A 44 y.o. policeman in LA county comes in with a rash.
What could it be?
Our patient had murine typhus caused by Rickettsia typhi. There is currently an outbreak of typhus in Los Angeles.
Thirteen people in the state were diagnosed with typhus in 2008, compared with 167 last year. More than 95% of the people falling sick in California are in Los Angeles and Orange counties, according to state health data. Recent outbreaks of typhus in Pasadena and Pomona have been linked not to rats — associated with dirty cities — but with stray cats and opossums. Outbreaks may be the consequence of building homes closer to wilderness areas.
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.
body lice are vectors of epidemic typhus
There are three types of typhus : Fleas spread murine typhus, body lice spread epidemic typhus and chiggers spread scrub typhus. All three can cause a disseminated vasculitis with perivascular leakage and end-organ damage. In addition to the rash and fever patients are often confused. ( The name typhus comes from the Greek word typhos meaning smoky or hazy . It is commonly used as a word for delusion)
MURINE TYPHUS- Murine typhus is important to recognize because it can result in myocarditis. Deaths have also been reported from hemophagocytic lymphohistiocytosis . Animals known to transmit it are rats, cats and possums. The rash starts on the trunk and typically spares the palms and soles.
EPIDEMIC TYPHUS- is so named because it killed thousands of people in WWII. Flying squirrels are known to be a reservoir of this bacteria. Body lice are found among impoverished groups where crowding and poor sanitation are common. It can remain dormant in the body for many years and reactivate when the immune system is weakened.
flying squirrels are a reservoir of epidemic typhus
Picture of flying squirrel
SCRUB TYPHUS- Scrub typhus is a serious health problem in the Asia-Pacific area in an area called the Tsutsugamushi triangle, with a million cases reported every year. Chiggers are also called red bugs but are actually small mites.
The differential for a fine papular rash is broad. It includes not only spirocetes, bacterial, and viral infections, but also drug reactions, and autoimmune diseases. History is occasionally helpful; including environmental exposures and travel exposures. The location of the rash may also be a clue with a “herald patch” occurring in pityriasis and lesions on the palms and soles in syphilis. The immunofluorescence assay (IFA) is the standard to identify IgM or I gG antibodies.
Murine typhus is treated with doxycycline. Our patient was treated and recovered without incident.
REMEMBER- Typhoid fever is not caused by Rickettsia, but Salmonella typhi. It is spread through contaminated food or water.
Bechah Y, Capo C, Mege J, et al. Epidemic typhus the lancet infectious Diseases, volume 8(7):417-426
Alarcon J, Sanosyan A, Contreras Z, et al. fleaborne typhus-associated deaths-Los Angeles County California, 2022. MMWR, Aug 4,23 72(31);838-842.
McQuiston JH, Knights EB, Demartino PJ, Paparello SF, Nicholson WL, Singleton J, et al. (September 2010). "Brill-Zinsser disease in a patient following infection with sylvatic epidemic typhus associated with flying squirrels". Clinical Infectious Diseases. C
McQuiston JH, Knights EB, Demartino PJ, Paparello SF, Nicholson WL, Singleton J, et al. (September 2010). "Brill-Zinsser disease in a patient following infection with sylvatic epidemic typhus associated with flying squirrels". Clinical Infectious Diseases
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Typhus fevers for healthcare providers. CDC.gov. Centers for Disease Control and Prevention 29 March 2021,