High SARS-CoV-2 incidence and asymptomatic fraction during Delta and Omicron BA.1 waves in The Gambia

Little is known about SARS-CoV-2 infection risk in African countries with high levels of infection-driven immunity and low vaccine coverage. We conducted a prospective cohort study of 349 participants from 52 households in The Gambia between March 2021 and June 2022, with routine weekly SARS-CoV-2 RT-PCR and 6-monthly SARS-CoV-2 serology. Attack rates of 45% and 57% were seen during Delta and Omicron BA.1 waves respectively. Eighty-four percent of RT-PCR-positive infections were asymptomatic. Children under 5-years had a lower incidence of infection than 18-49-year-olds. One prior SARS-CoV-2 infection reduced infection risk during the Delta wave only, with immunity from ≥2 prior infections required to reduce the risk of infection with early Omicron lineage viruses. In an African population with high levels of infection-driven immunity and low vaccine coverage, we find high attack rates during SARS-CoV-2 waves, with a high proportion of asymptomatic infections and young children remaining relatively protected from infection

Nosocomial or not? A combined epidemiological and genomic investigation to understand hospital-acquired COVID-19 infection on an elderly care ward

Background: COVID-19 has the potential to cause outbreaks in hospitals. Given the comorbid and elderly cohort of patients hospitalized, hospital-acquired COVID-19 infection is often fatal. Pathogen genome sequencing is becoming increasingly important in infection prevention and control (IPC). Aim: To inform the understanding of in-hospital SARS-CoV-2 transmission in order to improve IPC practices and to inform the future development of virological testing for IPC. Methods: Patients detected COVID-19 positive by polymerase chain reaction on Ward A in April and May 2020 were included with contact tracing to identify other potential cases. Genome sequencing was undertaken for a subgroup of cases. Epidemiological, genomic, and cluster analyses were performed to describe the epidemiology and to identify factors contributing to the outbreak. Findings: Fourteen cases were identified on Ward A. Contact tracing identified 16 further patient cases; in addition, eight healthcare workers (HCWs) were identified as being COVID-19 positive through a round of asymptomatic testing. Genome sequencing of 16 of these cases identified viral genomes differing by two single nucleotide polymorphisms or fewer, with further cluster analysis identifying two groups of infection (a five-person group and a six-person group). Conclusion: Despite the temporal relationship of cases, genome sequencing identified that not all cases shared transmission events. However, 11 samples were found to be closely related and these likely represented in-hospital transmission. This included three HCWs, thereby confirming transmission between patients and HCWs

A minimum income for healthy living

BACKGROUND—Half a century of research has provided consensual evidence of major personal requisites of adult health in nutrition, physical activity and psychosocial relations. Their minimal money costs, together with those of a home and other basic necessities, indicate disposable income that is now essential for health.
METHODS—In a first application we identified such representative minimal costs for healthy, single, working men aged 18-30, in the UK. Costs were derived from ad hoc survey, relevant figures in the national Family Expenditure Survey, and by pragmatic decision for the few minor items where survey data were not available.
RESULTS—Minimum costs were assessed at £131.86 per week (UK April 1999 prices). Component costs, especially those of housing (which represents around 40% of this total), depend on region and on several assumptions. By varying these a range of totals from £106.47 to £163.86 per week was detailed. These figures compare, 1999,( )with the new UK national minimum wage, after statutory deductions, of £105.84 at 18-21 years and £121.12 at 22+ years for a 38 hour working week. Corresponding basic social security rates are £40.70-£51.40 per week.
INTERPRETATION—Accumulating science means that absolute standards of living, "poverty", minimal official incomes and the like, can now be assessed by objective measurement of the personal capacity to meet the costs of major requisites of healthy living. A realistic assessment of these costs is presented as an impetus to public discussion. It is a historical role of public health as social medicine to lead in public advocacy of such a national agenda.


Keywords: income; public health; lifestyle; nutrition; housing; exercise; social exclusion; inequalitie