Epidemiology and Infection

Original Papers

Pneumococcal and meningococcal infection

The effect of distance on observed mortality, childhood pneumonia and vaccine efficacy in rural Gambia

S. M. A. ZAMANa1 c1, J. COXa2, G. C. ENWEREa1, C. BOTTOMLEYa3, B. M. GREENWOODa2 and F. T. CUTTSa1

a1 Medical Research Council Unit, Banjul, The Gambia

a2 Department of Disease Control, London School of Hygiene & Tropical Medicine, London, UK

a3 Medical Research Council Tropical Epidemiology Group, Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, UK


We investigated whether straight-line distance from residential compounds to healthcare facilities influenced mortality, the incidence of pneumonia and vaccine efficacy against pneumonia in rural Gambia. Clinical surveillance for pneumonia was conducted on 6938 children living in the catchment areas of the two largest healthcare facilities. Deaths were monitored by three-monthly home visits. Children living >5 km from the two largest healthcare facilities had a 2·78 [95% confidence interval (CI) 1·74–4·43] times higher risk of all-cause mortality compared to children living within 2 km of these facilities. The observed rate of clinical and radiological pneumonia was lower in children living >5 km from these facilities compared to those living within 2 km [rate ratios 0·65 (95% CI 0·57–0·73) and 0·74 (95% CI 0·55–0·98), respectively]. There was no association between distance and estimated pneumococcal vaccine efficacy. Geographical access to healthcare services is an important determinant of survival and pneumonia in children in rural Gambia.

(Received September 19 2013)

(Revised November 29 2013)

(Accepted January 29 2014)

(Online publication February 24 2014)

Key words

  • Access to healthcare facilities;
  • all-cause mortality;
  • distance;
  • pneumococcal conjugate vaccine;
  • pneumonia;
  • vaccine efficacy


c1 Author for correspondence: Dr S. M. A. Zaman, Child Survival Theme, Medical Research Council Unit, Atlantic Road, Fajara, P.O. Box 273 Banjul, The Gambia. (Email: azaman@mrc.gm)