Study: Norovirus kills 900, costs up to $720 million per year in US
Each year, norovirus causes about 900 deaths, 110,000 hospitalizations, 2.3 million clinic visits, and 470,000 emergency department (ED) visits, at an annual healthcare cost of $430 million to $720 million, providing a substantial opportunity for a vaccine, according to a study in Clinical Infectious Diseases.
Norovirus is a leading cause of acute gastroenteritis (AGE) and can lead to hospitalization or death in young children and older people. A candidate norovirus vaccine was recently evaluated in a phase 2b trial.
Researchers at the US Centers for Disease Control and Prevention analyzed administrative data on AGE outcomes from Jul 1, 2001, to Jun 30, 2015, to estimate the norovirus burden, determine the potential value of norovirus vaccines under development, provide a baseline against which future vaccine impact can be measured, and indicate which populations should be targeted for the biggest public health impact.
The researchers based models on data on ambulatory clinic and ED visits from the IBM MarketScan Commercial and Medicare Supplemental Databases, hospitalizations from the Healthcare Utilization Project National Inpatient Sample, and deaths from the National Center for Health Statistics.
The investigators found that rates of AGE-related outpatient visits were highest among children younger than 5 years (23% of clinic visits and 30% of ED visits), while rates of related hospitalization and death were highest among adults 65 years and older (43% of hospitalizations and 86% of deaths).
Norovirus-linked clinic visits cost, on average, $225 million a year, while ED visits cost $237 million. Adults 18 to 64 years old had the highest mean cost per norovirus-related clinic visit ($111) and ED visit ($586) and the highest total national costs for related clinic visits ($84 million) and ED visits ($141 million).
Norovirus-related hospitalizations cost, on average, $106 million a year, with over half of the costs attributed to children younger than 5 years, due to the highest mean cost per hospitalization, at $2,513.
"Norovirus causes a substantial health burden in the United States each year, and an effective vaccine could have an important health impact," the authors wrote. "Active surveillance of norovirus is warranted to refine burden estimates and provide more detail and precision, particularly with regards to specific norovirus genotypes and economic costs."
Apr 14 Clin Infect Dis abstract
Flu declines in Northern Hemisphere, but respiratory illness still elevated
Flu activity in the Northern Hemisphere has decreased, but flulike illness activity is still elevated in some countries, the World Health Organization (WHO) said in its latest regular update.
However, it warned that the global trends should be interpreted with caution because the COVID-19 pandemic might be influencing health-seeking behaviors and health system capacity for flu testing.
In the United States, for example, flulike illness remained elevated, with the percentage of deaths from pneumonia and flu above the epidemic threshold, though flu-related deaths declined.
In Europe, though flu activity decreased in all reporting countries, flulike illness remained elevated in several countries, including Belgium, Germany, and the Netherlands.
In East Asia, flulike illness markers were at inter-seasonal levels, though in South Asia, flu activity increased in Bhutan, and in South East Asia, flu activity rose in Laos. In the Southern Hemisphere, flu was at inter-seasonal levels, but in Australia, the number of emergency department visits for respiratory symptoms was higher than expected this time of year. Flulike illness indicators increased in some South American countries.
At the global level, influenza A made up 63.3% of positive samples, and of subtyped influenza A viruses, 68.1% were 2009 H1N1.
Apr 13 WHO global flu update