JONATHAN M. METSCH, Dr.P.H. – Tracking Emerging Public Health Challenges – July 28, 2026 – CHIKUNGUYA
“The first Harris County case of Chikungunya, a virus transmitted by mosquitoes, has been confirmed by the Harris County Public Health & Environmental Services.
While the Chikungunya virus has never been transmitted within the United States, some U.S. travelers visiting those areas have contracted the virus. The first Harris County case was confirmed last week by the HCPHES, about one week after the Texas Department of State Health Services confirmed the first Texas case in Williamson County, just north of Austin.”
The Chikungunya virus is spread via Aedes mosquitoes, which are present in Texas, and because there is no vaccine to prevent the virus health officials urge travelers and residents to take preventative measures to avoid contracting Chikungunya, or other viruses.”
Symptoms of Chikungunya are similar to Dengue Fever and commonly include fever and joint pain and may include headaches, muscle pain, joint swelling, or rashes, according to the CDC.
“There is some thought that at some point we may start to see local transmission of the cases if someone that is infected elsewhere comes back to Texas,” Van Duesen said. “We do have the Aedes mosquitoes, so if a mosquito bites someone that is infected, that can affect the mosquito and then transmit the disease to a new person, when that mosquito later bites somebody else. That is a possibility. We can’t say for sure that we will see that happen, but that is something we are on the lookout for.”
Similarly, the DSHS confirmed the states first Texas case of West Nile in early July in Travis County, and health officials urge Texas residents to take preventative measures to prevent the spread of mosquito borne diseases.” (1)
“On July 16, the U.S. Centers for Disease Control and Prevention placed Costa Rica under a Level 2 travel notice and told visitors to “practice enhanced precautions.””
“Although chikungunya is not often deadly, it can be highly debilitating. It is transmitted by infected Aedes aegypti mosquitoes, which also carry dengue and Zika, and symptoms may include fever, headache, muscle pain, rash, joint swelling, and especially severe joint pain.
Research suggests those effects can persist for years: one study found that some people were still coping with chronic joint pain six years after infection, along with severe fatigue and problems with mobility.
A Level 2 notice means federal health officials believe extra precautions are warranted right now.” (2)
“Pediatric health experts are urging parents to heighten vigilance following a recent surge in chikungunya infections across several areas of Samar. Health
The Pediatric Infectious Disease Society of the Philippines (PIDSP) issued an advisory Sunday warning that the viral illness spreads through bites from infected Aedes mosquitoes, which also carry dengue.
“It usually causes sudden fever, severe joint pain, rash, headache, and muscle pain. Most children recover completely, but joint pain may last for weeks,” the PIDSP said.
Medical professionals emphasize that any child exhibiting a fever must receive a prompt clinical assessment to rule out dengue because initial symptoms often overlap.”
Unlike chikungunya, which rarely involves serious hemorrhaging, severe dengue cases can trigger internal bleeding, intense stomach pain, persistent vomiting, and life-threatening shock.” (3)
“The Ministry of Health sent an alert to states and municipalities about the possibility of an increase in the transmission of arboviruses, such as dengue and chikungunya, due to the El Niño phenomenon.
According to projections developed by InfoDengue/Fiocruz, Brazil could register around 1.7 million cases of dengue in 2027.
According to the World Meteorological Organization (WMO) and the National Institute of Meteorology (Inmet), El Niño may manifest itself in a moderate to strong form, favoring conditions that increase the circulation of the Aedes aegypti mosquito, starting in the second half of this year. Increased temperatures and rainfall in some regions, as well as periods of drought in other areas, can stimulate water storage and the formation of breeding grounds for the vector.
This has prompted the Ministry of Health recommends that states and municipalities intensify surveillance and control actions, including transmission blocking in the first identified cases, reorganizing the activities of Endemic Disease Control Agents, and adopting vector control technologies recommended by the Ministry.” (4)
The European holiday hotspots battling deadly mosquito-borne diseases, https://www.dailymail.com/health/article-15964699/The-European-holiday-hotspots-battling-deadly-mosquito-borne-diseases-Spain-France-Italy-popular-destinations-affected-West-Nile-Virus-chikungunya.html
1.Mosquito borne Chikungunya virus makes first appearance in Harris County, by Jesse Mendoza, https://communityimpact.com/houston/news/mosquito-borne-chikungunya-virus-makes-first-appearance-in-harris-county-2/
2.CDC issues Costa Rica travel alert over painful mosquito-borne illness outbreak, by Vivian Tran, https://www.thecooldown.com/green-tech/chikungunya-outbreak-costa-rica-travel-alert/
3.Alert issued over rising chikungunya cases in Samar, By Ram Superable, https://manilastandard.net/news/public-health/314770413/health-experts-issue-alert-over-rising-chikungunya-cases-in-samar.html
4.Brazil officials warn of increases of dengue, chikungunya due to El Niño, by Robert Herriman, https://outbreaknewstoday.substack.com/p/brazil-officials-warn-of-increases
curated by Jonathan M. Metsch, Dr.P.H.
Clinical Professor of Environmental Medicine, Icahn School of Medicine at Mount Sinai