Salmonella Typhimurium outbreak associated with frozen tomato cubes at a restaurant in western Finland, January to February 2021.

Several individuals reported gastrointestinal symptoms following meals consumed in late January 2021 at a restaurant in western Finland. We conducted a retrospective cohort study and defined a case as a person who ate at the lunch restaurant between 27 and 29 January 2021 and had stomach pain, vomiting or diarrhoea and/or a laboratory-confirmed Salmonella Typhimurium infection within 2 weeks after the exposure. We collected faecal and food samples for microbiological analysis. Salmonella isolates were characterised in detail using whole genome sequencing (WGS) and cluster analysis by core genome multilocus sequence typing (cgMLST). Altogether, 393 meals were sold and 101 people (who ate 142 meals) participated in the cohort study. There were 49 cases; 23 were laboratory-confirmed infections with a multidrug-resistant S. Typhimurium. The S. Typhimurium isolates from cases and frozen tomato cubes used uncooked in salads were closely related and clustered together in cgMLST comparison. These salads were consumed by 76% of the cases. Based on the cgMLST clustering, they were the suggested source of the outbreak. Statistical association was not significant between eating the salads and being a case. Following the outbreak investigation, the producer decided to recommend cooking of their frozen tomato products before consumption.

Impaired immunity and high attack rates caused by SARS-CoV-2 variants among vaccinated long-term care facility residents.

INTRODUCTION: Long-term care facilities (LTCF) residents are at high risk for severe coronavirus disease 2019 (COVID-19), and therefore, COVID-19 vaccinations were prioritized for residents and personnel in Finland at the beginning of 2021. METHODS: We investigated COVID-19 outbreaks in two LTCFs, where residents were once or twice vaccinated. After the outbreaks we measured immunoglobulin G (IgG) antibodies to severe acute respiratory syndrome coronavirus 2 spike glycoprotein, neutralizing antibody (NAb) titers, and cell-mediated immunity markers from residents and healthcare workers (HCWs). RESULTS: In LTFC-1, the outbreak was caused by an Alpha variant (B.1.1.7) and the attack rate (AR) among once vaccinated residents was 23%. In LTCF-2 the outbreak was caused by a Beta variant (B.1.351). Its AR was 47% although all residents had received their second dose 1 month before the outbreak. We observed that vaccination had induced lower IgG concentrations, NAb titers and cell-mediated immune responses in residents compared to HCWs. Only 1/8 residents had NAb to the Beta variant after two vaccine doses. CONCLUSIONS: The vaccinated elderly remain susceptible to breakthrough infections caused by Alpha and Beta variants. The weaker vaccine response in the elderly needs to be addressed in vaccination protocols, while new variants capable of evading vaccine-induced immunity continue to emerge.

How to optimize hepatitis C virus treatment impact on life years saved in resource-constrained countries.

UNLABELLED: In resource-constrained countries where the prevalence of hepatitis C virus (HCV) disease is usually high, it is important to know which population should be treated first in order to increase treatment effectiveness. The aim was to estimate the effectiveness of different HCV treatment eligibility scenarios in three different countries. Using a Markov model, we estimated the number of life-years saved (LYS) with different treatment eligibility scenarios according to fibrosis stage (F1-F4 or F3-4), compared to base case (F2-F4), at a constant treatment rate, of patients between 18 and 60 years of age, at stages F0/F1 to F4, without liver complications or coinfections, chronically infected by HCV, and treated with pegylated interferon (IFN)/ribavirin or more-efficacious therapies (i.e. IFN free). We conducted the analysis in Egypt (prevalence = 14.7%; 45,000 patients treated/year), Thailand (prevalence = 2.2%; 1,000 patients treated/year), and Côte d'Ivoire (prevalence = 3%; 150 patients treated/year). In Egypt, treating F1 patients in addition to ≥F2 patients (SE1 vs. SE0) decreased LYS by 3.9%. Focusing treatment only on F3-F4 patients increased LYS by 6.7% (SE2 vs. SE0). In Thailand and Côte d'Ivoire, focusing treatment only on F3-F4 patients increased LYS by 15.3% and 11.0%, respectively, compared to treating patients ≥F2 (ST0 and SC0, respectively). Treatment only for patients at stages F3-F4 with IFN-free therapies would increase LYS by 16.7% versus SE0 in Egypt, 22.0% versus ST0 in Thailand, and 13.1% versus SC0 in Côte d'Ivoire. In this study, we did not take into account the yearly new infections and the impact of treatment on HCV transmission. CONCLUSION: Our model-based analysis demonstrates that prioritizing treatment in F3-F4 patients in resource-constrained countries is the most effective scenario in terms of LYS, regardless of treatment considered.

Effectiveness and cost of quick diagnostic tests to determine tetanus immunity in patients with a wound in French emergency departments.

BACKGROUND: Tétanos Quick Stick® (TQS) is a test for tetanus immunity screening for wounded patients in emergency departments (EDs), but represents additional costs compared with a medical interview on vaccination history. The study objective was to assess the effectiveness and cost of the TQS in French EDs. METHODS: We performed a model-based analysis that simulates screening of tetanus immunity and risk of tetanus based on prophylaxis administration. Strategies compared were: i) diagnosis of tetanus immunity by "TQS"; ii) "Medical Interview" (current practice). The study population was 1,658,000 French adults seeking ED care for a wound in 2012. Model parameters were estimated based on French national surveillance data, and published literature. Outcome measures were number of tetanus cases, life years gained and costs (2012 €) from a societal perspective. RESULTS: Use of TQS had negligible impact on health outcomes (0.02 tetanus cases/year in France vs. 0.41 for "Medical Interview"), but resulted in a decrease in annual costs of €2,203,000 (-42%). Base case and sub-group analysis showed that with the same effectiveness, the average cost per patient was: €13 with "Medical Interview" vs. €11.7 with TQS for the overall cohort; €28.9 with "Medical Interview" vs. €21 with "TQS" for tetanus-prone wounds; €15 with "Medical Interview" vs. €14.1 with "TQS" for patients aged ≥65 years; and €6.2 with "Medical Interview" vs. €7.8 with "TQS" for non-tetanus-prone wounds. CONCLUSIONS: Use of TQS is as effective and less costly than "Medical Interview" when applied in ED to wounded patients with tetanus-prone wounds or aged ≥65 years. However, it is more expensive in patients with non-tetanus-prone wounds.

Is expert opinion reliable when estimating transition probabilities? The case of HCV-related cirrhosis in Egypt.

BACKGROUND: Data on HCV-related cirrhosis progression are scarce in developing countries in general, and in Egypt in particular. The objective of this study was to estimate the probability of death and transition between different health stages of HCV (compensated cirrhosis, decompensated cirrhosis and hepatocellular carcinoma) for an Egyptian population of patients with HCV-related cirrhosis. METHODS: We used the "elicitation of expert opinions" method to obtain collective knowledge from a panel of 23 Egyptian experts (among whom 17 were hepatologists or gastroenterologists and 2 were infectiologists). The questionnaire was based on virtual medical cases and asked the experts to assess probability of death or probability of various cirrhosis complications. The design was a Delphi study: we attempted to obtain a consensus between experts via a series of questionnaires interspersed with group response feedback. RESULTS: We found substantial disparity between experts' answers, and no consensus was reached at the end of the process. Moreover, we obtained high death probability and high risk of hepatocellular carcinoma. The annual transition probability to death was estimated at between 10.1% and 61.5% and the annual probability of occurrence of hepatocellular carcinoma was estimated at between 16.8% and 58.9% (depending on age, gender, time spent in cirrhosis and cirrhosis severity). CONCLUSIONS: Our results show that eliciting expert opinions is not suited for determining the natural history of diseases due to practitioners' difficulties in evaluating quantities. Cognitive bias occurring during this type of study might explain our results.

Should we await IFN-free regimens to treat HCV genotype 1 treatment-naive patients? A cost-effectiveness analysis (ANRS 95141).

BACKGROUND & AIMS: In treatment-naive patients mono-infected with genotype 1 chronic HCV, treatments with telaprevir/boceprevir (TVR/BOC)-based triple therapy are standard-of-care. However, more efficacious direct-acting antivirals (IFN-based new DAAs) are available and interferon-free (IFN-free) regimens are imminent (2015). METHODS: A mathematical model estimated quality-adjusted life years, cost and incremental cost-effectiveness ratios of (i) IFN-based new DAAs vs. TVR/BOC-based triple therapy; and (ii) IFN-based new DAAs initiation strategies, given that IFN-free regimens are imminent. The sustained virological response in F3-4/F0-2 was 71/89% with IFN-based new DAAs, 85/95% with IFN-free regimens, vs. 64/80% with TVR/BOC-based triple therapy. Serious adverse events leading to discontinuation were taken as: 0-0.6% with IFN-based new DAAs, 0% with IFN-free regimens, vs. 1-10% with TVR/BOC-based triple therapy. Costs were €60,000 for 12weeks of IFN-based new DAAs and two times higher for IFN-free regimens. RESULTS: Treatment with IFN-based new DAAs when fibrosis stage ⩾F2 is cost-effective compared to TVR/BOC-based triple therapy (€37,900/QALY gained), but not at F0-1 (€103,500/QALY gained). Awaiting the IFN-free regimens is more effective, except in F4 patients, but not cost-effective compared to IFN-based new DAAs. If we decrease the cost of IFN-free regimens close to that of IFN-based new DAAs, then awaiting the IFN-free regimen becomes cost-effective. CONCLUSIONS: Treatment with IFN-based new DAAs at stage ⩾F2 is both effective and cost-effective compared to TVR/BOC triple therapy. Awaiting IFN-free regimens and then treating regardless of fibrosis is more efficacious, except in F4 patients; however, the cost-effectiveness of this strategy is highly dependent on its cost.

Effectiveness and cost-effectiveness of immediate versus delayed treatment of hepatitis C virus-infected patients in a country with limited resources: the case of Egypt.

BACKGROUND: Because of logistical and economic issues, in Egypt, as in other resource-limited settings, decision makers should determine for which patients hepatitis C virus (HCV) treatment should be prioritized. We assessed the effectiveness and cost-effectiveness of different treatment initiation strategies. METHODS: Using a Markov model, we simulated HCV disease in chronically infected patients in Egypt, to compare lifetime costs, quality-adjusted life expectancy (QALE), and the incremental cost-effectiveness ratio (ICER) of different treatment initiation strategies. RESULTS: Immediate treatment of patients at stages F1/F2/F3 was less expensive and more effective than delaying treatment until more severe stages or not providing treatment (in patients diagnosed at F1: QALE = 18.32 years if treatment at F1 vs 18.22 if treatment at F2). Treatment of F4 patients was more effective than no treatment at all (QALE = 10.33 years vs 8.77 years) and was cost-effective (ICER = $1915/quality-adjusted life-year [QALY]). When considering that affordable triple therapies, including new direct-acting antivirals, will be available starting in 2016, delaying treatment until stage F2, then treating all patients regardless of their disease stage after 2016, was found to be cost-effective (ICER = $33/QALY). CONCLUSIONS: In Egypt, immediate treatment of patients with fibrosis stage F1-F3 who present to care is less expensive and more effective than delaying treatment. However, immediate treatment at stage F1 is only slightly more effective than waiting for disease to progress to stage F2 before starting treatment and is sensitive to the forthcoming availability of new treatments. Treating patients at stage F4 is highly effective and cost-effective. In Egypt, decision makers should prioritize treatment for F4 patients and delay treatment for F1 patients who present to care.

Age-dependent Mendelian predisposition to herpes simplex virus type 1 encephalitis in childhood.

OBJECTIVE: To test the hypothesis that predisposition to childhood herpes simplex virus (HSV) type 1 encephalitis (HSE) may be determined in part by human genetic factors. STUDY DESIGN: A genetic epidemiologic survey of childhood HSE (onset at age 3 months to 15 years) over a 20-year period (1985-2004) was conducted throughout France (comprising 29 university hospital neuropediatric centers). A total of 85 children fulfilled the diagnostic criteria for inclusion. Family and personal histories were obtained by face-to-face interview for 51 patients. RESULTS: No familial cases of HSE were identified in our survey; however, a high proportion (20%) of the children interviewed had a relevant family history: parental consanguinity (12% of patients), early-onset herpetic keratitis in a first-degree relative (6%), or both (2%). The narrow window of high susceptibility to HSE before age 3 years (62% of patients) further indicates that predisposition to HSE is tightly age-dependent. CONCLUSIONS: This survey suggests that childhood HSE, although sporadic, may result from Mendelian predisposition (from autosomal recessive susceptibility in particular), at least in some children. There likely is incomplete penetrance, however, which may reflect, at least in part, the impact of age at the time of HSV-1 infection.

Evidence for a dominant major gene conferring predisposition to hepatitis C virus infection in endemic conditions.

Hepatitis C virus (HCV), infecting 170 million people worldwide, is a major public health problem. In developing countries, unsafe injections and blood transfusions are thought to be the major routes of transmission. However, our previous work in a population from Egypt, endemic for HCV, revealed highly significant familial correlations, strongly suggesting the existence of both familial transmission of the virus and genetic predisposition to HCV infection. We investigated the hypothesis of genetic predisposition by carrying out a segregation analysis of HCV infection in the same population. We used a logistic regression model simultaneously taking into account a major gene effect, familial correlations and relevant risk factors. We analyzed 312 pedigrees (3,703 subjects). Overall HCV seroprevalence was 11.8% and increased with age. The main associated risk factors were previous parenteral treatment for schistosomiasis and blood transfusions. We found strong evidence for a dominant major gene conferring a predisposition to HCV infection. The frequency of the predisposing allele was 0.013, reflecting a strong predisposition to HCV infection in 2.6% of the subjects, particularly those under the age of 20. This study provides evidence for the involvement of host genetic factors in susceptibility/resistance to HCV infection in endemic conditions.

Mitochondrial dysfunction in lyssavirus-induced apoptosis.

Lyssaviruses are highly neurotropic viruses associated with neuronal apoptosis. Previous observations have indicated that the matrix proteins (M) of some lyssaviruses induce strong neuronal apoptosis. However, the molecular mechanism(s) involved in this phenomenon is still unknown. We show that for Mokola virus (MOK), a lyssavirus of low pathogenicity, the M (M-MOK) targets mitochondria, disrupts the mitochondrial morphology, and induces apoptosis. Our analysis of truncated M-MOK mutants suggests that the information required for efficient mitochondrial targeting and dysfunction, as well as caspase-9 activation and apoptosis, is held between residues 46 and 110 of M-MOK. We used a yeast two-hybrid approach, a coimmunoprecipitation assay, and confocal microscopy to demonstrate that M-MOK physically associates with the subunit I of the cytochrome c (cyt-c) oxidase (CcO) of the mitochondrial respiratory chain; this is in contrast to the M of the highly pathogenic Thailand lyssavirus (M-THA). M-MOK expression induces a significant decrease in CcO activity, which is not the case with M-THA. M-MOK mutations (K77R and N81E) resulting in a similar sequence to M-THA at positions 77 and 81 annul cyt-c release and apoptosis and restore CcO activity. As expected, the reverse mutations, R77K and E81N, introduced in M-THA induce a phenotype similar to that due to M-MOK. These features indicate a novel mechanism for energy depletion during lyssavirus-induced apoptosis.