A man hospitalized for dehydration a few months ago at Los Angeles County-USC Medical Center started suffering a severe fever, and doctors weren't sure why.
The patient was homeless, a clue to doctors that he might have typhus. Every year people contract flea-borne typhus in Southern California, mostly in Los Angeles County. Doctors did a blood test.
"We sent it off, and lo and behold—typhus," County-USC Chief Medical Officer Dr. Brad Spellberg said.
Since July, there have been nine cases of typhus in downtown Los Angeles, six of which infected homeless people, prompting health officials last week to declare an outbreak there. There have also been 20 cases in Pasadena this year, far more than the five typically seen there annually.
Typhus outbreaks are often associated with poor hygiene and overcrowding. Los Angeles officials say they're corralling stray animals that could carry fleas, cleaning streets and encouraging people to treat their pets for fleas and put away trash that may attract infected animals.
The outbreak has also fueled debates about homelessness and housing. L.A. Mayor Eric Garcetti this week pledged $300,000 to increase street cleaning downtown. But many fear that won't be enough to curb the growing number of cases and clear out the trash that has accumulated as the city's homeless population has spread.
"The sidewalks weren't ever intended for habitation, our storm drains were never intended for human waste, and rats (are) crawling all over people," said Estela Lopez, executive director of the L.A. Downtown Industrial Business Improvement District. "This is unimaginable, that in such an advanced society we would be facing this problem."
More people have been falling sick with typhus in Los Angeles County over the last decade, though experts are unsure why. The rise in homelessness is prominent among the theories, which also include warmer temperatures and people spending more time outside.
There were five typhus cases in 2008, compared with 79 cases so far this year, according to the California Department of Public Health.
Typhus spreads when fleas become infected with bacteria known as Rickettsia typhi or Rickettsia felis. The illness reaches humans when fleas bite them or when infected flea feces are rubbed into cuts or scrapes in the skin, according to the U.S. Centers for Disease Control and Prevention.
"It's very hard to say—these microbes have a mind of their own. They come when they want, and they seem to go when they want," Spellberg said. "I don't think anybody really knows."
Typhus is distinct from typhoid fever, a foodborne illness that is rarely contracted within the United States and can be spread from person to person. Typhus, by contrast, cannot be passed between people.
Typhus causes fever, body aches, stomach pain and a rash. Most people recover on their own, but more severe cases can lead to damage to the heart, brain and lungs without treatment. The infection can lead to death in rare cases.
Alex Comisar, a spokesman for Garcetti, said the city and the county have formed a task force to address the outbreak and are stepping up cleaning efforts using the extra funding.
"We're deploying every available resource to help control and stop this outbreak," Comisar said.
Next week, city workers will begin picking up trash and cleaning within what has been designated the "typhus zone," a downtown area bounded by 3rd, 7th, Spring and Alameda streets.
Already, workers clean some streets in the zone encompassing parts of skid row as part of a program called Operation Healthy Streets. They are cleared of debris, washed and then misted with a liquid containing bleach every two weeks.
But the new effort will expand the cleaning area from 100 acres to 279, according to a map provided by Comisar. The new funding will last for nine months.
Enrique Zaldivar, director of the city's sanitation department, said the new effort will allow collaboration with private businesses that may help stem the outbreak in a way that would not have been possible before.
"There may be a privately owned building that is not being utilized, and it's a perfect place for rodents to nest, and that's totally outside the reach of our cleaning operations," he said.
But many expressed anger that the cleanup area would not extend south of 7th Street. Rena Leddy, executive director of the L.A. Fashion District Business Improvement District, said heaps of trash are accumulating south of the typhus zone, from 8th Street down to the edge of her district near 18th Street.
On Thursday, several tents lined an alleyway just south of 7th Street, surrounded by crates and trash. Pigeons pecked at food fallen on the sidewalk. At the corner of 8th Street and Central Avenue, also outside of the typhus zone, a large heap of trash had accumulated against a brick wall.
"There are other parts of downtown that also have mass amounts of accumulated garbage. That's what we've all been told is collecting the rats that are then spreading the fleas," Leddy said.
But officials say that although rats, cats and opossums can all carry fleas, different outbreaks have different causes.
The uptick in cases in Pasadena this year is probably linked to opossums and cats—not rats, said Levy Sun, public information officer for the San Gabriel Valley Mosquito and Vector Control District.
"Rats are kind of a red herring here," Sun said.
Sun said that testing of rats in the region shows they don't carry many fleas.
During the last typhus outbreak in Los Angeles County in 2015, a single opossum captured in a mobile home park in Pomona had 1,087 fleas on it. Three-fifths of the fleas tested from the cats and opossums that were trapped tested positive for typhus.
Health officials were able to control that outbreak by starting flea control, trapping feral animals in the area, offering free typhus tests and monitoring flea populations. People who lived in the mobile home community had to clear feeding sites and limit the number of pets to one, a rule dictated by the property owner that hadn't been followed.
One person had 32 pets, according to an academic paper published about the response to the outbreak.
Sun encouraged people to clean up debris and buckets in their backyards and make sure their pets are treated for fleas. The solution, he said, is not to "shake typhus and wildlife from our environment, but shake the habits we have."
Of the 945 typhus cases in California since 2001, 726 have been in Los Angeles County—and those numbers only seem to be going up.
"We've been thinking about typhus for a long time," Spellberg said.
Explore further: Flea-borne typhus outbreak in Los Angeles County