key: cord-1042737-66lf3bmm
authors: Suthar, A.; Schubert, S.; Garon, J.; Couture, A.; Brown, A.; Charania, S.
title: COVID-19 case definitions, diagnostic testing criteria, and surveillance across the pandemic's 25 highest burden countries
date: 2021-05-14
journal: nan
DOI: 10.1101/2021.05.11.21257047
sha: 04d91a23037bfb52128cb4fb4a96efd2f22f3288
doc_id: 1042737
cord_uid: 66lf3bmm

Objective: We compared suspect, probable, and confirmed case definitions, as well as diagnostic testing criteria, used in the COVID-19 pandemic's 25 highest burden countries to aid interpretation of global and national surveillance data. Methods: We identified the COVID-19 pandemic's 25 countries with the highest disease burden based on the number of cumulative reported cases to the World Health Organization (WHO) as of 1 October 2020. We searched official websites of these countries for suspect, probable, and confirmed case definitions. Given that confirmation of COVID-19 usually requires diagnostic testing, we also searched for diagnostic testing eligibility criteria in these countries. Extracted case definitions and testing criteria were managed in a database and analyzed in Microsoft Excel. Findings: We identified suspect, probable, and confirmed case definitions in 96%, 64%, and 100% of countries, respectively. Testing criteria were identified in 100% of countries. 56% of identified countries followed WHO recommendations for using a combination of clinical and epidemiological criteria as part of the suspect case definition. 75% of identified countries followed WHO recommendations on using clinical, epidemiological, and diagnostic criteria for probable cases. 72% of countries followed WHO recommendations on using PCR testing for confirming a case of COVID-19. Finally, 64% of countries used testing eligibility criteria at least as permissive as WHO. Conclusion: There is marked heterogeneity in who is eligible for testing in countries and how countries define a case of COVID-19. This affects the ability to compare burden, transmission, and response impact estimates derived from case surveillance data across countries.

To find these data, we searched government websites using the following key words: case 98 definition, suspect case, confirmed case, COVID-19, case criteria, surveillance, testing criteria, 99 guidelines, laboratory, reverse transcriptase-polymerase chain reaction (RT-PCR), and 100 asymptomatic. All surveillance definitions and testing criteria were verified as current as of 1 101 January 2021. Several of the official policies were not available in English. For these documents, 102 we used Google Translate to identify the definitions and testing policies. 103 104 Data management and analysis 105 (SARI)); and (3) epidemiological criteria, including travel to a high-burden region or contact 109 with a confirmed or suspect case. For each country's testing policy, we considered individuals 110 eligible for diagnostic testing. Countries were classified as testing asymptomatic individuals 111 without any additional criteria, testing asymptomatic individuals with some epidemiological 112 criteria, such as contact with a confirmed case, or recommending testing exclusively for 113 symptomatic individuals. These analyses were based solely on diagnostic testing eligibility 114 criteria and did not consider exceptions, such as testing asymptomatic individuals prior to travel, 115 asymptomatic testing through the private sector, or local-level mass-testing. Elements of national 116 case definitions and testing criteria were compared against global norms from WHO. 117 118 Source assessment 119

To assess sources, we extracted information on their origin and timeliness. The origin was 120 categorized as a government source or personal communication while timeliness was based on 121 date of publication. 122 123

Suspect case definitions 125

We identified suspect case definitions in 24 of 25 countries (96%) ( Table 1 and Appendix 1) . 126

Israel relies on surveillance via cell phone data; we used these epidemiological criteria from 127 Israel to create a suspect case definition. The three most common criteria included in suspect 128 case definitions were fever, cough, and labored breathing (reported in 92%, 84%, and 84% of 25 129 countries). Seven countries (28%) used "other" criteria in addition to the common criteria listed 130 in Table 1 . The WHO suspected case definition includes clinical symptoms, including the three 131 most common stated above, and epidemiological criteria. Fourteen (56%) countries followed this 132 guidance broadly by including clinical and epidemiological criteria, ten (40%) countries required 133

We identified probable case definitions in 16 of 25 countries (64%) ( that countries may need to adapt the case definitions to their specific circumstances. 4-6,18 190 Beginning with the 20 March 2020 version, WHO also encouraged countries to publish their 191 adapted versions online and in periodic situation reports. 5, 6 Nearly all countries (92%) in this 192 analysis indeed chose to deviate from WHO's case definitions in some manner and 92% of 193 countries posted their case definition on an official government website. Suspect and confirmed 194 case classifications were found for nearly all countries, but over a third (36%) excluded the 195 probable case classification. In addition, substantial variation was observed among testing 196 criteria used across the national case definitions. While WHO reserved the use of laboratory 197 testing for confirmed cases only, two countries (8%) included laboratory evidence for suspect 198 cases, 14 countries (88%) for probable cases, and nearly a third (32%) included non-laboratory 199 criteria for confirmed cases. Laboratory evidence in some countries was not restricted to PCR, but rather included increasingly available antigen and antibody tests. Lastly, testing 201 for use under a CC0 license. This article is a US Government work. It is not subject to copyright under 17 USC 105 and is also made available (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted May 14, 2021. ; https://doi.org/10.1101/2021.05.11.21257047 doi: medRxiv preprint eligibility criteria also differed widely with many countries either excluding asymptomatic 202 individuals from routine testing (36%) or only including them under certain conditions (32%). The wide variation we found in suspect and probable case criteria -and the complete omission 227 of the probable case classification in some nations -is of particular interest. When test results are 228 still pending or tests are unavailable, inclusion of suspected and probable cases allows for early 229 isolation and treatment of these cases. 7 In addition, in its 7 August 2020 guidance, WHO 230 requested that countries include counts of probable cases along with confirmed cases in weekly 231 for use under a CC0 license. This article is a US Government work. It is not subject to copyright under 17 USC 105 and is also made available (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. an important tool for early detection and to prevent asymptomatic spread. 9 However, their 246 sensitivity is generally lower than NAAT leading to false negatives. 27 Antibody tests have 247 typically been recommended as a surveillance assay rather than a standalone diagnostic tool. 11,28 248

Despite the limitations of NAAT alternatives, they are increasingly available in many areas and 249 have important benefits, such as lower overall cost, simplified logistics and supply chain 250 management, and faster turnaround of results for rapid versions that may explain their integration 251 in some national confirmed case definitions. 252 253 WHO's public health surveillance guidance also includes recommendations for laboratory testing 254 of all suspect and probable cases but acknowledges that testing priorities would be dependent on 255 intensity of transmission, the number of cases, and laboratory capacity. Therefore, guidance was 256 also developed on testing asymptomatic and mildly symptomatic individuals. 6,26 National 257 differences in testing eligibility criteria may also reflect resource limitations and differences in 258 national health insurance coverage of tests. 12 A number of testing strategies proposed to target 259 segments of the population believed to be at greatest risk of exposure to SARS-CoV-2. For 260 example, some have proposed testing all symptomatic individuals and asymptomatic individuals 261 for use under a CC0 license.

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with known or suspected contact with COVID-19 case for optimal NAAT testing. 9,26 Testing 262 asymptomatic individuals without an exposure was suggested if results would impact isolation, 263 quarantine, personal protective equipment usage decisions, surgery eligibility, or inform 264 administration of immunosuppressive therapy. 29 In Australia, the national testing policy 265 emphasized defining and targeting high-risk settings, such as residential care facilities or 266 correctional facilities for testing. 30 In May 2020, the European Centre for Disease Prevention and 267

Control expanded the pool of individuals eligible for laboratory testing, resources permitting, to 268 include asymptomatic individuals in healthcare settings and long-term care facilities, to identify 269 potential sources of infection and protect vulnerable individuals. 13 270 271

In order to get accurate case counts, detecting both symptomatic and asymptomatic cases is 272 necessary due to the large proportion of COVID-19 cases presenting with no or mild 273 symptoms. 29 Inclusion of asymptomatic cases also impacts key epidemiological metrics, such as 274 incidence and the case fatality ratio. While expansive testing criteria will increase the likelihood 275 of capturing asymptomatic infections, they should be balanced against the burden for the public 276 health system in tracing and testing these eligible individuals. 30 This article is a US Government work. It is not subject to copyright under 17 USC 105 and is also made available (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. This article is a US Government work. It is not subject to copyright under 17 USC 105 and is also made available (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted May 14, 2021. ; 

This article is a US Government work. It is not subject to copyright under 17 USC 105 and is also made available (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted May 14, 2021. This article is a US Government work. It is not subject to copyright under 17 USC 105 and is also made available (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. This article is a US Government work. It is not subject to copyright under 17 USC 105 and is also made available (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. This article is a US Government work. It is not subject to copyright under 17 USC 105 and is also made available (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. This article is a US Government work. It is not subject to copyright under 17 USC 105 and is also made available (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. This article is a US Government work. It is not subject to copyright under 17 USC 105 and is also made available (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. This article is a US Government work. It is not subject to copyright under 17 USC 105 and is also made available (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (2) of the following signs and symptoms: fever (even if referred), chills, sore throat, headache, cough, runny nose, olfactory disorders or taste disorders. In children in addition to the previous items, nasal obstruction is also considered, in the absence of another specific diagnosis. In the elderly specific aggravation criteria such as syncope, mental confusion, excessive sleepiness, irritability and inappetence should also be considered. If COVID-19 is suspected, fever may be absent and gastrointestinal symptoms (diarrhea) may be present.

2. Individual with Influenza like illness who has: dyspnea / respiratory discomfort Or persistent pressure in the chest Or O 2 saturation less than 95% in room air Or bluish color of the lips or face. In children in addition to the previous items, observe the flapping of the nose, cyanosis, intercostal circulation, dehydration and lack of appetite.

Clinical manifestations of acute respiratory infection (ARI) (temperature above 37.5 ° C and one or more of the following: cough -dry or with scanty sputum, shortness of breath, feeling of congestion in the chest, satiety blood oxygen according to pulse oximetry (SpO2) ≤ 95%, sore throat, nasal congestion or mild rhinorrhea, impaired or loss of smell (hyposmia or anosmia), loss of taste (dysgeusia), conjunctivitis, weakness, muscle pain, headache, vomiting, diarrhea, skin rash) in the absence of other known causes, which explain the clinical picture regardless of the epidemiological anamnesis.

Person with exposure due to having been in a place with community transmission or endemic or outbreak or to probable cases, and with respiratory OR non-respiratory clinical manifestations of COVID-19, of any severity, clinical laboratory findings or radiological, belonging to groups of risk factors or vulnerability. Also asymptomatic individuals with exposure to probable or confirmed COVID-19 cases. Respiratory clinical manifestations: fever greater than 38°C, cough, fatigue, expectoration, shortness of breath / dyspnea, sore throat, rhinorrhea, Sp02 <93%. Non-respiratory clinical manifestations: anosmia, hyposmia, ageusia, dysgeusia, diarrhea, anorexia, nausea and vomiting, abdominal pain or discomfort, acute conjunctivitis, seizures, vertigo, headache, myalgia, skeletal muscle injuries, altered consciousness, acute cerebrovascular disease, ataxia, seizures, meningoencephalitis, Guillain-Barre syndrome, mental status disorders, hepatic compromise due to elevated aminotransferases, erythematous rash, hive rash, vesicles, acral ischemia, unilateral transient livedo reticularis, acute cardiac injury, heart failure arrhythmia, shock, acute myocarditis, chest tightness, acute kidney injury, urinary symptoms / cystitis, coagulation disorders, thrombotic events, antiphospholipid antibodies, hearing loss or hearing discomfort Clinical Laboratory and Radiological findings: Laboratory and non-etiological clinical diagnostic tests: Albumin Decrease (81%), CRP increase (79%) (MIS-C 94%), LDH increased (69.3%), Thrombocytosis (61%), Lymphopenia (57.5%, 25%, 56.5%), Interleukin 6 increased (56%), AST increase (37%), Leukopenia (28%, 25%), Leukocytosis (18.3%), Neutrophilia (MIS-C 83%), Thrombocytopenia (13%, 16.4-32.3%), Increase in D-dimer, Ferritin, Decrease in T3 and T 4 Troponin T (MIS-C 68%), pro BNP (MIS-C 77%). Pulmonary radiological findings Bilateral commitment (81%), Consolidation (73.5%), Ground Glass Opacity (73.5%), Abnormal echocardiogram (MIS-C 59%, 63%). Factors of Vulnerability: Health workers, Workers who serve in high volumes of public work in social protection, workers with high mobility due to occupational activity and internal Colombia migrants.

Person with Acute Respiratory Infection, who presents cough or pain from throat and at least one or more of the following signs / symptoms: General discomfort, Fever, Headache, Difficulty breathing, Nasal congestion.

for use under a CC0 license. This article is a US Government work. It is not subject to copyright under 17 USC 105 and is also made available (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted May 14, 2021. ; * These countries use a "Possible" case definition in place of a "Suspected" case definition †World Health Organization Definition ‡ European Centres for Disease Control and Prevention Definition 530 531 for use under a CC0 license. This article is a US Government work. It is not subject to copyright under 17 USC 105 and is also made available (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. This article is a US Government work. It is not subject to copyright under 17 USC 105 and is also made available (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted May 14, 2021. ; https://doi.org/10.1101/2021.05.11.21257047 doi: medRxiv preprint

Probable case by laboratory result: patient who meets the definition of a suspected case in which the PCR result is indeterminate or has a positive antigenic test for SARS-CoV-2

Probable case due to epidemiological link: person who has been in close contact with a confirmed case and develops fever (axillary temperature ~ 37.8) or at least two symptoms compatible with COVID-19 within 14 days of contact. The probable case due to an epidemiological link does not require an RT-PCR test for SARS-CoV-2. If for any reason, a probable case is carried out a confirmatory examination and it is positive

Probable case by imaging: suspicious case with negative RT-PCR result for SARS-CoV-2 but with a chest CT scan with characteristic images of COVID-19 according to the radiological report

Probable case due to symptoms: person with sudden and complete loss of smell (anosmia) or taste (ageusia) without an explanation

Any individual, irrespective of presence or absence of clinical signs and symptoms, who was laboratory confirmed for COVID-19 in a test conducted at the national reference laboratory, a subnational reference laboratory, and/or DOH-licensed COVID-19 testing laboratory

Any suspect or probable COVID-19 cases, who tested positive using antigen tests in areas without breaks and/or in remote settings where RT-PCR is not immediately available; provided that the antigen tests satisfy the recommended minimum regulatory, technical and operational specifications set by the Health Technology Assessment India A person with laboratory confirmation of 2019-nCoV infection, irrespective of clinical signs and symptoms. Pakistan USA Meets confirmatory laboratory evidence (Detection of severe acute respiratory syndrome coronavirus 2 ribonucleic acid (SARS-CoV-2 RNA)

Italy ‡ Any person meeting laboratory criteria (Detection of SARS-CoV-2 nucleic acid or antigen in a clinical specimen

Case of ILI or SARI with clinical confirmation associated with anosmia (olfactory dysfunction) OR ageusia (gustatory dysfunction) without any other previous cause

Case of ILI or SARI with history of close or home contact, in the 14 days prior to appearance of signs and symptoms with confirmed case

Case of ILI or SARI or death due to SARS that could not be confirmed by laboratory criteria AND that presents at least one (1) of the following tomographic changes: peripheral, bilateral, frosted glass opacity , with or without consolidation or visible intralobular lines ("paving"), Or Multifocal matte glass opacity with rounded morphology with or without consolidation or visible intralobular lines

Case of ILI or SARI with test of positive result for SARS-CoV-2 performed by the RT-PCR method in real time. Or REAGENT result for IgM, IgA and / or IgG * performed by the following methods: Immunoenzymatic assay

Immunochromatography (rapid test) for antibody detection

Or Antigen Search: reagent result for SARS-CoV-2 by the Immunochromatography method for antigen detection

Asymptomatic individuals with one of the following results: positive result for SARS-CoV-2 performed by the RT-PCR method in real time. Or immunological reagent result for IGM and / or IGA performed by the following methods: ELISA or Immunochromatography (rapid test) for antibody detection

Russia 1. A positive laboratory test result for the presence of RNA SARS-CoV-2 using nucleic acid amplification techniques (NAAT) or SARS-CoV-2 antigen using immunochromatographic analysis regardless of clinical manifestations. 2. Positive result for IgA, IgM and / or IgG antibodies in patients with a clinically confirmed COVID-19 infection

13-69%) or Antigen detection test (alternative diagnosis. May change according to new evidence)) with positive results of active infection by the SARS-CoV-2 virus regardless of the presence or absence of clinical criteria, since the tests can be performed in asymptomatic

Suspected case with a positive laboratory test for COVID 19, be it a reverse transcriptase polymerase chain reaction (RT-PCR) test in respiratory samples RT-PCR and / or a rapid IgM

RT-PCR), by molecular biology tests by loop-mediated isothermal amplification reaction (LAMP), or SARS-cov-2 antigens by non-molecular tests. Confirmatory diagnosis in suspected cases with mild / moderate symptoms, only during the first 7 days from the onset of symptoms 2. Confirmed by clinical / epidemiological criteria COVID-19: In the last 14 days Has been in close contact with a confirmed case OR Is part of a conglomerate of cases, with at least one case confirmed by laboratory, with no other defined diagnosis, and presenting two or more of the following symptoms: fever, cough, odynophagia, difficulty breathing, vomiting / diarrhea / headache / myalgia 3. Any person who, in the absence of any other identified cause, begins with: Sudden loss of taste or smell 4. Any deceased person who: Do not have a defined etiological diagnosis Has had a clinical picture compatible with COVID-19 (known by the certifying doctor or referred by third parties) Regardless of previous health status and that it has

1. Anyone (of any age) who has two or more of the following symptoms: Fever (37.5 ° C or more), Cough, Odynophagia, Shortness of breath, Headache, Myalgia, Diarrhea / vomiting, No other etiology that fully explains the clinical presentation. This criterion includes any severe acute respiratory infection 2. Sudden loss of taste or smell, in the absence of any other identified cause 3. Anyone who is a health worker, resides or works in closed or long-term institutions, is essential personnel, lives in popular neighborhoods or native towns, or had close contact of confirmed COVID-19 case, that within 14 days of contact AND has 1 or more of these symptoms: fever (37.5 ° C or higher), cough, odynophagia, shortness of breath, sudden loss of taste or smell.

Anyone with a clinical picture of acute respiratory infection of onset sudden of any severity that occurs, among others, with fever, cough or feeling of shortness of breath. Other symptoms such as odynophagia, anosmia, ageusia, muscle pain, diarrhea, chest pain or headache, among others may also be considered symptoms of suspected SARS-CoV-2 infection according to clinical judgment.

Person of any age who has had at least one of the following signs and symptoms in the last 10 days: cough, fever, dyspnea (serious condition) or headache. In children under five years of age, irritability can replace headache.Accompanied by at least one of the following minor signs or symptoms: Myalgia, Arthralgias, Odynophagia, Chills, chest pain, Rhinorrhea, Anosmia, dysgeusia, Conjunctivitis.

Any person presenting with an acute (≤10days) respiratory tract infection or other clinical illness compatible with COVID-19, or an asymptomatic person who is a close contact a of a confirmed case. Symptoms include ANY of the following respiratory symptoms: cough, sore throat, shortness of breath, anosmia (loss of sense of smell) or dysgeusia (alteration of the sense of taste), with or without other symptoms (which may include fever, weakness, myalgia, or diarrhea) 1. At least one of the following signs and symptoms: fever, cough, shortness of breath, sore throat, headache, muscle aches, loss of taste and smell, diarrhea AND The clinical picture cannot be explained by another cause / disease AND one of the following within 14 days before the onset of symptoms: he or close contact has history of being in a high-risk area for the disease or he has confirmed contact with a COVID-19 case.2. At least one of the signs and symptoms of fever and SARI (cough and respiratory distress), requiring hospitalization and the clinical picture cannot be explained by another cause / disease. SARI: The need for hospitalization due to fever, cough and dyspnea, tachypnea, hypoxemia, hypotension, diffuse radiological findings on lung imaging and change in consciousness in a patient with acute respiratory tract infection that developed in the last 14 days 3. Combination of at least two of the following signs and symptoms: fever, cough, shortness of breath, sore throat, headache, muscle aches, loss of taste and smell or diarrhea, and this situation cannot be explained by another cause / disease.

A person who has one of the following criteria: People with Acute Respiratory Infections (ARI) (namely fever (≥38oC) or a history of fever; and accompanied by any of the symptoms / signs of respiratory disease such as: cough / shortness of breath / sore throat / runny nose / pneumonia from mild to severe) * AND in the last 14 days before symptoms appeared had a history travel or live in a country / territory of Indonesia reporting local transmissions 2.People with any of the symptoms / signs of ARI AND in the last 14 days before symptoms develop had a history of contact with a confirmed / probable COVID-19 case. 3. People with severe ARD / severe pneumonia requiring hospitalization AND no other cause based on a convincing clinical picture.

Israel does not have official surveillance case definitions; individuals are considered suspect based on contact with confirmed cases determined by digital surveillance of cellphones Ukraine 1. A patient with acute respiratory illness (sudden onset, fever, and at least one of the following symptoms: cough or difficulty breathing), regardless of the need for hospitalization, and who 14 days before the onset of symptoms meets at least one of the following epidemiological criteria: Had contact with a confirmed or probable case of COVID-19 or visited or resided in a country / region with local transmission of the virus in the community according to WHO situation reports. Meets presumptive laboratory evidence (Detection of SARS-CoV-2 by antigen test in a respiratory specimen) 3. Meets vital records criteria with no confirmatory laboratory evidence Clinical Criteria: At least two of the following symptoms: fever (measured or subjective), chills, rigors, myalgia, headache, sore throat, nausea or vomiting, diarrhea, fatigue, congestion or runny nose OR At least one of the following symptoms: cough, shortness of breath, difficulty breathing, new olfactory disorder, new taste disorder OR Severe respiratory illness with at least one of the following: Clinical or radiographic evidence of pneumonia, Acute respiratory distress syndrome (ARDS). Epi Criteria: One or more of the following exposures in the prior 14 days: Close contact with a confirmed or probable case of COVID-19 disease; OR Member of a risk cohort as defined by public health authorities during an outbreak. Italy ‡ Any person meeting clinical criteria (at least one of the following symptoms: cough, fever, shortness of breath, sudden onset of anosmia, ageusia or dysgeusia) with Epi link (Close contact with confirmed case within 14 days prior to onset or having been a resident or staff in an institution with ongoing transmission within 14 days prior to onset) OR