The objective of this study was to describe the epidemiology of COVID-19 in Nigeria with a view of generating evidence to enhance planning and response strategies. A national surveillance dataset between 27 February and 6 June 2020 was retrospectively analysed, with confirmatory testing for COVID-19 done by real-time polymerase chain reaction (RT-PCR). The primary outcomes were cumulative incidence (CI) and case fatality (CF). A total of 40 926 persons (67% of total 60 839) had complete records of RT-PCR test across 35 states and the Federal Capital Territory, 12 289 (30.0%) of whom were confirmed COVID-19 cases. Of those confirmed cases, 3467 (28.2%) had complete records of clinical outcome (alive or dead), 342 (9.9%) of which died. The overall CI and CF were 5.6 per 100 000 population and 2.8%, respectively. The highest proportion of COVID-19 cases and deaths were recorded in persons aged 31–40 years (25.5%) and 61–70 years (26.6%), respectively; and males accounted for a higher proportion of confirmed cases (65.8%) and deaths (79.0%). Sixty-six per cent of confirmed COVID-19 cases were asymptomatic at diagnosis. In conclusion, this paper has provided an insight into the early epidemiology of COVID-19 in Nigeria, which could be useful for contextualising public health planning.

Background: On 3 rd April 2020, an outbreak of Coronavirus disease-2019 (COVID-19) was confirmed in Ondo State, Southwest Nigeria. Field investigations were conducted by the State Ministry of Health (MoH) to identify and confirm additional cases. This paper provides the outcome of the epidemiological investigation of the outbreak to further guide outbreak response activities. Methods: Field epidemiology methods coordinated by the State Public Health Emergency Operations Center (PHEOC) were used in the outbreak investigation. Suspected cases were reported through the routine Integrated Disease Surveillance and Response (IDSR) network in the State. Also, active case search/finding to communities and health facilities using the operational case definitions was conducted. Furthermore, the state COVID-19 emergency call center was established with toll-free phone number provided to members of the public to call-in to report suspected persons with symptoms consistent with the COVID-19 operational case definition (signal). All cases reported were investigated with nasopharyngeal sample collected and confirmatory testing for COVID-19 done by real-time polymerase chain reaction (RT-PCR) in a national reference laboratory. Information of each case investigated was documented using the COVID-19 case investigation form and COVID-19 line-list which captured socio-demographic characteristics, history of exposure to COVID-19, presenting symptoms, travel history and sample collection details. Data were extracted from the case investigation form and line list and analyzed using SPSS version 20, with a p-value set at < 0.05. Results: A total of 4353 suspected cases were reported and investigated,

Background Large outbreaks of Lassa fever (LF) occur annually in Nigeria. The case fatality rate among hospitalised cases is ~ 20%. The antiviral drug ribavirin along with supportive care and rehydration are the recommended treatments but must be administered early (within 6 days of symptom onset) for optimal results. We aimed to identify factors associated with late presentation of LF cases to a healthcare facility to inform interventions. Methods We undertook a retrospective cohort study of all laboratory confirmed LF cases reported in Nigeria from December 2018 to April 2019. We performed descriptive epidemiology and a univariate Cox proportional-hazards regression analysis to investigate the effect of clinical (symptom severity), epidemiological (age, sex, education, occupation, residential State) and exposure (travel, attendance at funeral, exposure to rodents or confirmed case) factors on time to presentation. Results Of 389 cases, median presentation time was 6 days (IQR 4–10 days), with 53% attending within 6 days. There were no differences in presentation times by sex but differences were noted by age-group; 60+ year-olds had the longest delays while 13–17 year-olds had the shortest. By sex and age, there were differences seen among the younger ages, with 0–4-year-old females presenting earlier than males (4 days and 73% vs. 10 days and 30%). For 5–12 and 13–17 year-olds, males presented sooner than females (males: 5 days, 65% and 3 days, 85% vs. females: 6 days, 50% and 5 days, 61%, respectively). Presentation times differed across occupations 4.5–9 days and 20–60%, transporters (people who drive informal public transport vehicles) had the longest delays. Other data were limited (41–95% missing). However, the Cox regression showed no factors were statistically associated with longer presentation time. Conclusions Whilst we observed important differences in presentation delays across factors, our sample size was insufficient to show any statistically significant differences that might exist. However, almost half of cases presented after 6 days of onset, highlighting the need for more accurate and complete surveillance data to determine if there is a systemic or specific cause for delays, so to inform, monitor and evaluate public health strategies and improve outcomes.

Objectives: Rapid and accurate identification of persons infected with SARS-CoV-2 which causes COVID-19 is key to managing the pandemic. The urgent need to scale up access to COVID-19 testing in Nigeria has led to the government's introduction of the use of COVID-19 Ag rapid diagnostic test (RDT) across various settings in the country. However, field performance evaluation of the rapid SARS-CoV-2 antigen detection test is required to be conducted periodically and compared with the gold standard real-time reverse transcription-polymerase chain reaction (RT-PCR) test for diagnosis of COVID-19 cases. Design: A prospective COVID-19 screening and un-blinded verification of the performance of the STANDARD Q COVID-19 Ag test kit. Setting: The rapid SARS-CoV-2 antigen detection test, Standard TM Q COVID-19 Ag kit was compared with the RT-PCR test for detection of SARS-CoV-2 in nasopharyngeal samples for COVID-19 screening from persons and personnel attending a national youth camp orientation exercise during the second wave of the COVID-19 outbreak (January to March 2021) in Ondo state, southwest Nigeria. Participants: Three hundred fifty-one persons and personnel were screened for COVID-19 infection. Results: Of 351 respondents screened, 68 (19.4%) were positive, and 264 (75.2%) were negative for both COVID-19 Ag RDT and RT-PCR assay. The rapid SARS-CoV-2 antigen detection test's sensitivity and specificity were 78.16% (95% CI = 68.02% -86.31%) and 100.0%

Introduction: This report shows the outcomes and lessons learnt from a 3-month intervention focused on decentralization of COVID-19 coordination, testing and contact tracing activities in three hotspot local government areas (LGAs) of a state in the southwest of Nigeria.Methods: A description of COVID-19 outbreak response from the occurrence of the index case was documented. A health facility and community-based intervention implemented in three hotspots LGA as part of response to COVID-19 pandemic from 24 th May to 22 nd August, 2021 was described. The interventions implemented focused on integrating COVID-19 testing into routine healthcare services in 103 health facilities, engagement of communitybased volunteers to conduct contact tracing, and improving coordination of the response through the conduct of incident management meetings at state and LGA levels. The COVID-19 dataset from 22 nd February to 22 nd August, was obtained from the State Ministry of Health and analyzed. Data were summarized using charts and maps.Results: A higher number of cases (3879) were tested between 24 th May to 22 nd August, 2021 (during intervention) compared to 1667 cases tested between 23 February to 23 May, 2021 (before intervention) across the three LGAs. Generally, there was a decline in the cumulative number of contacts traced and line-listed during the intervention (778) compared to the period before the intervention (1170) in two of the three LGAs. The number of weekly incident management meetings held improved by 25% at State level, while 83% of weekly LGA meetings were held at the three hot spot LGAs during the intervention compared to the period before the intervention, where no meeting was held at LGA level. Conclusions:The decentralization of the COVID-19 outbreak response from a central approach to the LGA level improved only testing numbers and the number of incident management meetings conducted across the three hot spot LGAs. The number of contacts line-listed, positivity rate and reported cases reduced following the interventions. The need to supplement contact tracing activities using information technology for self-report as done in other climes, as well as engaging community, religious leaders and key community groups as integral members of the contact tracing team was emphasized.