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Covid 19: Where’s the strategy for testing?

BMJ 2020; 369 doi: https://doi.org/10.1136/bmj.m2518 (Published 26 June 2020) Cite this as: BMJ 2020;369:m2518

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Does Peru really have that high number of COVID-19 confirmed cases? The deception of combining RT-PCR and rapid test results

Dear Editor

As of June 30, Peru reported a total of 285,213 COVID-19 confirmed cases (1), which places Peru as the second country in Latin America only after Brazil (2) and sixth in the world with most cases. Even though Peru enabled the most restrictive measures in its national public health history to control the current outbreak (3), it seemed that it is not working as the number of confirmed cases keep increasing. The majority (75.06%) of reported confirmed cases are based on the rapid test (serological or antibody test)1, which has been reported to have low specificity and accuracy and it is currently banned by the Dubai Health Authority (4).

It is unclear why Peru combines the results of two tests that use different biological matrices, have significantly different sensitivity and specificity (5), and more importantly detect different moments of the COVID-19 infection (6). RT-PCR uses nasopharyngeal swab to detect viral RNA for a current infection, while rapid test uses blood to detect antibodies produced for a past infection (6). It has been recommended that states should not include serology or antibody tests within their overall COVID-19 testing numbers because that would cause a misrepresentation of their testing capacity and the extent to which they are working to identify COVID-19 infections within their communities (7).

It has been reported that the United States, currently the country with the highest number of cases, is also combining results of these two tests without any logical explanation (8). Based on our review it was unclear if the other countries (Brazil, Russia, India and the United Kingdom) that lead the total number of COVID-19 confirmed cases in the world are only reporting RT-PCR positive results or if they are combining them with rapid test results. We urge the Ministry of Health of Peru to revisit their methodology for reporting the total confirmed cases since this statistic is used to make decision as of when to lift the lockdown, currently until June 30. The phrase: “I rather die of COVID-19 than hunger” has become infamous in Peru. It clearly represents the economic burden that most of Peruvian citizens already have, which gets worsen by the mental distress burden of having erroneous and not scientifically sounded statistics that makes the Peruvian citizens believe their contagion risk is much higher than what it really is.

Conflict of interest: We declare no competing interests.

References:
1. MINSA. Sala Situacional COVID-19 Peru: Ministerio de Salud del Perú (MINSA); 2020 [Available from: https://covid19.minsa.gob.pe/sala_situacional.asp accessed 30 June 2020.
2. COVID-19 Dashboard by the Center for Systems Science and Engineering (CSSE) at Johns Hopkins University (JHU) 2019 [Available from: https://coronavirus.jhu.edu/map.html accessed 18 May 2020.
3. Alvarez-Risco A, Mejia CR, Delgado-Zegarra J, et al. The Peru Approach against the COVID-19 Infodemic: Insights and Strategies. The American Journal of Tropical Medicine and Hygiene 2020 doi: https://doi.org/10.4269/ajtmh.20-0536
4. El Sherif A. Dubai Health Authority bans rapid viral testing for COVID-19: HealthcareIT News; 2020 [Available from: https://www.healthcareitnews.com/news/europe/dubai-health-authority-bans... accessed 21 june 2020.
5. Watson J, Whiting PF, Brush JE. Interpreting a covid-19 test result. BMJ (Clinical research ed 2020;369:m1808. doi: 10.1136/bmj.m1808
6. CDC. Test for Past Infection (Antibody Test): Center for Disease Control; 2020 [Available from: https://www.cdc.gov/coronavirus/2019-ncov/testing/serology-overview.html accessed 21 June 2020.
7. Testing Hub. All State Comparison of Testing Efforts: Johns Hopkins University & Medicine Coronavirus Resource Center; 2020 [Available from: https://coronavirus.jhu.edu/testing/states-comparison accessed 21 June 2020.
8. Madrigal AC, Meyer R. How Could the CDC Make That Mistake? : The Atlantic; 2020 [Available from: https://www.theatlantic.com/health/archive/2020/05/cdc-and-states-are-mi... accessed 21 June 2020.

Competing interests: No competing interests

01 July 2020
Jaime A Yáñez
Professor
Aldo Alvarez-Risco (Universidad de Lima); Jaime Delgado-Zegarra (Universidad San Martin de Porres)
Universidad Peruana de Ciencias Aplicadas
Lima, Peru