirus and genotyping kenyan Isolates of the emerging virus

Abstract

In Kenya, most surveys on viral respiratory tract infections, often, have always concentrated on the classical pathogens, which are respiratory syncytial virus, adenovirus, rhinovirus, parainfluenza and influenza virus as the commonest viral causes of upper respiratory tract infections whereas newer pathogens have emerged that cause similar symptoms. Human bocavirus (HBoV) is one of the recently discovered viruses isolated from respiratory specimens globally. This virus may cause respiratory symptoms clinically indistinguishable from influenza. The primary aim of this study was to generate data that will provide baseline information on a newer and potential aetiological agent of acute respiratory tract infections in our communities. The data generated confirms that human bocavirus is already circulating in Kenya and can be isolated from clinical specimens of patients experiencing influenza like symptoms. Only 1.8 % of samples analyzed were positive for HBoV DNA, making the frequency of detection of HBoV less common than all the other classic pathogens but probably more common than herpes simplex virus type 1. Human bocavirus infection in Kenya seems to affect children less than two years of age indicating that infection with the virus might primarily be during the early stages of life. A BLASTsearch of GenBank with sequences obtained from Kenyan HBoV isolates identified several human bocaviruses that showed 99% identity based on VP1/2 region. Furthermore, phylogenetic analysis of the Kenyan isolates and several other previously sequenced viruses (HBoVl-4) indicated that the HBoVllike lineage (ST2genotype) is the main strain circulating in Kenya.There is need to understand more on the role of the virus in cases of lower respiratory tract and gastrointestinal infections, because patients with HBoV infections present with non-specific clinical manifestations. This is the first report documenting the existence of HBoV in Kenya and describing the genotype. This information should add to the body of knowledge needed to monitor for emerging viral infections.