Progress towards meningitis prevention in the conjugate vaccines era

Abstract

Acute bacterial meningitis is an important cause of morbidity and mortality among children less than five years old, Haemophilus influenzae, Streptococcus pneumoniae and Neisseria meningitidis being the most important agents of bacterial meningitis in developing countries. The development of the conjugate vaccines in the beginning of the 90's, especially type b H. influenzae (Hib), and more recently the heptavalent pneumococcal and the serogroup C meningococcal vaccines, have contributed directly to changes in the epidemiological profile of these invasive diseases (direct effect) and of their carriage status (indirect effect). We review the impact of the Hib conjugate vaccine in Latin American countries, where this vaccine has been implemented, and the potential of pneumococcal and meningococcal conjugate vaccines for the reduction of meningitis worldwide. We also address constraints for the development and delivery of these vaccines and review new candidate state-of-the-art vaccines. The greatest challenge, undoubtedly, is to implement these vaccines worldwide, especially in the developing regions.

<i>Haemophilus influenzae</i> type b vaccination: long-term protection

“…Da mesma forma, a vacinação produziu grande impacto nos países em desenvolvimento, com queda expressiva especialmente das meningites por Hib 7,31,32 . Em diversas regiões industrializadas, a existência de sistemas de vigilância eficientes viabilizou uma linha de base epidemiológica, facilitando o monitoramento da meningite por Hib em condições programáti-cas.…”

Vacinação contra Haemophilus influenzae tipo b: proteção a longo prazo

“…[26][27][28][29][30] Similarly, the vaccination produced great impact in developing countries, with significant decline especially of meningitis due to Hib. 7,31,32 In several industrialized regions, the availability of efficient surveillance systems with reliable epidemiological baseline made it feasible to monitor Hib meningitis under programmatic conditions. Thus, the majority of studies about the effectiveness of vaccination come from the USA and Europe.…”

“…Surveillance data in these countries have detected a decline higher than 80% in Hib meningitis soon after the vaccine was introduced. 14,26,29,33 In Latin America, the vaccination impact on meningitis was assessed in Cuba, Colombia, Uruguay, Chile and Brazil, 31 showing a 40 to 95% decline in the incidence rates of Hib meningitis in the post-vaccination period, compared with the pre-vaccination period, as shown in Table 1 [1990][1991][1992][1993]. 32 In Asia, in the probe trial conducted in Lombok, vaccination was introduced in the health services in a randomized fashion, with DPT vaccination as a comparison group, and the results showed a considerable decline in the incidence of meningitis preventable by vaccination against Hib, which ranged from 67 to 158 per 100,000 children-year.…”

Determination of Bacterial Meningitis Agents by Culture and PCR in Patients Diagnosed with Meningitis

“…N. meningitidis, S. pneumoniae, H. influenzae tip b ve Listeria monocytogenes'in etken olduğu toplum kökenli akut bakteriyel menenjitler ise daha enderdir (7) . Ülkemizde 50 yaş üzeri toplum kaynaklı ABM hastalarında yapılan bir çalışmada, S. pneumoniae'nin birinci sırada, L. monocytogenes'in ise ikinci sırada etken olarak saptandığı belirtilmiştir (8) .…”