The Report Analyzes Vector-Borne Illness Trends from 2017-2022
HOUSTON –Harris County Public Health (HCPH) announces the release of its 2024 Vector-Borne Disease report, providing valuable information on vector-borne disease trends and prevention strategies in Harris County.
The report aims to inform county leadership, stakeholders, health and medical partners, and the community about the burden of vector-borne diseases in Harris County. By comparing the top five most reported vector-borne diseases in Harris County between 2017 and 2022 with national and state data, the report sheds light on areas of concern and identifies key demographics at risk.
Key highlights from the report include:
- Overview of Vector-Borne Diseases: Vector-borne diseases result from an infection transmitted to humans and other animals by living organisms known as vectors. Vectors are living organisms capable of carrying disease-causing viruses and bacteria and transmitting them from infected animals to humans or other animals. Vector-borne diseases can lead to widespread illness and significantly impact the community’s health. A significant vector group includes insects that bite to feed on blood, such as mosquitoes, ticks, and fleas.
- Notifiable Conditions: Twelve vector-borne diseases are required to be reported to public health officials upon a diagnosis in Texas. They include malaria, dengue, West Nile virus, Zika virus, chikungunya virus, Chagas disease, typhus, Lyme disease, St. Louis encephalitis virus, yellow fever virus, Eastern equine encephalitis virus, and Western equine encephalitis virus.
- Data Analysis: In Harris County, between 2017 and 2022, nine out of the 12 vector-borne diseases were reported; there were no reported cases of yellow fever virus, Eastern equine encephalitis virus, or Western equine encephalitis virus.
- Outbreak Investigation: Between 2017 and 2022, a total of 683 vector-borne disease cases were reported in Harris County.
Key findings regarding specific vector-borne diseases from 2017 – 2022 in Harris County include:
- West Nile Virus: Seventy-three West Nile virus cases were reported in Harris County. Since 2019, Harris County has had lower West Nile virus incidence rates than Texas and the United States.
- Malaria: One hundred and seventy-three malaria cases were reported in Harris County. The malaria incidence rates in Harris County were higher than in Texas and the U.S. rates. All cases reported to Harris County during this period were related to travel.
- Dengue: Fifty-one dengue cases were reported in Harris County. Harris County had higher dengue incidence rates than Texas for most years. All cases reported to Harris County during this period were related to travel. In Harris County, most cases were between 5 and 66 years of age.
- Zika Virus: Eleven Zika virus cases were reported in Harris County related to travel. In 2017, Harris County had higher Zika virus incidence rates than Texas and the U.S. From 2018 to 2022, the incidence rate in Harris County was zero.
- Chikungunya Virus: Three chikungunya virus cases were reported in Harris County. From 2017 to 2019, the chikungunya virus rates in Harris County were lower than in Texas and the national level. However, there was a slight increase in Harris County’s rates in 2020, surpassing national and state rates. In 2021 and 2022, no cases were reported in Harris County.
- St Louis Encephalitis Virus: Only one St. Louis encephalitis virus case was reported in Harris County in 2022.
- Typhus: Three hundred eleven flea-borne (murine) typhus cases were reported in Harris County. The typhus incidence rates in Harris County have remained below the state rates. No nationwide data was available for typhus. The 6- to 18-year-old age group accounted for 29% of murine typhus cases.
- Lyme Disease: Thirty-one Lyme disease cases were reported in Harris County. The rates in Harris County and Texas were similar between 2017 and 2022. In Harris County, the 6- to 18-year-old age group was most affected by Lyme disease.
- Chagas Disease: Twenty-nine Chagas disease cases were reported in Harris County. Compared to Texas, Harris County had higher rates of Chagas disease in most years between 2017 and 2022. Nationwide case incidence information for Chagas disease is not available.
In addition to presenting data on vector-borne diseases, the report highlights HCPH programs and services aimed at reducing and preventing the incidence of vector-borne diseases.
For more information about HCPH, visit hcphtx.org.