Covert cases of Severe Acute Respiratory Syndrome Coronavirus 2: An obscure but present danger in regions endemic for Dengue and Chikungunya viruses

Abstract

Background The impact of SARS-CoV-2 in regions endemic for both Dengue and Chikungunya is still not fully understood. Considering that symptoms/clinical features displayed during Dengue, Chikungunya and SARS-CoV-2 acute infections are similar, undiagnosed cases of SARS-CoV-2 in co-endemic areas may be more prevalent than expected. This study was conducted to assess the prevalence of covert cases of SARS-CoV-2 among samples from patients with clinical symptoms compatible with either Dengue or Chikungunya viral infection in the state of Espírito Santo, Brazil. Methods Presence of immunoglobulin G (IgG) antibody specific to SARS-CoV-2 nucleoprotein was detected using a chemiluminescent microparticle immunoassay in samples from 7,370 patients, without previous history of COVID-19 diagnosis, suspected of having either Dengue (n = 1,700) or Chikungunya (n = 7,349) from December 1st, 2019 to June 30th, 2020. Findings Covert cases of SARS-CoV-2 were detected in 210 (2.85%) out of the 7,370 serum samples tested. The earliest undiagnosed missed case of COVID-19 dated back to a sample collected on December 18, 2019, also positive for Dengue Virus. Cross-reactivity with either Dengue virus or other common coronaviruses were not observed. Interpretation Our findings demonstrate that concomitant Dengue or Chikungunya outbreaks may difficult the diagnosis of SARS-CoV-2 infections. To our knowledge, this is the first study to demonstrate, with a robust sample size (n = 7,370) and using highly specific and sensitive chemiluminescent microparticle immunoassay method, that covert SARS-CoV-2 infections are more frequent than previously expected in Dengue and Chikungunya hyperendemic regions. Moreover, our results suggest that SAR-CoV-2 cases were occurring prior to February, 2020, and that these undiagnosed missed cases may have contributed to the fast expansion of SARS-CoV-2 outbreak in Brazil. Data presented here demonstrate that in arboviral endemic regions, SARS-CoV-2 infection must be always considered, regardless of the existence of a previous positive diagnosis for Dengue or Chikungunya.

Decrypting the role of predicted SARS-CoV-2 miRNAs in COVID-19 pathogenesis: A bioinformatics approach

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Pulmonary hemorrhage in dengue: differential diagnosis with acute viral respiratory syndromes including COVID-19

“…However, some studies have shown that serology for COVID-19 can exhibit cross-reactivity with dengue even when protein S is used 17 , 18 . On the other hand, in the initial phase of both diseases, in which viremia peaks, the RT-PCR diagnostic tests for COVID-19 and the NS1 detection for dengue diagnosis have been identified as tools with good discriminatory capacity between these diseases 19 , 20 .…”

Epidemiological profile of covid-19 in the state of espírito santo, brazil, from march 2020 to june 2021

“…In a study that analyzed samples of 7,370 patients, without prior suspicion of COVID-19, but who had symptoms compatible with viral infections such as Dengue or Chikungunya, from December 1, 2019, to June 30, 2020, the results illustrated that 210 SARS-CoV-2 positive cases were detected. These hidden cases possibly indicate delays in seeing patients, which may have contributed to the rapid expansion of the COVID-19 outbreak 29 .…”