Infection fatality risk for SARS-CoV-2 in community dwelling population of Spain: nationwide seroepidemiological study
BMJ 2020; 371 doi: https://doi.org/10.1136/bmj.m4509 (Published 27 November 2020) Cite this as: BMJ 2020;371:m4509Read our latest coverage of the coronavirus outbreak

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Dear Editor
It was very enlightening to read this article by Pastor-Barriuso, R., et al entitled “Infection fatality risk for SARS-CoV-2 in community dwelling population of Spain: nationwide seroepidemiological study.” It’s a given fact that as people get older, their body slowly deteriorates and comorbidities creep in which increases their vulnerability. With the advent of Covid-19, a substantial number of the elderly have fallen victim to this disease, causing their demise.
Research has shown that with increase health complications, the elderly are an easy target for mortality related to covid-19 infections. According to Burn et al, “The higher mortality in elderly people might result from a greater number of comorbidities (cardiovascular disease, type 2 diabetes, lung and chronic kidney diseases)” (Burn et al., 2020). Pastor-Barriuso, R., et al found that elderly men are more prone to dying from Covid-19 complications than women, due to smoking and alcohol consumption. In men aged 80 or older, the infection fatality risk estimate was 11.6% (95% confidence interval 8.1% to 16.5%) for deaths with confirmed covid-19 and 16.4% (11.4% to 23.2%) for excess deaths. In women aged 80 or older, the corresponding estimates were 4.6% (3.4% to 6.3%) and 6.5% (4.7% to 8.8%) (Pastor-Barriuso, 2020). With such compelling statistics, it is necessary that we aim to protect the elderly from this life changing infection.
It is our belief that the nutritional status of the elderly does play a part in the progression of Covid-19 and their ability to combat the infection. T. Li et al concluded that among Covid-19 patients, the elderly had the worse prognosis, which maybe due to the poor nutritional status of the elderly. Furthermore, Corcoran C et al also found evidence that the elderly are more prone to malnutrition. Our cross-sectional study found that 27.5% of patients over 65 years old were at risk of malnutrition and 52.7% were malnourished, which was generally higher than that of elderly patients with other disease spectrums (Corcoran, Murphy, Culligan, Walton, & Sleator, 2019). We strongly suggest proper nutritional planning for the elderly, to strengthen their bodies and boost their immune system for fighting off Covid-19.
Burn, E., Tebe, C., Fernandez-Bertolin, S., Aragon, M., Recalde, M., Roel, E., . . . Duarte-Salles, T. (2020). The natural history of symptomatic COVID-19 in Catalonia, Spain: a multi-state model including 109,367 outpatient diagnoses, 18,019 hospitalisations, and 5,585 COVID-19 deaths among 5,627,520 people. MedRxiv.
Corcoran, C., Murphy, C., Culligan, E. P., Walton, J., & Sleator, R. D. (2019). Malnutrition in the elderly. Science Progress, 102(2), 171-180.
Pastor-Barriuso, R., et al. (2020). Infection fatality risk for SARS-CoV-2 in community dwelling population of Spain: nationwide seroepidemiological study. The BMJ, 371:m4509. doi:https://doi.org/10.1136/bmj.m4509
Competing interests: No competing interests
Dear Editor
Is the infection fatality rate for COVID-19 worse than that for influenza?
Pastor-Barriuso et al. found an infection fatality rate for COVID-19 of 0.8% in Spain (1). They quote an unpublished review that found 0.68%, with estimates ranging from 0.16% to 1.60% (2). In their discussion, they mention this review again: “Our overall estimate of infection fatality risk was similar to that found in seroepidemiological surveys with a low risk of bias.”
But what about other reviews? They quote in the introduction a 2020 review by John Ioannidis, which is in press in the Bulletin of the World Health Organization, (3) but do not say what he found, only that the magnitude of the infection fatality risk is being debated. Sure, but that is not informative.
Ioannidis included 61 studies (74 estimates) and eight preliminary national estimates. He reported that the infection fatality rates ranged from 0.00% to 1.63% and that the median rate was 0.27% (3).
Pastor-Barriuso et al. concluded that the infection fatality rate they found was about 10 times larger than those for seasonal influenza. They quoted the US Centers for Disease Control (4), but this agency may be a highly unreliable source when it comes to influenza (5).
Infection fatality rates for virus infections depend on the infectious dose (5), which is higher in settings with overcrowding. We can therefore only estimate death rates approximately. In outbreaks of measles, a commonly used estimate is 0.2%, but it can be many times higher. When measles hit a nonimmune population in the Faroe Islands in 1846, 78% were attacked and the case fatality rate was 2.8%, over 10 times higher than the usual rate of 0.2% (5, 6).
It is therefore not surprising that for influenza, as for all viral diseases, there are huge variations in reported case-fatality rates. In a systematic review, the median was about 1% for laboratory confirmed influenza during the mild influenza pandemic in 2009 and the following years (estimated by me from figure 3 in the paper) (7).
These data contradict the assertion by Pastor-Barriuso et al. that the infection fatality rate for COVID-19 is about 10 times larger than that for influenza. It seems to be about the same. In Denmark, when blood donors were tested for coronavirus antibodies, the death rate for COVID-19 was only 0.16% (8).
Pastor-Barriuso et al. concluded that their result supports existing measures, “e.g. social distancing, face masks, and educational campaigns.”
I disagree. The infection fatality rate seems to be about the same as for influenza, but we have never introduced these drastic measures before, when we had influenza pandemics. And we cannot live with them for years to come. The World Bank has just estimated that the corona pandemic has caused an increase of about 100 million people living in extreme poverty (9). This is not because of COVID-19. It is because of the draconian measures we have introduced. We need a better strategy.
1 Pastor-Barriuso R, Pérez-Gómez B, Hernán MA, et al. Infection fatality risk for SARS-CoV-2 in community dwelling population of Spain: nationwide seroepidemiological study. BMJ 2020;371:m4509ht.
2 Meyerowitz-Katz G, Merone L. A systematic review and meta-analysis of published research data on COVID-19 infection fatality rates. Int J Infect Dis 2020;101:138-48. doi:10.1016/j.ijid.2020.09.146.
3 Ioannidis J. Infection fatality rate of COVID-19 inferred from seroprevalence data. Bull World Health Organ (in press). https://www.who.int/bulletin/online_first/BLT.20.265892.pdf.
4 Centers for Disease Control and Prevention. Disease burden of influenza. 2020. https://www.cdc.gov/flu/about/burden/index.html.
5 Gøtzsche PC. Vaccines: truth, lies and controversy. Copenhagen: People’s Press; 2020.
6 Panum PL. Observations made during the epidemic of measles on the Faroe Islands in the year 1846.
http://www.med.mcgill.ca/epidemiology/courses/EPIB591/Fall%202010/mid-te....
7 Ahmed F, Lindley M, Allred N, et al. Effect of influenza vaccination of healthcare personnel on morbidity and
mortality among patients: systematic review and grading of evidence. Clin Infect Dis 2014;58:50-7.
8 Jørgensen AS. Dødelighed skal formentlig tælles i promiller: Danske blodprøver kaster nyt lys over coronasmitten.
DR TV 2020; Apr 8.
9 COVID-19 to Add as Many as 150 Million Extreme Poor by 2021. World Bank 2010; Oct 7. https://www.worldbank.org/en/news/press-release/2020/10/07/covid-19-to-a....
Competing interests: No competing interests
Use of the Nasalferon to foreign travelers in Cuba.
Dear Editor
Cuba began applying Nasalferon on January 7 to travelers and their families, a drug from the Cuban biotechnology industry to prevent the transmission of SARS-CoV-2, and strengthen the immune system. Nasalferon is a recombinant human IFN-alpha-2b-formulation for nasal administration that, thanks to the immunomodulatory and antiviral properties of IFN-alpha, achieves protection against exposure to the virus, the medicine is applied in two moments, in the morning and at night, through drops in the nasal route, for a time between five and 10 days. According to the research report carried out by the Center for Genetic Engineering and Biotechnology (CIGB) to contribute to the control of the COVID-19 epidemic, it was shown that the passage of Interferon into the blood, detecting the maximum concentration levels at 30- 45 minutes after nasal administration, evidence of increases in the markers of innate antiviral and immune responses at the level of the oropharyngeal mucosa and in peripheral blood lymphocytes. Specialists say that it prevents the replication of the disease and modifies the number of colonies present in the body. It also strengthens the immune system and ensures that if the person becomes infected they do not develop severe symptoms
Competing interests: No competing interests