BackgroundIt has been demonstrated that infection with human parvovirus B19 (B19V) is associated with rash–fever illnesses. The present study aimed to investigate B19V as an aetiological agent of rash–fever syndromes in Congolese children confirmed as measles and rubella IgM-negative. An ELISA IgM test and PCR were performed to screen for B19V.MethodsA total of 177 archived serum samples were randomly selected from the measles biobank of the National Institute for Biomedical Research (INRB). Samples were investigated for anti-B19V IgM and B19V DNA. These samples originated from children <5 years of age with measles-like rashes, previously confirmed as negative for both measles and rubella IgM.ResultsOut of 177 serum samples tested by ELISA and 168 tested by PCR, 109 were positive for B19V IgM antibodies (61.6%) and 87 (51.8%) were positive for B19V DNA. Positive samples in both assays were from all provinces of DRC.ConclusionsB19V plays a role in rash–fever illnesses in children under 5 years of age suspected of having measles or rubella infections in DRC. As an aetiological cause of rash and fever syndromes, the present study demonstrates that B19V should also be considered during the laboratory investigation of rash–fever illnesses in DRC, particularly in the paediatric population. There is a need to conduct further studies in order to gain a better understanding of the spatiotemporal pattern of B19V and to define the genotype(s) of B19V circulating in DRC.

Background The control of Ebola virus disease (EVD) outbreaks relies on rapid diagnosis and prompt action, a daunting task in limited-resource contexts. This study develops prediction scores that can help healthcare workers improve their decision-making at the triage-point of EVD suspect-cases during EVD outbreaks. Methods We computed accuracy measurements of EVD predictors to assess their diagnosing ability compared with the reference standard GeneXpert® results, during the eastern DRC EVD outbreak. We developed predictive scores using the Spiegelhalter-Knill-Jones approach and constructed a clinical prediction score (CPS) and an extended clinical prediction score (ECPS). We plotted the receiver operating characteristic curves (ROCs), estimated the area under the ROC (AUROC) to assess the performance of scores, and computed net benefits (NB) to assess the clinical utility (decision-making ability) of the scores at a given cut-off. We performed decision curve analysis (DCA) to compare, at a range of threshold probabilities, prediction scores’ decision-making ability and to quantify the number of unnecessary isolation. Results The analysis was done on data from 10432 subjects, including 651 EVD cases. The EVD prevalence was 6.2% in the whole dataset, 14.8% in the subgroup of suspects who fitted the WHO Ebola case definition, and 3.2% for the set of suspects who did not fit this case definition. The WHO clinical definition yielded 61.6% sensitivity and 76.4% specificity. Fatigue, difficulty in swallowing, red eyes, gingival bleeding, hematemesis, confusion, hemoptysis, and a history of contact with an EVD case were predictors of EVD. The AUROC for ECPS was 0.88 (95%CI: 0.86–0.89), significantly greater than this for CPS, 0.71 (95%CI: 0.69–0.73) (p < 0.0001). At -1 point of score, the CPS yielded a sensitivity of 85.4% and specificity of 42.3%, and the ECPS yielded sensitivity of 78.8% and specificity of 81.4%. The diagnostic performance of the scores varied in the three disease contexts (the whole, fitting or not fitting the WHO case definition data sets). At 10% of threshold probability, e.g. in disease-adverse context, ECPS gave an NB of 0.033 and a net reduction of unnecessary isolation of 67.1%. Using ECPS as a joint approach to isolate EVD suspects reduces the number of unnecessary isolations by 65.7%. Conclusion The scores developed in our study showed a good performance as EVD case predictors since their use improved the net benefit, i.e., their clinical utility. These rapid and low-cost tools can help in decision-making to isolate EVD-suspicious cases at the triage point during an outbreak. However, these tools still require external validation and cost-effectiveness evaluation before being used on a large scale.