Burden of Rotavirus Diarrhoea in Children in Abuja

Background: Diarrhoea is the second leading cause of death in children. Nigeria has the continent’s highest mortality due to diarrhoeal diseases with little information on specific causes and the proportion affected by rotavirus infection. The main objectives of this study were to describe the features of young children with diarrhoea, with and without rotavirus, in Abuja the Federal Capital Territory.

Materials and Methods: Retrospective review of local hospital activity data related to diarrhoea was retrieved from General Hospitals in Abuja. Then a one-year prospective descriptive study of children under 5 years of age with acute diarrhoea was conducted from September 2012 to August 2013. Children with acute diarrhoea attending three government hospitals and one private hospital were recruited. Children without diarrhoea were recruited as the control group. Faecal specimens were transported in cold chain boxes from Nigeria and stored at -80 °C at the Institute of Global Health, virology section of the University of Liverpool, where all laboratory work was performed.

Results: Hospital records were poorly preserved and did not provide meaningful data for trend analyses or disease surveillance. 1331 participants were enrolled in this prospective study. Stool samples were collected from 1242 (93.3%) participants, of whom 957 (77.0%) were ambulatory, 123 (9.9%) hospitalised and 160 (12.8%) controls without diarrhoea. 881 and 450 children with diarrhoea were recruited from government and the private hospitals, respectively. The median age of the children was 8 months in the ambulatory and 9.5 months in the hospitalized group (p<0.05). A total of 209 (16.8%) children were vaccinated, 858 (69.1%) were unvaccinated, and 174 (14.0%) had an unclear vaccination status. Rotavirus ELISA was positive in 123 (11.4%) children with diarrhoea and 2 (1.2%) controls. Among children with diarrhoea, 92 (10.4%) of 881 children attending government hospitals had rotavirus, compared to 33 (7.3%) of 450 children attending a private hospital (p<0.001) where a vaccination program had been in place. The peak months for rotavirus infection were November and February. The efficacy of Rotarix® RV1 vaccine in preventing rotavirus diarrhoea was indirectly assessed to be 64.5%.

Conclusion: Rotavirus is an important pathogen in children, especially in unvaccinated children in Abuja. The introduction of a rotavirus vaccine is highly desirable in Nigeria, but this is still awaited. Local and national infrastructure are inadequate for basic surveillance of diarrhoeal disease, and this will have to be improved, together with access to virological stool testing, to monitor the planned vaccine program. The retrospective studies reported here provide indirect evidence of vaccine efficacy in Abuja but need prospective confirmation.