Norovirus Infections Spread like Wildfire: Recent Outbreaks Sicken Hundreds (*Thousands)

*Updated on 4/6/2016 at 11:31 AM EST

As if American college students didn’t have enough to worry about with the recent surge in nation-wide mumps outbreaks, several campuses across the country have now reported norovirus infections, some exceeding hundreds.

The Centers for Disease Control and Prevention (CDC) report that norovirus “is the most common cause of acute gastroenteritis (the inflammation of the stomach and/or intestines) in the United States,” with up to 21 million connected illnesses each year. The disease has also caused 56,000-71,000 hospitalizations and 570-800 deaths annually. For children and young adults, norovirus related illnesses can be serious.

Infections

Thus far, there have been several outbreaks across the country:

1. Lafayette College - Pennsylvania (47 cases)
2. Miami University of Ohio - Ohio (225 cases)
3. University of Michigan - Michigan (~150 cases)
4. Michigan State University’s Kellogg Center - Michigan (375 cases)
5. Ursinus College - Pennsylvania (200 cases)
6. University of California - Berkeley - California (# of cases to be confirmed)
7. University of Regina - Saskatchewan - Canada (# of cases to be confirmed)
8. Carnival Sunshine of Carnival Cruise Line (178 cases)
9. Anthem of the Seas of Royal Caribbean Cruise Line (148 cases)
10. Tri County Public Schools - Michigan* (# of cases to be confirmed)
11. Washington Oak Elementary School - Rhode Island (31 cases)**
12. Norwegian Gem of Norwegian Cruise Line (135 cases)
13. Oregon State University - Oregon (50-60 cases)

**confirmed by Rhode Island Department of Health

Hit hardest is Michigan, with three separate outbreaks: 150 University of Michigan students were diagnosed with a norovirus illness on February 19, while 375 individuals attending events from February 16 to the 21 at Michigan State University’s Kellogg Center are said to show symptoms. The source of the outbreak at Kellogg Center has yet to be identified due to the plethora of people who visited the Center daily during that time. Commenting on the severity of the case, Ingham County Health Department’s health officer, Linda Vail, MPA stated, "A very small amount [of the virus] can literally infect a thousand people. We are analyzing data, but there may not be one identifiable source."

At Miami University of Ohio, 225 students have been treated for norovirus, however, residence hall officials state that the number of infected individuals could be higher.

Recently, the Royal Caribbean Cruise Line Anthem of the Seas experienced an outbreak during its February 21-March 4 voyage, which was cut short. Of the 4,061 passengers on board, 132 individuals have shown symptoms of norovirus, mainly vomiting and diarrhea. Likewise, 16 of the 1,592 crewmembers experienced the same symptoms.

The Royal Caribbean Cruise Line, along with the on-board crew took initiatives to prevent further norovirus infection. Stool specimens from symptomatic individuals were collected for testing, and the Vessel Sanitation Program (VSP) at the CDC has been receiving daily reports of illnesses. Cleaning and disinfection procedures were increased according to the outbreak prevention and response plan, with public health staff and housekeeping operations managers sent in to oversee the process. The cause of the infection is still unknown, however, the CDC reports that two VSP officers as well as an epidemiologist have boarded the ship and collected specimens for CDC testing to evaluate the outbreak and response activities.

Norovirus Transmission

Norovirus is one of the more easily infectious diseases sweeping the country. The CDC reports that the disease can be transmitted through contact with an infected individual, contaminated food, water or surfaces. Norovirus spreads fastest in closed areas and more easily in restaurant-settings, such as cruise ships, daycare centers, nursing homes or schools. Outbreaks usually occur through infected servers handling food, or through contamination at the source, as with fruits, vegetables or even oysters. The disease is most contagious while the patient is sick, as well as the first few days after recovery. Due to the variety of noroviruses, infection with one type does not render an individual immune to the disease.

Dorothy McCoy, PharmD, BCPS-AQ ID, Clinical Associate Professor at the Ernest Mario School of Pharmacy at Rutgers University and Clinical Pharmacist, Infectious Diseases Hackensack University Medical Center, explains why the norovirus spreads so efficiently.

Symptoms

The virus can be found in stool before an individual starts to experience symptoms, and for two weeks afterwards. Individuals usually present the following symptoms 12-48 hours after viral exposure:

• Diarrhea
• Vomiting
• Dehydration (resulting in dizziness and dry mouth and throat)
• Nausea
• Stomach pain
• Fever
• Headache
• Body aches

Drinking plenty of liquids is important to avoid dehydration so as to prevent further related illnesses.

Prevention

Since there is no specific medication to treat norovirus, it is crucial to take the necessary preventive precautions, most importantly, proper handwashing, as advised by David Weismantel, MD, MS, university physician at MSU. Fruits and vegetables should always be washed properly to avoid norovirus infection, as well as other food borne illnesses. Not only this, but any shellfish should be cooked at temperatures exceeding 140°F. Infected individuals should not be in close proximity of places where food is kept or prepared and it is important to routinely disinfect all virus-contaminated surfaces with chlorine (a concentration of 1000-5000 parts per million, or by diluting 5-25 tablespoons of household bleach in a gallon of water).