Coronavirus disease (COVID-19) technical guidance by WHO Household transmission investigation protocol | Page 5
Summary
Household transmission investigation protocol for coronavirus disease 2019 (COVID-19)
Population
Potential output and analysis
Design
Duration
Minimum information and
specimens to be obtained from
participants.
All household contacts of confirmed cases of COVID-19
Key epidemiological data to complement and reinforce the
findings of The First Few X cases and contacts (FFX)
investigation protocol for coronavirus disease 2019
(COVID-19) (1), in the areas of, primarily:
the proportion of asymptomatic cases and
symptomatic cases.
the incubation period and the duration of
infectiousness and of detectable shedding.
the serial interval of COVID-19 infection.
the reproduction numbers: R 0 and R of COVID-19
clinical risk factors for COVID-19, and the clinical
course and severity of disease.
high-risk population subgroups
the secondary infection rate and secondary clinical
attack rate of COVID-19 infection among household
contacts.
• patterns of health-care seeking
Prospective study of household contacts of laboratory-
confirmed cases of COVID-19, ideally before widespread
community transmission occurs.
At a minimum, enrolled household cases and contacts will
complete data and specimen collection at enrolment (Day
1) and for 28 days of follow-up, with four home visits.
Household visit with respiratory sample collection at
Days 1, 7, 14 and 28.
Serum sample collection is needed at Days 1 and 28,
and highly encouraged at Day 14.
Symptom diaries recorded by household contacts from
Day 0 to Day 14 and highly encouraged until Day 28.
This document sets out the methods to guide data collection and the public health investigation for
the comprehensive assessment of household contacts of confirmed COVID-19 cases.
The World Health Organization (WHO), in collaboration with technical partners, has developed a
series of enhanced surveillance protocols that are harmonized to help provide detailed insight into
the epidemiological characteristics of COVID-19. Other COVID-19 investigations and study protocols
currently available include:
The First Few X cases and contacts (FFX) investigation protocol for coronavirus disease
2019 (COVID-19) (1);
Protocol for assessment of potential risk factors for coronavirus disease 2019 (COVID-19)
infection among health workers in a health-care setting (2); and
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