SARS-CoV-2 PCR positivity rate and seroprevalence of related antibodies among a sample of patients in Cairo: Pre-wave 2 results of a screening program in a university hospital.

BACKGROUND: Research has revealed that asymptomatic and pre-symptomatic infections are important contributors to the transmission of SARS-CoV-2 in populations. In Egypt, the true prevalence of infections is veiled due to the low number of screening tests. The aim of this study was to determine the SARS-CoV-2 PCR positivity rate as well the seroprevalence of the SARS-CoV-2 antibodies before the ultimate development of a second wave of the epidemic in Cairo, Egypt. METHODS: Our study was carried out between May 5 and the end of October 2020. It included all patients requiring admission to Ain Shams University hospitals. An interview questionnaire was used to collect demographic and clinical data. Laboratory tests for all participants included RT-PCR and total antibody assay for SARS-CoV-2. RESULTS: A total of 4,313 subjects were enrolled in our study, with females representing 56% of the sample. Adults and middle-aged individuals represented around 60% of the study sample. The positivity rate of SARS-CoV-2 PCR was 3.84% (95% CI 3.29-4.48), and the SARS-CoV-2 antibody seroprevalence was 29.82% (95% CI: 28.16-31.51). Males showed a higher risk for getting the COVID-19 infection, while middle-age group had significantly higher antibody seroprevalence rates. CONCLUSION: SARS-CoV-2 infection imposes a high burden on the community as detected by high seroprevalence rates.

SARS-CoV-2 seroconversion among 4040 Egyptian healthcare workers in 12 resource-limited healthcare facilities: A prospective cohort study.

BACKGROUND: We examined Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) seroconversion incidence and risk factors 21 days after baseline screening among healthcare workers (HCWs) in a resource-limited setting. METHODS: A prospective cohort study of 4040 HCWs took place at 12 university healthcare facilities in Cairo, Egypt; April-June 2020. Follow-up exposure and clinical data were collected through online survey. SARS-CoV-2 testing was done using rapid IgM and IgG serological tests and reverse transcriptase-polymerase chain reaction (RT-PCR) for those with positive serology. Cox proportional hazards modelling was used to estimate adjusted hazard ratios (HR) of seroconversion. RESULTS: 3870/4040 (95.8%) HCWs tested negative for IgM, IgG and PCR at baseline; 2282 (59.0%) returned for 21-day follow-up. Seroconversion incidence (positive IgM and/or IgG) was 100/2282 (4.4%, 95% CI:3.6-5.3), majority asymptomatic (64.0%); daily hazard of 0.21% (95% CI:0.17-0.25)/48 746 person-days of follow-up. Seroconversion was: 4.0% (64/1596; 95% CI:3.1-5.1) among asymptomatic; 5.3% (36/686; 95% CI:3.7-7.2) among symptomatic HCWs. Seroconversion was independently associated with older age; lower education; contact with a confirmed case >15 min; chronic kidney disease; pregnancy; change/loss of smell; and negatively associated with workplace contact. CONCLUSIONS: Most seroconversions were asymptomatic, emphasizing need for regular universal testing. Seropositivity was three-fold that observed at baseline. Cumulative infections increased nationally by a similar rate, suggesting HCW infections reflect community not nosocomial transmission.

Universal COVID-19 screening of 4040 health care workers in a resource-limited setting: an Egyptian pilot model in a university with 12 public hospitals and medical centers.

BACKGROUND: The scale of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among health care workers (HCWs), particularly in resource-limited settings, remains unclear. To address this concern, universal (non-symptom-based) screening of HCWs was piloted to determine the proportion of SARS-CoV-2 infection and the associated epidemiological and clinical risk factors at a large public health care facility in Egypt. METHODS: Baseline voluntary screening of 4040 HCWs took place between 22 April and 14 May 2020 at 12 hospitals and medical centres in Cairo. Epidemiological and clinical data were collected using an online survey. All participants were tested for SARS-CoV-2 using reverse transcription polymerase chain reaction (RT-PCR) and rapid IgM and IgG serological tests. RESULTS: Of the 4040 HCWs screened, 170 [4.2%; 95% confidence interval (CI): 3.6-4.9] tested positive for SARS-CoV-2 by either of the three tests (i.e. infected); 125/170 (73.5%) tested PCR-positive. Most infected HCWs were nurses (97/170, 57.5%). Median age of infected HCWs was 31.5 [interquartile range (IQR): 27.0-41.3] years. Of infected HCWs, 78 (45.9%) reported contact with a suspected case and 47 (27.6%) reported face-to-face contact within 2 m with a confirmed case. The proportion of infection among symptomatic HCWs (n = 54/616) was 8.8% (95% CI: 6.7-11.3); 6/54 (11.1%) had fever ≥38°C and 7/54 (13.0%) reported severe symptoms. Most infected HCWs were asymptomatic (116/170, 68.2%). The proportion of infection among asymptomatic HCWs (n = 116/3424) was 3.4% (95% CI: 2.8-4.0). CONCLUSIONS: The high rate of asymptomatic infections among HCWs reinforces the need for expanding universal regular testing. The infection rate among symptomatic HCWs in this study is comparable with the national rate detected through symptom-based testing. This suggests that infections among HCWs may reflect community rather than nosocomial transmission during the early phase of the COVID-19 epidemic in Egypt.