Corpus overview


MeSH Disease

Human Phenotype

Fever (16)

Cough (12)

Pneumonia (10)

Anosmia (7)

Fatigue (4)


    displaying 1 - 10 records in total 115
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    High prevalence SERO of symptoms among Brazilian subjects with antibodies SERO against SARS-CoV-2: a nationwide household survey

    Authors: Ana Maria Baptista Menezes; Cesar G Victora; Fernando P Hartwig; Mariangela F Silveira; Bernardo L Horta; Aluisio J D Barros; Fernando C Whermeister; Marilia A Mesenburg; Lucia C Pellanda; Odir A Dellagostin; Claudio J Struchiner; Marcelo N Burattini; Fernando C Barros; Pedro C Hallal

    doi:10.1101/2020.08.10.20171942 Date: 2020-08-12 Source: medRxiv

    Since the beginning of the pandemic of COVID-19, there has been a widespread assumption that most infected persons are asymptomatic TRANS. A frequently-cited early study from China suggested that 86% of all infections MESHD were undocumented, which was used as indirect evidence that patients were asymptomatic TRANS. Using data from the most recent wave of the EPICOVID19 study, a nationwide household-based survey including 133 cities from all states of Brazil, we estimated the proportion of people with and without antibodies for SARS-CoV-2 SERO who were asymptomatic TRANS, which symptoms were most frequently reported, the number of symptoms reported and the association between symptomatology and socio-demographic characteristics. We were able to test 33,205 subjects using a rapid antibody test SERO that was previously validated. Information on symptoms was collected before participants received the test result. Out of 849 (2.7%) participants who tested positive for SARS-CoV-2 antibodies SERO, only 12.1% (95%CI 10.1-14.5) reported no symptoms since the start of the pandemic, compared to 42.2% (95%CI 41.7-42.8) among those who tested negative. The largest difference between the two groups was observed for changes in smell or taste (56.5% versus 9.1%, a 6.2-fold difference). Symptoms change in smell or taste, fever MESHD fever HP and myalgia MESHD myalgia HP were most likely to predict positive test results as suggested by recursive partitioning tree analysis. Among individuals without any of these three symptoms (74.2% of the sample), only 0.8% tested positive, compared to 18.3% of those with both fever MESHD fever HP and changes in smell or taste. Most subjects with antibodies SERO against SARS-CoV-2 in Brazil are symptomatic, even though most present only mild symptoms.

    High prevalence SERO of SARS-CoV-2 antibodies SERO in care homes affected by COVID-19; a prospective cohort study in England

    Authors: Shamez N Ladhani; Anna J Jeffery-Smith; Monika Patel; Roshni Janarthanan; Jonathan Fok; Emma Crawley-Boevey; Amoolya Vusirikala; Elena Fernandez; Marina Sanchez-Perez; Suzanne Tang; Kate Dun-Campbell; Edward Wynne-Evans; Anita Bell; Bharat Patel; Zahin Amin-Chowdhury; Felicity Aiano; Karthik Paranthaman; Thomas Ma; Maria Saavedra-Campos; Joanna Ellis; Meera Chand; Kevin Brown; Mary E Ramsay; Susan Hopkins; Nandini Shetty; J Yimmy Chow; Robin Gopal; Maria Zambon

    doi:10.1101/2020.08.10.20171413 Date: 2020-08-12 Source: medRxiv

    Background: We investigated six London care homes experiencing a COVID-19 outbreak and found very high rates of SARS-CoV-2 infection MESHD among residents and staff. Here we report follow-up serological analysis in these care homes five weeks later. Methods: Residents and staff had a convalescent blood SERO sample for SARS-CoV-2 antibody SERO levels and neutralising antibodies SERO by SARS-COV-2 RT-PCR five weeks after the primary COVID-19 outbreak investigation. Results: Of the 518 residents and staff in the initial investigation, 208/241 (86.3%) surviving residents and 186/254 (73.2%) staff underwent serological testing SERO. Almost all SARS-CoV-2 RT-PCR positive residents and staff were antibody SERO positive five weeks later, whether symptomatic (residents 35/35, 100%; staff, 22/22, 100%) or asymptomatic TRANS (residents 32/33, 97.0%; staff 21/22, 95.1%). Symptomatic but SARS-CoV-2 RT-PCR negative residents and staff also had high seropositivity rates (residents 23/27, 85.2%; staff 18/21, 85.7%), as did asymptomatic TRANS RT-PCR negative individuals (residents 62/92, 67.3%; staff 95/143, 66.4%). Neutralising antibody SERO was present in 118/132 (89.4%) seropositive individuals and was not associated with age TRANS or symptoms. Ten residents (10/108, 9.3%) remained RT-PCR positive, but with lower RT-PCR cycle threshold values; all 7 tested were seropositive. New infections MESHD were detected in three residents and one staff member. Conclusions: RT-PCR testing for SARS-CoV-2 significantly underestimates the true extent of an outbreak in institutional settings. Elderly TRANS frail residents and younger healthier staff were equally able to mount robust and neutralizing antibody SERO responses to SARS-CoV-2. More than two-thirds of residents and staff members had detectable antibodies SERO against SARS-CoV-2 irrespective of their nasal swab RT-PCR positivity or symptoms status.

    CRISPR-based and RT-qPCR surveillance of SARS-CoV-2 in asymptomatic TRANS individuals uncovers a shift in viral prevalence SERO among a university population

    Authors: Jennifer N Rauch; Eric Valois; Jose Carlos Ponce-Rojas; Zach Aralis; Ryan L Lach; Francesca Zappa; Morgane Audouard; Sabrina C Solley; Chinmay Vaidya; Michael Costello; Holly Smith; Ali Javanbakht; Betsy Malear; Laura Polito; Stewart Comer; Katherine Arn; Kenneth S Kosik; Diego Acosta-Alvear; Maxwell Z Wilson; Lynn Fitzgibbons; Carolina Arias

    doi:10.1101/2020.08.06.20169771 Date: 2020-08-07 Source: medRxiv

    Background: The progress of the COVID-19 pandemic profoundly impacts the health of communities around the world, with unique impacts on colleges and universities. Transmission TRANS of SARS-CoV-2 by asymptomatic TRANS people is thought to be the underlying cause of a large proportion of new infections MESHD. However, the local prevalence SERO of asymptomatic TRANS and pre-symptomatic carriers TRANS of SARS-CoV-2 is influenced by local public health restrictions and the community setting. Objectives: This study has three main objectives. First, we looked to establish the prevalence SERO of asymptomatic TRANS SARS-CoV-2 infection MESHD on a university campus in California. Second, we sought to assess the changes in viral prevalence SERO associated with the shifting community conditions related to non-pharmaceutical interventions (NPIs). Third, we aimed to compare the performance SERO of CRISPR- and PCR-based assays for large-scale virus surveillance sampling in COVID-19 asymptomatic TRANS persons. Methods: We enrolled 1,808 asymptomatic TRANS persons for self-collection of oropharyngeal (OP) samples to undergo SARS-CoV-2 testing. We compared viral prevalence SERO in samples obtained in two time periods: May 28th-June 11th; June 23rd-July 2nd. We detected viral genomes in these samples using two assays: CREST, a CRISPR-based method recently developed at UCSB, and the RT-qPCR test recommended by US Centers for Disease MESHD Control and Prevention (CDC). Results: Of the 1,808 participants, 1,805 were affiliates of the University of California, Santa Barbara, and 1,306 were students. None of the tests performed on the 732 samples collected between late May to early June were positive. In contrast, tests performed on the 1076 samples collected between late June to early July, revealed nine positive cases. This change in prevalence SERO met statistical significance, p = 0.013. One sample was positive by RT-qPCR at the threshold of detection, but negative by both CREST and CLIA-confirmation testing. With this single exception, there was perfect concordance in both positive and negative results obtained by RT-qPCR and CREST. The estimated prevalence SERO of the virus, calculated using the confirmed cases TRANS, was 0.74%. The average age TRANS of our sample population was 28.33 (18-75) years, and the average age TRANS of the positive cases was 21.7 years (19-30). Conclusions: Our study revealed that there were no COVID-19 cases in our study population in May/June. Using the same methods, we demonstrated a substantial shift in prevalence SERO approximately one month later, which coincided with changes in community restrictions and public interactions. This increase in prevalence SERO, in a young and asymptomatic TRANS population which would not have otherwise accessed COVID-19 testing, indicated the leading wave of a local outbreak, and coincided with rising case counts in the surrounding county and the state of California. Our results substantiate that large, population-level asymptomatic TRANS screening using self-collection may be a feasible and instructive aspect of the public health approach within large campus communities, and the almost perfect concordance between CRISPR- and PCR-based assays indicate expanded options for surveillance testing

    An improved methodology for estimating the prevalence SERO of SARS-CoV-2

    Authors: Virag Patel; Catherine McCarthy; Rachel A Taylor; Ruth Moir; Louise A Kelly; Emma L Snary

    doi:10.1101/2020.08.04.20168187 Date: 2020-08-06 Source: medRxiv

    Since the identification of Coronavirus disease MESHD 2019 (COVID-19) caused by severe acute respiratory syndrome MESHD coronavirus 2 (SARS-CoV-2) in China in December 2019, there have been more than 17 million cases of the disease MESHD in 216 countries worldwide. Comparisons of prevalence SERO estimates between different communities can inform policy decisions regarding safe travel TRANS between countries, help to assess when to implement (or remove) disease MESHD control measures and identify the risk of over-burdening healthcare providers. Estimating the true prevalence SERO can, however, be challenging because officially reported figures are likely to be significant underestimates of the true burden of COVID-19 within a community. Previous methods for estimating the prevalence SERO fail to incorporate differences between populations (such as younger populations having higher rates of asymptomatic TRANS cases) and so comparisons between, for example, countries, can be misleading. Here, we present an improved methodology for estimating COVID-19 prevalence SERO. We take the reported number of cases and deaths MESHD (together with population size) as raw prevalence SERO for the population. We then apply an age TRANS-adjustment to this which allows the age TRANS-distribution of that population to influence the case-fatality rate and the proportion of asymptomatic TRANS cases. Finally, we calculate the likely underreporting factor for the population and use this to adjust our prevalence SERO estimate further. We use our method to estimate the prevalence SERO for 166 countries (or the states of the United States of America, hereafter referred to as US state) where sufficient data were available. Our estimates show that as of the 30th July 2020, the top three countries with the highest estimated prevalence SERO are Brazil (1.26%, 95% CI: 0.96 - 1.37), Kyrgyzstan (1.10%, 95% CI: 0.82 - 1.19) and Suriname (0.58%, 95% CI: 0.44 - 0.63). Brazil is predicted to have the largest proportion of all the current global cases (30.41%, 95%CI: 27.52 - 30.84), followed by the USA (14.52%, 95%CI: 14.26 - 16.34) and India (11.23%, 95%CI: 11.11 - 11.24). Amongst the US states, the highest prevalence SERO is predicted to be in Louisiana (1.07%, 95% CI: 1.02 - 1.12), Florida (0.90%, 95% CI: 0.86 - 0.94) and Mississippi (0.77%, 95% CI: 0.74 - 0.81) whereas amongst European countries, the highest prevalence SERO is predicted to be in Montenegro (0.47%, 95% CI: 0.42 - 0.50), Kosovo (0.35%, 95% CI: 0.29 - 0.37) and Moldova (0.28%, 95% CI: 0.23 - 0.30). Our results suggest that Kyrgyzstan (0.04 tests per predicted case), Brazil (0.04 tests per predicted case) and Suriname (0.29 tests per predicted case) have the highest underreporting out of the countries in the top 25 prevalence SERO. In comparison, Israel (34.19 tests per predicted case), Bahrain (19.82 per predicted case) and Palestine (9.81 tests per predicted case) have the least underreporting. The results of this study may be used to understand the risk between different geographical areas and highlight regions where the prevalence SERO of COVID-19 is increasing most rapidly. The method described is quick and easy to implement. Prevalence SERO estimates should be updated on a regular basis to allow for rapid fluctuations in disease MESHD patterns.

    Seroprevalence SERO of SARS-CoV-2-Specific IgG Antibodies SERO Among Adults TRANS Living in Connecticut Between March 1 and June 1, 2020: Post- Infection MESHD Prevalence SERO (PIP) Study

    Authors: Shiwani Mahajan; Rajesh Srinivasan; Carrie A Redlich; Sara K Huston; Kelly M Anastasio; Lisa Cashman; Dan Witters; Jenny Marlar; Shu-Xia Li; Zhenqiu Lin; Domonique Hodge; Manas Chattopadhyay; Mark D Adams; Charles Lee; Lokinendi V Rao; Chris Stewart; Karthik Kuppusamy; Albert I Ko; Harlan M Krumholz

    doi:10.1101/2020.08.04.20168203 Date: 2020-08-06 Source: medRxiv

    Importance: A seroprevalence SERO study can estimate the percentage of people with SARS-CoV-2 antibodies SERO in the general population. Most existing reports have used a convenience sample, which may bias their estimates. Objective: To estimate the seroprevalence SERO of antibodies SERO against SARS-CoV-2 based on a random sample of adults TRANS living in Connecticut between March 1 and June 1, 2020. Design: Cross-sectional. Setting: We sought a representative sample of Connecticut residents who completed a survey between June 4 and June 23, 2020 and underwent serology testing for SARS-CoV-2-specific IgG antibodies SERO between June 10 and July 6, 2020. Participants: 505 respondents, aged TRANS [≥]18 years, residing in non-congregate settings who completed both the survey and the serology test. Main outcomes and measures: We estimated the seroprevalence SERO of SARS-CoV-2-specific IgG antibodies SERO among the overall population and across pre-specified subgroups. We also assessed the prevalence SERO of symptomatic illness, risk factors for virus exposure, and self-reported adherence to risk mitigation behaviors among this population. Results: Of the 505 respondents (mean age TRANS 50 [{+/-}17] years; 54% women; 76% non-Hispanic White individuals) included, 32% reported having at least 1 symptom suggestive of COVID-19 since March 1, 2020. Overall, 18 respondents had SARS-CoV-2-specific antibodies SERO, resulting in the state-level weighted seroprevalence SERO of 3.1 (90% CI 1.4-4.8). Individuals who were asymptomatic TRANS had significantly lower seroprevalence SERO (0.6% [90% CI 0.0-1.5]) compared with the overall state estimate, while those who reported having had [≥]1 and [≥]2 symptoms had a seroprevalence SERO of 8.0% (90% CI 3.1-12.9) and 13.0% (90% CI 3.5-22.5), respectively. All 9 of the respondents who reported previously having a positive coronavirus test were positive for SARS-CoV-2-specific IgG antibodies SERO. Nearly two-third of respondents reported having avoided public places (74%) and small gatherings of family or friends TRANS (75%), and 97% reported wearing a mask outside their home, at least part of the time. Conclusions and relevance: These estimates indicate that most people in Connecticut do not have detectable levels of antibodies SERO against SARS-CoV-2. There is a need for continued adherence to risk mitigation behaviors among Connecticut residents, to prevent resurgence of COVID-19 in this region.

    Transient dynamics of SARS-CoV-2 as England exited national lockdown

    Authors: Steven Riley; Kylie E. C. Ainslie; Oliver Eales; Caroline E Walters; Haowei Wang; Christina J Atchison; Peter Diggle; Deborah Ashby; Christl A. Donnelly; Graham Cooke; Wendy Barclay; Helen Ward; Ara Darzi; Paul Elliott

    doi:10.1101/2020.08.05.20169078 Date: 2020-08-06 Source: medRxiv

    Control of the COVID-19 pandemic requires a detailed understanding of prevalence SERO of SARS-CoV-2 virus in the population. Case-based surveillance is necessarily biased towards symptomatic individuals and sensitive to varying patterns of reporting in space and time. The real-time assessment of community transmission TRANS antigen study (REACT-1) is designed to overcome these limitations by obtaining prevalence SERO data based on a nose and throat swab RT-PCR test among a representative community-based sample in England, including asymptomatic TRANS individuals. Here, we describe results comparing rounds 1 and 2 carried out during May and mid June / early July 2020 respectively across 315 lower tier local authority areas. In round 1 we found 159 positive samples from 120,620 tested swabs while round 2 there were 123 positive samples from 159,199 tested swabs, indicating a downwards trend in prevalence SERO from 0.13% (95% CI, 0.11%, 0.15%) to 0.077% (0.065%, 0.092%), a halving time of 38 (28, 58) days, and an R of 0.89 (0.86, 0.93). The proportion of swab-positive participants who were asymptomatic TRANS at the time of sampling increased from 69% (61%, 76%) in round 1 to 81% (73%, 87%) in round 2. Although health care and care home workers were infected far more frequently than other workers in round 1, the odds were markedly reduced in round 2. Age TRANS patterns of infection MESHD changed between rounds, with a reduction by a factor of five in prevalence SERO in 18 to 24 year olds. Our data were suggestive of increased risk of infection TRANS risk of infection TRANS infection MESHD in Black and Asian (mainly South Asian) ethnicities. Using regional and detailed case location data, we detected increased infection MESHD intensity in and near London. Under multiple sensitivity SERO analyses, our results were robust to the possibility of false positives. At the end of the initial lockdown in England, we found continued decline in prevalence SERO and a shift in the pattern of infection MESHD by age TRANS and occupation. Community-based sampling, including asymptomatic TRANS individuals, is necessary to fully understand the nature of ongoing transmission TRANS.

    Seroprevalence SERO of COVID-19 in Niger State

    Authors: Hussaini Majiya; Mohammed Aliyu-Paiko; Vincent Tochukwu Balogu; Dickson Achimugu Musa; Ibrahim Maikudi Salihu; Abdullahi Abubakar Kawu; Ishaq Yakubu Bashir; Aishat Rabiu Sani; John Baba; Amina Tako Muhammad; Fatima Ladidi Jibril; Ezekiel Bala; Nuhu George Obaje; Yahaya Badeggi Aliyu; Ramatu Gogo Muhammad; Hadiza Mohammed; Usman Naji Gimba; Abduljaleel Uthman; Hadiza Muhammad Liman; Sule Alfa Alhaji; Joseph Kolo James; Muhammad Muhammad Makusidi; Mohammed Danasabe Isah; Ibrahim Abdullahi; Umar Ndagi; Bala Waziri; Chindo Ibrahim Bisallah; Naomi John Dadi-Mamud; Kolo Ibrahim; Abu Kasim Adamu

    doi:10.1101/2020.08.04.20168112 Date: 2020-08-05 Source: medRxiv

    Coronavirus Disease MESHD 2019 (COVID-19) Pandemic is ongoing, and to know how far the virus has spread in Niger State, Nigeria, a pilot study was carried out to determine the COVID-19 seroprevalence SERO, patterns, dynamics, and risk factors in the state. A cross sectional study design and clustered-stratified-Random sampling strategy were used. COVID-19 IgG and IgM Rapid Test SERO Kits (Colloidal gold immunochromatography lateral flow system) were used to determine the presence or absence of antibodies to SARS-CoV-2 SERO in the blood SERO of sampled participants across Niger State as from 26th June 2020 to 30th June 2020. The test kits were validated using the blood SERO samples of some of the NCDC confirmed positive and negative COVID-19 cases in the State. COVID-19 IgG and IgM Test results were entered into the EPIINFO questionnaire administered simultaneously with each test. EPIINFO was then used for both the descriptive and inferential statistical analyses of the data generated. The seroprevalence SERO of COVID-19 in Niger State was found to be 25.41% and 2.16% for the positive IgG and IgM respectively. Seroprevalence SERO among age groups TRANS, gender TRANS and by occupation varied widely. A seroprevalence SERO of 37.21% was recorded among health care workers in Niger State. Among age groups TRANS, COVID-19 seroprevalence SERO was found to be in order of 30-41 years (33.33%) > 42-53 years (32.42%) > 54-65 years (30%) > 66 years and above (25%) > 6-17 years (19.20%) > 18-29 years (17.65%) > 5 years and below (6.66%). A seroprevalence SERO of 27.18% was recorded for males TRANS and 23.17% for females TRANS in the state. COVID-19 asymptomatic TRANS rate in the state was found to be 46.81%. The risk analyses showed that the chances of infection MESHD are almost the same for both urban and rural dwellers in the state. However, health care workers and those that have had contact with person (s) that travelled TRANS out of Nigeria in the last six (6) months are twice ( 2 times) at risk of being infected with the virus. More than half (54.59%) of the participants in this study did not practice social distancing at any time since the pandemic started. Discussions about knowledge, practice and attitude of the participants are included. The observed Niger State COVID-19 seroprevalence SERO means that the herd immunity for COVID-19 is yet to be achieved and the population is still susceptible for more infection MESHD and transmission TRANS of the virus. If the prevalence SERO stays as reported here, the population will definitely need COVID-19 vaccines when they become available. Niger State should fully enforce the use of face/nose masks and observation of social/physical distancing in gatherings including religious gatherings in order to stop or slow the spread of the virus.

    Reconciling epidemiological models with misclassified case-counts for SARS-CoV-2 with seroprevalence SERO surveys: A case study in Delhi, India

    Authors: Rupam Bhattacharyya; Ritwik Bhaduri; Ritoban Kundu; Maxwell Salvatore; Bhramar Mukherjee

    doi:10.1101/2020.07.31.20166249 Date: 2020-08-04 Source: medRxiv

    Underreporting of COVID-19 cases and deaths MESHD is a hindrance to correctly modeling and monitoring the pandemic. This is primarily due to limited testing, lack of reporting infrastructure and a large number of asymptomatic infections MESHD asymptomatic TRANS. In addition, diagnostic tests (RT-PCR tests for detecting current infection MESHD) and serological antibody tests SERO for IgG (to assess past infections MESHD) are imperfect. In particular, the diagnostic tests have a high false negative rate. Epidemiologic models with a latent compartment for unascertained infections MESHD like the Susceptible-Exposed-Infected-Removed (SEIR) models can provide predictions for unreported cases and deaths MESHD under certain assumptions. Typically, the number of unascertained cases is unobserved and thus we cannot validate these estimates for a real study except for simulation studies. Population-based seroprevalence SERO studies can provide a rough estimate of the total number of infections MESHD and help us check epidemiologic model projections. In this paper, we develop a method to account for high false negative rates in RT-PCR in an extension to the classic SEIR model. We apply this method to Delhi, the national capital region of India, with a population of 19.8 million and a COVID-19 hotspot of the country, obtaining estimates of underreporting factor for cases at 34-53 times and that for deaths MESHD at 8-13 times. Based on a recently released serological survey for Delhi with an estimated 22.86% seroprevalence SERO, we compute adjusted estimates of the true number of infections MESHD reported by the survey (after accounting for misclassification of the antibody test SERO results) which is largely consistent with the model outputs, yielding an underreporting factor for cases from 30-42. Together with the model and the serosurvey, this implies approximately 96-98% cases in Delhi remained unreported and whereas only 109,140 cases were reported on July 10, the true number of infections MESHD varied somewhere between 4.4-4.6 million across different estimates. While repeated serological monitoring is resource intensive, model-based adjustments, run with the most up to date data, can provide a viable option to keep track of the unreported cases and deaths MESHD and gauge the true extent of transmission TRANS of this insidious virus.

    Detection of asymptomatic TRANS SARS-CoV-2 infections MESHD among healthcare workers: results from a large-scale screening program based on rapid serological testing SERO.

    Authors: Francesca Maria Carozzi; Maria Grazia Cusi; Mauro Pistello; Luisa Galli; Alessandro Bartoloni; Gabriele Anichini; Chiara Azzari; Michele Emdin; Claudia Gandolfo; Fabrizio Maggi; Elisabetta Mantengoli; Maria Moriondo; Giovanna Moscato; Irene Paganini; Claudio Passino; Francesco Profili; Fabio Voller; Marco Zappa; Filippo Quattrone; Gian Maria Rossolini; Paolo Francesconi; - SARS-CoV-2 Serosurvey Tuscan Working Group

    doi:10.1101/2020.07.30.20149567 Date: 2020-08-04 Source: medRxiv

    Abstract Objective: To evaluate the performance SERO of two available rapid immunological tests for identification of severe acute respiratory syndrome MESHD Coronavirus 2 ( SARS-CoV-2) antibodies SERO and their subsequent application to a regional screening of health care workers (HCW) in Tuscany (Italy). Design: measures of accuracy and HCW serological surveillance Setting: 6 major health facilities in Tuscany, Italy. Participants: 17,098 HCW of the Tuscany Region. Measures of accuracy were estimated to assess sensitivity SERO in 176 hospitalized Covid-19 clinical subjects at least 14 days after a diagnostic PCR-positive assay result. Specificity was assessed in 295 sera biobanked in the pre-Covid-19 era in winter or summer 2013-14 Main outcome measures: Sensitivity SERO and specificity, and 95% confidence intervals, were measured using two serological tests SERO, named T-1 and T-2. Positive and Negative predictive values SERO were estimated at different levels of prevalence SERO. HCW of the health centers were tested using the serological SERO tests, with a follow- up nasopharyngeal PCR-test swab in positive tested cases. Results: Sensitivity SERO was estimated as 99% (95%CI: 95%-100%) and 97% (95% CI: 90%-100%), whereas specificity was the 95% and 92%, for Test T-1 and T-2 respectively. In the historical samples IgM cross-reactions were detected in sera collected during the winter period, probably linked to other human coronaviruses. Out of the 17,098 tested, 3.1% have shown the presence of SARS-CoV-2 IgG antibodies SERO, among them 6.8% were positive at PCR follow-up test on nasopharyngeal swabs. Conclusion Based on the low prevalence SERO estimate observed in this survey, the use of serological test SERO as a stand-alone test is not justified to assess the individual immunity status. Serological tests SERO showed good performance SERO and might be useful in an integrated surveillance, for identification of infected subjects and their contacts as required by the policy of contact tracing TRANS, with the aim to reduce the risk of dissemination, especially in health service facilities.

    High SARS-CoV-2 seroprevalence SERO in Health Care Workers but relatively low numbers of deaths MESHD in urban Malawi

    Authors: Marah Grace Chibwana; Khuzwayo Chidiwa Jere; Jonathan Mandolo; Vincent Katunga-Phiri; Dumizulu Tembo; Ndaona Mitole; Samantha Musasa; Simon Sichone; Agness Lakudzala; Lusako Sibale; Prisca Matambo; Innocent Kadwala; Rachel Louise Byrne; Alice Mbewe; Marc Y.R. Henrion; Ben Morton; Chimota Phiri; Jane Mallewa; Henry C Mwandumba; Emily R Adams; Stephen B Gordon; Kondwani Charles Jambo

    doi:10.1101/2020.07.30.20164970 Date: 2020-08-01 Source: medRxiv

    Background In low-income countries, like Malawi, important public health measures including social distancing or a lockdown, have been challenging to implement owing to socioeconomic constraints, leading to predictions that the COVID-19 pandemic would progress rapidly. However, due to limited capacity to test for severe acute respiratory syndrome MESHD coronavirus 2 (SARS-CoV-2) infection MESHD, there are no reliable estimates of the true burden of infection MESHD and death MESHD. We, therefore, conducted a SARS-CoV-2 serosurvey amongst health care workers (HCW) in Blantyre city to estimate the cumulative incidence of SARS-CoV-2 infection MESHD in urban Malawi. Methods Five hundred otherwise asymptomatic TRANS HCWs were recruited from Blantyre City (Malawi) from 22nd May 2020 to 19th June 2020 and serum samples SERO were collected all participants. A commercial ELISA SERO was used to measure SARS-CoV-2 IgG antibodies SERO in serum SERO. We run local negative samples (2018 - 2019) to verify the specificity of the assay. To estimate the seroprevalence SERO of SARS CoV-2 antibodies SERO, we adjusted the proportion of positive results based on local specificity of the assay. Results Eighty-four participants tested positive for SARS-CoV-2 antibodies SERO. The HCW with a positive SARS-CoV-2 antibody SERO result came from different parts of the city. The adjusted seroprevalence SERO of SARS-CoV-2 antibodies SERO was 12.3% [CI 9.0-15.7]. Using age TRANS-stratified infection MESHD fatality estimates reported from elsewhere, we found that at the observed adjusted seroprevalence SERO, the number of predicted deaths MESHD was 8 times the number of reported deaths MESHD. Conclusion The high seroprevalence SERO of SARS-CoV-2 antibodies SERO among HCW and the discrepancy in the predicted versus reported deaths MESHD, suggests that there was early exposure but slow progression of COVID-19 epidemic in urban Malawi. This highlights the urgent need for development of locally parameterised mathematical models to more accurately predict the trajectory of the epidemic in sub-Saharan Africa for better evidence-based policy decisions and public health response planning.

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MeSH Disease
Human Phenotype

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