Respiratory syncytial virus a and b display different temporal patterns in a 4-year prospective cross-sectional study among children with acute respiratory infection in a tropical city

Abstract

Respiratory syncytial virus (RSV) is one of the most common etiological agents of childhood respiratory infections globally. Information on seasonality of different antigenic groups is scarce. We aimed to describe the frequency, seasonality, and age of children infected by RSV antigenic groups A (RSVA) and B (RSVB) among children with ARI in a 4-year period.Children (6–23 months old) with respiratory infection for ≤7 days were enrolled in a prospective cross-sectional study, from September, 2009 to October, 2013, in Salvador, in a tropical region of Brazil. Upon recruitment, demographic, clinical data, and nasopharyngeal aspirates (NPA) were collected. A multiplex quantitative real-time polymerase chain reaction (RT-PCR) with a group-specific primer and probeset for RSVA and RSVB was used. Seasonal distribution of infection by RSV different antigenic groups was evaluated by Prais-Wisten regression.Of 560 cases, the mean age was 11.4 ± 4.5 months and there were 287 (51.3%) girls. Overall, RSV was detected in 139 (24.8%; 95% CI: 21.4%–28.5%) cases, RSVA in 74 (13.2%; 95% CI: 10.6%–16.2%) cases, and RSVB in 67 (12.0%; 95% CI: 9.5%–14.9%) cases. Two (0.4%; 95% CI: 0.06%–1.2%) cases had coinfection. RSVA frequency was 9.6%, 18.4%, 21.6%, and 3.1% in 2010, 2011, 2012, and 2013, respectively. RSVB frequency was 19.2%, 0.7%, 1.4%, and 35.4% in the same years. RSVA was more frequently found from August to January than February to July (18.2% vs. 6.4%, P < 0.001). RSVB was more frequently found (P < 0.001) between March and June (36.0%) than July to October (1.0%) or November to February (1.6%). RSVB infection showed seasonal distribution and positive association with humidity (P = 0.02) whereas RSVA did not. RSVA was more common among children ≥1-year-old (17.8% vs. 1.8%; P = 0.02), as opposed to RSVB (11.5% vs. 12.2%; P = 0.8).One quarter of patients had RSV infection. RSVA compromised more frequently children aged ≥1 year. RSVA predominated in 2011 and 2012 whereas RSVB predominated in 2010 and 2013. In regard to months, RSVA was more frequent from August to January whereas RSVB was more often detected between March and June. Markedly different monthly as well as yearly patterns for RSVA and RSVB reveal independent RSV antigenic groups’ epidemics.

Metatranscriptomics to characterize respiratory virome, microbiome, and host response directly from clinical samples

“…Even with a cutoff of >40% genome coverage, we identi ed RSV in 79% (although most RSV infections in children are thought to be symptomatic) and CoVs in 47% of HC samples ( Supplementary Table S1). Similarly, this study revealed a high frequency (56%) of RSV-A and RSV-B co-infections in RSV-ARI samples, while previous studies have shown RSV-A and RSV-B coinfections ranging from 0.1% to 0.4% of RSV-ARI 43,44 . The frequency of RSV coinfections was greater in the RSV severe group (69.6%) compared to RSV mild group (37.5%) (Figure 2b).…”

Acute Respiratory Illness in Rural Haiti

“…RSV detection was significantly lower at only 2.3% of tested patients compared to previously published reports of 30-40% in other developing countries where the bulk of the children were seen in hospitals or emergency rooms (McCracken et al, 2013;Dawood et al, 2015;Bouzas et al, 2016). This low level of detection may have been due to initial storage of nasal swabs at À20 C which has been found to decrease RSV detection (Nunes and Moura, 2006) and our patients being 3-20 years old when the highest rate of the RSV positivity are typically among children 2 years of age.…”

High incidence of rhinovirus infection in children with community‐acquired pneumonia from a city in the Brazilian pre‐Amazon region

“…On the other hand, Caini et al demonstrated that influenza cases peaked between June and September (dry season), in countries of the Southern hemisphere, including south and southeast Brazil. Regarding the seasonality of RSV, Bouzas et al analyzed the incidence of RSV associated with seasonal distribution in the city of Salvador, Brazil. They observed the prevalence of RSV group A genotype in the dry seasons and, on the other hand, the higher incidence RSV group B genotype in the rainy season.…”