SARS-CoV-2 transmission from contaminated surfaces, or fomites, has been a concern during the COVID-19 pandemic. Households have been important sites of transmission throughout the COVID-19 pandemic, but there is limited information on SARS-CoV-2 contamination of surfaces in these settings. We describe environmental detection of SARS-CoV-2 in households of persons with COVID-19 to better characterize the potential risks of fomite transmission. Ten households with ≥1 person with laboratory-confirmed COVID-19 and with ≥2 members total were enrolled in Utah, U.S.A. Nasopharyngeal and anterior nasal swabs were collected from members and tested for the presence of SARS-CoV-2 by RT-PCR. Fifteen surfaces were sampled in each household and tested for presence and viability of SARS-CoV-2. SARS-CoV-2 RNA was detected in 23 (15%) of 150 environmental swab samples, most frequently on nightstands (4/6; 67%), pillows (4/23; 17%), and light switches (3/21; 14%). Viable SARS-CoV-2 was cultured from one sample. All households with SARS-CoV-2-positive surfaces had ≥1 person who first tested positive for SARS-CoV-2 ≤ 6 days prior to environmental sampling. SARS-CoV-2 surface contamination occurred early in the course of infection when respiratory transmission is most likely, notably on surfaces in close, prolonged contact with persons with COVID-19. While fomite transmission might be possible, risk is low.

Influenza Surveillance Systems and COVID-19

Giardia has been associated with reduced risk of diarrhea in children in low-resource settings, but the mechanism underlying this association is unknown. To assess whether Giardia may shape colonization or infection with other enteric pathogens and impact associations with diarrhea, we examined Giardia and enteric pathogen codetection among children <5 years old in Kenya, The Gambia, and Mali as part of the Vaccine Impact on Diarrhea in Africa study. We tested for Giardia and other enteric pathogens using enzyme-linked immunosorbent assays and real-time polymerase chain reaction (PCR) on stool, respectively. We evaluated associations between Giardia and enteric pathogen detection using multivariable logistic regression models separately for children with moderate-to-severe diarrhea (MSD, cases) and free of diarrhea (controls). Among 11 039 enrolled children, Giardia detection was more common among controls (35%) than cases (28%, P < .001). Campylobacter coli/jejuni detection was associated with Giardia in controls in The Gambia (adjusted odds ratio [aOR] [95% confidence interval {CI}]: 1.51 [1.22‒1.86]) and cases across all sites (1.16 [1.00‒1.33]). Among controls, the odds of astrovirus (1.43 [1.05‒1.93]) and Cryptosporidium spp. (1.24 [1.06‒1.46]) detection were higher among children with Giardia. Among cases, the odds of rotavirus detection were lower in children with Giardia in Mali (.45 [.30‒.66]) and Kenya (.31 [.17‒.56]). Giardia was prevalent in children <5 years old and was associated with detection of other enteric pathogens, with differing associations in cases versus controls and by site. Giardia may affect colonization or infection by certain enteric pathogens associated with MSD, suggesting an indirect mechanism of clinical impact.

Hand drying is the critical, final step of handwashing. A cross-sectional survey of U.S. adults assessed self-reported hand drying practices in public bathrooms and found increased preference for using electric hand dryers, wiping hands on clothing, and shaking hands and decreased preference for using paper towels during the COVID-19 pandemic relative to before. Respondents expressed concerns about contacting SARS-CoV-2 when touching surfaces in public bathrooms which may be influencing self-reported drying method preference.

We conducted a randomized controlled trial to evaluate whether adjuvanted quadrivalent inactivated influenza vaccine (aIIV4) generates superior immunogenicity against influenza viruses compared to conventional quadrivalent inactivated influenza vaccine (IIV4) among healthcare personnel (HCP) in Lima, Peru. During 2022-2023, we randomized 192 HCP aged ≥18 years to receive 2022 Southern Hemisphere IIV4 or aIIV4 and collected pre-, 1-month post-, and 6-months post-vaccination sera. Geometric mean titers (GMTs), GMT ratios, seroconversion rates (SCR), and seroprotection rates (SPR) were compared against vaccine reference viruses-influenza A(H1N1)pdm09, A(H3N2), B/Victoria, and B/Yamagata-using hemagglutination inhibition assays. Most HCP (77-99%) had titers ≥40 following vaccination. One-month post-vaccination, aIIV4 induced higher GMTs (GMT ratio: 1.7 [95% confidence interval 1.1-2.7]) and SCR (88.4% [80.4-93.4] vs 62.1% [52.1-71.2]) against A(H1N1)pdm09 and higher SCR (82.1% [73.2-88.5] vs 62.1% [52.1-71.2]) against A(H3N2) compared to IIV4. At 6 months, aIIV4 induced higher SPR against A(H3N2) (90.4% [82.8-94.9] vs 74.0% [64.4-81.7]) than IIV4. IIV4 recipients vaccinated the preceding influenza season had lower odds of seroconverting to A(H1N1)pdm09 compared to IIV4 recipients who were not vaccinated (adjusted odds ratio: 0.29 [0.13-0.63], P = 0.002). These findings provide insights into the benefits of an enhanced influenza vaccine (aIIV4) to help overcome the immune blunting effects of repeat vaccination among HCP. NCT06054269.