Risk of Secondary Household Transmission of COVID-19 from Health Care Workers in a Hospital in Spain.

Miren Remón-Berrade,Maria Pilar Garcia-Garcia,Francisco Guillen-Grima,Maria Del Carmen Lerga-Berruezo,Laura Guillen-Aguinaga,Isabel Sarrate-Adot,Sara Guillen-Aguinaga

doi:10.3390/epidemiologia3010001

Miren Remón-Berrade, Maria Pilar Garcia-Garcia + Show 5 more

Open Access

https://doi.org/10.3390/epidemiologia3010001

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Abstract

Hospital health care workers are at high risk of developing COVID-19 and transmitting the disease to their family upon returning home; the aim here is to estimate the secondary attack rate of COVID-19 in household contacts of health care workers and their transmission risk factors. COVID-19 cases in the health care workers of an academic hospital in Pamplona, Spain, from 2 March to 26 May 2020, were followed up. The secondary attack rate (SAR) was estimated from cases in household contacts of index cases and their risk factors by Poisson regression. 89 index cases were studied from 99 notified cases in health care workers (89.0%), excluding secondary cases or those who lived alone. Forty-six secondary cases confirmed by the laboratory were found among 326 household contacts, a secondary attack rate of 14.11% (95% CI 10.75-18.31), and 33 household contacts with acute infection symptoms without microbiologic confirmation 10.12% (95% CI 7.30-13.87). Considering all the cases, the secondary attack rate was 27.3 (95% CI 22.75-32.38). Risk factors were the gender and profession of the index case, the number of people living in the household, and the number of persons per bedroom. When the index case health worker used a single room, it had a protective effect, with an incidence rate ratio (IRR) of 0.493 (95% CI 0.246-0.985); Conclusions: The secondary attack rate found among household contacts of health care workers is high. The preventive isolation of health care workers in individual rooms in their house may reduce the transmission in their families.

Highlights

Introduction published maps and institutional affilCOVID-19 is a disease caused by SARS-CoV-2
This study aims to estimate in an academic hospital in Navarra (Spain) the secondary attack rate of COVID-19 in household contacts of health care workers and their transmission risk factors
The maximum number of cases among health care workers occurred in the week of 16 March (Figure 1)

Summary

Introduction

Introduction published maps and institutional affilCOVID-19 is a disease caused by SARS-CoV-2. SARS-CoV-2 is highly contagious, and numerous studies have been conducted to learn the secondary attack rate in families in which a member develops COVID-19 [2,3]. Hospital health care workers are at high risk of developing COVID-19 and transmitting the disease to their family upon returning home; the aim here is to estimate the secondary attack rate of COVID-19 in household contacts of health care workers and their transmission risk factors. The secondary attack rate (SAR) was estimated from cases in household contacts of index cases and their risk factors by Poisson regression. When the index case health worker used a single room, it had a protective effect, with an incidence rate ratio (IRR) of 0.493 (95% CI 0.246–0.985); Conclusions: The secondary attack rate found among household contacts of health care workers is high. The preventive isolation of health care workers in individual rooms in their house may reduce the transmission in their families

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