The etiological structure of cases of acute primary meningitis/encephalitis hospitalized in shymkent city infectious diseases hospital in 2017

Introduction: Encephalitis and meningitis are severe diseases that damage central nervous system. They are characterized by high rates of morbidity and mortality. According to surveillance data from different regions of Kazakhstan, etiology is not deciphered in 30-70% of cases. In Kazakhstan, bacterial meningitis, including meningococcal meningitis, is monitored using a bacteriological confirmation method.Tick-borne encephalitis is monitored using PCR confirmation in regional laboratories. Viral meningitis is not deciphered at the level of the infectious hospitals.

Method: From February 2017 to January 2018 we have established surveillance of cases of meningitis/ encephalitis, corresponding to the standard case definition, hospitalized in Shymkent City Infectious Diseases Hospital(SCIDH). Most patients with meningitis/encephalitis in the region came to this hospital. When the patients were hospitalized in other hospitals in the region, theirCSF samples were delivered to the SCIDH laboratory. Patients who agreed to participate in the study filled out the questionnaire and submitted CSF samples. The samples were investigated in the bacteriological and PCR laboratories of SCIDH. In the CSF,cytosis was counted, the percentages of neutrophils, lymphocytes, protein, and glucose were determined. In addition to the routine testing, CSF samples were tested in PCRusing the AmpliSens test systems for: Neisseria meningitidis, Haemophilus influenza, Streptococcus pneumoniae, Enteroviruses, Virus Herpes Simplex 1,2, Virus Zoster, Listeria monocytogenes. 23 CSF samples with PCR-confirmed enteroviral meningitis were randomly selected and were tested in the Republican Virology Laboratory on the cell culture of RD Hep-2 sensitive to Echo Coxsackie viruses to determine the type of virus. Data was collected and processed in EpiInfo7.

Results:A total of 557 cases were recorded that met the standard definition of a case of meningitis or encephalitis. In 8 of this cases (1.1%, 95% CI 0.3-3.4%) the CSF sample was not taken. Of the remaining 549 cases, 492 (89.6%, 95% CI: 81.6% - 99.3%) were caused by viruses, 33 (6.0%, 95% CI: 2.8% -14.6%) by bacteria and 8 (1.4%, 95% CI : 0.2% - 6.7%) by both (mixed etiology). 12 cases (2.2%, 95% CI 1.2% -3.9%) had no etiology and four were clinically registered for rabies (0.7%, 95% CI: 0.2% -2.0%). Enteroviruses accounted for 82.3% (n = 405) of cases with a viral etiology. Among the cases with bacterial and mixed etiology, N. meningitidis was determined in 51.2% (n = 21). Disease incidencerate per 100 thousand population of enterovirus meningitis was 14.5,and for meningococcal meningitis – 0.7. Those indicators were 2.8 and 1.7 times higher than those officially recorded using routine diagnostic methods. The serotype Echo13 was determined in 14 (60.9%) of 23 samples of CSF of the enteroviral meningitis. Antibiotics were used for treatment in 97% (n = 477) cases with a viral etiology.

Conclusions: 89.6% (n = 492) of hospitalized and examined cases of meningitis / encephalitis had a viral etiology, among which enteroviruses prevailed - 82.3% (n = 405). The use of the PCR method for routine diagnosis of meningitis / encephalitis will allow to have accurate data on morbidity, timely detection of outbreaks and avoid unreasonable use of antibiotics for treatment in case of meningitis / encephalitis with a viral etiology of the disease.

Year: 2018
City: Shymkent
Category: Medicine