Health Update
INFLUENZA SURVEILLANCE UPDATE

This is a general update on influenza surveillance activity in Delaware and the nation. Information is also provided for infection control in the health care setting.

Surveillance Update

Delaware

Summary:

• Reports of influenza-like illness (ILI) and rapid test positive influenza are beginning to increase in Delaware.
• DPH’s classification of the state’s flu status has changed to "widespread," in accordance with the definition established by the Centers for Disease Control and Prevention. In Delaware, this indicates that there are cases in all three counties. The state’s status had remained at "regional"(occurring in two counties) during December and early January.

Details:

• The Division of Public Health (DPH) has received 45 reports of rapid positive influenza tests this influenza, but actual morbidity is certainly much greater. Twenty-two (22) of these reports were in January, 2005.
• The DPH Laboratory has tested 116 specimens to date of which 24 had a positive isolate for influenza. Of these, 21 were Influenza A (H3N2) Wyoming-like virus (related to A/Fujian/411/2002-like), and 3 were Influenza B Shanghai/Jilin-like viruses.
• All hospitals (including outpatients and admissions) in Delaware participate in weekly reporting of ILI to DPH. Reports of ILI sharply increased during the week of January 2-7, 2005.

National

Summary:

• During week 52 (December 26, 2004-January 1, 2005), influenza activity continued to increase mostly in the eastern United States.

Details:

• The proportion of patient visits to sentinel providers for ILI is above the national baseline. The proportion of deaths attributed to pneumonia and influenza is below the national baseline.
• New York, Vermont, and New York City reported widespread influenza activity, 12 states reported regional influenza activity, and 13 states and the District of Columbia reported local activity. Twenty-two states reported sporadic influenza activity and 1 state did not report.
• Three hundred nineteen (12.1%) specimens tested by U.S. World Health Organization (WHO) and National Respiratory and Enteric Virus Surveillance System (NREVSS) collaborating laboratories were positive for influenza viruses. Fifty-six isolates were influenza A (H3N2) viruses, 237 were influenza A viruses that were not subtyped, and 26 were influenza B viruses. Fifty percent of all isolates this season have been reported from the Mid-Atlantic and New England surveillance regions.
• CDC has antigenically characterized 107 influenza viruses collected by U.S. laboratories since October 1, 2004: eighty-five influenza A (H3N2) viruses and 22 influenza B viruses. All of the influenza A (H3N2) isolates were characterized as A/Fujian/411/2002-like (H3N2), which is the influenza A (H3N2) component recommended for the 2004-05 influenza vaccine. Nineteen of the influenza B viruses isolated this season belong to the B/Yamagata lineage and were characterized as B/Shanghai/361/2002-like, which is the influenza B component recommended for the 2004-05 influenza vaccine. Three influenza B viruses belong to the B/Victoria lineage and were characterized as B/Hong Kong/330/2001-like.

Infection Control in Health Care Settings

In addition to influenza immunization, the following infection control measures are recommended to prevent person-to-person transmission of influenza and to control influenza outbreaks in health-care facilities:

Respiratory Hygiene/Cough Etiquette

Respiratory Hygiene/Cough Etiquette programs should be implemented at the first point of contact with a potentially infected person to prevent the transmission of all respiratory tract infections in health-care settings, including influenza. A Respiratory Hygiene/Cough Etiquette program includes posting visual alerts instructing patients and persons who accompany them to inform health-care personnel if they have symptoms of respiratory infection; providing tissues to patients and visitors to cover their mouth and nose when coughing and sneezing; providing dispensers of alcohol-based hand rubs; ensuring that supplies for handwashing are available where sinks are located; offering masks to persons who are coughing; encouraging coughing persons to sit at least 3 feet away from others; and having health personnel observe Standard Precautions.

Standard Precautions

During the care of a patient with suspected or confirmed influenza:

• Wear gloves if hand contact with respiratory secretions or potentially contaminated surfaces is expected.
• Wear a gown if soiling of clothes with patient’s respiratory secretions is expected.
• Change gloves and gowns after each patient encounter and perform hand hygiene.
• Decontaminate hands before and after touching the patient, after touching the patient’s environment, or after touching the patient’s respiratory secretions, whether or not gloves are worn.
• When hands are visibly soiled or contaminated with respiratory secretions, wash hands with either a non-antimicrobial or an antimicrobial soap and water.
• If hands are not visibly soiled, use an alcohol-based hand rub for routinely decontaminating hands in clinical situations. Alternatively, wash hands with an antimicrobial soap and water.

Droplet Precautions

In addition to Standard Precautions, observe Droplet Precautions during the care of a patient with suspected or confirmed influenza:

• Place patient into a private room. If a private room is not available, place (cohort) suspected influenza patients with other patients suspected of having influenza; cohort confirmed influenza patients with other patients confirmed to have influenza. Scientific evidence is insufficient to make a recommendation upon the routine use of negative-pressure rooms for influenza patients.
• Wear a surgical mask upon entering the patient’s room or when working within 3 feet of the patient. Remove the mask when leaving the patient’s room and dispose of the mask in a waste container.
• If patient movement or transport is necessary, have the patient wear a surgical mask, if possible.

Visitor and Worker Restrictions

• Discourage persons with symptoms of a respiratory infection from visiting patients.
• Exclude health-care personnel with symptoms of respiratory infection from work for the duration of illness.

Control of Influenza Outbreaks in Health-care Settings

When influenza outbreaks occur in health-care settings, additional measures should be taken to limit transmission. These include:

• Identify influenza as the causative agent, early in the outbreak, by performing rapid influenza virus testing of patients with recent onset of symptoms suggestive of influenza. In addition, obtain viral cultures from a subset of patients to determine the infecting virus type and subtype.
• Implement Droplet Precautions for all patients with suspected or confirmed influenza.
• Separate suspected or confirmed influenza patients from asymptomatic patients.
• Restrict staff movement between units and buildings.
• For all patients without influenza illness in the involved unit and for whom the antiviralagent is not contraindicated, administer influenza antiviral prophylaxis according to current recommendations.
• Administer influenza antiviral therapy to patients acutely ill with influenza, within 48 hours of onset of illness.
• Administer current inactivated influenza vaccine to unvaccinated patients and health-care personnel.
• Offer influenza antiviral prophylaxis to unvaccinated personnel for whom the antiviral agent is not contraindicated and who work in the affected unit or who are taking care of high-risk patients.
• Consider prophylaxis for all health-care personnel, regardless of their vaccination status, if the outbreak is caused by a variant of influenza that is not well matched by the vaccine.
• Curtail or eliminate elective medical and surgical admissions and restrict cardiovascular and pulmonary surgery to emergency cases only, when influenza outbreaks, especially those characterized by high attack rates and severe illness, occur in the community or acute care facility.

For Further information:

• Please call DPH, Bureau of Epidemiology at 1-888-295-5156. The number is available during normal business hours and during non-business hours for emergencies.
• You can obtain additional information about Influenza on the Centers for Disease Control and Prevention website at: http://www.cdc.gov/flu/