key: cord-0765630-3yfk3k51 authors: Noushad, Mohammed; Al Saqqaf, Inas Shakeeb title: COVID-19 case fatality rates can be highly misleading in resource poor and fragile nations: the case of Yemen date: 2021-01-08 journal: Clin Microbiol Infect DOI: 10.1016/j.cmi.2021.01.002 sha: 98f05b9fef571ad919a926ba7e1ceaea08620aaa doc_id: 765630 cord_uid: 3yfk3k51 During a disease outbreak, estimation of case fatality rate (CFR) is used as an indication of its severity, and a guide to plan public health strategies. Several factors affect the CFR of COVID-19 leading to false disparities between nations, especially resource poor and fragile nations. Therefore, CFRs of resource poor and fragile nations should be carefully interpreted considering all associated parameters, to serve as a guide in planning public health strategies, and channeling the limited resources and donations appropriately, taking into consideration other equally important healthcare needs in crippled healthcare systems. a specified time". To calculate the CFR, the number of deaths from a given disease (numerator) is divided by the number of diagnosed cases of that disease (denominator), multiplied by 100. 1 Underestimation of CFR may lead to the disease threat not being taken seriously, while overestimation may lead to unnecessary panic. Governments of certain nations with low CFR often boast about it as a sign of efficient management of the pandemic. However, apart from patient related factors like the presence of comorbidities, age distribution of the population, ethnicity, etc., several other factors affect the CFR of COVID-19 leading to false disparities between nations, especially resource poor and fragile nations. These include disparities in resources (shortage in healthcare professionals, testing capacities, etc.) and social and logistic problems associated with the ongoing conflict. Although CFR may be a useful measure to assess the magnitude of a disease outbreak, it could be highly inaccurate and misleading in certain resource poor and fragile nations, necessitating careful investigation and interpretation. For example, intentional or unintentional underreporting and lack of coordination between ministries and governorates can lead to wide inaccuracies in both the numerator and the denominator. This is especially true in war-torn nations that may be divided on the basis of different ruling factions. While a low case reporting will lead to an overestimation of the CFR, a low death registration will lead to its underestimation. Testing capacity, which is associated with the availability of resources and manpower is the single most important factor that can affect the CFR tremendously as more asymptomatic, and mildly symptomatic cases who are not likely to die are identified with increased testing. News media and scientific journal publications reporting on the CFR of fragile nations like Yemen have not considered this important parameter, thereby raising a false alarm and misleading readers. For example, the title of an article in a mainstream journal reads that "Covid-19: Deaths in Yemen are five times global average". 2 It should be noted that the same publication reports a case count of only 1600 (one of the lowest in the world, which is understandably an underestimation) in Yemen, after about three months from the first confirmed case. It is true that the reported CFR from COVID-19 in Yemen is several times the global average, but it does not necessarily represent the actual, primarily due to the severe shortage in testing capacity. If the actual CFR in Yemen was 29% as reported, we would be witnessing another humanitarian catastrophe with hundreds of thousands of fatalities. Although the crude mortality rate in Yemen stands at about 6 per 1000 people from 2013 (just before the beginning of the conflict) through 2018, the seven years-long conflict has killed more than 100,000 people so far and displaced 3.6 million people internally. 3, 4 With about 29 million people, the population density of Yemen is only 54 people/sq. km, with more than 95% of the population being under the age of 60 years. 5 Although largescale studies on COVID-19 CFR in Yemen are scarce, it has been shown that surveillance strategies in Yemen have detected mainly severe cases, with mortality occurring in those reaching health facilities in critical condition. This has been confirmed by a study that infections and 607 deaths. 7 On the other hand, Saudi Arabia which shares borders with Yemen and has a population similar to that of Yemen has a CFR of only about 1.6, even though the reported mortality is almost ten times higher. This is understandably due to its large-scale testing capacity leading to the identification of more than 359,000 infections (a high denominator). 8 Saudi Arabia is reported to have carried out at least 4 million tests by the middle of August 2020, whereas Yemen is capable of testing only highly suspected cases, or patients with severe symptoms who are likely to die, thereby increasing the CFR. 9 Considering the brief and slack lockdown, and nonadherence to preventive measures like social distancing and donning of mouth masks, there is good reason to believe that infections in Yemen may have been widespread but remain undetected due to the shortage of testing kits and facilities. In such a case-scenario, the CFR in Yemen would be tremendously lower than the reported 29%. Detecting fatality from COVID-19 may be subject to less bias than case detection, and since the probability of reporting to hospitals with severe symptoms is high, the probability of recording fatality also becomes higher, unless left out intentionally. A CFR close to the actual in Yemen will only become apparent when more testing kits are supplied and the testing capacity increased. Seroprevalence studies for COVID-19 have suggested that the number of reported infections at a given time is far lower than the actual, thereby suggesting a significant variation between the IFR and CFR. For example, a seroprevalence study in India suggested that the number of infections on 3 May 2020 was 6.4 million against the reported number of infections of only 49,720, a 130-fold difference. 11 Unfortunately, due to reasons mentioned earlier, seroprevalence studies are difficult to be carried out in war torn nations. So far, there have not been any seroprevalence studies for COVID-19 in Yemen. Healthcare systems of fragile nations are already overburdened by other disease outbreaks (like cholera, diphtheria, etc.), famine, malnutrition, injuries from the ongoing conflict, etc., and depend largely on humanitarian assistance from donor nations and non-governmental organizations for resources. 12 Therefore, CFRs of resource poor and fragile nations should be carefully interpreted considering all associated parameters, to identify deficiencies. This will serve as a guide in planning public health strategies, and channeling the limited resources and J o u r n a l P r e -p r o o f donations appropriately, taking into consideration other equally important healthcare needs in a crumbling healthcare system. No external funding was received. A Dictionary of Epidemiology Covid-19: Deaths in Yemen are five times global average as healthcare collapses Death rate, crude (per 1,000 people) -Yemen Estimating access to health care in Yemen, a complex humanitarian emergency setting: a descriptive applied geospatial analysis Population density (People per sq. km of land area) -Yemen The first 2 months of the SARS-CoV-2 epidemic in Yemen: Analysis of the surveillance data WHO. WHO Health Emergency Dashboard. WHO COVID-19 Homepage WHO. WHO Health Emergency Dashboard. WHO COVID-19 Homepage Over 4 million coronavirus tests conducted in Saudi Arabia so far, says ministry. Al Arabiya tests-conducted-in-Saudi-Arabia-so-far-says-ministry Infection Fatality Rate -A Critical Missing Piece for Managing Covid-19 Prevalence of SARS-CoV-2 infection in India: Findings from the national serosurvey Genomic insights into the Yemeni cholera epidemic The authors extend their appreciation to the Deanship of Post Graduate and ScientificResearch at Dar Al UIoom University for their support for this work