Enteric fever burden in North Jakarta, Indonesia: a prospective, community-based study.

INTRODUCTION: We undertook a prospective community-based study in North Jakarta, Indonesia, to determine the incidence, clinical characteristics, seasonality, etiologic agent, and antimicrobial susceptibility pattern of enteric fever. METHODOLOGY: Following a census, treatment centre-based surveillance for febrile illness was conducted for two-years. Clinical data and a blood culture were obtained from each patient. RESULTS: In a population of 160,261, we detected 296 laboratory-confirmed enteric fever cases during the surveillance period, of which 221 (75%) were typhoid fever and 75 (25%)  were paratyphoid fever.  The overall incidence of typhoid and paratyphoid cases was 1.4, and 0.5 per thousand populations per year, respectively. Although the incidence of febrile episodes evaluated was highest among children under 5 years of age at 92.6 per thousand persons per year, we found that the burden of typhoid fever was greatest among children between 5 and 20 years of age. Paratyphoid fever occurred most commonly in children and was infrequent in adults. CONCLUSION: Enteric fever is a public health problem in North Jakarta with a substantial proportion due to paratyphoid fever. The results highlight the need for control strategies against enteric fever.

Immunogenicity and safety of four different doses of Haemophilus influenzae type b-tetanus toxoid conjugated vaccine, combined with diphtheria-tetanus-pertussis vaccine (DTP-Hib), in Indonesian infants.

Widespread use of Haemophilus influenzae type b (Hib) conjugated vaccine in industrialized countries has resulted in a dramatic decline in the incidence of invasive Hib diseases, but the vaccine's cost has prevented its inclusion in basic immunization programs in developing countries. To overcome this problem, combination with diphtheria-tetanus-pertussis (DTP) vaccine or reduction in the dose of Hib vaccine has been proposed. To evaluate the immunogenicity and adverse reactions from lower doses of Hib-polyribosylphosphate (PRP) conjugated with tetanus toxoid (PRP-T), a double-blind study was conducted in Jakarta, Indonesia, and its suburbs. A total of 1048 infants 6 weeks to 6 months of age received three doses of DTP vaccine combined with the usual 10 microg dose or with a reduced dose of 5, 2.5 or 1.25 microg of PRP-T at two-monthly intervals. Antibodies were measured prior to the first dose and 4-6 weeks following the third dose. Adverse reactions were similar among all four groups. The only significant difference was a higher rate of irritability (p<0.02) and of temperature elevation >38 degrees C (p<0.009) after doses 1 and 2 in the lowest dose group (1.25 microg PRP-T) compared to the other groups. All participants tested had a 4-fold increase in antibodies against all DTP antigens. In addition, after a fourth booster dose of Hib, 99.6% of infants produced >or=0.15 microg/ml of antibody to Hib-PRP, and 96.4% showed levels >or=1.0 microg/ml after primary immunization, level that correlate with short- and long-term immunity, respectively. Antibody titers to the PRP antigen showed no significant differences among dosage groups with the exception of the 5.0 microg group, which had a significantly higher GMC than the 1.25 microg group (p<0.012). This study demonstrates that primary vaccination with half, one-fourth, or one-eighth of the usual dose of PRP-T, combined with DTP vaccine, produces protective immune responses, and has side effects that are comparable to DTP vaccination alone. In these lower dosages, PRP-T conjugate vaccine can lower vaccine costs to a level that is affordable for infant immunization programs in developing countries.