A Prolonged Outbreak of Human Adenovirus A31 (HAdV-A31) Infection on a Pediatric Hematopoietic Stem Cell Transplantation Ward with Whole Genome Sequencing Evidence of International Linkages.

A surge in hematopoietic stem cell transplantation (HSCT) human adenovirus A31 (HAdV-A31) infections was initially observed in late 2014/2015 at SickKids (SK) Hospital, Toronto, Canada. In response, enhanced laboratory monitoring for all adenovirus infections was conducted. Positive samples underwent genotyping, viral culture, and, in selected cases, whole-genome sequencing (WGS). HAdV-A31 specimens/DNA obtained from four international pediatric HSCT centers also underwent WGS. During the SK outbreak period (27 October 2014 to 31 October 2018), 17/20 HAdV-A31 isolates formed a distinct clade with 0 to 8 mutations between the closest neighbors. Surveillance before and after the outbreak detected six additional HAdV-A31 HSCT cases; three of the four sequenced cases clustered within the outbreak clade. Two SK outbreak isolates were identical to sequences from two patients in an outbreak in England. Three SK non-outbreak sequences also had high sequence similarity to strains from three international centers. Environmental PCR testing of the HSCT ward showed significant adenovirus contamination. Despite intense infection control efforts, we observed re-occurrence of infection with the outbreak strain. Severe but nonfatal infection was observed more commonly with HAdV-A31 compared to other genotypes, except HAdV-C1. Our findings strongly implicate nosocomial spread of HAdV-A31 over 10 years on a HSCT unit and demonstrate the value of WGS in defining and mapping the outbreak. Close linkages among strains in different countries suggest international dissemination, though the mechanism is undetermined. This large, extended outbreak emphasizes the pre-eminent role of HAdV-A31 in causing intractable pediatric HSCT outbreaks of severe illness worldwide.

Pretravel plans and discrepant trip experiences among travelers attending a tertiary care centre family travel medicine clinic.

BACKGROUND: International travel can expose travelers to a number of health risks. Pretravel consultation (PC) helps mitigate risk and prepare travelers for health concerns that might arise. The assessment of risk, mitigation strategies, and relevance of pretravel advice is dependent on how closely travelers adhere to their planned travel itinerary and activities. We determined the proportion of returned travelers whose completed travel experiences differed from their stated travel itineraries, and identified discrepancies that significantly altered the traveler's health risk and would have required alternative counseling during their PC. METHODS: We conducted a prospective cohort study at the SickKids' Family Travel Clinic between October 2014 and November 2015. Returned travelers who completed a post-travel survey were included. Pretravel consultation assessments and post-trip surveys were compared to identify discrepant trip experiences. RESULTS: A total of 389 travelers presented to the clinic for a PC during the study period and 302 (77.6%) were enrolled. Post-travel surveys were received from 119 (39.4%) participants, representing 101 unique itineraries. The median participant age was 36.3 years (IQR 26.6-47.5) and there were 73 female travelers (61%). Most participants (n = 87,73%) were healthy as well as Canadian born (n = 84, 71%). A quarter of travelers were visiting friends and relatives (VFR) (n = 30, 25.2%). The vast majority of returned travelers (n = 109, 92%) reported discrepant trip experiences involving trip duration, countries visited, accommodations, environmental surroundings and/or activities. Almost two thirds of these individuals (n = 68, 62%) would have required alternative pretravel counseling. We did not identify any demographic or planned trip characteristics that predicted discrepant trip experiences requiring alternative pretravel counseling. CONCLUSIONS: The majority of travelers reported discrepant trip experiences and the discrepancies often affected health risk. Therefore, clinicians should consider providing broader counselling during the PC as discrepancies from planned travel are common.

Adherence to recommendations at a Canadian tertiary care Family Travel Clinic - A single centre analysis.

BACKGROUND: Infectious and non-infectious risks associated with international travel can be reduced with adherence to pre-travel advice from practitioners trained in travel medicine. METHODS: A prospective cohort study was conducted in a tertiary care children's hospital to assess adherence to malaria chemoprophylaxis, safe water and food consumption, mosquito bite protection, motor vehicle safety and travel vaccines using structured questionnaires. High risk groups assessed included child travelers and those visiting friends and relatives (VFRs). RESULTS: In total, 290 participants (133 children and 157 adults) were enrolled and completed at least one study questionnaire. In general, with the exception of vaccines, adherence to recommendations was sub-optimal. Among children and adults, adherence to malaria prophylaxis recommendations was lower in VFRs than in non-VFRs. The proportion of children VFRs (cVFRs) and adult VFRs (aVFRs) who adhered to the following recommendations were malaria chemoprophylaxis (47%, 33%), safe water (71%, 74%) and food recommendations (18%, 6%), insect bite avoidance (21%, 12%), and motor vehicle safety (13%, 11%) respectively. Adherence to recommended vaccines uptake was greater than 90% in all groups. CONCLUSION: With the exception of vaccine uptake, sub-optimal adherence levels to travel recommendations was identified in all groups, and in particular VFRs, highlighting the need for proactive discussions around barriers to adherence.

Clinical disease severity of respiratory viral co-infection versus single viral infection: a systematic review and meta-analysis.

BACKGROUND: Results from cohort studies evaluating the severity of respiratory viral co-infections are conflicting. We conducted a systematic review and meta-analysis to assess the clinical severity of viral co-infections as compared to single viral respiratory infections. METHODS: We searched electronic databases and other sources for studies published up to January 28, 2013. We included observational studies on inpatients with respiratory illnesses comparing the clinical severity of viral co-infections to single viral infections as detected by molecular assays. The primary outcome reflecting clinical disease severity was length of hospital stay (LOS). A random-effects model was used to conduct the meta-analyses. RESULTS: Twenty-one studies involving 4,280 patients were included. The overall quality of evidence applying the GRADE approach ranged from moderate for oxygen requirements to low for all other outcomes. No significant differences in length of hospital stay (LOS) (mean difference (MD) -0.20 days, 95% CI -0.94, 0.53, p = 0.59), or mortality (RR 2.44, 95% CI 0.86, 6.91, p = 0.09) were documented in subjects with viral co-infections compared to those with a single viral infection. There was no evidence for differences in effects across age subgroups in post hoc analyses with the exception of the higher mortality in preschool children (RR 9.82, 95% CI 3.09, 31.20, p<0.001) with viral co-infection as compared to other age groups (I2 for subgroup analysis 64%, p = 0.04). CONCLUSIONS: No differences in clinical disease severity between viral co-infections and single respiratory infections were documented. The suggested increased risk of mortality observed amongst children with viral co-infections requires further investigation.