Influenza activity has seen an increase nationally and within Texas, with a new variant identified that may affect vaccine efficacy. Health authorities in Dallas and Houston have reported rising case numbers, though one local health system noted a temporary decrease in positive tests during late December. Experts anticipate the flu season's peak may still be approaching.
Current Flu Activity and Trends
Data indicates an increasing influenza season, with a nationwide surge beginning in 14 states, leading to a doubling of national flu activity. The Centers for Disease Control and Prevention (CDC) has identified Texas as one of nine states experiencing a high volume of influenza activity.
In Dallas County, influenza cases stand at 12.8%. Dr. Jeffrey Kahn, chief of infectious diseases at Children's Health and a professor at UT Southwestern, observed an increase in flu cases across the Children's Health Network starting mid-December. This trend aligns with data from Dallas County and the CDC.
Children's Health documented a significant rise in cases:
- During the week of December 14, 673 influenza cases were recorded, a 175% increase from the preceding week.
- By December 21, this number rose to 1,090 cases, a 63% increase.
The Houston Health Department reported a continuous increase in flu cases, with Dr. Theresa Tran, the department's director, noting an observed increase in influenza A detected through wastewater monitoring. Healthcare-related visits in Houston have nearly doubled compared to the previous month.
Data from the state health and human services department indicates a rise in emergency room visits for respiratory illnesses across all age groups in Texas. Children aged five to eleven years constitute over 25% of these visits for that demographic, an increase from approximately 15% during the same period last year.
The increase in flu cases began around Thanksgiving and has progressed since. While Dr. Kahn and Dr. Tran acknowledge this as a typical seasonal trend, Dr. Tran noted that this year's trend is marginally higher than the previous year and is anticipated to continue its upward trajectory.
Conversely, Houston Methodist's respiratory snapshot indicated a slight decrease in reported flu cases within its health system. While 1,051 positive influenza A tests were recorded during the week of December 19, this number decreased to 756 for Christmas week. Despite this reduction, the total remains higher than figures from a month prior.
National Impact and Severity
The CDC estimates 7.5 million flu-related illnesses, 81,000 hospitalizations, and 3,100 deaths nationwide, which include eight pediatric fatalities. During a recent flu season, the CDC reported 280 pediatric deaths, with 89% of those deaths occurring in unvaccinated children. Dr. Kahn stated that children with influenza are currently receiving care in intensive care units and wards.
Identification of New Influenza Variant
A new influenza variant has been identified. Informally termed the "Super Flu," it is contributing to increased cases and may affect vaccine efficacy. Dr. Kahn explained that typically three to four influenza viruses circulate each season, including H3N2. A mutation, Subclade K, now accounts for the majority of influenza viruses detected in the United States. Dr. Kahn stated that these mutations reduce the variant's susceptibility to vaccine-induced immunity. While vaccines may demonstrate reduced effectiveness against this variant, available antiviral therapies remain effective.
Public Health Recommendations and Outlook
Health officials highlight that holiday breaks, gatherings, and school re-entry provide environments conducive to viral transmission. Omar Umanzor stated his intention to reinforce basic hygiene practices with his children, including handwashing and mouth covering. Dr. Kahn also suggested mask-wearing as a potentially beneficial measure for immunocompromised individuals.
Symptoms of influenza can manifest within one to four days following exposure, with the initial days of illness considered significant for management.
The Houston Health Department provides the following advice for individuals experiencing flu symptoms:
- Maintain adequate hydration and nutrition.
- Utilize at-home flu tests for symptom confirmation.
- Over-the-counter medications can alleviate symptoms.
- The flu typically resolves over time.
As students return to school, health departments suggest that the flu season's peak may still be approaching. Dr. Tran commented that cases tend to increase in January and February, with potential spikes also observed in May and April, making precise forecasting challenging.