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. 2022 Jan 4;22(1):21.
doi: 10.1186/s12879-021-07003-9.

SARS-CoV2 infection in symptomatic patients: interest of serological tests and predictors of mortality: experience of DR Congo

Jean-Robert Makulo  1 , Madone Ndona Mandina  1 , Placide Kingebeni Mbala  1   2 , Roger Dimosi Wumba  1 , Pierre Zalagile Akilimali  3 , Yannick Mayamba Nlandu  4 , Jerome Ossam Odio  1 , Ben Izizag Bepouka  1 , Murielle Mashi Longokolo  1 , Eric Kasongo Mukenge  1 , Guyguy Kamwiziku  1 , Jonathan Mutombo Muamba  1 , Augustin Luzayadio Longo  1 , Crispin Muanza Lufu  2 , Hervé Letin Keke  2 , Marcel Mambimbi Mbula  1 , Hippolyte Nanituma Situakibanza  1 , Ernest Kiswaya Sumaili  1 , Jean-Marie Ntuma Kayembe  1   2
Affiliations

SARS-CoV2 infection in symptomatic patients: interest of serological tests and predictors of mortality: experience of DR Congo

Jean-Robert Makulo et al. BMC Infect Dis. .

Abstract

Background: In symptomatic patients, the diagnostic approach of COVID-19 should be holistic. We aimed to evaluate the concordance between RT-PCR and serological tests (IgM/IgG), and identify the factors that best predict mortality (clinical stages or viral load).

Methods: The study included 242 patients referred to the University hospital of Kinshasa for suspected COVID-19, dyspnea or ARDS between June 1st, 2020 and August 02, 2020. Both antibody-SARS-CoV2 IgM/IgG and RT-PCR method were performed on the day of admission to hospital. The clinical stages were established according to the COVID-19 WHO classification. The viral load was expressed by the CtN2 (cycle threshold value of the nucleoproteins) and the CtE (envelope) genes of SARS- CoV-2 detected using GeneXpert. Kappa test and Cox regression were used as appropriate.

Results: The GeneXpert was positive in 74 patients (30.6%). Seventy two patients (29.8%) had positive IgM and 34 patients (14.0%) had positive IgG. The combination of RT-PCR and serological tests made it possible to treat 104 patients as having COVID-19, which represented an increase in cases of around 41% compared to the result based on GeneXpert alone. The comparison between the two tests has shown that 57 patients (23.5%) had discordant results. The Kappa coefficient was 0.451 (p < 0.001). We recorded 23 deaths (22.1%) among the COVID-19 patients vs 8 deaths (5.8%) among other patients. The severe-critical clinical stage increased the risk of mortality vs. mild-moderate stage (aHR: 26.8, p < 0.001). The values of CtE and CtN2 did not influence mortality significantly.

Conclusion: In symptomatic patients, serological tests are a support which makes it possible to refer patients to the dedicated COVID-19 units and treat a greater number of COVID-19 patients. WHO Clinical classification seems to predict mortality better than SARS-Cov2 viral load.

Keywords: COVID-19; Concordance; Mortality; RT-PCR; Serological tests; Symptomatic patients.

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Conflict of interest statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be considered as a potential conflict of interest.

Figures

Fig. 1
Fig. 1
Survival according to WHO COVID-19 clinical classification
Fig. 2
Fig. 2
Survival according to viral load expressed by CtE
Fig. 3
Fig. 3
Survival according to viral load expressed by CtN2
Fig. 4
Fig. 4
Survival curves according to patient age
Fig. 5
Fig. 5
Survival curves of COVID-19 vs non COVID-19 patients
Fig. 6
Fig. 6
Survival curves of COVID-19 patients according to the clinical stage of the disease
Fig. 7
Fig. 7
Survival curves as a function of the CtN2 value
Fig. 8
Fig. 8
Survival curves as a function of the CtE value
See this image and copyright information in PMC

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