Investigation of two suspected diarrhoeal-illness outbreaks in Northern Cape and KwaZulu-Natal provinces, South Africa, April-July 2013: The role of rotavirus.

Andronica M Shonhiwa,Juno Thomas,Noreen Crisp,Maureen B Taylor,Genevie Ntshoe,Ayo J Olowolagba,Vusi Mbuthu,Nicole A Page

doi:10.4102/sajid.v35i1.159

Abstract

BackgroundSuspected diarrhoeal-illness outbreaks affecting mostly children < 5 years were investigated between May and July 2013 in Northern Cape province (NCP) and KwaZulu-Natal (KZN) province. This study describes the epidemiological, environmental and clinical characteristics and diarrhoeal-illnesses causative agent(s).MethodsA descriptive cross-sectional study was conducted. Cases were patients presenting at healthcare facilities with diarrhoeal-illness between 09 April and 09 July 2013 in NCP and 01 May and 31 July 2013 in KZN. Laboratory investigations were performed on stools and water samples using microscopy, culture and sensitivity screening and molecular assays.ResultsA total of 953 cases including six deaths (case fatality rate [CFR]: 0.6%) were recorded in the Northern Cape province outbreak. Children < 5 years accounted for 58% of cases. Enteric viruses were detected in 51% of stools, with rotavirus detected in 43%. The predominant rotavirus strains were G3P[8] (45%) and G9P[8] (42%). Other enteric viruses were detected, with rotavirus co-infections (63%). No enteric pathogens detected in water specimens. KwaZulu-Natal outbreak: A total of 1749 cases including 26 deaths (CFR: 1.5%) were recorded. Children < 5 years accounted for 95% of cases. Rotavirus was detected in 55% of stools; other enteric viruses were detected, mostly as rotavirus co-infections. The predominant rotavirus strains were G2P[4] (54%) and G9P[8] (38%).ConclusionAlthough source(s) of the outbreaks were not identified, the diarrhoeal-illnesses were community-acquired. It is difficult to attribute the outbreaks to one causative agent(s) because of rotavirus co-infections with other enteric pathogens. While rotavirus was predominant, the outbreaks coincided with the annual rotavirus season.

Highlights

A study conducted in low-income countries to estimate pathogen-specific burdens of diarrhoea in children aged 0–24 months reported the highest attributable fractions for norovirus genogroup II (GII), rotavirus, Campylobacter species, astrovirus, Cryptosporidium spp. and Shigella spp. in the first and second years of life.[8]
Children < 5 years of age accounted for a high proportion of cases (58%, 553/953), and the majority (44%, 244/553) of whom were < 1 year of age (Figure 3)
Six diarrhoea-associated deaths were reported, with a 0.6% (6/953) outbreak case fatality rate (CFR); all deaths were in Number of cases

Summary

Introduction

A study conducted in low-income countries to estimate pathogen-specific burdens of diarrhoea in children aged 0–24 months reported the highest attributable fractions for norovirus genogroup II (GII), rotavirus, Campylobacter species (spp.), astrovirus, Cryptosporidium spp. and Shigella spp. in the first and second years of life.[8] Enteric bacteria and parasites along with rotavirus http://www.sajid.co.za. Rotavirus was found in 22% and enteric parasites (Giardia intestinalis and Entamoeba histolytica) in 16% of children with diarrhoea.[11] Almost 43% of stool specimens from children with diarrhoea, screened using molecular techniques, identified at least one viral agent.[12,13,14] An estimated 40% of acute diarrhoeal-illness cases in children < 5 years are because of rotavirus infections, with approximately 30% because of norovirus and adenovirus infections.[12] An additional 20% of diarrhoeal cases can be attributed to bacterial infections, 5% to parasites and the remaining 5% to other causes.[15]. This study describes the epidemiological, environmental and clinical characteristics and diarrhoeal-illnesses causative agent(s)

Methods

Results

Discussion

Conclusion