Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 8 de 8
Filter
1.
Food Control ; 136: 108845, 2022 Jun.
Article in English | MEDLINE | ID: covidwho-1670500

ABSTRACT

Countries continue to debate the need for decontamination of cold-chain food packaging to reduce possible severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) fomite transmission among frontline workers. While laboratory-based studies demonstrate persistence of SARS-CoV-2 on surfaces, the likelihood of fomite-mediated transmission under real-life conditions is uncertain. Using a quantitative microbial risk assessment model of a frozen food packaging facility, we simulated 1) SARS-CoV-2 fomite-mediated infection risks following worker exposure to contaminated plastic packaging; and 2) reductions in these risks from masking, handwashing, and vaccination. In a frozen food facility without interventions, SARS-CoV-2 infection risk to a susceptible worker from contact with contaminated packaging was 1.5 × 10-3 per 1h-period (5th - 95th percentile: 9.2 × 10-6, 1.2 × 10-2). Standard food industry infection control interventions, handwashing and masking, reduced risk (99.4%) to 8.5 × 10-6 risk per 1h-period (5th - 95th percentile: 2.8 × 10-8, 6.6 × 10-5). Vaccination of the susceptible worker (two doses Pfizer/Moderna, vaccine effectiveness: 86-99%) with handwashing and masking reduced risk to 5.2 × 10-7 risk per 1h-period (5th - 95th percentile: 1.8 × 10-9, 5.4 × 10-6). Simulating increased transmissibility of current and future variants (Delta, Omicron), (2-, 10-fold viral shedding) among a fully vaccinated workforce, handwashing and masking continued to mitigate risk (1.4 × 10-6 - 8.8 × 10-6 risk per 1h-period). Additional decontamination of frozen food plastic packaging reduced infection risks to 1.2 × 10-8 risk per 1h-period (5th - 95th percentile: 1.9 × 10-11, 9.5 × 10-8). Given that standard infection control interventions reduced risks well below 1 × 10-4 (World Health Organization water quality risk thresholds), additional packaging decontamination suggest no marginal benefit in risk reduction. Consequences of this decontamination may include increased chemical exposures to workers, food quality and hazard risks to consumers, and unnecessary added costs to governments and the global food industry.

2.
Nat Commun ; 12(1): 7063, 2021 12 03.
Article in English | MEDLINE | ID: covidwho-1550283

ABSTRACT

Serological testing remains a passive component of the public health response to the COVID-19 pandemic. Using a transmission model, we examine how serological testing could have enabled seropositive individuals to increase their relative levels of social interaction while offsetting transmission risks. We simulate widespread serological testing in New York City, South Florida, and Washington Puget Sound and assume seropositive individuals partially restore their social contacts. Compared to no intervention, our model suggests that widespread serological testing starting in late 2020 would have averted approximately 3300 deaths in New York City, 1400 deaths in South Florida and 11,000 deaths in Washington State by June 2021. In all sites, serological testing blunted subsequent waves of transmission. Findings demonstrate the potential benefit of widespread serological testing, had it been implemented in the pre-vaccine era, and remain relevant now amid the potential for emergence of new variants.


Subject(s)
COVID-19 Serological Testing/statistics & numerical data , COVID-19/diagnosis , Pandemics/prevention & control , Physical Distancing , COVID-19/mortality , COVID-19/transmission , COVID-19/virology , Computer Simulation , Florida/epidemiology , Humans , New York City/epidemiology , Pandemics/statistics & numerical data , Washington/epidemiology
3.
Food Control ; 133: 108632, 2022 Mar.
Article in English | MEDLINE | ID: covidwho-1474566

ABSTRACT

The SARS-CoV-2 global pandemic poses significant health risks to workers who are essential to maintaining the food supply chain. Using a quantitative risk assessment model, this study characterized the impact of risk reduction strategies for controlling SARS-CoV-2 transmission (droplet, aerosol, fomite-mediated) among front-line workers in a representative indoor fresh fruit and vegetable manufacturing facility. We simulated: 1) individual and cumulative SARS-CoV-2 infection risks from close contact (droplet and aerosols at 1-3 m), aerosol, and fomite-mediated exposures to a susceptible worker following exposure to an infected worker during an 8 h-shift; and 2) the relative reduction in SARS-CoV-2 infection risk attributed to infection control interventions (physical distancing, mask use, ventilation, surface disinfection, hand hygiene, vaccination). Without mitigation measures, the SARS-CoV-2 infection risk was largest for close contact (droplet and aerosol) at 1 m (0.96, 5th - 95th percentile: 0.67-1.0). In comparison, risk associated with fomite (0.26, 5th - 95th percentile: 0.10-0.56) or aerosol exposure alone (0.05, 5th - 95th percentile: 0.01-0.13) at 1 m distance was substantially lower (73-95%). At 1 m, droplet transmission predominated over aerosol and fomite-mediated transmission, however, this changed by 3 m, with aerosols comprising the majority of the exposure dose. Increasing physical distancing reduced risk by 84% (1-2 m) and 91% (1-3 m). Universal mask use reduced infection risk by 52-88%, depending on mask type. Increasing ventilation (from 0.1 to 2-8 air changes/hour) resulted in risk reductions of 14-54% (1 m) and 55-85% (2 m). Combining these strategies, together with handwashing and surface disinfection, resulted in <1% infection risk. Partial or full vaccination of the susceptible worker resulted in risk reductions of 73-92% (1 m risk range: 0.08-0.26). However, vaccination paired with other interventions (ACH 2, mask use, or distancing) was necessary to achieve infection risks <1%. Current industry SARS-CoV-2 risk reduction strategies, particularly when bundled, provide significant protection to essential food workers.

4.
J Infect Dis ; 224(2): 371-372, 2021 07 15.
Article in English | MEDLINE | ID: covidwho-1319180
5.
J Infect Dis ; 224(1): 9-13, 2021 07 02.
Article in English | MEDLINE | ID: covidwho-1294727

ABSTRACT

In April 2020, the incidence of norovirus outbreaks reported to the National Outbreak Reporting System dramatically declined. We used regression models to determine if this decline was best explained by underreporting, seasonal trends, or reduced exposure due to nonpharmaceutical interventions (NPIs) implemented for severe acute respiratory syndrome coronavirus 2 using data from 9 states from July 2012 to July 2020. The decline in norovirus outbreaks was significant for all 9 states, and underreporting and/or seasonality are unlikely to be the primary explanation for these findings. These patterns were similar across a variety of settings. NPIs appear to have reduced incidence of norovirus, a nonrespiratory pathogen.


Subject(s)
COVID-19/epidemiology , COVID-19/virology , Caliciviridae Infections/epidemiology , Caliciviridae Infections/virology , Coinfection , Norovirus , SARS-CoV-2 , COVID-19/diagnosis , COVID-19/therapy , Cross Infection , Disease Management , Disease Outbreaks , Humans , Incidence , Seasons , United States/epidemiology
6.
Epidemiology ; 32(4): 518-524, 2021 07 01.
Article in English | MEDLINE | ID: covidwho-1211432

ABSTRACT

BACKGROUND: Serology tests can identify previous infections and facilitate estimation of the number of total infections. However, immunoglobulins targeting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been reported to wane below the detectable level of serologic assays (which is not necessarily equivalent to the duration of protective immunity). We estimate the cumulative incidence of SARS-CoV-2 infection from serology studies, accounting for expected levels of antibody acquisition (seroconversion) and waning (seroreversion), and apply this framework using data from New York City and Connecticut. METHODS: We estimated time from seroconversion to seroreversion and infection fatality ratio (IFR) using mortality data from March to October 2020 and population-level cross-sectional seroprevalence data from April to August 2020 in New York City and Connecticut. We then estimated the daily seroprevalence and cumulative incidence of SARS-CoV-2 infection. RESULTS: The estimated average time from seroconversion to seroreversion was 3-4 months. The estimated IFR was 1.1% (95% credible interval, 1.0%, 1.2%) in New York City and 1.4% (1.1, 1.7%) in Connecticut. The estimated daily seroprevalence declined after a peak in the spring. The estimated cumulative incidence reached 26.8% (24.2%, 29.7%) at the end of September in New York City and 8.8% (7.1%, 11.3%) in Connecticut, higher than maximum seroprevalence measures (22.1% and 6.1%), respectively. CONCLUSIONS: The cumulative incidence of SARS-CoV-2 infection is underestimated using cross-sectional serology data without adjustment for waning antibodies. Our approach can help quantify the magnitude of underestimation and adjust estimates for waning antibodies.


Subject(s)
COVID-19 , SARS-CoV-2 , Antibodies, Viral , Connecticut/epidemiology , Cross-Sectional Studies , Humans , Incidence , New York City , Seroepidemiologic Studies
7.
Emerg Infect Dis ; 27(4): 1229-1231, 2021 04.
Article in English | MEDLINE | ID: covidwho-1147201

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 can persist on surfaces, suggesting possible surface-mediated transmission of this pathogen. We found that fomites might be a substantial source of transmission risk, particularly in schools and child daycares. Combining surface cleaning and decontamination with mask wearing can help mitigate this risk.


Subject(s)
COVID-19 , Disease Transmission, Infectious/prevention & control , Fomites/virology , Infection Control , SARS-CoV-2/isolation & purification , Aged , Basic Reproduction Number , COVID-19/epidemiology , COVID-19/prevention & control , COVID-19/transmission , COVID-19/virology , Child , Child Day Care Centers/standards , Decontamination/methods , Equipment Contamination/prevention & control , Hand Disinfection/methods , Humans , Infection Control/instrumentation , Infection Control/methods , Masks , Nursing Homes/standards , Schools/standards , United States/epidemiology
SELECTION OF CITATIONS
SEARCH DETAIL