Epidemiological characteristics and climatic variability of viral meningitis in Kazakhstan, 2014-2019

Background

The comprehensive epidemiology and impact of climate on viral meningitis (VM) in Kazakhstan are unknown. We aimed to study the incidence, in-hospital mortality and influence of climatic indicators on VM from 2014 to 2019.

Methods

Nationwide electronic healthcare records were used to explore this study. ICD-10 codes of VM, demographics, and hospital outcomes were evaluated using descriptive statistics and survival analysis.

Results

During the 2014-2019 period, 10,251 patients with VM were admitted to the hospital. 51.35% of them were children, 57.85% were males, and 85.9% were from the urban population. Enteroviral meningitis was the main cause of VM in children. The incidence rate was 13 and 18 cases per 100,000 population in 2014 and 2019, respectively. Case fatality rate was higher in 2015 (2.3%) and 2017 (2.0%). The regression model showed 1°C increment in the daily average temperature might be associated with a 1.05-fold (95% CI 1.047-1.051) increase in the daily rate of VM cases, 1hPa increment in the average air pressure and 1% increment in the daily average humidity might contribute to a decrease in the daily rate of VM cases with IRRs of 0.997 (95% CI 0.995-0.998) and 0.982 (95% CI 0.981-0.983), respectively. In-hospital mortality was 35% higher in males compared to females. Patients residing in rural locations had a 2-fold higher risk of in-hospital death, compared to city residents. Elderly patients had a 14-fold higher risk of in-hospital mortality, compared to younger patients.

Conclusion

This is the first study in Kazakhstan investigating the epidemiology and impact of climate on VM using nationwide healthcare data. There was a tendency to decrease the incidence with outbreaks every 5 years, and mortality rates were higher for Russians and other ethnicities compared to Kazakhs, for males compared to females, for elder patients compared to younger patients, and for patients living in rural areas compared to city residents. The climatic parameters and the days of delay indicated a moderate interaction with the VM cases.

Incidence and mortality rates of strokes in Kazakhstan in 2014-2019

There is a lack of information on the epidemiology of acute ischemic stroke (AIS), intracerebral hemorrhage (ICH), and subarachnoid hemorrhage (SAH) in developing countries. This research presents incidence and mortality rates of stroke patients based on hospital admission and discharge status in one of the Central Asian countries by analysis of large-scale healthcare data. The registry data of 177,947 patients admitted to the hospital with the diagnosis of stroke between 2014 and 2019 were extracted from the National Electronic Health System of Kazakhstan. We provide descriptive statistics and analyze the association of socio-demographic and medical characteristics such as comorbidities and surgical treatments. Among all stroke patients, the incidence rate based on hospital admission of AIS was significantly higher compared to SAH and ICH patients. In 5 year follow-up period, AIS patients had a better outcome than SAH and ICH patients (64.7, 63.1 and 57.3% respectively). The hazard ratio (HR) after the trepanation and decompression surgery was 2.3 and 1.48 for AIS and SAH patients; however, it was protective for ICH (HR = 0.87). The investigation evaluated an increase in the all-cause mortality rates based on the discharge status of stroke patients, while the incidence rate decreased over time.