Using Clinical Profiles and Complete Blood Counts to Differentiate Causes of Acute Febrile Illness during the 2009-11 Outbreak of Typhoid and Chikungunya in a Dengue Endemic Area

Infections transmitted via the faecal-oral route: a simple score for a global risk map

INTRODUCTION

Faecal-oral transmission refers to the process whereby disease is transmitted via the faeces of an infected individual to the mouth of a susceptible individual. This transmission can occur through failures in sanitation systems leading to exposure via various routes in particular contaminated water, food, and hands. Travellers' diarrhoea is the most common travel-related illness. A score could enhance risk assessment and pre-travel advice.

METHODS

A simple score was developed based on the frequency of defecating in the open (country prevalence > 1%), occurrence of cholera in the period between 2021 and 2017 (one or more case in a country) and reported typhoid fever cases between 2015 and 2019.

RESULTS

Data were available for 199 out of 214 countries for the score to be applied. 19% of the 199 countries scored as high risk countries for faecal-oral transmission (score 3), 47% as medium risk (score 2), and 34% as minimal risk (score 0). The percentage of countries scoring 3 was highest in Africa (63%) and lowest in Europe and Oceania (score 0).

CONCLUSIONS

A global risk map was developed based on a simple score that could aid travel medicine providers in providing pre-travel risk assessment. For travellers to high and medium risk countries, pre-travel consultation must include detailed advice on food and water hygiene.

SARS-CoV-2 Spike Protein Expression In Vitro and Hematologic Effects in Mice Vaccinated With AZD1222 (ChAdOx1 nCoV-19)

Severe COVID-19 can be associated with a prothrombotic state, increasing risk of morbidity and mortality. The SARS-CoV-2 spike glycoprotein is purported to directly promote platelet activation via the S1 subunit and is cleaved from host cells during infection. High plasma concentrations of S1 subunit are associated with disease progression and respiratory failure during severe COVID-19. There is limited evidence on whether COVID-19 vaccine-induced spike protein is similarly cleaved and on the immediate effects of vaccination on host immune responses or hematology parameters. We investigated vaccine-induced S1 subunit cleavage and effects on hematology parameters using AZD1222 (ChAdOx1 nCoV-19), a simian, replication-deficient adenovirus-vectored COVID-19 vaccine. We observed S1 subunit cleavage in vitro following AZD1222 transduction of HEK293x cells. S1 subunit cleavage also occurred in vivo and was detectable in sera 12 hours post intramuscular immunization (1x10¹⁰ viral particles) in CD-1 mice. Soluble S1 protein levels decreased within 3 days and were no longer detectable 7–14 days post immunization. Intravenous immunization (1x10⁹ viral particles) produced higher soluble S1 protein levels with similar expression kinetics. Spike protein was undetectable by immunohistochemistry 14 days post intramuscular immunization. Intramuscular immunization resulted in transiently lower platelet (12 hours) and white blood cell (12–24 hours) counts relative to vehicle. Similarly, intravenous immunization resulted in lower platelet (24–72 hours) and white blood cell (12–24 hours) counts, and increased neutrophil (2 hours) counts. The responses observed with either route of immunization represent transient hematologic changes and correspond to expected innate immune responses to adenoviral infection.