Isolation and characterization of human enteroviruses from stored samples of children with acute respiratory infections attending Kenyatta National Hospital, Nairobi

Abstract

Enteroviruses are small non-enveloped isometric viruses that multiply in the gut mucosa and are transmitted from person to person by the faecal-oral route. Enteroviruses are a major cause of respiratory disturbances. Most infections occur during childhood, and they are usually transient but produce lifelong immunity. Clinical are generally mild, but occasionally infections may cause serious disease e.g. meningitis. In this cross sectional laboratory based study, the prevalence of enteroviruses infection was assessed in stored 287 samples from children with Acute Respiratory Infection (ARI) attending Kenyatta National Hospital in Nairobi. Throatswabsamples were inoculated in human Rhabdomysarcoma cells (RD cells) where positive samples were further characterized using indirect fluorescent antibody tests (IDFAT) to confirmenteroviruses.Ribonucleic Acid (RNA) was extracted frompositively identified enteroviruses and polymerase chain reaction (PCR) was performed to confirm them. These were sequenced, compared to otherenterovirusesdeposited at GenBank and phylogenetic trees were drawn to establish genetic relatedness. There were 24 (8.4%) CPE positive samples which were confirmed as enteroviruses. Of these positive samples, 10 (41.7%) were further identified as enterovirus, 9 (37.5%) coxsackie virus, 4 (16.7%) echovirus and 1 (4.2%) poliovirus. Eventhough no significant correlations (χ2 (df=3) = 0.320; p = 0.956)were noted, enteroviruses were more common in patients in their 1st year (n=19; 79.2%) followed by the 2nd year (n=5; 20.8%).In the 3 months periodof sample collection, between April and June, most infections were detected in the month of April followed by May and June respectively.Male patients had slightly more (n=13; 54.2%) infections than females . PCR and sequencing results confirmed this study’s isolates to a range of 90-99% to other similar enterovirusesin GenBank. Phylogenetic analysis of this study’s isolates gave bootstrap values ranging from 36%-87% when compared to other enteroviruses in the GenBank. In conclusion, the detection of these virusessuggests theinvolvement of enteroviruses in paediatrics in Kenya