Epidemiology of COVID-19 infections on routine polymerase chain reaction (PCR) and serology testing in Coastal Kenya

Wellcome Open Research

article

James Nyagwange¹  Leonard Ndwiga¹  Kelvin Muteru¹  Kevin Wamae¹  James Tuju¹  COVID testing team¹  Bernadette Kutima¹  John Gitonga¹  Henry Karanja¹  Daisy Mugo¹  Kadondi Kasera²  Patrick Amoth²  Nickson Murunga¹  Lawrence Babu¹  Edward Otieno¹  George Githinji¹  D.J. Nokes¹  Benjamin Tsofa¹  Benedict Orindi¹  Edwine Barasa¹  George Warimwe¹  Charles N. Agoti¹  Philip Bejon¹  Lynette Isabella Ochola-Oyier¹ 

[1] Kenya Medical Research Institute;Ministry of Health

关键词: SARS-CoV-2;    COVID-19;    epidemiology;    serology;    RT-PCR;    ELISA;    clinical characteristics;   

DOI  :  10.12688/wellcomeopenres.17661.1

学科分类：内科医学

来源: Wellcome

【 摘 要 】

Background: There are limited studies in Africa describing the epidemiology, clinical characteristics and serostatus of individuals tested for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We tested routine samples from the Coastal part of Kenya between 17th March 2020 and 30th June 2021.Methods: SARS-CoV-2 infections identified using reverse transcription polymerase chain reaction (RT-PCR) and clinical surveillance data at the point of sample collection were used to classify as either symptomatic or asymptomatic. IgG antibodies were measured in sera samples, using a well validated in-house enzyme-linked immunosorbent assay (ELISA).Results: Mombasa accounted for 56.2% of all the 99,694 naso-pharyngeal/oro-pharyngeal swabs tested, and males constituted the majority tested (73.4%). A total of 7737 (7.7%) individuals were SARS-CoV-2 positive by RT-PCR. The majority (i.e., 92.4%) of the RT-PCR positive individuals were asymptomatic. Testing was dominated by mass screening and travellers, and even at health facility level 91.6% of tests were from individuals without symptoms. Out of the 97,124 tests from asymptomatic individuals 7,149 (7%) were positive and of the 2,568 symptomatic individuals 588 (23%) were positive. In total, 2458 serum samples were submitted with paired naso-pharyngeal/oro-pharyngeal samples and 45% of the RT-PCR positive samples and 20% of the RT-PCR negative samples were paired with positive serum samples. Symptomatic individuals had significantly higher antibody levels than asymptomatic individuals and become RT-PCR negative on repeat testing earlier than asymptomatic individuals.Conclusions: In conclusion, the majority of SARS-CoV-2 infections identified by routine testing in Coastal Kenya were asymptomatic. This reflects the testing practice of health services in Kenya, but also implies that asymptomatic infection is very common in the population. Symptomatic infection may be less common, or it may be that individuals do not present for testing when they have symptoms.

【 授权许可】

CC BY