Maine Weekly Influenza Surveillance Report

January 19, 2006

Synopsis

During the past week, (Week 2 [January 8 - 14, 2006]) deaths associated with influenza and pneumonia increased. Of the 548 respiratory specimens that have been submitted for viral testing at Maine’s Health and Environmental Testing Laboratory (HETL) and two reference laboratories as of January 14, 2006, 5 specimens were positive for influenza A (H3), 7 specimens were positive for influenza A (unsubtyped), 6 were positive for influenza B, 162 were positive for respiratory syncytial virus (RSV), 19 were positive for parainfluenza-1, 11 were positive for parainfluenza-2, 5 were positive for parainfluenza–3, and 17 were positive for adenovirus.

Moderate Disease Surveillance

Outpatient influenza-like illness (ILI)

During week 2, 0.7% of sentinel provider patient visits were due to ILI. The range of patient visits for ILI was 0% to 6.5%.

Percentage of Patient Visits for Influenza-like Illness -- Maine, 2004-2006

# New England is defined as Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont.

Severe Disease Surveillance

Hospital inpatient

During week 1, two hospitals reported that 6.4% of emergency department admissions were due to respiratory illness. Comparison with previous years data is complicated by changes in which hospitals participate in this surveillance effort and the methods they use to extract data reported.

Percentage of Hospital Admissions from Sentinel Emergency Departments due to Respiratory Illness -- Maine, 2004-06

Laboratory Reporting

During week 2, a total of 3 respiratory specimens were submitted to HETL; results are pending on theses specimens. As of January 14, 2006, a total of 108 respiratory specimens have been submitted for viral testing to HETL this season. Of these, five specimens were positive for influenza A (H3), 2 specimens were positive for influenza A (unsubtyped), 3 were positive for influenza B, 1 was positive for parainfluenza-1, 1 was positive for parainfluenza-2, 1 was positive for adenovirus, and results are pending on 7 specimens.

Figure 4: Percentage of Submitted Respiratory Specimens Positive for Influenza – Maine Health and Environmental Testing Laboratory, 2003-2005

During week 2, a total of 48 respiratory specimens were submitted to two reference laboratories in Maine. Of these, no specimens were positive for influenza A or B. As of January 14, 2006, a total of 440 respiratory specimens have been submitted for viral testing to two reference laboratories in Maine since October when influenza surveillance season began. Five specimen were positive for influenza A, three were positive for influenza B, 162 were positive for respiratory syncytial virus (RSV), 18 were positive for parainfluenza-1, 10 were positive for parainfluenza-2, 4 were positive for parainfluenza-3, and 16 were positive for adenovirus.

Percentage of Submitted Respiratory Specimens Positive for Influenza – Two Reference Laboratories, Maine 2005-06

Outbreaks

No outbreaks of influenza were reported during week 2. Two outbreaks of influenza or influenza-like illness have been reported this season as of January 14, 2006.

Table: Influenza-like illness outbreaks by selected characteristics – Maine, 2005-06.

Facility Type*	Region	Date Reported	Attack Rate %		Hospital-izations #	Deaths #	Vaccination rate %		Lab-confirmed
			Residents	Staff			Residents	Staff
School	Midcoast	11/8/05	20.7	0	0	0	^	^
LTC	Midcoast	1/5/06	26.8	8.9	1	0	94.6	32.9	√

* Outbreak definition is specific to facility type. An outbreak in long-term care facilities (LTC) is defined as >3 patients with ILI identified on same floor or ward during a short (e.g., 48-72 hour) period OR >1 patients with lab-confirmed influenza; an outbreak in an acute care facility is defined as >1 patients with ILI or lab-confirmed influenza with symptom onset >48 hours post-admission (i.e., nosocomial); and an outbreak in a school is defined as >15% absentee rate among student population due to ILI or lab-confirmed influenza.

^ Data unavailable

Human Avian Influenza A (H5N1)

Enhanced surveillance guidelines for detecting suspected cases of human avian influenza A (H5N1) have been issued by federal partners. Maine CDC publishes these guidelines on the Maine influenza web site (see web link: https://www.maine.gov/dhhs/mecdc/epi/influenza/influenza-surveillance-avian-info.htm). As of week 2, no suspected cases of avian influenza A H5N1 meeting both clinical and epidemiological criteria have been reported in Maine this season.

Fatalities Surveillance

Death Certificates

During week 2, 12.2% of deaths reported by three city vital records offices were attributable to pneumonia and influenza. The rate at which deaths were attributable to pneumonia and influenza ranged from 5.6% to 18.4%.

Percentage of Deaths Attributable to Pneumonia and Influenza – Maine, New England and the United States, 2005-06

^ New England includes the following reporting areas: Boston, MA; Bridgeport, CT; Cambridge, MA; Fall River, MA; Hartford, CT; Lowell, MA; Lynn, MA; New Bedford, MA; New Haven, CT; Providence, RI; Somerville, MA; Springfield, MA; Waterbury, CT; Worcester, MA.

Pediatric Fatalities

No influenza-associated pediatric deaths were reported this season as of week 2.

* At time of publication, reporting may be incomplete. Numbers presented here may change as more reports are received.