A complete analysis of the epidemiological scenario around a SARS-CoV-2 reinfection: previous infection events and subsequent transmission

Rationale: The first descriptions of reinfection by SARS-CoV-2 have been recently reported. However, these studies focus exclusively on the reinfected case, without considering the epidemiological context of the event.Objectives: To perform a complete analysis of the sequential infections and transmission events around a SARS-CoV-2 reinfection, including the infection events preceding it, the exposure and subsequent transmissions.Methods: Our analysis was supported by host genetics, viral whole genome sequencing, phylogenomic viral population analysis, and refined epidemiological data obtained from interviews with the involved subjects.Results: The reinfection involved a 53-year-old woman with asthma (Case A), with a first COVID-19 episode in April-2020 and a much more severe second episode four months and a half later, with COVID-19 seroconversion in August, and requiring hospital admission. An extended genomic analysis allowed us to demonstrate that the strain involved in Case A´s reinfection was circulating in the epidemiological context of Case A and was also transmitted subsequently from Case A to her family context. The reinfection was also supported by a phylogenetic analysis, including 348 strains from Madrid, which revealed that the strain involved in the reinfection was circulating by the time Case A suffered the second episode, August/September-2020, but absent at the time range corresponding to Case A´s first episode.Conclusion: We present the first complete analysis of the epidemiological scenario around a reinfection by SARS-CoV-2, more severe than the first episode, including three cases preceding the reinfection, the reinfected case per se, and the subsequent transmission to another seven cases.

Lessons learnt in recruiting schoolchildren into a large asthma case-control study in urban Uganda

Schools present an excellent opportunity for research among children and adolescents. We share our experiences and lessons learnt in enrolling schoolchildren into a large asthma case-control study from schools in urban Uganda, and make recommendations for best practices. Our key lessons were as follows: working closely with the school administration and teachers was vital in gaining timely access to parents of the schoolchildren; having a meeting with parents, within their children’s school premises, was a cost-effective way of reaching a wide audience of potential research participants with our message and an opportunity to seek their participation; allowing flexibility within our processes enabled us to fit our research activities within the school schedule, and with minimal disruptions; however, obtaining informed written consent from parents of children in the boarding section of school remained a challenge. In conclusion, conducting research in schools in Uganda is feasible and may be a cost-effective way to make the most of limited resources to remedy the research and data deficiencies among school-age children in sub-Saharan Africa.

Changes in gut microbiota with bronchial asthma

Aim.To study the intestinal microbiota changes in patients with bronchial asthma (BA). Materials and methods.40 patients and 15 healthy individuals were included for the study. The microbiota study in feces samples was performed by sequencing the 16SpRNA gene. Results.It was noted an increasing of theProteobacteriaproportion in the patients with BA. The fractions ofBetaproteobacteriaиGammaproteobacteriawere increased in the patients with allergic BA and at the same time, only theGammaproteobacteriapart was increased in patients with non-allergic form of BA. It was found an increase inBacilliand a decrease in the proportion bacteria forming butyrate (Anaerostipes, Faecalibacterium) and acetate (Alistipes), which was corresponded to a decrease in the proportion of strict anaerobic symbionts and an increase in the proportion of opportunistic facultative anaerobes. The relative bacteria amount was reduced for theNegativicutes Erysipelotrichia, Bacteroidia classes, theErysipelotrichaceae,Pseudomonadaceae, Rhodospirillaceae, Bacillaceae familiesand for the kinds ofBarnesiella, Paraprevotella, Pyrolobus, Bifidobacterium, Pseudomonas, Coprobacter, Bacillusin the allergic asthma patients with syndrome of intensive bacterial overgrowth (SIBO) cases. In the non-allergic asthma case, the presence of SIBO was accompanied by the relative bacteria amount increasing of theBacteroidaceaeand theParaprevotellafamilies and theOdoribacter,Bacteroides, Butyricicoccus, Parasutterellagenera. The bacterial spectrum changes correlated with the main clinical and laboratory manifestations of BA in the patients. Conclusion.The results have indicated the differences in the intestinal microflora composition of healthy volunteers and patients with bronchial asthma in including the SIBO presence. It is necessary more detail study of the bacterial composition changes in the intestine for the bronchopulmonary pathology case.