Naturally acquired immunity to Haemophilus influenzae type B in healthy Cuban children

National Reference Center for Haemophilus, Instituto de Medicina Tropical Pedro Kouri, Havana, Cuba.
Memórias do Instituto Oswaldo Cruz (Impact Factor: 1.59). 12/2004; 99(7):687-9. DOI: 10.1590/S0074-02762004000700004
Source: PubMed


We have evaluated the prevalence of antibody to immunogenicity of Haemophilus influenzae type b (Hib) in a group of 4 to 5 years old healthy children, who were too old to be included in the first vaccinated cohort when Hib vaccination begun in Cuba in 1999. Serum capsular polysaccharide specific IgG antibody concentrations were measured in 974 healthy children, between February and May 2002. The prevalence of Hib nasopharyngeal carriage was also estimated. The majority of children (99.7%) had more than 1 microg/ml of antibody. The preliminary report of the nasopharyngeal cultures was positive for H. influenzae in 16 children, but in only one was confirmed as Hib after serotyping (0.1% Hib nasopharyngeal carrier). These results provide evidence that in Cuba the natural active immunity to Hib can be acquired at an early age.

Download full-text


Available from: Gilda Toraño Peraza, Oct 03, 2014
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Aim: The Haemophilus influenzae type b (Hib) vaccine was introduced into the routine immunization schedule in Turkey on January 1, 2007. This study investigates the immunity to Hib prior to the introduction of the vaccine. Materials and methods: Serum samples were collected from healthy volunteers between the ages of 6 months and 50 + years of age, living in the area of 26 health centers in the Samsun, Antalya, and Diyarbakir provinces during 2000-2001. In total, 1713 sera were selected for this study, and the younger age groups were given priority (range 0-82). A commercial ELISA test was used to measure anti-Hib IgG. Hib antibody concentrations of ≤ 0.15, > 0.15 to < 1.0, and ≥ 1.0 μg/mL were considered as non protective, short-term protection, and long term protection, respectively. The statistical analyses performed were the chi-square test and logistic regression. Results: The antibody levels considered non-protective were 58.0%, 35.3%, 28.1%, 19.8%, 18.4%, 15.3%, and 20.6% among < 5, 5-9, 10-19, 20-29, 30-39, 40-49, and 50 and over age groups, respectively. Protection against Hib infection increased by age in all 3 provinces. Conclusion: This study provides important baseline data on anti-Hib antibody levels in Turkey before routine immunization was introduced, and shows that there is a considerable percentage of subjects with non-protective antibody levels.
    Turkish Journal of Medical Sciences 01/2010; 40(6):5-9. DOI:10.3906/sag-0811-50 · 0.50 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Hemophilus influenza type b (Hib) infection has a high morbidity and mortality rate especially in children less than 5 years of age. The incidence of Hib disease in Iran is not known and Hib vaccine is not included in the National Immunization Program. The aim of the present study was to investigate the level of antibody to Hib of children five years or younger living in Jahrom, Iran. Three hundred eighty six children 5 years or younger were selected by random sampling method. A blood samples were taken from those children. Anti-Hib IgG antibody (anti-PRP) level was determined in the serum by using anti-Hemophilus influenza IgG EIA kit (IBL, Germany). An anti-PRP antibody levels of 0.15 microg mL(-1) and over were accepted as the natural immunity. The mean concentration of Hib antibody was 0.94 +/- 0.480 microg mL(-1). Natural immunity was determined in three hundred and twenty six (84.5%) of the children. The proportion of natural immunity was increased from 64.9% among children = 12 month old to 95.2% in children aged 49-60 month (p < 0.001). The exposure rate of children with Hib was higher than expected, even in children who were just a few months old. Present data revealed need to be introducing Hib conjugate vaccine in the National Immunization Programs.
    Pakistan Journal of Biological Sciences 02/2012; 15(3):160-3. DOI:10.3923/pjbs.2012.160.163
  • [Show abstract] [Hide abstract]
    ABSTRACT: During the first six-month period of 2001, a descriptive cross-sectional study of carriage in healthy children attending a day-care center in Havana City was performed. The objective was to find out the prevalence of potentially pathogenic bacteria and its association with possible risk factors. The design took into account the international and domestic regulatory bioethical requirements. Swabs of posterior nasopharynx of 160 children were directly cultured in brain heart agar plus sheep blood and in brain heart agar plus NAD, hemine and bacitracin and incubated for 18-24 h. Resulting isolates were identified using conventional techniques and the API NH system. Male children aged 3-4 years were predominant. A high percentage of nasopharyngeal carriage was detected; Haemophilus was isolated in 92.50% of cases, being Haemophilus influenzae present in 54.72% of children. Other pathogens were Streptococcus pneumoniae, beta-hemolythic Streptococcus, Staphylococcus aureus and Moraxella catarrhalis. A statistically significant difference was observed when comparing S. pneumoniae carriage and non-carriage in less than 2 years-old children. The colonizing patterns of potentially pathogenic bacteria were disclosed in children attending a day care center in Havana City.
    Revista cubana de medicina tropical 02/2013; 58(3):181-9.
Show more