A Prospective, Population-Based Study of Haemophilus influenzae Type b Meningitis in The Gambia and the Possible Consequences

Abstract

A prospective population-based field study on Haemophilus influenzae type b (Hib) meningitis was carried out in The Gambia, West Africa. The annual incidence was 60 cases/100,000 children less than 5 years old and 297 cases/100,000 less than 1 year. The peak incidence was in those 5 months old, and 45% of cases occurred in those less than 6 months. The case fatality rate was 37%. Because the outcome did not appear to be affected by the logistics of receiving care, and resistance to chloramphenicol and ampicillin is not yet a problem, prevention of Hib disease at an early age seems the best solution. There are several options for vaccine trials. On the basis of available data, at least one of these trials seems warranted before Hib vaccination can be introduced in developing countries. Extrapolation of successful results in industrialized countries to a population of different genetic origin and living under different conditions seems questionable.

The epidemiology ofHaemophilus influenzaetype b disease in the Republic of Ireland

“…Although slightly higher mortality rates occurred in Gwynedd (2 %) [5], Denmark (2%) [11], Minnesota (3 9%) and Dallas (4%) [9], these rates from industrialized countries are substantially lower than those experienced by African children (37 %) where lack of access to healthcare facilities plays a major part in poor outcome [34]. In our study 4% of children were discharged from hospital with some sequelae pertaining to the central nervous system.…”

“…The annual incidence of Hib disease in Ireland was similar to that experienced in England and Wales [8], Scotland [13] and France [12], lower than that in northern Europe [2, 1 1], Australia and New Zealand [6] and American populations of European origin [9], and substantially lower than rates experienced in native American [14,15] aboriginal [16] and African [34] children. The pattern of illness in the ROI differs somewhat from that of Hib disease in the UK with meningitis comprising a smaller proportion (45 %) in Irish children compared to 71 % in Oxford [4], 62 % in Gwynedd [5] and 56 % in England and WAales [8].…”

“…Ampicillin resistance in beta-lactamase producing strains of Hib has long been recognized [35] and is seen to be as prevalent as 50 % in highly medicalized societies [3,12] in comparison to its rarity in the developing world [34]. The level of ampicillin resistance (16 1 %) in isolates from Ireland is almost identical to that found in Gwynedd [51 and more recently in England and Wales [8].…”

Worldwide Haemophilus influenzae Type b Disease at the Beginning of the 21st Century: Global Analysis of the Disease Burden 25 Years after the Use of the Polysaccharide Vaccine and a Decade after the Advent of Conjugates

“…In Senegal, Africa, the incidence rate among 0-to 11-month-old infants was twice that in the entire cohort of children aged 0 to 4 years for this country (25). In Gambia, this difference was fivefold: 297 per 100,000 and 60 per 100,000, respectively (13).…”

“…At the same time, the situation was dramatically worse in the developing world-even in the 1980s, 63, 37, 38, and 30% of patients with Hib meningitis died in Ghana, Gambia, northeastern Brazil (Bahia), and Papua New Guinea, respectively (13,24,64,188). In Gambia, the mortality attributable to Hib meningitis was calculated as 23 per 100,000 per year, a rate as high as the incidence of Hib meningitis in Germany before vaccinations were begun (65,82).…”