key: cord-0878931-nb9cxutt
authors: Ahmed, Mohammed A.M.; Colebunders, Robert; Siewe Fodjo, Joseph Nelson
title: Evidence for important COVID-19 community transmission in Somalia using a clinical case definition
date: 2020-06-25
journal: Int J Infect Dis
DOI: 10.1016/j.ijid.2020.06.068
sha: c1bd1f4b5e9da6c2d2c09924023a79c5f9367d3d
doc_id: 878931
cord_uid: nb9cxutt

• Current COVID-19 surveillance strategies, as recommended by the World Health Organization (WHO), may be underestimating the real burden of the disease. • A clinical definition taking into account anosmia as a diagnostic symptom increases the sensitivity of the WHO clinical definition. • The proposed clinical definition can complement existing COVID-19 surveillance measures particularly in resource-poor settings where testing and contact tracing capacities are limited.

In March 2020, researchers at the University of Antwerp (Belgium) launched the International Citizen Project COVID-19 (ICPCovid) which uses web-based surveys to investigate the impact of COVID-19 and associated restrictions on residents of several countries. 3 The survey tool was translated to the Somali language and locally disseminated via social media platforms.

Participants in Somalia were consecutively recruited using a snow-ball approach from April 23 rd to May 7 th , 2020; responses were submitted using mobile phones. The questionnaire included questions about the presence or absence of flu-like symptoms during the last 14 days, and the specific symptom(s) experienced by the respondents. Participants were asked whether they had been tested for COVID-19 within the last month (tests performed by the government using nucleic acid amplification techniques), and eventual test results. The protocol was approved by Table 1 ). Based on these findings, we propose the following clinical criteria for COVID-19 suspicion: Any individual presenting at least one major sign (fever and/or anosmia) with one or more respiratory symptoms (cough, shortness of breath, sore throat, coryza), with an epidemiological context of COVID-19 transmission. Upon applying these criteria on all 4124 respondents and making abstraction of any previous COVID-19 contacts, the participants' self-reported symptoms predicted 334 (8.1%) suspected cases as opposed to 259 (6.3%) detected by the WHO definition (p<0.0001).

These results strongly suggest a high level of community transmission of COVID-19 in Somalia, which is most likely under-reported using current approaches. This implies that a significant portion of infected Somalis go undetected and unwittingly serve as asymptomatic spreaders. We demonstrate that the inclusion of anosmia into a case definition for COVID-19 may result in fewer false negatives, thus ensuring that a larger number of cases are quarantined J o u r n a l P r e -p r o o f until they no longer pose a public health threat. It appears that the onset of anosmia precedes the full-blown clinical disease, 4 thereby enabling the early detection of infected persons. Several studies have shown that hyposmia/anosmia is very prevalent in COVID-19 patients. 5, 6 These observations are supported by two meta-analyses 7,8 which further highlighted that validated methods to evaluate smell and taste in COVID-19 patients are more sensitive than subjective self-reporting. Therefore, objectively assessing these symptoms could prove useful in screening for COVID-19 even in primary healthcare settings. Notably, hyposmia/anosmia is seldom reported spontaneously by the patients themselves and should be intentionally investigated during history taking, especially during an ongoing COVID-19 outbreak.

The major weaknesses in our study include: the web-based, anonymous data collection technique with no possibility of verifying the information for accuracy; a small sample size; no information on the ear-nose-throat medical history of respondents which may affect their sense of smell; and a possible selection bias of respondents when assessing the performance of the screening tools (those who had been tested were most likely symptomatic or were contacts of an index case, and may not be representative of the general population). By June 16 th 2020, 2642 COVID-19 cases and 88 deaths had officially been reported in Somalia. 9 Our study suggests that 2 : Individuals presenting at least one respiratory symptom (dry cough, productive cough, shortness of breath, sore throat, coryza), with or without fever b WHO + anosmia definition (assuming contacts): Individuals presenting at least one respiratory symptom (dry cough, productive cough, shortness of breath, sore throat, coryza) or anosmia, with or without fever c WHO definition (ignoring contacts) 2 : Individuals presenting fever, AND at least one respiratory symptom (dry cough, productive cough, shortness of breath, sore throat, coryza) d WHO + anosmia definition (ignoring contacts): Individuals presenting fever, AND at least one respiratory symptom (dry cough, productive cough, shortness of breath, sore throat, coryza) or anosmia e New definition: Individuals presenting fever and/or anosmia, with at least one respiratory symptom (dry cough, productive cough, shortness of breath, sore throat, coryza)

Asymptomatic Transmission, the Achilles' Heel of Current Strategies to Control Covid-19

World Health Organization. Global surveillance for COVID-19 caused by human infection with COVID-19 virus: interim guidance

International Citizen Project Covid-19

Self-reported Olfactory and Taste Disorders in Patients With Severe Acute Respiratory Coronavirus 2 Infection: A Cross-sectional Study

Sudden hyposmia as a prevalent symptom of COVID-19 infection

Loss of sense of smell as marker of COVID-19 infection

Smell and Taste Dysfunction in Patients With COVID-19: A Systematic Review and Meta-analysis

The authors declare that they have no conflicts of interest. (Grant number 671055)