The threat of disease in urban and suburban areas are the primary focus of interest in the public health field since community health and safety affects all people. Murine typhus (Endemic typhus) is a zoonotic disease transmitted by arthropod vectors that prevails in urban and suburban areas globally.

1. Heather Melendez
Dr. Mian
HSCI 403 Vector-Borne Disease Control
17 November 2015

2. Murine typhus (Endemic typhus) is a zoonotic
disease transmitted by arthropod vectors that
prevails in urban and suburban areas.
The etiological agent that causes disease are
Rickettsia typhi and Rickettsia felis.
The transmission of R. typhi and R. felis are
associated with Ctenocephalides felis, the cat flea,
and Xenopsylla cheopis, the rat flea.
The reservoirs of Murine typhus are domestic cats,
rats, and peridomestic opossums.

3. The pathogens R. typhi and R. felis are
introduced by an arthropod ingesting
a blood meal infected with the
disease.
The pathogen Rickettsia is an obligate
intracellular coccobacillus alpha-
proteobacterium.
As the pathogen circulates in the
flea’s body, the pathogens that
replicate in the midgut epithelial cells
are shed and excreted in the feces.

5. The rat is the host for the flea X. cheopis.
The pathogen is introduced into the
circulatory system of the rat and the
Rickettsia is transmitted back to the flea
on subsequent blood meals.
The rat flea prefers to feed on rats;
however, it will search for other hosts if
rats are not available.
The urban cycle is a route of infection
common in overcrowded cities with
unsanitary conditions.

6. In the suburban cycle, the reservoirs are feral and domestic cats
and peridomestic opossums.
Risk of domestic cats acquiring the infected fleas.
Feral cats & opossums interact in suburban neighborhoods,
entering backyards if food, water and nesting sites are available.

7. The incubation time of 7 to 14 days passes
before onset of the illness.
The onset begins with a fever that lasts 3 to 7
days and will cause a severe headache,
myalgia, nausea, and vomiting.
After one week, a maculopapular rash appears
on the trunk and axilla parts of the body that
lasts 1 to 4 days.

8. Misdiagnosis is common since the
illness is similar to other dieases.
Flea bites found on the body during a
medical examination is indicator for
doctors to consider testing for
Rickettsia as a possible pathogen.
The differentiation of R. typhi & R.
felis are confirmed through PCR
testing and sequencing of the genes.

9. Murine Typhus is a treatable illness with antibiotic therapy. The
mortality rate with antibiotic use is 1% and 4% without
antibiotic use
The antibiotic, doxycycline has proven effective in killing both R.
typhi and R. felis pathogens and so far, no resistance to the
antibiotic treatment has occurred

10. Close and or cover any open cracks,
crevices or openings that rodents, cats, or
opossums can enter to hide or nest.
Remove any overgrown foliage and clutter
in the yard, which are ideal harborage
sites. Remove all ripe fruit from trees and
pick up fallen fruit.
Remove all possible food and water
sources such as bringing in pet food/water
bowls at night. Cover all refuse containers
tightly.

11. Outdoor pets on the property, ensure proper
flea control is in use. Flea drops, collars,
powders containing larvicides and adulticides,
such as fenoxycarb, and permethrin.
Mechanical methods such as washing bedding
and vacuuming are an excellent way to prevent
pesticide resistance.
Vacuuming will remove up to 95% of emerging
fleas, 90% of eggs, and 50% of larvae .
If a flea infestation is out of control contact a
local pest control specialist

12. Abdad, M. Y., Stenos, J., & Graves, S. (2011). Rickettsia Felis, an
Emerging Flea-transmitted Human Pathogen. Emerging Health
Threats, 4, 1-7. doi: 10.3402/ehtj.v4i0.7168
Abramowicz, K. F., Wekesa, J.W., Nwadike, C.N., Zambrano, M.L.,
Karpathy, S.E., Cecil, D., Burns, J., Hu, R., & Eremeeva, M.E.
(2012). Rickettsia Felis in Cat Fleas, Ctenocephalides Felis
Parasitizing Opossums, San Bernardino County,
California. Medical & Veterinary Entomology, 26(4), 458-
462. doi: 10.1111/j.1365-2915.2012.01017.x
Beaty, Barry J., & Marquardt, William C. (1996) The Biology of
Disease Vectors, 146-155.

13. Civen, R., & Ngo, V. (2008). Murine Typhus: An Unrecognized
Suburban Vectorborne Disease. Clinical Infectious
Diseases, 46(6), 913-918. doi: 10.1086/527443
County of Los Angeles – Department of Health Service. (n.d.).
What is Murine Typhus? County of Los Angeles- Department of
Health Services. Retrieved from
http://publichealth.lacounty.gov/vet/docs/mtyphus.pdf
Rust, Michael K., & Michael W. Dryden. (1997). The Biology,
Ecology, and Management of the Cat Flea. (1997). Annual
Review of Entomology, 42(1), 451.