Increase in mice heightens typhus concerns on Maui
The number of mice spotted around Maui has scurried upwards in recent months, raising concerns among residents and health care professionals of the possible spread of murine typhus.
Murine typhus is a bacterial disease carried by rodents – most commonly rats, though it may also be carried by mice, cats or dogs – and spread through the bites of infected fleas. Symptoms are similar to that of the flu (fever, headache, muscle soreness, joint pain and, in some cases, a rash) but without the head cold (stuffed sinuses, cough, sore throat).
So far this year, there have been no confirmed cases of typhus reported in Hawaii, according to state Department of Health records.
But there has been at least one suspected case in Kihei that emerged just this week, though doctors are still waiting on blood test results for confirmation, which may take a few weeks. In the meantime, they are treating the patient and providing antibiotics, the patient told The Maui News.
The patient, who declined to be identified, said she lives near the Kihei Fire Station next to an open field that is “crawling with mice.” All of a sudden last week, she came down with flulike symptoms and a fever that spiked upwards of 101 degrees. When she visited her doctor on Monday, the doctor was “fairly convinced I had typhus.”
“My whole body aches. My knuckles hurt. The tops of my feet hurt, my rib cage, my back,” she said.
A relative who was visiting from the Mainland two weeks prior also came down with similar symptoms, she said.
Murine typhus is not contagious from person to person. It is spread solely through the bites of fleas that have contracted it from an infected rodent. A person who has already had murine typhus once is unlikely to get it again.
Two other suspected typhus cases have been reported on Maui, but all remained unconfirmed, department officials said.
It is not uncommon for Maui to have a dozen or so murine typhus cases a year, Maui District Health Officer Dr. Lorrin Pang said.
“It’s not a start of an outbreak. It’s just a routine low number of cases,” Pang said. “If I saw 15 or so (in a year), I wouldn’t be concerned. When we start seeing 30 or 40, that’s kinda bad.”
Pang said his office has been getting a lot of reports of mice in recent months, which is “a little early” because mice sightings usually peak around fall months when the fields get drier.
“We’re just watching the mice. It makes me wonder if the mice are here early because we have so many waiting to descend upon us when things get drier in the fall,” Pang said.
Dry areas in South and West Maui, Upcountry and sometimes Kahului, are hot spots for mice and the fleas they carry, Pang said.
The number of murine typhus cases reported on Maui and in Hawaii has dropped considerably since 2005, when it peaked at 47 confirmed cases statewide, with 42 of those coming from Maui, according to DOH records. Last year, there were four confirmed cases reported, all on Maui, state officials said.
About 90 percent of murine typhus cases in Hawaii happen on Maui, state health officials said, though “it’s hard to know exactly why.”
Dr. Sarah Park, state epidemiologist and chief of the DOH Disease Outbreak Control Division, said possible factors could be large open fields and agricultural lands in close proximity to residential areas, less urbanization and wetter weather.
Though there have been isolated cases of murine typhus – sometimes affecting an entire hiking group – Park said there has never been a massive epidemic. An epidemic would require a large number of cases in vastly different households, living conditions and locations all occurring simultaneously.
Symptoms usually appear seven to 14 days after someone has been bitten by an infected flea. The illness seldom lasts longer than two weeks, and its duration is usually much shorter with treatment.
While murine typhus (the only type of typhus known in Hawaii) is one of the milder strains of typhus, if left untreated, it can lead to complications such as encephalitis (brain inflammation) or organ failure. A 50-year-old Lahaina man who contracted the disease in 2002 reportedly died in a hospital a year later. Confidentiality laws barred the hospital from releasing information on whether his death was due to complications linked to the disease, news outlets reported at the time.
The Maui District Health Office’s Vector Control Branch used to survey and control rodent populations around Maui, but stopped many of those services in 2009, after budget cuts reduced its office staff from seven to two employees. Those two are in charge of covering vector concerns on Molokai, Lanai and Maui.
“In the old days, we would go and put out poison, but at this time we’re just not capable of that,” Maui Vector Control Supervisor Donald Taketa said. He encouraged residents to be vigilant in keeping their living quarters clean, making sure their doors and air vents are sealed and not leaving doors or windows open for mice to come in.
He estimated the number of mice and rats on Maui to be in the millions.
“We did have a lot of rain this past winter, so all the grass up on the mountains and hills is nice and green. There’s a lot of food for the mice to multiply,” Taketa said. “Now that everything is starting to dry, they’re moving down to look for food and water.”
Taketa said his office has received more complaints about mice in the last couple of months from Ukumehame, Olowalu, Launiupoko and Wailea, but it is normal for more calls to come in when it gets hotter and drier. While there may be more sightings earlier in the year, Taketa said he does not anticipate a massive mice migration similar to ones that infested Kihei, Kula and Lahaina about 10 years ago.
* Eileen Chao can be reached at email@example.com.