Error processing SSI file
Error processing SSI file
Error processing SSI file
Error processing SSI file
Error processing SSI file
Error processing SSI file
Error processing SSI file
Error processing SSI file

Weekly Report: Influenza Summary Update

Week ending October 15, 2005-Week 41

Error processing SSI file

Synopsis:

During week 41 (October 9 - October 15, 2005)*, influenza activity occurred at a low level in the United States. One (0.2%) specimen tested by U.S. World Health Organization (WHO) and National Respiratory and Enteric Virus Surveillance System (NREVSS) collaborating laboratories was positive for influenza. The proportion of patient visits to sentinel providers for influenza-like illness (ILI) and the proportion of deaths attributed to pneumonia and influenza were below baseline levels. One state reported local influenza activity, 8 states and New York City reported sporadic influenza activity, and 40 states and the District of Columbia reported no influenza activity.

Laboratory Surveillance*:

During week 41, WHO and NREVSS laboratories reported 590 specimens tested for influenza viruses, and 1 (0.2%) was positive. The influenza virus identified was an influenza A virus that was not subtyped from the South Atlantic region.**

INFLUENZA Virus Isolated


View Chart Data

Pneumonia and Influenza (P&I) Mortality Surveillance*:

During week 41, 6.3% of all deaths reported by the vital statistics offices of 122 U.S. cities were reported as due to pneumonia or influenza. This percentage is below the epidemic threshold of 6.8% for week 41.

Pneumonia And Influenza Mortality

View Full Screen

Influenza-Associated Pediatric Mortality*:

No influenza-associated pediatric deaths were reported for week 41.

Influenza-Associated Pediatric Hospitalizations*:

Laboratory-confirmed influenza-associated pediatric hospitalizations are monitored in two population-based surveillance networks : the Emerging Infections Program (EIP) and the New Vaccine Surveillance Network (NVSN). EIP's estimated rates of hospitalization for influenza will be reported every 2 weeks beginning October 28, 2005. NVSN's estimated rates of hospitalization for influenza will be reported every 2 weeks beginning November 25, 2005.

In years 2000-05, the end-of-season hospitalization rate for NVSN ranged from 3.7 (2002-03) to 12 (2003-04) per 10,000 children. The 2003-04 end-of-season hospitalization rate for EIP was 8.9 per 10,000 children aged 0-4 years and 0.8 per 10,000 for children aged 5-17 years. The 2004-05 NVSN end-of-season hospitalization rate for children aged 0-4 years was 7 per 10,000. The preliminary 2004-05 end-of-season hospitalization rate for EIP was 3.3 per 10,000 children aged 0-4 years and 0.6 per 10,000 for children aged 5-17 years. The difference in rates between NVSN and EIP may be due to different case-finding methods and the different populations monitored. For a summary of the methods used in each system, please refer to the surveillance methods in the Flu Activity section of the CDC influenza website.

Influenza-like Illness Surveillance*:

During week 41, 1.3%*** of patient visits to U.S. sentinel providers were due to ILI. This percentage is less than the national baseline of 2.2%. On a regional level**, the percentage of visits for ILI ranged from 0.4% to 2.8%. Due to wide variability in regional level data, it is not appropriate to apply the national baseline to regional level data.

Bar Chart for Influenza-like Illness
View Chart Data

Influenza Activity as Assessed by State and Territorial Epidemiologists*:

During week 41, Idaho reported local influenza activity. Eight states (Alaska, California, Florida, Hawaii, New York, North Dakota, Oregon, and Texas) and New York City reported sporadic influenza activity. Forty states and the District of Columbia reported no influenza activity, and 1 state did not report.

U. S. map for Weekly Influenza Activity
View Full Screen

--------------------------------------------------------------------------------

Foot notes

Report prepared October 21, 2005

Error processing SSI file
Error processing SSI file
Error processing SSI file
Error processing SSI file