Temporal Association of Rotavirus Vaccine Introduction and Reduction in All-Cause Childhood Diarrheal Hospitalizations in South Africa

Abstract

Background: The public health impact of rotavirus vaccination in African settings with a high human immunodeficiency virus (HIV) infection prevalence is yet to be established. We evaluated trends in all-cause diarrheal hospitalizations in Soweto, Johannesburg, before and after the introduction of rotavirus vaccine into South Africa's national immunization program in August 2009.

Methods: Hospitalizations in children <5 years of age with a diagnosis of diarrhea, defined byInternational Classification of Diseases, Tenth Revisioncodes A00-A05, A06.0-A06.3, A06.9, A07.0-A07.2, A07.9, and A08-A09, were identified at the Chris Hani Baragwanath Academic Hospital from 1 January 2006 to 31 December 2014. The median annual prevaccine (2006-2008) hospitalization incidence was compared to that of the vaccine era (2010-2014), and stratified by age group and HIV infection status.

Results: Incidence reductions (per 1000 population) were greatest in children aged <12 months: 54.4 in the prevaccine era vs 30.0, 23.6, 20.0, 18.8, and 18.9 in the postvaccine years 2010-2014, respectively (a 44.9%-65.4% reduction). Lower incidence reductions (39.8%-49.4%) were observed among children aged 12-24 months from the second year post-vaccine introduction onward. Reductions were observed in both HIV-infected and HIV-uninfected children. There was a change in the seasonal pattern of diarrheal hospitalizations post-vaccine introduction, with flattening of the autumn-winter peaks seen in the prevaccine years.

Conclusions: An accelerated and sustained decline in all-cause diarrheal hospitalizations, temporally associated with rotavirus vaccine introduction, was observed in children <2 years of age. However, the impact of other interventions such as improved sanitation and changes in HIV management cannot be discounted.

Keywords: HIV; children; diarrhea; rotavirus vaccine.

Figure 1.

Monthly count of all-cause diarrheal hospitalizations in children <5 years of age at Chris Hani Baragwanath Academic Hospital, Soweto, South Africa, 2006–2014. Vertical line represents introduction of rotavirus vaccine into the national immunization program in August 2009.

Figure 2.

Annual incidence per 1000 population (95% confidence interval) of diarrheal hospitalizations among human immunodeficiency virus (HIV)–uninfected children <5 years of age in Soweto, 2006–2014. Values are incidence difference = incidence in vaccine-era years 2010, 2011, 2012, 2013, and 2014, respectively, minus median incidence in the prevaccine years 2006–2008 (percentage change). A negative value indicates a reduction in incidence; a positive value indicates an increase in incidence. *P < .05. The 95% confidence intervals and P values are provided in Supplementary Table 1.

Figure 3.

Annual incidence per 1000 population (95% confidence interval) of diarrheal hospitalizations among human immunodeficiency virus (HIV)–infected children <5 years of age in Soweto, 2006–2014. Values are incidence difference = incidence in vaccine-era years 2010, 2011, 2012, 2013, and 2014, respectively, minus median incidence in the prevaccine years 2006–2008 (percentage change). A negative value indicates a reduction in incidence; a positive value indicates an increase in incidence. *P < .05. The 95% confidence intervals and P values are provided in Supplementary Table 2.