Prevalence of Cryptosporidium parvum, Giardia intestinalis and molecular characterization of group A rotavirus associated with diarrhea in children below five years old in Gaborone, Botswana

Abstract

Introduction: Cryptosporidium, Giardia and rotaviruses are amongst the leading causes of acute gastroenteritis in children ≤5 years worldwide. The purpose of this study was to determine the occurrence of Cryptosporidium parvum, Giardia intestinalis and molecular characteristics of rotaviruses after Rotarix® introduction in Botswana.

Methods: in this case study, 200 diarrheic stool specimens and 100 control samples from children under five years old were collected between March and November, 2017. Samples were analyzed by modified Ziehl Neelsen staining technique for cryptosporidium, wet mount procedure for Giardia and negative samples were confirmed by immunochromatographic assay. Specimens were analyzed for rotavirus by ELISA, PAGE, RT-PCR, sequencing of VP7 and VP4 antigen followed by phylogenetic analysis.

Results: prevalence rates of 20.5%, 16.5% and 11.0% in diarrhea cases were observed for Cryptosporidium parvum, Giardia intestinalis and rotavirus, respectively. Four percent of diarrheic specimens had multiple infections. The predominant rotavirus genotype was GIP[8] (7/15) followed by G2P[4] (2/15) and G3P[8] (1/15). Twenty percent of specimens were non-typeable. One mixed strain, G1+G2P[4,8] (2/15), was detected. Phylogenetic analysis of VP4 and VP7 sequences clustered Botswana rotavirus strains within G1 lineages 1 and 2, G3 lineage 1, P[8] lineage 3 and P[4] lineage 5 together with Southern African strains.

Conclusion: this study provides important information on occurrence and demographic risk groups for Cryptosporidium parvum, Giardia intestinalis and rotavirus in young children as well as genetic diversity of rotaviruses after vaccine introduction in Botswana. Constant monitoring of circulating rotavirus strains is essential in assessing effectiveness of current vaccines in Botswana.