Evaluation of a phased pneumococcal conjugate vaccine introduction in Mongolia using enhanced pneumonia surveillance and community carriage surveys: a study protocol for a prospective observational study and lessons learned.

BACKGROUND: Streptococcus pneumoniae causes substantial morbidity and mortality among children. The introduction of pneumococcal conjugate vaccines (PCV) has the potential to dramatically reduce disease burden. As with any vaccine, it is important to evaluate PCV impact, to help guide decision-making and resource-allocation. Measuring PCV impact can be complex, particularly to measure impact on one of the most common and significant diseases caused by the pneumococcus, namely pneumonia. Here we outline the protocol developed to evaluate the impact of 13-valent PCV (PCV13) on childhood pneumonia in Mongolia, and a number of lessons learned in implementing the evaluation that may be helpful to other countries seeking to undertake pneumonia surveillance. METHODS: From 2016 PCV13 was introduced in a phased manner into the routine immunisation programme with some catch-up by the Government of Mongolia. We designed an evaluation to measure vaccine impact in children aged 2-59 months with hospitalised radiological pneumonia as a primary outcome, with secondary objectives to measure impact on clinically-defined pneumonia, nasopharyngeal carriage of S. pneumoniae among pneumonia patients and in the community, and severe respiratory infection associated with RSV and/or influenza. We enhanced an existing hospital-based pneumonia surveillance system by incorporating additional study components (nasopharyngeal swabbing using standard methods, C-reactive protein, risk factor assessment) and strengthening clinical practices, such as radiology as well as monitoring and training. We conducted cross-sectional community carriage surveys to provide data on impact on carriage among healthy children. DISCUSSION: Establishing a robust surveillance system is an important component of monitoring the impact of PCV within a country. The enhanced surveillance system in Mongolia will facilitate assessment of PCV13 impact on pneumonia, with radiological confirmed disease as the primary outcome. Key lessons arising from this evaluation have included the importance of establishing a core group of in-country staff to be responsible for surveillance activities and to work closely with this team; to be aware of external factors that could potentially influence disease burden estimates; to be flexible in data collection processes to respond to changing circumstances and lastly to ensure a consistent application of the pneumonia surveillance case definition throughout the study period.

Coverage of hepatitis b vaccination of children in age of 4-6 year old in Mongolia / Монголын Анагаах Ухаан

Hepatitis B virus (HBV) infection is highly prevalent in Mongolia and its sequelae including liver cirrhosis and liver cancer are crucial public health problems in Mongolia. HBV infection is preventable through the vaccination. Universal hepatitis B vaccination has been introduced in 1991 after the 3 years field trial, making our country the 20th country with obligatory immunization against hepaitis B of all eligible population. In addition a penta vaccine (DTP+HipB+HBV) was introduced since 2005 in urban and rural areas. Although statistical information is available regarding the coverage of these hepatitis B vaccines, no study has been conducted on the coverage of hepatitis B vaccination based on the immunization cards of children that is important to reveal the current situation in the country. Objective: To study the coverage of Hepatitis B vaccination among children born after more than 10 years since its implementation in Mongolia. Materials and Methods: Nationwide cross-sectional survey was conducted during 2009-2010. A total of 5894 children was enrolled in this survey selected from Ulaanbaatar, Darkhan, Erdenet as well as 11 provinces and 50 soums. Iimmunization data of each child was abstracted from the health records or immunization cards at the actual Health Center, Local or Family hospital. The hepatitis B vaccination coverage was assessed by measuring HepB-birth dose, second and third dose. The vaccination status of the child was determined by counting the immunizations that were recorded by health/immunization registry or card. Data analyses was performed using SPSS 17.0 software. Results: A total of 5894 children were participated in the survey out of 6380 selected children (response rate 92.38%). Vaccination cards or registrations were available for 4944 (83.9%) children that was higher in rural areas compared to cities (Ulaanbaatar, Darkhan, Erdenet 75.5%, province centers 87.3%, soums 90.5%, p<0.001). In addition, the proportion of children with vaccination card was significantly decreased by age from age of 4 years to 6 years (p<0.0001). Vaccination coverage rate of those who received at least one dose of hepatitis B or penta vaccine was 98.6% [(95% confidence interval: 98.36-98.98) and 81.9% of them were fully vaccinated whereas 16.7% were partially vaccinated. Vaccination rate was 97.8% in Ulaanbaatar, Darkhan and Erdenet cities, 99.2% in province centers and 99.1% in rural soums. According to the results of 11 provinces and, coverage rate in provinces was 98.3%-100% where Umnugovi and Khentii provinces had highest rate (100%) and Selenge and Zavkhan provinces had lower rates (98.7%). Around 95% of the children were received the first dose of hepatitis B vaccine, of whom 3413 (76.5%) received within 24 hours while 1274 (27.8%) had received later than the schedule. Among study population 13.1% were vaccinated with penta vaccine that was introduced in 1995 in Mongolia. Conclusion: 1. Vaccination cards were available for 4944 (83.9%) children that was significantly higher in rural areas compared to cities. 2. Vaccination coverage rate of those who received at least one dose of hepatitis B or penta vaccine was 98.6% [(95% confidence interval: 98.36-98.98) and 81.9% of them were fully vaccinated whereas 16.7% were partially vaccinated. 3. Around 95% of the children were received the first dose of hepatitis B vaccine, of whom 3413 (72.8%) received within 24 hours while 1274 (27.8%) had received later than the schedule.

The attack rates of the pandemic influenza infection, Ulaanbaatar, November 2009 / Монголын Анагаах Ухаан

BACKGROUND: In Ulaanbaatar, the first case of the pandemic influenza infection has been reported on 12 October 2010.By November 9, a total of 929 cases laboratory-confirmed had been reported to National Center for CommunicableDiseases (NCCD). Of these cases reported, 9 people died.METHODS: The objectives of the study were to describe patients who admitted and hospitalized at NCCD and to determineoverall attack rates among health workers, secondary attack rates among students of colleges and universities. Datawas analyzed using Epi-Info2000.RESULTS: Among 929 of laboratory-confirmed cases, 50.3% (95% CI 43.0-57.5) were males aged 23 (±14.9) in averagewith youngest – 7 months, oldest – 76 years old. Data analysis by districts among the hospitalized patients, showed32.8% (139) of total cases in Bayanzurkh district including the first case of the pandemic influenza infection. The majorityof patients who admitted and hospitalized to NCCD mostly experienced fever (288, 68.1%), dry cough (251, 59.3%),headache (203, 48.0%), sore throat (175, 41.6%). With 1020 physicians and health workers in total, 41.4% (422) ofthem work at NCCD, 35.4% (361) – at MCHRC. 11.1% of health workers out of total become ill with pandemic H1N12009 (overall attack rate 11.1%) with the most common symptom, 380C and higher fever (100.0%, 113), sore throat(83.2%, 94), cough (76.1%, 86) and runny nose (59.3%, 67). The higher attack rates of health workers by occupationwere doctor (18.0%) and auxiliary (13%). The secondary attack rates among university students for influenza-likeillness(ILI) were 12.9%. These secondary attack rates were higher among students of art’s college as compared withother universities (52.4%). For students, the main clinical symptoms were fever + sore throat (75.0%, 18), fever+ cough(70.8%, 17).DISCUSSION: In China, as of 27 September, 2009, from reported total 19981 cases infected with pandemic influenza,61.0% were males, mean age was 17, mainly affected with 83% school students that consistent with our study result.The similar results on clinical symptoms were obtained in Russia. Out of 130 patients, 28.6% had 380Ñ and higherfever, for 54.3% the body temperature reached 38.1-390Ñ where as 17.1% - higher 390Ñ and 96% had cough, 89%had muscle ache, 65% had headache, 14% had diarrhea.