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Author Simmons, Kirsten ♦ Gambhir, Manoj ♦ Leon, Juan ♦ Lopman, Ben
Source CiteSeerX
Content type Text
File Format PDF
Subject Domain (in DDC) Computer science, information & general works ♦ Data processing & computer science
Subject Keyword Research Duration ♦ Industrialized Country ♦ Human Challenge Study ♦ Emergency Care Visit ♦ Common Cause ♦ Community Nov Transmission ♦ Outpatient Visit ♦ Maximum Likelihood ♦ Antibody Seroprevalence ♦ Short Period ♦ Natural Immunity ♦ Various Model ♦ Economic Benefit ♦ Acute Gastroenteritis ♦ Prototype Nov Strain ♦ Potential Health ♦ Age Group ♦ Inoculum Multiple Time ♦ Age-specific Incidence Data ♦ Mathematical Model ♦ Several Scenario ♦ Young Child ♦ Nov Gastroenteritis ♦ Several Observation ♦ Disease Occur ♦ Norwalk Virus ♦ United State ♦ Infection Rate
Abstract The duration of immunity to norovirus (NoV) gastroenteritis has been believed to be from 6 months to 2 years. However, several observations are inconsistent with this short period. To gain better estimates of the duration of immunity to NoV, we developed a mathematical model of community NoV transmission. The model was parameterized from the literature and also fit to age-specific incidence data from England and Wales by using maximum likelihood. We developed several scenarios to determine the effect of unknowns regarding transmission and immunity on estimates of the duration of immunity. In the various models, duration of immunity to NoV gastroenteritis was estimated at 4.1 (95 % CI 3.2–5.1) to 8.7 (95 % CI 6.8–11.3) years. Moreover, we calculated that children (<5 years) are much more infectious than older children and adults. If a vaccine can achieve protection for duration of natural immunity indicated by our results, its potential health and economic benefits could be substantial. Noroviruses (NoVs) are the most common cause of acute gastroenteritis (AGE) in industrialized countries. In the United States, NoV causes an estimated 21 million cases of AGE (1), 1.7 million outpatient visits (2), 400,000 emergency care visits, 70,000 hospitalizations (3), and 800 deaths annually across all age groups (4). Although the highest rates of disease are in young children, infection and disease occur throughout life (5), despite an antibody seroprevalence>50%, and infection rates approach 100% in older adults (6,7). Frequently cited estimates of the duration of immunity to NoV are based on human challenge studies conducted in the 1970s. In the first, Parrino et al. challenged volunteers with Norwalk virus (the prototype NoV strain) inoculum multiple times. Results suggested that the immunity to
Educational Role Student ♦ Teacher
Age Range above 22 year
Educational Use Research
Education Level UG and PG ♦ Career/Technical Study