High bacterial and viral load in the upper respiratory tract of children in the Democratic Republic of the Congo

Abstract

Background Respiratory pathogens including Streptococcus pneumoniae and Haemophilus influenzae , are implicated in the pathogenicity of acute lower respiratory infection (ALRI). These are also commonly found in both healthy and sick children. In this study, we describe the first data on the most frequent bacteria and viruses detected in the nasopharynx of children from the general population in the Eastern DR Congo. Methods From January 2014 to June 2015, nasopharyngeal samples from 375 children aged from 2 to 60 months attending health centres for immunisation or growth monitoring were included in the study. Multiplex real-time PCR assays were used for detection of 15 different viruses and 5 bacterial species and for determination of pneumococcal serotypes/serogroups in the nasopharyngeal secretions. Results High levels of S. pneumonia e were detected in 77% of cases, and H . influenzae in 51%. Rhinovirus and enterovirus were the most commonly found viruses, while respiratory syncytial virus (RSV) was rare (1%). Co-occurrence of both bacteria and viruses at high levels was detected in 33% of the children. The pneumococcal load was higher in those children who lived in a dwelling with an indoor kitchen area with an open fire, i.e. a kitchen with an open fire for cooking located inside the dwelling with the resultant smoke passing to the living room and/or bedrooms; this was also higher in children from rural areas as compared to children from urban areas or children not living in a dwelling with an indoor kitchen area with an open fire/not living in this type of dwelling. Immunization with 2–3 doses of PCV13 was associated with lower rates of pneumococcal detection. Half of the identified serotypes were non-PCV13 serotypes. The most common non-PCV13 serotypes/serogroups were 15BC, 10A, and 12F, while 5, 6, and 19F were the most prevalent PCV13 serotypes/serogroups. Conclusions The burden of respiratory pathogens including S. pneumonia e in Congolese children was high but relatively few children had RSV. Non-PCV13 serotypes/serogroups became predominant soon after PCV13 was introduced in DR Congo.

Bacteria and viruses in the upper respiratory tract of Congolese children with radiologically confirmed pneumonia

“…Nucleic acids were extracted from 200 µL of the nasopharyngeal sample as described earlier [ 21 ]. Eluted nucleic acids were stored at − 20 °C until further analysis.…”

Bacterial and viral etiology of acute respiratory infection among the Forcibly Displaced Myanmar Nationals (FDMNs) in fragile settings in Cox’s Bazar- a prospective case-control study

“…Moreover, ≤5 years group was likely to be positive for RSV, HMPV, and IFV-B in a higher percentage than the other age groups. Prior investigations of bacterial and viral loads in the upper respiratory tracts of young Congolese children suggested the importance of the load pathogens [ 63 ] and to our best knowledge there is no study conducted among the FDMNs focusing on the viral and bacterial load in ARI cases and healthy individuals. Cycle threshold (Ct) values are continuous, semi-quantitative assessments of viral load used in qRT-PCR [ 63 , 64 ].…”

“…Prior investigations of bacterial and viral loads in the upper respiratory tracts of young Congolese children suggested the importance of the load pathogens [ 63 ] and to our best knowledge there is no study conducted among the FDMNs focusing on the viral and bacterial load in ARI cases and healthy individuals. Cycle threshold (Ct) values are continuous, semi-quantitative assessments of viral load used in qRT-PCR [ 63 , 64 ]. However, our study evaluated the bacterial and viral prevalence according to Ct value detected by RT-PCR where the detection number was higher for all the bacteria considering Ct≤30 in the case group than the control group.…”