Wisconsin influenza activity is at baseline. Influenza A has been this season’s dominant strain in Wisconsin, but the relative proportion of influenza B is increasing, now representing 84% of cases.
As of April 14, 2018, there had been 7,229 influenza-related hospitalizations since September 1, 2017; 65% of hospitalizations have been in individuals aged ≥65 years. There have been 930admissions to ICUs, 58% were aged ≥65 years; and there have been 259 cases requiring mechanical ventilation, 53% aged ≥65 years.
Wisconsin's influenza vaccination rate to date: 35.6% (data from the Wisconsin Immunization registry)
The prevalence of influenza-like illness [fever of 100oF or higher and either cough or sore throat] in Wisconsin's primary care patients is at 1.4% and is at baseline.
7.2% of last week's primary care patients had all-cause respiratory infections.
The prevalence of acute diarrheal illness (ADI) in Wisconsin's primary care patients is at 1.6%
The most commonly identified viral causes of Acute Respiratory infections (ARI) in Wisconsin are Influenza B. Over the past 4 weeks the typical ARI case presenting for primary care has been 41.2 years old and 69% of patients have been female. 41% of patients identified a sick contact 1-to-3 days before illness onset and typically present to the clinic 4.7 days after illness onset. 32% of illnesses are characterized as mild, with 60% having moderate symptoms and 6% having severe symptoms.
|Typical Symptoms||Percent||Viruses in Circulation||Percent|
|Symptoms in Patients with PCR-Confirmed Influenza (n=183 cases for season)||Percent|
Antivirals need to be started with 48 hours of symptom onset to be effective against influenza
Antivirals started after 48 hours may be effective for hospitalized patients with confirmed influenza
For the 2017-2018 season to date (last week):
For up to date information, visit the zika page on CDC.
* The weekly influenza update is adapted from an email from Jon Temte, MD, PhD; Chair, Wisconsin Council on Immunization Practices; Professor, Department of Family Medicine and Community Health, University of Wisconsin School of Medicine and Public Health.