Risk groups for clinical complications of norovirus infections: an outbreak investigation

Abstract

Norovirus infections have been described as self-limiting diseases of short duration. An investigation of a norovirus outbreak in a university hospital provided evidence for severe clinical features in patients with several underlying diseases. Clinical outcomes of norovirus infection were defined. Risk-factor analysis targeting underlying diseases and medication was performed using multivariate analyses. In five outbreak wards, 84 patients and 60 nurses were infected (an overall attack rate of 32% in patients, and 76% in nurses). The causative agent was the new variant Grimsby virus. Severe clinical features, including acute renal failure, arrhythmia and signs of acute graft organ rejection in renal transplant patients, were observed in seven (8.3%) patients. In multivariate analyses, cardiovascular disease (OR 17.1, 95% CI 2.17-403) and renal transplant (OR 13.0, 95% CI 1.63-281) were risk-factors for a potassium decrease of >20%. Age >65 years (OR 11.6, 95% CI 1.89-224) was a risk-factor for diarrhoea lasting >2 days. Immunosuppression (OR 5.7, 95% CI 1.78-20.1) was a risk-factor for a creatinine increase of >10%. Norovirus infections in patients with underlying conditions such as cardiovascular disease, renal transplant and immunosuppressive therapy may lead to severe consequences typified by decreased potassium levels, increased levels of C-reactive protein and creatine phosphokinase. In the elderly, norovirus infection may lead to an increased duration of diarrhoea. Therefore patients at risk should be hospitalised early and monitored frequently. Strict preventional measures should be implemented as early as possible to minimise the risk of nosocomial outbreaks.

Within-Host Evolution Results in Antigenically Distinct GII.4 Noroviruses

“…Noroviruses are an important cause of gastroenteritis in immunocompromised individuals (44,45), who are at increased risk for severe disease outcomes (1,44). Recent vaccine trials utilizing a VLP-based vaccine approach support the idea that efficacious vaccines that elicit short-term protection in some healthy individuals can be generated, but vaccines may not protect immunocompromised populations, making development of therapeutics that effectively treat or prevent norovirus infections a top health priority.…”

“…While typically an acute disease, norovirus infections can be serious in the young, old, and immunocompromised, as these groups are at risk for more severe disease and death (1)(2)(3). Norovirus is spread rapidly in environments where people are found in close proximity, including schools and daycare centers, nursing homes, cruise ships, and hospitals.…”

Murine Noroviruses Comprising a Single Genogroup Exhibit Biological Diversity despite Limited Sequence Divergence

“…81,2007 MNVs COMPRISE A SINGLE GENOTYPE AND GENOGROUP 10469 (17,41,52,58). The recent demonstration that children of less than 6 weeks of age can shed noroviruses for 6 weeks (57) raises the intriguing possibility that persistent infection with these viruses may be more common than is presently appreciated.…”

“…Symptoms of norovirus infection, which include vomiting, diarrhea, lowgrade fever, malaise, and abdominal cramping or pain, usually resolve within 48 h, although noroviruses can be shed for 3 weeks after infection in adults and at least 6 weeks after infection in children of less than 6 weeks of age (13,21,57,68). Norovirus infection is usually mild and self-limiting; however, severe disease and long-term virus shedding (lasting from 4 months to Ͼ2 years) have been documented previously in patients with underlying chronic conditions or immunosuppression (17,41,52,58).…”

Norovirus Gastroenteritis

“…20,33 Virus can be shed in low titers for up to 8 weeks in previously healthy persons 19 and for more than a year in patients who are immunocompromised and in those who have undergone transplantation; making a diagnosis can be critical when gastrointestinal symptoms can be an early sign of rejection or a side effect of drugs. 34,35 Fatalities have been reported in association with outbreaks of gastroenteritis among the elderly in nursing home facilities, 36,37 and in the United Kingdom, an estimated 80 deaths from norovirus infections occur each year among persons older than 64 years of age. 38 Recent reports have suggested possible associations of norovirus infection with necrotizing enterocolitis in newborns, with benign seizures in infants, and with exacerbations of inflammatory bowel disease in pediatric patients; further study is needed to confirm these links.…”