This review provides for the first time an assessment of the current understanding about the occurrence and the clinical significance of gastrointestinal (GI) symptoms in influenza patients, and their correlation with the presence of human influenza viruses in stools of patients with confirmed influenza virus infection. Studies exploring how human influenza viruses spread to the patient’s GI tract after a primary respiratory infection have been summarized. We conducted a systematic search of published peer-reviewed literature up to June 2015 with regard to the above-mentioned aspects, focusing on human influenza viruses (A(H1N1), A(H1N1)pdm09, A(H3N2), and B). Forty-four studies were included in this systematic review and meta-analysis. The pooled prevalence of any digestive symptoms ranged from 30.9 % (95 % CI, 9.8 to 57.5; I 2 = 97.5 %) for A(H1N1)pdm09 to 2.8 % (95 % CI, 0.6 to 6.5; I 2 = 75.4 %) for A(H1N1). The pooled prevalence of influenza viruses in stool was 20.6 % (95 % CI, 8.9 to 35.5; I 2 = 96.8 %), but their correlation with GI symptoms has rarely been explored. The presence of viral RNA in stools because of haematogenous dissemination to organs via infected lymphocytes is likely, but the potential to cause direct intestinal infection and faecal–oral transmission warrants further investigation. This review highlights the gaps in our knowledge, and the high degree of uncertainty about the prevalence and significance of GI symptoms in patients with influenza and their correlation with viral RNA positivity in stool because of the high level of heterogeneity among studies.

Unrealistic optimism, the underestimation of one’s risk of experiencing harm, has been investigated extensively to understand better and predict behavioural responses to health threats. Prior to the COVID-19 pandemic, a relative dearth of research existed in this domain regarding epidemics, which is surprising considering that this optimistic bias has been associated with a lack of engagement in protective behaviours critical in fighting twenty-first-century, emergent, infectious diseases. The current study addresses this gap in the literature by investigating whether people demonstrated optimism bias during the first wave of the COVID-19 pandemic in Europe, how this changed over time, and whether unrealistic optimism was negatively associated with protective measures. Taking advantage of a pre-existing international participative influenza surveillance network (n = 12,378), absolute and comparative unrealistic optimism were measured at three epidemic stages (pre-, early, peak), and across four countries—France, Italy, Switzerland and the United Kingdom. Despite differences in culture and health response, similar patterns were observed across all four countries. The prevalence of unrealistic optimism appears to be influenced by the particular epidemic context. Paradoxically, whereas absolute unrealistic optimism decreased over time, comparative unrealistic optimism increased, suggesting that whilst people became increasingly accurate in assessing their personal risk, they nonetheless overestimated that for others. Comparative unrealistic optimism was negatively associated with the adoption of protective behaviours, which is worrying, given that these preventive measures are critical in tackling the spread and health burden of COVID-19. It is hoped these findings will inspire further research into sociocognitive mechanisms involved in risk appraisal.

Although Hepatitis E is increasingly described as a major cause of liver disease in industrialized countries, the epidemiology is far from being fully elucidated. We provide here a comprehensive review of documented clusters of cases, and of serological studies conducted in populations with distinct types of exposure. Seroprevalence rates range from 50% depending on the countries and the groups of population. Such discrepancies can be attributed to the type of serological assay used, but this solves only a part of the problem. We performed a meta-analysis of studies performed with the broadly used Wantai HEV-IgG ELISA and found striking differences that remain difficult to understand with the current knowledge of transmission pathways.

Hepatitis E virus (HEV) is a positive-strand RNA virus transmitted by the fecal–oral route. HEV genotypes 1 and 2 infect only humans and cause mainly waterborne outbreaks. HEV genotypes 3 and 4 are widely represented in the animal kingdom, and are mainly transmitted as a zoonosis. For the past 20 years, HEV infection has been considered an imported disease in developed countries, but now there is evidence that HEV is an underrecognized pathogen in high-income countries, and that the incidence of confirmed cases has been steadily increasing over the last decade. In this review, we describe current knowledge about the molecular biology of HEV, its clinical features, its main routes of transmission, and possible therapeutic strategies in developed countries.

Although livestock farming (sheep, goats, pigs, and cattle) is an important economic activity in Corsica, a French Mediterranean island, knowledge about the tick fauna and microorganisms carried by them remains scarce. This study aimed to investigate the presence and perform molecular characterization of Anaplasmataceae, Rickettsia spp., and Borrelia burgdorferi sensu lato (sl) in tick species collected in Corsica. Ticks from cattle (Bos taurus), sheep (Ovis aries), and rodents (Rattus rattus) were collected from May to September 2016. DNA was purified from ticks, submitted to quantitative real-time polymerase chain reaction (qPCR) and sequenced for phylogenetic analysis. In total, 660 ticks were collected from 111 animals during the study. The most abundant collected tick species from cattle was Rhipicephalus bursa (n = 495; 84.5%), followed by Hyalomma marginatum (n = 91; 15.5%). Rhipicephalus bursa and Ixodes ricinus were the only tick species collected from sheep and rodents, respectively. Overall, Rickettsia was the most common pathogen group (n = 48; 24%) detected in ticks. Sequence analysis of partial gltA and ompA genes revealed the presence of Ri. aeschlimannii and Candidatus Ri. barbariae. Anaplasmataceae DNA was detected in eight (6%) of the 127 cattle pools and in one (2%) of the 61 R. bursa specimens collected from sheep. Sequence analysis of the rpoB gene revealed the presence of one Anaplasma species, A. marginale. Borrelia burgdorferi sl DNA was detected in one pool of H. marginatum collected from cattle and in two (15%) of the 13 I. ricinus pools collected from nine black rats. To our knowledge, this is the first report of the occurrence and molecular characterization of Candidatus Ri. barbariae, an emerging member of the Rickettsia group causing spotted fever, in Corsica. The detection of B. burgdorferi sl DNA, which was previously believed to be rare in Corsica, confirms the presence of this agent on the island.

Gastrointestinal (GI) symptoms, such as diarrhea, vomiting, abdominal pain and nausea are not an uncommon manifestation of an acute respiratory infection (ARI). We therefore evaluated clinical and microbiological factors associated with the presence of GI symptoms in patients consulting a general practitioner (GP) for ARI. Nasopharyngeal swabs, stool specimens and clinical data from patients presenting to GPs with an ARI were prospectively collected during two winter seasons (2014-2016). Samples were tested by quantitative real-time PCR for 12 respiratory pathogen groups and for 12 enteric pathogens. Two hundred and four of 331 included patients (61.6%) were positive for at least one respiratory pathogen. Sixty-nine stools (20.8%) were positive for at least one pathogen (respiratory and/or enteric). GI symptoms were more likely declared in case of laboratory confirmed-enteric infection (adjusted odds ratio (aOR) = 3.2; 95% confidence interval [CI] [1.2–9.9]; p = 0.02) or human coronavirus (HCoV) infection (aOR = 2.7; [1.2–6.8]; p = 0.02). Consumption of antipyretic medication before the consultation seemed to reduce the risk of developing GI symptoms for patients with laboratory-confirmed influenza (aOR = 0.3; [0.1–0.6]; p = 0.002). The presence of GI symptoms in ARI patients could not be explained by the detection of respiratory pathogens in stools. However, the detection of enteric pathogens in stool samples could explained by the presence of GI symptoms in some of ARI cases. The biological mechanisms explaining the association between the presence of HCoVs in nasopharynx and GI symptoms need to be explored.