Six people have died of rickettsia in Tijuana since January, and most of the victims are children. José Abel Delgado Peraza, head of the regional health jurisdiction covering Tijuana, Tecate, and Playas de Rosarito, confirmed 15 total cases in 2026, with fatalities concentrated in eastern Tijuana neighborhoods. The numbers arrive just as warmer weather pushes tick activity higher, and health officials are urging residents to act at the first sign of fever.
Rickettsia Has Killed Hundreds in Baja California Since 2009
Rickettsia is not new to the Tijuana corridor. The disease, caused by the bacterium Rickettsia rickettsii and transmitted through the bite of the brown dog tick, has been a recurring public health crisis in Baja California for more than 15 years. The state recorded its first modern outbreak in Mexicali in 2009. Since then, Baja California has consistently reported among the highest rickettsial fatality rates in Mexico.
Between 2015 and 2023, Baja California averaged roughly 10 to 20 confirmed deaths per year from Rocky Mountain spotted fever, the most severe form of rickettsial disease. In 2024, six people also died of rickettsia in Ensenada alone by April of that year. The same count of six deaths has now been reached in Tijuana by early May 2026, with five months of peak tick season still ahead.
The disease hits children and teenagers hardest. Of the 15 confirmed cases this year, the majority involve patients between 10 and 19 years old. The second most affected group is children aged five to nine, followed by infants up to four years old. Cases among adults aged 20 to 39 have also been recorded. Children who play outdoors in unpaved yards, near stray dogs, or in areas with accumulated debris face the greatest exposure to brown dog ticks.
Rocky Mountain spotted fever is caused by the same bacterium found across the Americas, but in Baja California it behaves with particular lethality. The case fatality rate in parts of northern Mexico has historically exceeded 30 percent when treatment is delayed, compared to under 5 percent in the United States where early diagnosis is more common. The key difference is timing: the antibiotic doxycycline is highly effective, but only if administered within the first five days of symptoms.
Eastern Tijuana Colonias Report All 2026 Cases
All confirmed Tijuana cases in 2026 have come from eastern neighborhoods: Tres de Octubre, Granjas Familiares, Mariano Matamoros, Valle Verde, El Niño, Urbi Villa del Prado, and Villas del Campo. These colonias share common features: unpaved streets, large populations of free-roaming dogs, and informal construction with open patios where ticks thrive in discarded furniture and debris.
Tecate recorded two confirmed cases but no deaths. Playas de Rosarito has reported zero confirmed cases and zero deaths so far in 2026. Delgado Peraza said that when the health jurisdiction confirms a positive case, fumigation crews visit the patient’s home, yard, and surrounding blocks. A second fumigation pass follows to eliminate remaining ticks.
The early symptoms of rickettsia are almost identical to the flu: fever, intense headache, muscle pain, and general fatigue. That resemblance is what makes the disease so dangerous. Many patients or their families assume they have a common cold and wait days before seeking care. The telltale rash of red or purple spots on wrists and ankles only appears once the infection is advanced, often too late for treatment to prevent organ failure.
Tick Prevention Steps for Pet Owners and Outdoor Activity
Anyone living in or visiting the Tijuana, Tecate, or Rosarito areas should take tick prevention seriously from now through November, when transmission peaks. Health officials recommend the following specific steps.
Keep dogs and cats treated year-round with veterinary-grade flea and tick medication. Oral tick preventatives such as those containing afoxolaner or fluralaner are widely available at Tijuana veterinary clinics and pet pharmacies. Monthly topical treatments also work but must be applied consistently.
Clear yards and patios of old furniture, mattresses, piled lumber, and accumulated trash. Brown dog ticks hide in crevices and shaded debris, especially near areas where dogs rest. If you have an outdoor dog, inspect its ears, neck, and between its toes weekly for engorged ticks. Remove ticks with fine-tipped tweezers, pulling straight up without twisting.
When hiking in the Tecate valley or rural areas east of Tijuana, wear long pants tucked into socks and apply permethrin-based repellent to clothing. After returning home, check your body and your pets for ticks before going inside.
If you or a family member develops a sudden high fever with headache and muscle pain, tell the doctor about possible tick exposure. Do not wait for a rash. Request doxycycline treatment immediately. Early treatment within the first five days of fever onset is the single most important factor in survival.
Delgado Peraza made the announcement on May 7 at the inauguration of a health module at Plaza Las Fuentes in Tijuana. Summer and fall typically bring the highest case counts, so officials expect additional cases in the months ahead. This story was first reported by Punto Norte.