Immunogenicity and safety of Haemophilus influenzae type b capsular polysaccharide tetanus conjugate vaccine (PRP-T) presented in a dual-chamber syringe with DTP

Separate injections of Haemophilus influenzae type b capsular polysaccharide-tetanus conjugate (PRP-T) vaccine and diphtheria-tetanus-pertussis (DTP) reconstitution of freeze-dried PRP-T vaccine with liquid DTP vaccine have been shown to be safe and immunogenic in infants. The present study was conducted to test the safety and immunogenicity of the liquid combination vaccine administered to young infants in the dual-chamber syringe. The study was a monocenter, open clinical trial of 3 month-old infants receiving PRP-T and DTP vaccines in the dual-chamber syringe reconstituted prior to injection. Healthy infants were immunized according to a 3, 4 and 5 months-of-age schedule. The vaccine was administered in a dual-chamber syringe, ready to use with two chambers. The proximal chamber contained freeze-dried PRP-T and the distal chamber contained liquid combination-vaccine DTP. The freeze-dried PRP-T vaccine was reconstituted with the liquid DTP vaccine in the same unidose dual-chamber syringe (0.5 mL) and was injected intramuscularly into the deltoid region. Blood sampling was performed prior to vaccination at 3 months of age and after the third vaccination at 6 months. The primary end-point was the serological response to PRP-T vaccine as expressed by the percentage of infants with an antibody titer greater than or equal to 1 μg/mL. The reactogenicity was expressed as the percentage of reported local and systemic reactions. A total of 108 infants were included in the study and received the dual-chamber syringe vaccine. After the third injection, all the infants had a PRP antibody titer greater than or equal to 0.15 μg/mL and 94.4% of infants had a PRP antibody titer greater than or equal to 1 μg/mL; the pertussis agglutinin titers were over the threshold 40 and 80 in all infants and 98.1% were over the threshold 320. After the third injection, all the infants had diphtheria antibody titers greater than 0.1 IU/mL and 83.3% had titers greater than 1 IU/mL; all the infants had tetanus antibody titers greater than 0.1 IU/mL and 97.2% had results over 1 IU/mL. Thirty-seven infants (34.6%) had local reactions and 64.5% had systemic reactions. The dual-chamber syringe may reduce the cost of vaccine delivery, as well as the workload, and increase the vaccine acceptability and coverage rate of vaccines.     

Shigella gastroenteritis: Clinical and epidemiological aspects,and antibiotic susceptibility

The epidemiology and antibiotic sensitivity of Shigella species is changing worldwide. The present study surveyed the changing clinical and epidemiological characteristics and antibiotic susceptibility of Shigella gastroenteritis in Hacettepe University Ihsan Dogramaci Children's Hospital Diarrhoea Training and Treatment Unit between 1987 and 1994. Among 19 812 diarrheal admissions, 618 (3.2%) patient files with Shigella gastroenteritis were reviewed retrospectively. Shigella soneii has been the commonest isolate (64%) since 1987 followed by S. flexineri (30%), S. boydii (5%) and S. dysenteriae (1%), the latter having not been isolated since 1990. The isolate rate of S. sonnei has increased whereas the isolation rate of S. flexineri has decreased concomitantly since 1987 (r = ?0.94; P< 0.001). The majority of cases (365/618, 59%) were between 1 and 5 years of age. On admission bloody diarrhea was present in 36%, seizures in 3% and mild-moderate dehydration in 11% of cases. No case had severe dehydration. Only six patients (1%) were hospitalized. No deaths were recorded. The resistance rate for trimethoprim-sulfamethoxazole has increased from 27% in 1990 to 66% in 1994 (P < 0.05) while the resistance rate for ampicillin has decreased from 81% in 1987 to 32% in 1993 (P< 0.001). Shigella flexineri was found to have higher resistance rates to ampicillin, sulbactam-ampicillin, chloramphenicol and gentamicin than S. sonnei. Changing Shigella sp. over the years may be the reason for the mild course of Shigella gastroenteritis. Further regional epidemiological studies are necessary to develop more appropriate management guidelines, especially in developing countries.     

Serum zinc levels in children with acute gastroenteritis

BACKGROUND: The aim of the present study was to determine the serum zinc levels on admission and 7-10 days after clinical recovery from acute gastroenteritis of <8 days' duration. METHODS: This prospective study included 82 infants aged 2-24 months who had no associated bacterial infection, chronic disease, prior antibiotic use, moderate or severe malnutrition or dysentery. Forty-one healthy children formed the control group. RESULTS: The mean serum zinc level on admission (Zn1) was 11.85 +/- 2.83 micromol/L and at 7-10 days after recovery (Zn2) was 10.92 +/- 2.17 micromol/L; mean serum zinc level of the control group was 11.81 +/- 3.45 micromol/L. Zn2 was significantly lower than Zn1, but there was no statistical difference between the mean of the control group and Zn1 and Zn2. When dehydrated patients were excluded from the patient group, Zn1 and Zn2 did not differ. Although asymptomatic, 39% of the control group had low zinc. Serum zinc levels were not affected by sex, age, clinical characteristics of the patients or severity of gastroenteritis. CONCLUSION: Serum zinc levels of the patients admitted with acute gastroenteritis without any other disease and without moderate or severe malnutrition were not affected by disease state. Gastroenteritis did not further decrease serum zinc levels in patients with asymptomatic or subclinical zinc deficiency.