Bacterial meningitis among children under the age of 2 years in a high human immunodeficiency virus prevalence area after Haemophilus influenzae type b vaccine introduction.

AIM: The aim of this study was to describe bacterial causes of meningitis among children < 2 years in a high human immunodeficiency virus (HIV) prevalence area after introduction of routine Haemophilus influenzae type b vaccination. METHODS: Data collected between April 2003 and December 2008 were extracted from a surveillance database and medical records of children < 2 years admitted in Mbarara Hospital, Uganda with suspected bacterial meningitis. HIV infection was confirmed using rapid tests and polymerase chain reaction and bacterial meningitis by using cerebrospinal fluid culture. RESULTS: Between April 2003 and December 2008, 1464 children under 5 years were admitted with suspected bacterial meningitis of which 1235 (84.4%) had cerebrospinal fluid collected; 894 (72.4%) of these samples were from children < 2 years. Of the 894 samples, 64 (7.2%) grew an organism including Streptococcus pneumoniae (26; 41%), Salmonella species (20; 31%), H. influenzae (6; 9%) and coliforms (7; 11%), and five (8%) grew contaminants that are all coagulase negative Staphylococcus. Of the 894 children, 468 (52.3%) were tested for HIV; 16.7% were positive. Fifty-one children had a pathogenic isolate and a treatment outcome, and 23 (45%) died; 13 (56.6%) deaths were due to S. pneumoniae, eight (34.8%) were due to Salmonella spp., one (4.3%) was due to H. influenzae and one (4.3%) was due to coliforms. HIV infection was associated with a threefold increase in mortality, increased likelihood of a bacterial isolate and decreased likelihood of malaria parasitaemia. CONCLUSION: Following H. influenzae type b vaccine introduction, S. pneumoniae and Salmonella spp. are the major causes of bacterial meningitis among children < 2 years in Uganda. Pneumococcal conjugate vaccines and reduction in mother to child transmission of HIV could reduce the observed mortality.

Coverage and causes of missed Haemophilus influenzae type B vaccination in urban and rural areas of Peshawar.

BACKGROUND: Haemophilus influenza type b (Hib) is a major cause of morbidity and mortality in Pakistan. Hib vaccine was introduced in 2009 in EPI programme. The purpose of this study was to find out the coverage and factors associated with non-immunization of Hib in urban and rural areas of Peshawar. METHODS: Data was collected through random sampling in Peshawar University, Peshawar Saddar, Hashtnagri, Naway Kalay and Pawaka from 9th to 19th of June 2010. A questionnaire was used to interview parents of 600 children aged 1 year and below about demographics, Hib vaccination status, reasons for missed vaccination and views on immunization. Pearson's Chi-square test was used for statistical testing, and p<0.05 was considered significant. RESULTS: Completely vaccinated children were 64.2%, 25% not vaccinated at all, and 11% were incompletely vaccinated. The reasons for not vaccinating were lack of awareness (26%), family problem/mother busy (18%), centre too far (16.9%), wrong ideas (12.2%), fear of reaction (5.4%), child illness (8.1%) and miscellaneous causes (13.7%). CONCLUSION: Low Hib vaccination coverage in Peshawar is mainly due to low awareness among people, poor economic conditions and illiteracy.

Production of chondroitin sulfate and chondroitin.

The production of microbial polysaccharides has recently gained much interest because of their potential biotechnological applications. Several pathogenic bacteria are known to produce capsular polysaccharides, which provide a protection barrier towards harsh environmental conditions, and towards host defences in case of invasive infections. These capsules are often composed of glycosaminoglycan-like polymers. Glycosaminoglycans are essential structural components of the mammalian extracellular matrix and they have several applications in the medical, veterinary, pharmaceutical and cosmetic field because of their peculiar properties. Most of the commercially available glycosaminoglycans have so far been extracted from animal sources, and therefore the structural similarity of microbial capsular polysaccharides to these biomolecules makes these bacteria ideal candidates as non-animal sources of glycosaminoglycan-derived products. One example is hyaluronic acid which was formerly extracted from hen crests, but is nowadays produced via Streptococci fermentations. On the other hand, no large scale biotechnological production processes for heparin and chondrotin sulfate have been developed. The larger demand of these biopolymers compared to hyaluronic acid (tons vs kilograms), due to the higher titre in the final product (grams vs milligrams/dose), and the scarce scientific effort have hampered the successful development of fermentative processes. In this paper we present an overview of the diverse applications and production methods of chondroitin reported so far in literature with a specific focus on novel microbial biotechnological approaches.

[Surveillance programmes to evaluate the effectiveness of vaccination programmes using vaccination against Haemophilus influenzae type b and varicella as examples]. / Durchführung von Surveillanceprogrammen zur Uberprüfung der Wirksamkeit von Impfprogrammen am Beispiel von Haemophilus influenzae Typ b und Varizellen.

To evaluate the effectiveness of vaccination programmes, it is not only important to know the effectiveness of the specific vaccine itself but also to have knowledge about the epidemiology of the corresponding vaccine-preventable disease. Only a high acceptance of a vaccination programme by the population will show an effect at the population level (herd immunity). At the moment, data routinely collected in Germany are not sufficient to evaluate the effectiveness of vaccination programmes. Hence, additional surveillance programmes have to be initialised. The frequency of the vaccine-preventable disease in the population under surveillance determines mainly the design of the surveillance. In this article we describe the different requirements for surveillance programmes for common as well as for rare vaccine-preventable diseases. An example for the latter will be the ESPED study on the effectiveness of hexavalent vaccines against Haemophilus influenzae type b, an example for the first will be the varicella sentinel of the Working Group on Measles and Varicella. Both surveillance programmes for evaluation of the effectiveness of the respective vaccination programme are financed only partly by the public funds. We discuss the possible limitations of a funding from other sources.

The impact of vaccines on pneumonia: key lessons from Haemophilus influenzae type b conjugate vaccines.

This article explores key lessons learned from vaccination with Haemophilus influenzae type b (Hib) conjugate vaccine and how these lessons may provide insight into the impact of emergent pneumococcal vaccines against pneumonia. The worldwide value of Hib vaccination for reducing Hib disease burden and carriage is reviewed. Using comparisons of data for pneumococcus versus Hib, the article concludes that epidemiological and biological differences between these pathogens will complicate efforts to use results from the Hib vaccine experience to predict outcomes following pneumococcal conjugate vaccine introduction.

Acute bacterial meningitis among children < 5 years of age in Oman: a retrospective study during 2000-2005.

BACKGROUND: During the last two decades, significant changes have taken place in the epidemiology of meningitis, especially due to the global availability and expanding use of Hib vaccines. The introduction of conjugate Hib vaccine in the Expanded Programme of Immunization (EPI) in Oman and recent availability of meningococcal vaccines against serogroups A and C plus the introduction of pneumococcal heptavalent conjugate vaccine are expected to influence the epidemiology of the disease in the country. We conducted this periodic review of acute bacterial meningitis in children younger than five years of age in Oman from January 2000 to December 2005 to reflect changes in the epidemiological pattern of these pathogens. METHODOLOGY: Retrospective analysis of all cases of acute bacterial meningitis in children younger than five years of age reported to the Department of Communicable Diseases Surveillance and Control, Ministry of Health, Oman. RESULTS: There were 344 cases of meningitis due to suspected bacterial etiologies reported in children younger than 5 years of age. Although Haemophilus influenzae 76 (22%) was the most common pathogen identified during the study period, the incidence of meningitis due to Haemophilus influenzae has been dramatically reduced since the introduction of conjugate Hib vaccination in Oman in October 2001. Streptococcus pneumoniae 53 (15%) and Neisseria meningitidis 37 (11%) were the next two leading agents of meningitis respectively. In one hundred seventy four (52%) cases of presumptive bacterial meningitis, the etiologic organism remains unidentified. The peak occurrence of meningitis was in young children younger than one year old. The total male to female ratio was 1.4:1 and the case fatality rate (7 deaths) was 2%. CONCLUSIONS: With the introduction of Hib vaccine in Oman in October 2001, the absolute number of cases due to Haemophilus influenzae significantly declined over the years. The incidence of meningitis due to other pathogens such as S. pneumoniae and N. meningitidis remains steady. There is significant need to improve laboratory methods of bacterial detection and identification, which will help to formulate better antibiotic policies and strengthen control measures through newly introduced vaccines in Oman.

Pneumococcal disease in Sweden: experiences and current situation.

During the last decade, the incidence of invasive pneumococcal disease in Sweden has risen, seemingly due chiefly to an increasing incidence of pneumococcal bacteremia among the elderly. On the other hand, mortality due to invasive disease in Sweden is low, approximately 10% for bacteremic pneumococcal pneumonia. Beta-lactam resistance in Streptococcus pneumoniae is still a relatively minor problem in Sweden, with only 3%-4% of strains demonstrating decreased susceptibility to penicillin. However, local outbreaks of pneumococcal disease with up to 10% resistance have occurred among children, especially in southern Sweden.

Meningococcal serogroup C conjugate vaccine is immunogenic in infancy and primes for memory.

The safety, immunogenicity, and immunologic priming of 2 dosages (2 microgram or 10 microgram) of a meningococcal C oligosaccharide-CRM197 conjugate vaccine was evaluated in 114 infants vaccinated at ages 2, 3, and 4 months. Antibody persistence and response to boosting with 10 microgram of meningococcal C polysaccharide were assessed. The meningococcal conjugate vaccine produced fewer local reactions than concurrent routine immunizations. Total serogroup C-specific immunoglobulin geometric mean concentration (GMC) increased from 0.3 microgram/mL before vaccination to 13.1 microgram/mL at age 5 months. Serum bactericidal antibody (SBA) geometric mean titers (GMTs) rose from <1:4 to 1:1057 at 5 months and fell by 14 months to 1:19. Following boosting, anti-C-specific immunoglobulin GMC rose to 15.9 microgram/mL and SBA GMT to 1:495. Antibody responses in the 10-microgram dose cohort were significantly higher at 5 months (P<.01) than in the 2-microgram dose cohort but were lower after polysaccharide boosting (P=.02). This meningococcal conjugate vaccine was well tolerated and immunogenic and induced immunologic memory in infants.

Discrimination of virulent and avirulent Streptococcus suis capsular type 2 isolates from different geographical origins.

In an effort to relate the protein profile to virulence, proteins from the cellular fractions and from culture supernatants of Streptococcus suis capsular type 2 strains from different geographical origins were compared by using Western blots (immunoblots). The protein profiles of the cellular fractions were similar for the majority of virulent and avirulent isolates studied, with the exception of three virulent Canadian strains for which a 135-kDa protein was not detected. Examination of the culture supernatants revealed the presence of a 135-kDa protein in all strains except the same three virulent Canadian isolates. In addition, a 110-kDa protein was present in 14 of 16 virulent strains and not in avirulent isolates. When injected into mice, the 110-kDa protein induced an immunoglobulin G response and protected against infection with homologous and heterologous virulent strains. Four strains (1330, 0891, TD10, and R75/S2) that were avirulent in the mouse model of infection and four other strains (1591, 999, JL590, and AAH4) that were virulent in the mouse model were injected into pigs. All virulent strains reproduced the disease, and all avirulent strains failed to reproduce the disease (with the exception of transient lameness in one case and fever in another case). The 110-kDa protein therefore appears to be a reliable virulence marker and a good candidate for a subunit vaccine.