Typhus fever outbreak in LA prompts the question: What is it?

The Los Angeles County Department of Public Health announced on Thursday that it is actively investigating an outbreak of typhus in downtown LA.

While officials are looking into exactly where the cases occurred and how many people are affected, the infection is one that is usually spread via fleas from animals to humans. It has been reported in the past in California, Hawaii and Texas.

In the wake of this news, it’s helpful to get acquainted with what typhus is and what to do to minimize the risk of getting it.

Typhus, also referred to as typhus fevers, is actually a group of diseases caused by several different types of bacteria. Scrub typhus, epidemic typhus, and murine typhus are the various subtypes. While scrub typhus is seen worldwide and epidemic typhus is observed in areas of overcrowding and unhygienic surroundings, murine typhus is what has been mostly observed in the United States.

Murine typhus is carried in infected fleas, which, as the name suggests, usually infect rats or mice. However, these infected fleas can also get onto cats, dogs, and even opossums.

The bacteria the fleas carry is called Rickettsia typhi, and although the animals the fleas hang around on don’t often get sick, humans can get infected if they’re near lots of these animals when flea feces comes into contact with open sores or scratches on their skin. These fleas flourish in tropical and subtropical climates, which makes sense when you consider the warm climate of LA.

The primary symptom of typhus is fever, which often begins a week or two after exposure. Headaches and rash are also very common, and they typically begin on the body, spreading to the arms and legs, but sparing the palms and soles.

People can also experience a lot of other general symptoms, including fatigue, loss of appetite, nausea, abdominal pain, and even confusion. These symptoms aren’t necessarily specific to typhus, and that can make it difficult for doctors to nail the diagnosis.

Anyone with these symptoms who has been around animals that might contain fleas (including rats or mice) should assume they’ve caught the disease at first so as to not miss any diagnoses.

While patients might have to wait for blood test results to confirm the diagnosis, doctors will still treat the patients immediately with antibiotics, because a delay in treatment can lead to more serious problems.

Most of the time, people do well with treatment and the illness doesn’t progress too far. Doctors might observe some abnormalities in blood count and liver enzymes, but those usually go away with treatment.

Typhus is treated with an antibiotic — usually doxycycline — that targets the bacteria in question, usually until the fever goes away or the person starts to feel better.

Although it’s rare, typhus does occasionally cause symptoms so severe that it can result in death. This is usually when the infection reaches the lungs or the brain and is usually seen when there are delays in diagnosis or treatment.

With an outbreak reported in LA, it’s important to safeguard your health. The LA County Department of Public Health has offered several important reminders to avoid infection, including treating your pets with the appropriate flea medications in order to prevent risk of exposure, throwing away trash in the proper receptacles in order to avoid attracting infected animals and, of course, washing your hands properly after making contact with any animals that are known to harbor fleas.

Finally, if you are experiencing symptoms and have been exposed to these animals, seek medical attention immediately. Delays in getting treatment are most often what results in severe disease.

Amisha Ahuja is an internal medicine resident at Thomas Jefferson University Hospital and a contributor to the ABC News Medical Unit