Neutralizing immunity against coronaviruses in Tanzanian health care workers.

The ongoing vaccination efforts and exposure to endemic and emerging coronaviruses can shape the population's immunity against this group of viruses. In this study, we investigated neutralizing immunity against endemic and emerging coronaviruses in 200 Tanzanian frontline healthcare workers (HCWs). Despite low vaccination rates (19.5%), we found a high SARS-CoV-2 seroprevalence (94.0%), indicating high exposure in these HCWs. Next, we determined the neutralization capacity of antisera against human coronavirus NL63, and 229E, SARS-CoV-1, MERS-CoV and SARS-CoV-2 (including Omicron subvariants: BA.1, BQ.1.1 and XBB.1.5) using pseudovirus neutralization assay. We observed a broad range of neutralizing activity in HCWs, but no neutralization activity detected against MERS-CoV. We also observed a strong correlation between neutralizing antibody titers for SARS-CoV-2 and SARS-CoV-1, but not between other coronaviruses. Cross-neutralization titers against the newer Omicron subvariants, BQ.1.1 and XBB.1.5, was significantly reduced compared to BA.1 and BA.2 subvariants. On the other hand, the exposed vaccinated HCWs showed relatively higher median cross-neutralization titers against both the newer Omicron subvariants and SARS-CoV-1, but did not reach statistical significance. In summary, our findings suggest a broad range of neutralizing potency against coronaviruses in Tanzanian HCWs with detectable neutralizing immunity against SARS-CoV-1 resulting from SARS-CoV-2 exposure.

Outcomes of Surgical Tracheostomy on Mechanically Ventilated COVID-19 Patients Admitted to a Private Tertiary Hospital in Tanzania.

OBJECTIVES:  The coronavirus disease 2019 (COVID-19) pandemic has resulted in an increase in the number of patients necessitating prolonged mechanical ventilation. Data on patients with COVID-19 undergoing tracheostomy indicating timing and outcomes are very limited. Our study illustrates--- outcomes for surgical tracheotomies performed on COVID-19 patients in Tanzania. METHODS:  This was a retrospective observational study conducted at the Aga Khan Hospital in Dar es Salaam, Tanzania. RESULTS:  Nineteen patients with COVID-19 underwent surgical tracheotomy between 16th March and 31st December 2021. All surgical tracheostomies were performed in the operating theatre. The average duration of intubation prior to tracheotomy and tracheostomy to ventilator liberation was 16 days and 27 days respectively. Only five patients were successfully liberated from the ventilator, decannulated, and discharged successfully. CONCLUSIONS:  This is the first and largest study describing tracheotomy outcomes in COVID-19 patients in Tanzania. Our results revealed a high mortality rate. Multicenter studies in the private and public sectors are needed in Tanzania to determine optimal timing, identification of patients, and risk factors predictive of improved outcomes.