Denton County Public Health

Denton County Influenza Surveillance

DCPH Weekly Influenza Surveillance Report for week 15 (4/9/17 – 4/15/17).

Low influenza activity was reported in Denton County for week 16. 16 positive influenza tests (2 Flu A,  14 Flu B) and 2 hospitalizations were reported by Denton County sentinel providers for week 15. Syndromic surveillance for influenza-like illness (ILI) in Denton County decreased during week 15 compared to the previous week.

 

During week 14, influenza activity decreased in the United States. Geographic influenza activity in Texas increased to regional for week 15 compared to the previous week. The percentage of specimens testing positive for influenza decreased in Texas to 11.6% in week 14 and decreased in the US to 12.6% in week 15 compared to the previous weeks. The percentage of visits for ILI in Texas as reported by ILINet providers decreased to 4.3% in week 14, which is below the Texas baseline of 6.3%. The proportion of outpatient visits for ILI in the US in week 15 was 2.0%, which is below the national baseline of 2.2%, and a decrease compared to the previous week. Three of ten regions reported ILI at or above their region-specific baseline levels. Two states experienced moderate ILI activity; three states experienced low ILI activity; and 45 states experienced minimal ILI activity. The geographic spread of influenza in 10 states was reported as widespread; 15 states reported regional activity; 19 states reported local activity; and six states reported sporadic activity. The proportion of deaths attributed to pneumonia and influenza (P&I) from the National Center for Health Statistics Mortality Surveillance System for week 13 was 7.2%. This percentage is below the epidemic threshold of 7.3% for week 13.

 

Healthcare providers should be aware of the following recommendations:

  • Clinicians should encourage all patients 6 months of age and older who have not yet received an influenza vaccine this season to be vaccinated against influenza.

  • Rapid influenza diagnostic tests (RIDTs) have limited sensitivities and predictive values; negative results of RIDTs do not exclude influenza virus infection in patients with signs and symptoms suggestive of influenza. Therefore, antiviral treatment should not be withheld from patients with suspected influenza, even if they test negative.

  • Clinicians should encourage all persons with influenza-like illness who are at high risk for influenza complications to seek care promptly to determine if treatment with influenza antiviral medications is warranted.

  • All Hospitalized, Severely Ill, and High Risk Patients with suspected influenza should be treated with antivirals. Prompt treatment with influenza antiviral drugs can reduce serious illness and death. These drugs work best when started soon after influenza symptoms begin (within 2 days), but persons with high-risk conditions can benefit even when antiviral treatment is started after the first two days of illness.