Serotyping of Neisseria meningitides in conscripts with meningitis admitted to five military hospital in Tehran between September 2004 and September 2006

Meningococcal meningitis is one of the most feared disorders with high rate morbidity and mortality. There is no exact information of meningococcal meningitis incidence in military personnel. Obligate vaccination of the military with meningococcal vaccine is a strategy with the potency to provide active protection of the conscripts before being dispatched to training centers. Although sporadic cases of meningitis in conscripts occurred The aim of this study was serotyping of the bacterium; Neisseria meningitides isolated from patients with meningitis which admited to five military Hospitals. In this cross- sectional study for determination of meningococcal meningitis serotypes in conscripts submit to five military hospitals the investigation was designed and carried out from September 2003 to September 2006. In this period, 12 cerebrospinal fluids of conscripts with clinical signs and symptoms of meningitis were collected, and the laboratory tests were done. In this study enriched Thayer Martin medium and standard bacteriological methods were used. The sample without bacterial cells or PMNs were centrifuged [10000 xg for 5 min], The precipitate was cultured and direct smear was performed.Isolated bacterial strains was recognized by biochemical tests, and Neisseria meningitides strains were serotyped by specific antiserum. During the study, 12 cases of meningitis in conscripts were seen. Neisseria meningitides was isolated only from 6 patients. Serotyping analysis revealed that 5 strains belong to Serotype C and 1 strain was to serotype B. Neisseria sica was isolated from one patient. In three patients there was no bacteriological evidence. In two patients, consumption of antibiotic before lumbar puncture results to no bacterial growth, but direct smear showed gram negative diplococci. In one patient recurrent meningococcal infection has occurred. Complement components analysis revealed deficiency in C3, C4 and CH50 [the rate was below 80 mg per deciliter]. The results of this study showed that, Neisseria meningitides was isolated from six patients which are all conscripts. It is necessary to find the reasons that why vaccinated conscripts infected by Neisseria meningitides serotype C. Further analysis showed that, five patients had complement deficiency and further research is necessary. However, 6 Neisseria meningitides strains were isolated from meningococcal vaccinated conscripts around the country [Tehran, Shiraz, Yazd and Oslavieh] in the period of study. Based on the findings of this study, effectiveness of the vaccine was desirable and the disease had been controlled in this population group. Because of complements deficiency in patients with meningococcal meningitis, other preventing methods for eradication of disease are necessary