Seroepidemiological assessment of SARS-CoV-2 vaccine responsiveness and associated factors in the vaccinated community of the Casablanca-Settat Region, Morocco.

Assessing the prevalence of SARS-CoV-2 IgG positivity through population-based serological surveys is crucial for monitoring COVID-19 vaccination efforts. In this study, we evaluated SARS-CoV-2 IgG positivity within a provincial cohort to understand the magnitude of the humoral response against the SARS-CoV-2 vaccine and to inform evidence-based public health decisions. A community-based cross-sectional seroprevalence study was conducted, involving 10,669 participants who received various vaccines (two doses for BBIBP-CorV/Sinopharm, Covishield vaccine, and Pfizer/BioNTech, and one dose for Johnson & Johnson's Janssen COVID-19 vaccine). The study spanned 16 provinces in the Casablanca-Settat region from February to June 2022, during which comprehensive demographic and comorbidity data were collected. We screened samples for the presence of IgG antibodies using the SARS-CoV-2 IgG II Quant assay, which quantifies antibodies against the receptor-binding domain (RBD) of the spike (S) protein, measured on the Abbott Architect i2000SR. The overall crude seroprevalence was 96% (95% CI: 95.6-96.3%), and after adjustment for assay performance, it was estimated as 96.2% (95% CI: 95.7-96.6). The adjusted overall seroprevalences according to vaccine brands showed no significant difference (96% for BBIBP-CorV/Sinopharm, 97% for ChAdOx1 nCoV-19/Oxford/AstraZeneca, 98.5% for BNT162b2/Pfizer-BioNTech, and 98% for Janssen) (p = 0.099). Participants of older age, female sex, those with a history of previous COVID-19 infection, and those with certain chronic diseases were more likely to be seropositive among ChAdOx1 nCoV-19/Oxford/AstraZeneca and BBIBP-CorV/Sinopharm vaccinee groups. Median RBD antibody concentrations were 2355 AU/mL, 3714 AU/mL, 5838 AU/mL, and 2495 AU/mL, respectively, after two doses of BBIBP-CorV/Sinopharm, ChAdOx1 nCoV-19/Oxford/AstraZeneca, BNT162b2/Pfizer-BioNTech, and after one dose of Janssen (p < 0.0001). Furthermore, we observed that participants vaccinated with ChAdOx1 nCoV-19/Oxford/AstraZeneca and BBIBP-CorV/Sinopharm with comorbid chronic diseases exhibited a more pronounced response to vaccination compared to those without comorbidities. In contrast, no significant differences were observed among Pfizer-vaccinated participants (p > 0.05). In conclusion, our serosurvey findings indicate that all four investigated vaccines provide a robust humoral immune response in the majority of participants (more than 96% of participants had antibodies against SARS-CoV-2). The BNT162b2 vaccine was found to be effective in eliciting a strong humoral response compared to the other three vaccines. However, challenges still remain in examining the dynamics and durability of immunoprotection in the Moroccan context.

The first and second waves of the COVID-19 pandemic in Africa: a cross-sectional study.

BACKGROUND: Although the first wave of the COVID-19 pandemic progressed more slowly in Africa than the rest of the world, by December, 2020, the second wave appeared to be much more aggressive with many more cases. To date, the pandemic situation in all 55 African Union (AU) Member States has not been comprehensively reviewed. We aimed to evaluate reported COVID-19 epidemiology data to better understand the pandemic's progression in Africa. METHODS: We did a cross-sectional analysis between Feb 14 and Dec 31, 2020, using COVID-19 epidemiological, testing, and mitigation strategy data reported by AU Member States to assess trends and identify the response and mitigation efforts at the country, regional, and continent levels. We did descriptive analyses on the variables of interest including cumulative and weekly incidence rates, case fatality ratios (CFRs), tests per case ratios, growth rates, and public health and social measures in place. FINDINGS: As of Dec 31, 2020, African countries had reported 2 763 421 COVID-19 cases and 65 602 deaths, accounting for 3·4% of the 82 312 150 cases and 3·6% of the 1 798 994 deaths reported globally. Nine of the 55 countries accounted for more than 82·6% (2 283 613) of reported cases. 18 countries reported CFRs greater than the global CFR (2·2%). 17 countries reported test per case ratios less than the recommended ten to 30 tests per case ratio range. At the peak of the first wave in Africa in July, 2020, the mean daily number of new cases was 18 273. As of Dec 31, 2020, 40 (73%) countries had experienced or were experiencing their second wave of cases with the continent reporting a mean of 23 790 daily new cases for epidemiological week 53. 48 (96%) of 50 Member States had five or more stringent public health and social measures in place by April 15, 2020, but this number had decreased to 36 (72%) as of Dec 31, 2020, despite an increase in cases in the preceding month. INTERPRETATION: Our analysis showed that the African continent had a more severe second wave of the COVID-19 pandemic than the first, and highlights the importance of examining multiple epidemiological variables down to the regional and country levels over time. These country-specific and regional results informed the implementation of continent-wide initiatives and supported equitable distribution of supplies and technical assistance. Monitoring and analysis of these data over time are essential for continued situational awareness, especially as Member States attempt to balance controlling COVID-19 transmission with ensuring stable economies and livelihoods. FUNDING: None.

Evaluation of a New Field Epidemiology Training Program Intermediate Course to Strengthen Public Health Workforce Capacity in Tanzania.

OBJECTIVES: Sub-Saharan Africa faces a shortage of skilled epidemiologists to prevent, detect, and respond to health threats. Tanzania has implemented one of the first Centers for Disease Control and Prevention Field Epidemiology Training Program (FETP) Intermediate courses in Africa. This course aims to strengthen health workforce capacity in surveillance system assessment, outbreak investigation, and evaluation, prioritizing HIV control. We conducted an outcome evaluation of this new course. METHODS: We used a pre/post evaluation design using data from 4 cohorts of trainees who took the FETP Intermediate course from 2017 to 2020. We conducted knowledge assessments before and after each cohort and combined those results. Outcomes included knowledge and self-rated competency and trends in integrated disease surveillance and response (IDSR) data. We collected data through tests, field assignments, exit interviews, and data audits. We compared the mean change in pre-/posttest scores using linear regression and 95% CIs. We used content analysis to summarize exit interviews. RESULTS: Fifty-three FETP trainees from 10 regions enrolled in the FETP Intermediate course, and 52 (99.0%) completed the course. We found substantial increases in mean knowledge (44.0 to 68.0 points) and self-rated competency (4.14 to 4.43) scores before and after the course. Trainees evaluated 52 surveillance systems and 52 district HIV care programs, and 39 (75.0%) trainees participated in outbreak investigations. From before to after cohort 1, timeliness and completeness of IDSR reports increased from 4.2% to 52.1% and from 27.4% to 76.5%, respectively. Course strengths were quality of instruction, individualized mentoring, and practical skills gained. Challenges were mentor availability, limited time for data analysis practice, and balancing work and field assignments. CONCLUSIONS: The Tanzania FETP Intermediate course substantially improved trainee knowledge and helped to improve local data quality and reporting. This course is a promising model to strengthen subnational capacity to prevent, detect, and respond to public health threats in Africa.

Risk factors associated with under nutrition among children aged 6-59 months in Ngorongoro, Arusha region, Tanzania: a case-control study, 2017.

INTRODUCTION: childhood undernutrition is one of the leading causes of morbidity and mortality in children below five years of age especially in developing countries like Tanzania, particularly in rural area. Inappropriate child caring and feeding practices have been strongly associated with it. Many actions have been taken to reduce prevalence of undernutrition in children in Ngorongoro district, however, the problem persist. This study identified risk factors associated with undernutrition in children under-five years of age in Ngorongoro district, Arusha region. METHODS: a health facility-based unmatched case-control study was conducted with 400 (100 cases and 300 controls) children aged 6-59 months. Cases included children with undernutrition according to the WHO anthropometric indicators. Controls were children within the normal range of these indicators. Both cases and controls, were obtained from children attending the Reproductive and Child Health (RCH) for assessment of growth and development or admitted in pediatric ward. A questionnaire was used to collect demographic characteristics, child health and caring practices and environmental factors. Height, weight and Mid Upper Arm Circumference (MUAC) were measured using standard approaches. We employed logistic regression analysis to identify significant risk factors for undernutrition. RESULTS: undernutrition was associated with young age of mothers/caregivers (adjusted Odds Ratio (aOR)=38.8, 95% CI: 15.38-59.03.); early age of initiation complementary foods (aOR=13.6, 95%CI: 3.15-59.06); a child having diarrhoea in past one month (aOR=4.0; 95%CI: 1.76-12.85); large family size (aOR=6.1, 95% CI: 2.16-16.90); low frequency of feeding (aOR=3.9, 95%CI: 1.59-9.58); low birth weight (aOR:=7.3, 95%: CI: 1.15-46.70); and source of drinking water; well (aOR=16.3, 95%: CI: 1.81-147.05) and surface water (aOR=16.18, 95%CI: 1.85-141.71). CONCLUSION: household and individual characteristics of the children and mother/caregiver are important predictors of undernutrition in this community. Tailored interventions, instead of blanket approaches, should be designed to mitigate and eliminate childhood undernutrition in Ngorongoro.

Investigating a paralytic shellfish poisoning in Gando Village, Wete District, Tanzania, July 2015.

The investigation of foodborne outbreaks requires a multi-disciplinary set of skills. Frequently, foodborne-related outbreaks are poorly investigated due to lack of all required skills on the part of the investigators. This case study, based on a shellfish poisoning outbreak investigation conducted in Wete, Zanzibar in July 2015 by the Tanzania Field Epidemiology Training Program (TFETP), seeks to reinforce principles and skills in foodborne outbreak investigation. It is primarily intended for training public health practitioners in a classroom setting. Facilitating this case study should take approximately 3 hours.