Incidences of vaccine-preventable Haemophilus influenzae type b pneumonia and meningitis in Indonesian children: hamlet-randomised vaccine-probe trial.

BACKGROUND: Most studies of Haemophilus influenzae type b (Hib) disease in Asia have found low rates, and few Asian countries use Hib vaccine in routine immunisation programmes. Whether Hib disease truly is rare or whether many cases remain undetected is unclear. METHODS: To estimate incidences of vaccine-preventable Hib pneumonia and meningitis among children younger than 2 years in Lombok, Indonesia, during 1998-2002, we undertook a hamlet-randomised, controlled, double-blind vaccine-probe study (818 hamlets). Children were immunised (WHO schedule) with diphtheria, tetanus, pertussis (DTP) or DTP-PRP-T (Hib conjugate) vaccine. Vaccine-preventable disease incidences were calculated as the difference in rates of clinical outcomes between DTP and DTP-PRP-T groups. Analyses included all children who received at least one vaccine dose. FINDINGS: We enrolled 55073 children: 28147 were assigned DTP-PRP-T and 26926 DTP. The proportion of pneumonia outcomes prevented by vaccine ranged from less than 0 to 4.8%. Calculated incidences of vaccine-preventable Hib disease (per 10(5) child-years of observation) for outcome categories were: substantial alveolar consolidation or effusion, less than zero (-43 [95% CI -185 to 98]); all severe pneumonia, 264 (95% CI less than zero to 629); all clinical pneumonia, 1561 (270 to 2853); confirmed Hib meningitis, 16 (1.4 to 31); meningitis with cerebrospinal-fluid findings consistent with a bacterial aetiology, 67 (22 to 112); and admission for suspected meningitis or presenting to a clinic with convulsions, 158 (42 to 273). INTERPRETATION: Hib vaccine did not prevent the great majority of pneumonia cases, including those with alveolar consolidation. These results do not support a major role for Hib vaccine in overall pneumonia-prevention programmes. Nevertheless, the study identified high incidences of Hib meningitis and pneumonia; inclusion of Hib vaccine in routine infant immunisation programmes in Asia deserves consideration.

Acute respiratory illness incidence and death among children under two years of age on Lombok Island, Indonesia.

No childhood pneumonia incidence data for Indonesia exist, and few data exist for Asia as a whole. From February 1, 1998, to January 31, 1999, we conducted acute respiratory illness (ARI) surveillance among children < 24 months of age in 50 mainly rural villages on Lombok Island, Indonesia. The total number of child-years at risk during the study period was 17,015. The documented incidences of simple, severe, hospitalized, and radiologically confirmed alveolar pneumonia were 21, 8.3, 5.3, and 1.8 per 100 child-years of observation, respectively. For all outcomes, the incidence was higher among younger and rural children. All cause and ARI-specific infant mortality rates were 84 and 33 per 1,000 live births, respectively. More than 65% of deaths due to ARI occurred outside of a hospital setting. The incidence of pneumonia is high in Lombok. Interventions should include introducing vaccines to prevent infections leading to pneumonia and increasing the access of critically ill infants to the health care system.

Case fatality proportions and predictive factors for mortality among children hospitalized with severe pneumonia in a rural developing country setting.

Few large studies have evaluated risk factors for mortality among children hospitalized for pneumonia and this may contribute to suboptimal case management efficiency. To identify useful screening criteria for mortality among children hospitalized for pneumonia in a developing country setting, we conducted a population-based hospital cohort study among children less than 2 years of age admitted for pneumonia during 1999-2001 at one of three major hospitals on Lombok Island, Indonesia. Of 4351 children admitted for pneumonia, 12 per cent died before discharge. Case fatality proportions were seasonal, with peaks occurring immediately after peaks in the proportion of cases positive for respiratory syncytial virus. Children with an oxygen saturation < or = 85 per cent or age younger than 4 months were 5.6 times more likely to die than children with none of these predictive factors (95 per cent CI, 4.5-7.1); 83 per cent of children who died had one of these two risk factors. For children < 4 months old, mortality increased at an oxygen saturation < 88 per cent compared with < 80 per cent for older children. Laboratory, physical examination, and radiological findings were not associated with or did not contribute substantially to mortality prediction. Among children hospitalized for pneumonia, age less than 4 months and hypoxia were identified with those at high risk of death. Age influences cut-off levels for hypoxia.