Effectiveness of two doses of Euvichol-plus oral cholera vaccine in response to the 2017/2018 outbreak: a matched case-control study in Lusaka, Zambia.

INTRODUCTION: Zambia experienced a major cholera outbreak in 2017-2018, with more than 5905 cases reported countrywide, predominantly from the peri-urban slums of Lusaka city. The WHO recommends the use of oral cholera vaccines (OCVs) together with traditional control measures, including health promotion, provision of safe water and improving sanitation, in cholera endemic areas and during cholera outbreaks. In response to this outbreak, the Zambian government implemented the OVC campaign and administered the Euvichol-plus vaccine in the high-risk subdistricts of Lusaka. Although OCVs have been shown to be effective in preventing cholera infection in cholera endemic and outbreak settings, the effectiveness of the Euvichol-plus vaccine has not yet been evaluated in Zambia. This study aimed to determine the effectiveness of two doses of OCV administered during the 2017/2018 vaccination campaign. METHODS: We conducted a matched case-control study involving 79 cases and 316 controls following the mass vaccination campaign in the four subdistricts of Lusaka (Chawama, Chipata, Kanyama and Matero). Matching of controls was based on the place of residence, age and sex. Conditional logistic regression was used for analysis. Adjusted OR (AOR), 95% CI and vaccine effectiveness (1-AOR) for two doses of Euvichol-plus vaccine and any dose were estimated (p<0.05). RESULTS: The AOR vaccine effectiveness for two doses of Euvichol-plus OCV was 81.0% (95% CI 66.0% to 78.0%; p<0.01). Secondary analysis showed that vaccine effectiveness for any dose was 74.0% (95% CI 50.0% to 86.0%; p<0.01). CONCLUSION: These findings show that two doses of Euvichol-plus OCV are effective in a cholera outbreak setting in Lusaka, Zambia. The findings also indicate that two doses are more effective than a single dose and thus support the use of two doses of the vaccine as part of an integrated intervention to cholera control during outbreaks.

Coronavirus Disease 2019 (COVID-19) Mitigation Efforts and Testing During an In-Person Training Event-Uganda, 12-29 October 2020.

Large public-health training events may result in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission. Universal SARS-CoV-2 testing during trainings for the Uganda Population-based HIV Impact Assessment identified 28 of 475 (5.9%) individuals with coronavirus disease 2019 (COVID-19) among attendees; most (89.3%) were asymptomatic. Until COVID-19 vaccine is readily available for staff and participants, effective COVID-19 mitigation measures, along with SARS-CoV-2 testing, are recommended for in-person trainings, particularly when trainees will have subsequent contact with survey participants.

Candida albicans cell-type switching and functional plasticity in the mammalian host.

Candida albicans is a ubiquitous commensal of the mammalian microbiome and the most prevalent fungal pathogen of humans. A cell-type transition between yeast and hyphal morphologies in C. albicans was thought to underlie much of the variation in virulence observed in different host tissues. However, novel yeast-like cell morphotypes, including opaque(a/α), grey and gastrointestinally induced transition (GUT) cell types, were recently reported that exhibit marked differences in vitro and in animal models of commensalism and disease. In this Review, we explore the characteristics of the classic cell types - yeast, hyphae, pseudohyphae and chlamydospores - as well as the newly identified yeast-like morphotypes. We highlight emerging knowledge about the associations of these different morphotypes with different host niches and virulence potential, as well as the environmental cues and signalling pathways that are involved in the morphological transitions.

Antiarrhythmic effects of simvastatin in canine pulmonary vein sleeve preparations.

OBJECTIVES: The purpose of this study was to determine the electrophysiologic effects of simvastatin in canine pulmonary vein (PV) sleeve preparations. BACKGROUND: Ectopic activity arising from the PV plays a prominent role in the development of atrial fibrillation. METHODS: Transmembrane action potentials were recorded from canine superfused left superior or inferior PV sleeves using standard microelectrode techniques. Acetylcholine (1 µM), isoproterenol (1 µM), high calcium ([Ca(2+)](o) = 5.4 mM), or a combination was used to induce early afterdepolarizations or delayed afterdepolarizations and triggered activity. Voltage clamp experiments were performed in the left atrium measuring fast and late sodium currents. RESULTS: Under steady-state conditions, simvastatin (10 nM, n = 9) induced a small increase in action potential duration measured at 85% repolarization and a significant decrease in action potential amplitude, take-off potential, and maximum rate of rise of action potential upstroke at the fastest rates. The V(max) decreased from 175.1 ± 34 V/s to 151.7 ± 28 V/s and from 142 ± 47 V/s to 97.4 ± 39 V/s at basic cycle lengths of 300 and 200 ms, respectively. Simvastatin (10 to 20 nM) eliminated delayed afterdepolarizations and delayed afterdepolarization-induced triggered activity in 7 of 7 PV sleeve preparations and eliminated or reduced late-phase 3 early afterdepolarizations in 6 of 6 PV sleeve preparations. Simvastatin (20 nM) did not affect late or fast sodium currents measured using voltage clamp techniques. CONCLUSIONS: Our data suggest that in addition to its upstream actions to reduce atrial structural remodeling, simvastatin exerts a direct antiarrhythmic effect by suppressing triggers responsible for the genesis of atrial fibrillation.