Acute respiratory infections among children in the Democratic Republic of Congo - nasopharyngeal pathogens, antibiotic resistance and vaccination

Sammanfattning: ABSTRACT Acute Lower Respiratory Infections (ALRI) remain a leading cause of morbidity and mortality among children in the Democratic Republic of the Congo (DR Congo). The pneumococcal conjugate vaccine PCV13 was introduced in the in the South-Kivu region in 2013. The aim of this thesis was to investigate the epidemiologic of ALRI, nasopharyngeal bacteria and viruses, pneumococcal serotypes and antibiotic resistance among children after the PCV13 introduction. In paper I 2,007 children hospitalised with ALRI during 2010-2015 were retrospectively reviewed and the case fatality rate among these children was 5%. The number of severe ALRI cases per year decreased after the vaccine introduction, while the total number of ALRI cases per year remained unchanged. Five percent of the cases were treated with non-recommended, broad-spectrum antibiotics. In paper II, 794 children from the general population attending health centres during 2014 and 2015 were sampled from nasopharynx. The prevalence of pneumococci was higher among children who had not received PCV13, and among those who lived in a house with an open fire used for cooking and with open access to the living areas. Multi-resistance among the isolated pneumococci was high (43%), and almost all isolates were resistant to trimethoprim-sulfamethoxazole. Multiplex PCR performed directly on 375 of the nasopharyngeal samples (paper III), showed a high load of bacteria and viruses although respiratory syncytial virus (RSV) was rare. Approximately 50% of the pneumococci were identified to a serotype not included in PCV13. Paper IV included 116 hospitalised children with radiologically confirmed pneumonia. High levels of any virus or any bacteria in nasopharynx were associated with severe pneumonia, and having a congenital disease as an underling condition was associated with fatal outcome. Conclusions: There were a high prevalence of bacteria and viruses in the upper respiratory tract of both healthy and sick Congolese children, and the level of antibiotic resistance in carried pneumococci was high. There is a need to modify current treatment guidelines in DR Congo and to reduce the prevalence of pathogens by interventions, including improved living conditions.