Epidemiology of pneumonia in the pre-pneumococcal conjugate vaccine era in children 2-59 months of age, in Ulaanbaatar, Mongolia, 2015-2016

Abstract

BackgroundRespiratory diseases, including pneumonia, are the second largest cause of under-five mortality in Mongolia and the most common cause of childhood hospitalization. However information regarding the contribution of Streptococcus pneumoniae to pneumonia causation in Mongolia is limited. We aimed to describe the epidemiology of hospitalized children aged 2–59 months with pneumonia, enrolled into a surveillance program in the period prior to pneumococcal conjugate vaccine (PCV) introduction, in Mongolia.MethodsAn expanded pneumonia surveillance program enrolled children, who met the surveillance case definition, at participating hospitals, between April 2015 and May 2016. Cumulative incidence rates were calculated by district for all pneumonia endpoints using district specific denominators from the Mongolian Health Department census for 2016. Socio-economic and disease-associated factors were compared between districts using chi-squared tests.ResultsA total of 4318 eligible children with pneumonia were enrolled over the 14 month period. Overall the incidence for all-cause pneumonia in children aged 12–59 months was 31.8 per 1000 population; children aged 2–11 months had an almost four-fold higher incidence than children aged 12–59 months.Differences were found between districts with regards to housing type, fuel used for cooking, hospital admission practices and the proportions of severe and primary endpoint pneumonia.DiscussionThis study shows a high burden of pneumonia in children aged 2–59 months in Mongolia prior to PCV introduction. Rates differed somewhat by district and age group and were influenced by a number of socio-economic factors. It will be important to consider these differences and risk factors when assessing the impact of PCV introduction.

Effect of Pneumococcal Conjugate Vaccine on Pneumonia Incidence Rates among Children 2–59 Months of Age, Mongolia, 2015–2021

“…Starting in 2016, PCV13 was introduced into the routine infant immunization program of Mongolia, phased by district, in the context of an expanded pneumonia surveillance program to monitor vaccine effect ( 13 ). Baseline data estimated that clinical pneumonia incidence among children 2–59 months was 31.8 cases/1,000 population and for severe pneumonia was 19.2 cases/1,000 population ( 14 ). To ensure sustainability of the program in Mongolia, PCV13 was introduced in stages because the country was transitioning from Gavi funding ( 15 ).…”

Distribution of TNF-α -308 G/A polymorphism among pediatric patients with pneumonia in Ulaanbaatar

“…The age of pediatric patients ranged from 1 month to 15 years (median 15 months, mode 10 months) and they were all unrelated. Subject blood came from 101 patients who were diagnosed with acute lower respiratory infections, including pneumonia [12]. Genomic DNA was isolated from blood by a standard phenol-chloroform method.…”

Epidemiology of pneumonia in hospitalized adults ≥18 years old in four districts of Ulaanbaatar, Mongolia, 2015–2019

“… 17 An expanded pneumonia surveillance program was established in the capital city of Ulaanbaatar (∼1·5 million population) to better understand the burden of all-cause pneumonia in children 2–59 months old, finding high rates of pneumonia. 18 A subsequent adult surveillance program was established in 2019, as part of a larger study aiming to determine the indirect effect of childhood PCV13 on community-acquired pneumonia in adults. 19 To quantify the burden of adult community-acquired pneumonia in Ulaanbaatar, hospital-based surveillance was initiated in four districts of the city.…”