Pneumonia Among Children Less Than 5 Years in Cameroon following introduction of a 13-valent Pneumococcal Conjugate Vaccine

Abstract

Degree Project Thesis, Programme in Medicine. TITLE: Pneumonia Among Children Less Than 5 Years in Cameroon following introduction of a 13-valent Pneumococcal Conjugate Vaccine Master thesis in Medicine. Abstract Master thesis, Sahlgrenska academy, pneumonia among children less <5 Years in Cameroon following introduction of a 13-valent pneumococcal conjugate vaccine, Björn Wallén, 2014, Gothenburg, Sweden. Introduction Pneumonia is the largest killer in children under 5 years worldwide. In Cameroon it accounts for 18% of deaths in children < 5. Immunization is the most effective way to prevent pneumonia. Several studies show good effect with Pneumococcal Conjugate Vaccines (PCV). In Cameroon the PCV-13 vaccine was launched 2013-07. No evaluation has been done in Cameroon about all-cause pneumonia incidence after introduction of the vaccine. Aim The aim of the study was to see if the number of pneumonia cases decreased after launching the PCV13-programme? Are there changes in severity and mortality after immunization? Have the rates of invasive pneumococcal disease (IPD) declined? Method It was a retrospective study conducted at Buea and Limbe Regional Hospital during two months in autumn 2013. Cases were collected from 2009-06 to 2013-10. Inclusion criteria were having a pneumonia diagnosis and being 1 month - 5 years old. The study time was divided into one period before introduction of the PCV-13 vaccine program, and one period after the introduction. Results No change in number of cases, no positive effect on proportion of severe cases, and no decline in mortality were observed after vaccine introduction. More boys than girls were affected by pneumonia. There was a seasonal variation with negative correlation between rainfall and number of pneumonia cases. Discussion Reasons for the negative results remain unclear. Herd effects also take time to develop. Supposedly, Cameroon has a high percentage of non-vaccine serotypes? Do other factors, such as rainfall contribute to the result? Conclusions It is too early to conclude no vaccine effect for children in the region. More studies are needed. Finally, knowledge about serotype distribution among disease-causing pneumococci in the area is needed.