HARLINGEN — Chase North of San Benito is 21, and his past two weeks have been pretty rough.
He started to feel poorly, and his blood pressure was rocketing this way and that, from too high to really too high.
“My dad said why don’t you take his temperature, and I said OK, and I checked it and it was like 104.9 and I was like ‘Oh, my gosh,” recalled his mother, Dana Rowe.
“So Monday I told my dad I’m fixing to take him into the ER, this is not letting up,” she recalled. “I thought something serious was going on.”
Dana had Chase checked into Valley Baptist Medical Center’s emergency room.
“Chase felt miserable so we got him back, they ran a strep test, they ran a flu test, they pulled huge vials of blood from his arm, I guess those were for the lactic acid,” Dana said. “They did a CT scan of his head, they did a chest X-ray to find out what’s going on.
“The blood work came back and his liver numbers were up and his white blood cell count was down, which is very odd considering that a fever means you have an infection,” she said.
After leaving the hospital at 3:30 a.m., with no better idea of what was wrong, things did not improve the next day. Dana took Chase to a local clinic.
Dr. Nina Torkelson knew the lack of a diagnosis in Chase’s case was becoming a problem.
“She started asking questions about when it started, the whole rundown of it, and she said let me look at the result of his blood work in the ER one more time,” Dana said. “She looked at the blood results and she noticed that the liver functions were high and like I said the white blood cell count is low and there was something else she mentioned that was low, and she said, ‘It’s got to be typhus.’
“I go, like, what?” Dana said. “Are you serious? This is like something in Colombia, or some place like that.”
Or some place like South Texas.
Cat flea, rat flea
“Murine typhus is a rickettsial disease caused by two distinct species of flea — you have the cat flea and the rat flea,” said Angel Guevara, a zoonosis control specialist with the Texas Department of State Health Services. “Primarily this disease is transmitted by the rat flea, by infected fleas that are harbored by rodents, opossums, cats, dogs and other small mammals.”
Zoonosis is a field of public health science which studies diseases transmitted from animals to humans. Guevara spoke recently at a seminar at DSHS’s Harlingen office for a dozen public health professionals who are on the front lines in the state’s battle against typhus and other zoonotic diseases.
“A typical flea can fit on the tip of a ballpoint pen,” Guevara told his audience. “Once born, they will look for a blood meal within seconds once they jump on your pet.
“A female flea can produce up to 40 to 50 eggs a day so it can produce at least 2,000 eggs during its whole life,” he added. “And they lay these eggs within 24 to 48 hours after they have a blood meal — they need that blood meal to produce offspring.”
Much like another emerging illness in South Texas, Chagas disease, murine typhus is transmitted by the flea’s unsavory practice of defecating when it bites a host. A person scratches the bite, and drives the rickettsia bacteria in the feces into the wound and into the bloodstream.
Once the bacteria makes it there, a patient starts to develop a fever, chills, headache, nausea and, after about five days after the onset of symptoms, a rash.
“Most people will recover without treatment, however that might require some hospitalization,” Guevara said. “We encourage you to get treated for it. If left untreated, severe illness can cause damage to one or more organs, including the liver, kidneys, heart, lungs and the brain.”
Diagnosing the problem
Guevara said, and Chase North surely corroborates it, that obtaining an early diagnosis of murine typhus can be difficult not just for patients but for physicians as well.
Since the symptoms often resemble common viral infections, it is only when a patient’s condition doesn’t improve — and symptoms can last for weeks — that many doctors call for a test to determine whether the rickettsial bacteria is present. Another rickettsial disease, Rocky Mountain spotted fever, also can come up positive in the test, but it is rare in the Valley.
“Here in Texas, these symptoms can be any variety of illnesses, so we have to rely on physicians,” Guevara said. “We let them know that we do have murine typhus here … and they have to order that test.”
In Cameron County, murine typhus cases from 2015 through last year were 39, 32, and 37, said Esmer Guajardo, health administrator with the Cameron County Department of Health and Human Services.
“Generally what we do in terms of alerts to the medical community is based on reporting,” she said. “We’ll see a spike and we tend to have our providers on alert. Because our numbers have been pretty consistent we just provide the general information about typhus, that it’s something that should not be overlooked.”
Why the Valley?
Murine typhus is an endemic disease in the tropics and the sub-tropics, which means it is one of those illnesses that are ever-present, and the sub-tropics is where the Rio Grande Valley falls latitude-wise.
Hidalgo, Nueces and Cameron counties generally lead the way in murine typhus cases reported in Texas. Part of the answer is found in the region’s mild weather, which means fleas, eggs and larvae are not subject to winter-kill like in most of the rest of the nation.
It also means many residents leave pets outside year-round, which then become reservoirs for fleas that can carry disease.
“In some areas, people keep their dogs indoors but a lot of people tend to keep their dogs outside around-the-clock,” Guajardo said, “and that’s obviously an avenue for having some exposure to more fleas within the household.”
Another reason, at least in Hidalgo County, is population growth.
“We’re a weird county because we’re the seventh-most populous county in Texas, and the only counties bigger than us are very urbanized — Bexar County, Tarrant County, Collin County up near Plano and Houston and Dallas,” said Eddie Olivarez, chief administrative officer for Hidalgo County Health and Human Services.
“We still have a lot of rural-ness to our area, especially in the unincorporated areas of our county, so what ends up happening is you still have lot of areas where, for lack of a better term, it’s prime for wildlife, prime for some of these other critters where fleas and ticks are an issue.”
Hidalgo County has traditionally led the state in the number of confirmed murine typhus cases annually, recording 97 cases in 2015, 85 in 2016 and 99 cases last year. Olivarez pinpoints the opossum and feral cats as prime suspects in the county’s high typhus numbers.
“We’re still up there among the higher problematic counties, but a lot of it has to do with population,” he added. “Our population density is so tight, as we have more and more people moving out into the country and into more rural areas, and we have a lot more domesticated animals getting in with the opossum population … those are the situations that are causing the problem for us.”
Passing the word
State health officials issued a statewide alert aimed at medical professionals to be on the lookout for murine typhus on Nov. 30 of last year.
While Cameron and Hidalgo counties’ numbers are relatively high but stable, other areas of the state are seeing spikes in murine typhus cases. State officials are saying only the numbers are “significantly” higher over the first three months of this year compared to 2017.
They are urging local physicians to be aware of the possibility patients may be showing symptoms not of a viral disease, but a bacterial one.
“Typhus actually gets a little bit more complicated because not only is it confusing for the flu, but it’s also confusing for Zika and it’s also confusing for dengue,” said Hidalgo County’s Olivarez. “We do have Rocky Mountain spotted fever here on occasion, but most of the time it’s imported, a person who becomes ill went on a vacation to another area.
“Actually we’ve seen a few cases of Lyme disease, which is very rare for us, but we’ve seen some of the more localized cases especially up in the Willacy County area in Port Mansfield just because of the high deer population,” he added.
For Chase North, the diagnosis of typhus proved a godsend, his mother said.
“His fever is almost gone, but other than that, he is getting better every day,” Dana Rowe said. “I am so thankful for Nina Torkelson, because nobody else could tell me, or would tell me.”
Controlling fleas
Pet treatment: Use only products labeled for use on pets. Check labels because insecticides for dogs may be dangerous for cats
Treat animals thoroughly around the ears, between legs and around tail
Wear gloves when applying dusts, spot-on treatments of sprays
Use insect growth regulators, flea collars, spot-on or spray treatments before fleas become a problem.
Indoor treatment:
Before treating, clean house thoroughly and vacuum under, on and around furniture where pets sit or sleep to remove flea eggs and larvae
Wash and air-dry pet bedding
Apply a spray insecticide or dust to pet bedding and other areas where pets sleep or play
Use only products designated for indoor use on label
Outdoor treatment:
Apply a spray flea insecticide to garages, under porches and decks and outside areas where pets sleep or play
Prevent pets from getting under the house so the area doesn’t become infested
Get rid of rats, mice and other animals that can carry fleas by cleaning up trash piles or debris in yard
Source: Texas Cooperative Extension Service, Texas A&M University
Signs and Symptoms
• Fever and chills
• Body aches and muscle pain
• Loss of appetite
• Nausea
• Vomiting
• Stomach pain
•Cough
• Rash (typically occurs around day five)
Symptoms become apparent two weeks after a bite from an infected flea. Most people will recover without treatment, but some cases may be severe. When left untreated, severe illness can cause damage to one or more organs including the liver, kidneys, heart, lungs and brain.
Source: Centers for Disease Control and Prevention
What is murine typhus?
Flea-borne or murine typhus is a rickettsial disease caused by Rickettsia typhi (rat flea), or possibly R. felis (cat flea), bacteria that can be transmitted by infected fleas carried by rats, opossums, cats, dogs and other small mammals. The disease is similar to louse-borne typhus (R. prowazekii) but is generally milder. Louse-borne typhus has been responsible for deadly epidemics for centuries.
Cases are reported year-round, but the majority of typhus cases in Texas occur between May and July, with another peak in December and January.
Typhus by the numbers
2,800 — Number of confirmed flea-borne typhus reported in Texas, 2000 through 2016
157 — Median number of cases per year
364 — Average maximum number of cases per year
400-plus — Cases reported in state in 2017
9 — Number of Texas counties reporting murine typhus in 2003
36 — Number of Texas counties reporting murine typhus in 2016
Source: Texas Department of State Health Services
Typhus by county, 2008-2016
Hidalgo — 673 cases
Nueces — 447 cases
Cameron — 251 cases
Bexar — 151 cases
Starr — 38 cases
Willacy — 18 cases
Source: Texas Department of State Health Services
