Welcome to the 2018-2019 Influenza Season. Over the next several months, I will try to provide weekly updates on influenza’s passage across Wisconsin, enhanced by excellent surveillance data made available by the Wisconsin Division of Public Health, the Wisconsin State Laboratory of Hygiene, the Centers for Disease Control and Prevention, and the World Health Organization. I will make predictions based on trend data and my experience in reading the seasonal patterns of influenza. I will also provide some clinical guidance. Should you have any questions, please do not hesitate to contact me.
Wisconsin has low influenza activity at present. Occasional detections occur, with the majority being Influenza A[H1N1]. There have been 21 influenza-related hospitalizations since September 1, 2018; 54.2% of hospitalizations have been in individuals age ≥ 65 years.
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 baseline.
7.4% 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 1.3%
The most commonly identified viral causes of Acute Respiratory infections (ARI) in Wisconsin is rhinovirus, followed by parainfluenza. Over the past 4 weeks the typical ARI case presenting for primary care has been 30.9 years old and 73% of patients have been female. 54% of patients identified a sick contact 1-to-3 days before illness onset and typically present to the clinic 5.0 days after illness onset. 34% of illnesses are characterized as mild, with 64% having moderate symptoms and 0% having severe symptoms.
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.