Influenza Outbreaks and Cruise Ships

1. Influenza Outbreaks and Cruise Ships Laura Martin 25 April 2002

2. General Information • Influenza is an acute respiratory illness caused by a virus and transmitted by respiratory secretions through sneezing or coughing. • Symptoms: • Abrupt onset of fever • Headaches • Muscle aches • Soar throat • Non-productive cough • Congestion • Extreme Fatigue

3. General Information • Change in the virus • “Antigenic Drift” • Small changes that occur continuously over time. • Produces new virus strains in both influenza A and B • “Antigenic Shift” • An abrupt and major change in the influenza A viruses. • Results in a new subtype of influenza A. • Why is this significant? • Whenever a new subtype or strain is introduced, the body’s immune system will not recognize it. • Type C causes a mild respiratory illness and is thought not to cause epidemics.

4. Cross Section

5. General Information • Groups at Risk for severe infection • People over the age of 65. • Residents of nursing homes or chronic care facilities. • Those with chronic disorders of the pulmonary or cardiovascular systems. • Patients who have required medication follow-up or hospitalization during the past year because of chronic metabolic diseases, renal dysfunction, or immunosuppression. • Children or teens who are receiving long-term aspirin therapy.

6. General Information • Prevention • Vaccine • Administered yearly because of the genetic changes in the virus and decreased immunity over time. • Also consider vaccination before traveling to the tropics or into the Southern Hemisphere. • Side effects: • malaise (a feeling of illness or depression), • myalgia (muscular pain), • fever, • or an allergic reaction.

7. General Information • Treatment • Bed rest • Fluid consumption • Symptom relief with over the counter drugs such as pain relievers, decongestants, and cough medicines. • The use of anti-viral drugs • Two are available. • Can prevent infection during continued exposure to the virus. • Can also reduce the severity and duration of the illness if administered shortly after the appearance of symptoms.

8. Cruise Ships • September and October 1997 – Two Cruise Ships • Majority of passengers 65 and older and at risk for flu-related complications. • Majority of passengers and crew also unvaccinated. • Action taken: • Active surveillance • Vaccination of crew members • Use of antivirals • The steps taken to control this outbreak were successful. • However, the overall level of influenza activity is typically low for this time of year, so this situation demonstrates how travel and large groupings of people can increase the likelihood of a problem occurring.

9. Cruise Ships • Another possible influenza outbreak was reported by the CDC Morbidity and Mortality Weekly Report after June of 2000 when an outbreak of respiratory illnesses occurred on the MS Rotterdam.

10. Outbreaks and Pandemics • 1918 – The Spanish Flu • 20-50 million people died worldwide. • Many died a few days after infection and some died of complications later. • This pandemic was unique because almost half the people that died were young, healthy adults.

11. This is an image from an emergency hospital in Camp Funston, Kansas during the 1918 influenza epidemic.

12. Outbreaks and Pandemics • Other Pandemics include: • The 1957 Asian Flu which killed approximately 70,000 people in the United States. • The 1968 Hong Kong Flu that caused nearly 35,000 deaths in the US. • Other outbreaks include: • The 1976 Swine Flu that infected soldiers at Fort Dix, New Jersey. Over 40 million Americans were vaccinated as a result to prevent a pandemic. • The 1997 Avian Flu in which 18 people in Hong Kong were infected with a flu strain previously only seen in birds. Swine Flu