Evidence map›Paper›PMID 40813964›Full record

Observational studyBMC infectious diseases2025

Household transmission of SARS-CoV-2 during the first wave of the COVID-19 pandemic: an analysis of secondary attack rates in Moroccan households.

Marwa El Baldi, Zakia Marsou, Fatima Zahra Chellat, Mohamed Chakib Benjelloun, Mohammed Faouzi Belahsen, Tarik Sqalli Houssaini, Khalid Lahmadi, Karima El Rhazi

Abstract readObservational Study
In one paragraph

Observational study in BMC infectious diseases, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

8 authors.

Marwa El BaldiLaboratory of Epidemiology and Research in Health Sciences, Faculty of Medicine, Pharmacy and Dentistry, Sidi Mohamed Ben Abdallah University, Fez, 30000, Morocco. marwa.elbaldi@usmba.ac.ma.
Zakia MarsouLaboratory of Epidemiology and Research in Health Sciences, Faculty of Medicine, Pharmacy and Dentistry, Sidi Mohamed Ben Abdallah University, Fez, 30000, Morocco.
Fatima Zahra ChellatLaboratory of Epidemiology and Research in Health Sciences, Faculty of Medicine, Pharmacy and Dentistry, Sidi Mohamed Ben Abdallah University, Fez, 30000, Morocco.
Mohamed Chakib BenjellounLaboratory of Epidemiology and Research in Health Sciences, Faculty of Medicine, Pharmacy and Dentistry, Sidi Mohamed Ben Abdallah University, Fez, 30000, Morocco.
Mohammed Faouzi BelahsenLaboratory of Epidemiology and Research in Health Sciences, Faculty of Medicine, Pharmacy and Dentistry, Sidi Mohamed Ben Abdallah University, Fez, 30000, Morocco.
Tarik Sqalli HoussainiLaboratory of Epidemiology and Research in Health Sciences, Faculty of Medicine, Pharmacy and Dentistry, Sidi Mohamed Ben Abdallah University, Fez, 30000, Morocco.
Khalid LahmadiImmuno-Serology Laboratory of the Moulay Ismail Military Hospital -Meknes-Morocco, Sidi Mohammed Ben Abdellah University, Fes, Morocco.
Karima El RhaziLaboratory of Epidemiology and Research in Health Sciences, Faculty of Medicine, Pharmacy and Dentistry, Sidi Mohamed Ben Abdallah University, Fez, 30000, Morocco.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundDespite efforts such as lockdowns and social distancing, household transmission remained a key driver of COVID-19 spread in Morocco. Social distancing within households is challenging, and isolating cases over the infectious period is difficult to maintain. Understanding intra-household transmission dynamics during the pandemic's early phase is essential to guide effective public health responses. This retrospective observational study aimed to estimate the secondary attack rate of SARS-CoV-2 among household contacts and identify factors influencing transmission during the first wave of COVID-19 in Morocco.

methodsThis study enrolled 104 confirmed index cases and 300 household contacts, all tested for SARS-CoV-2 via RT-PCR following the Moroccan Ministry of Health's diagnostic protocol. Participants were categorized based on PCR results. Data were extracted from medical records and supplemented by standardized telephone interviews conducted between March 23 and May 25, 2020. Statistical analyses were performed using IBM SPSS Statistics (version 21).

resultsThis study estimated the secondary attack rate of SARS-CoV-2 at 56.3%. A significant association was observed with comorbidities in household contacts (p = 0.015). The rate was lower when the index case was female (aOR: 0.28, 95% CI: 0.16-0.49, p < 0.001) but higher when the index case was symptomatic (aOR: 3.33, 95% CI: 1.95-5.69, p < 0.001). However, the secondary attack rate showed no significant link with the index case's compliance with infection control measures, whether inside or outside the household.

conclusionThis study revealed a high secondary attack rate of SARS-CoV-2 in households during the first wave of the COVID-19 pandemic. These findings offer critical insights for designing targeted preventive measures to curb household transmission in future COVID-19 waves or similar pandemics.

Indexed as

COVID-19Family CharacteristicsSARS-CoV-2AdolescentAdultAgedChildChild, PreschoolContact TracingFemaleHumansMaleMiddle AgedMoroccoPandemicsRetrospective StudiesCOVID-19Household transmission, MoroccoSARS-CoV-2

Identifiers

PMID40813964
PMCPMC12355784

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.