To the Editors:
The Cuban Ministry of Public Health’s Protocol for Attention to COVID-19 Patients establishes that case confirmations are determined by positive virological tests of persons with and without symptoms.[1] These studies are carried out for SARS-CoV-2 by real-time polymerase chain reaction (RT-PCR) in specimens of respiratory mucosa collected via nasopharyngeal swab. The Protocol also establishes three types of discharge: microbiological (based on negative RT-PCR), clinical-imaging (no signs or symptoms and negative chest scan) and epidemiological (14 days after negative RT-PCR). A microbiological release from hospital is warranted when a patient tests negative by RT-PCR at nine days after testing positive.[1]
For organizing case management, it becomes important to assess the usefulness of this RT-PCR at nine days post-confirmation. At the Pedro Kourí Tropical Medicine Institute, we analyzed the percent of patients who tested negative on day 9, as well as those testing negative on days 10–14, 15–21 and 22–28. All COVID-19 patients released from the Institute from April through August 2020 were included: 153 total, 95 symptomatic and 58 asymptomatic.
RT-PCRs were negative on day 9 for 75% of cases (115), with statistically significant differences between symptomatic and asymptomatic patients: 68.4% of symptomatic (65) and 86.2% of asymptomatic (50) (p = 0.0228).
For the remaining groups, symptomatic and asymptomatic patients tested negative post diagnosis as follows:
- 10–14 days: 10 symptomatic (10.5%) vs. 4 asymptomatic (6.9%);
- 15–21 days: 15 (15.8%) vs. 2 (3.4%); and
- 22–28 days: 5 (5.3%) vs. 2 (3.4%).
The fact that 75% of patients tested negative on day 9 validates the usefulness of the current clinical conduct and its impact on reducing hospital burdens, freeing up beds for other patients if necessary.
We thank Dr María Guadalupe Guzmán-Tirado and Dr Daniel González-Rubio for their revision of the findings expressed in this letter.
- Ministry of Public Health (CU). Protocolo de actuación nacional para la COVID-19 [Internet]. Havana: Ministry of Public Health (CU); 2020 Aug [cited 2020 Aug 31]. 215 p. Available at: https://files.sld.cu/editorhome/files/2020/08/VERSION-5-DEL-PROTOCOLO-PARA-PUBLICAR-13-DE-AGOSTO-2020.pdf. Spanish.
Osvaldo Enrique Castro-Peraza MD MS (osvaldo@ipk.sld.cu), Pedro Kourí Tropical Medicine Institute, Havana, Cuba. https://orcid.org/0000-0002-7208-099X
Alina Martínez-Rodríguez MD MS, Pedro Kourí Tropical Medicine Institute, Havana, Cuba. https://orcid.org/0000-0002-9946-9399
