Murine Typhus & Dipylidiasis Sara Rechsteiner May 28, 2009 Outline I. Murine Typhus 1. What is Murine Typhus? general informafon including symptoms, history, and distribufon 2. The parasite 3. Vectors and hosts 4. Treatments II. Dipylidiasis 1. What is Dipylidiasis? general informafon 2. The Parasite s life cycle 3. Vector and hosts 4. Treatments Murine Typhus Caused by bacteria Ricke&sia typhi and Ricke&sia felis Contracted by infected flea feces entering the bite site Has a variety of hosts including cats, dogs, rats, and opossums Symptoms include abdominal pain, backache, high fever, myalgia, and rash. Widely distributed First isolated 1929; First confirmed report 1948 < 2% of pafents die from Murine Typhus
The Parasites Ricke&sia typhi and Ricke&sia felis Class: Proteobacteria Grow by binary fission within host cells unfl they burst Grow in midgut of flea and are shed into their feces Humans are infected azer scratching a flea bite Once inside a vertebrate host the bacteria rapidly accumulates The only difference between R. typhi and R. felis are the hosts from which they acquire blood meals The Vectors Xenopsylla cheopis Tropical regions 1.5 4mm Lack ctenidia Life span 1 year Feed mainly on rats, but somefmes mice and humans Ctenocephalides felis Tropical regions 2mm Ctenidia Life span 2 3 years Feed mainly on cats, opossums, and dogs but somefmes humans Midgut secfons of X. cheopis exposing infected epithelial cells caused by R. typhi 3 5 days a)er infec0on, the bacteria is detected in a small group of midgut epithelial cells of the flea 10 days a)er infec0on the bacteria mul0ply. Now the fleas can transmit R. typhi through their feces
Treatments Once detected Murine Typhus is easily treated with anfbiofcs Chloramphenicol and Tetracycline Recovery only takes a few days PrevenFon: Eliminate rodents around your home Clean yard Limit exposure to vectors Dipylidiasis A common tapeworm infecfon of dogs and cats caused by Dipylidium caninum Linnaeus first described in humans in 1758 Humans become infected by accidental ingesfon of the cat flea Ctenocephalides felis Worldwide distribufon Mild symptoms: loss of appefte, abdominal pain, and allergic reacfon IntesFnal obstrucfon is a rare complicafon Life Cycle of Dipylidium caninum
The proglocds of D. Caninum contain egg packets that are passed in the feces of an infected host. The egg packets are released from the proglocds and fleas ingest them. Treatments include the anthelminfcs Praziquantel and Niclosamide. If you nofce proglocds on yourself or your pets go to the doctor! Summary Overview of both diseases The similarifes and differences between Murine Typhus and Dipylidiasis.
Lit. cited Abdu F. Azad, S. Radulovic, J. A. Higgins, B. H. Noden, and J M Troyer. Flea borne Ricke&sioses: Ecologic Considera@ons. 1997. Emerging Infec@ous Diseases 3: 1 12 Animal Diversity. University of Michigan Museum of Zoology. Accessed online at hkp://animaldiversity.ummz.umich.edu/site/accounts/informafon/ctenocephalies_felis.ht Animal Diversity. University of Michigan Museum of Zoology. Accessed online at hkp://animaldiversty.ummz.umich.edu/site/accounts/informafon/ctenocephalides_felis.ht Azad A. F. Epidemiology of Murine typhus. 1990. Annu Rev Entomol 35:553 69 Center for Disease Control. 2007. Murine fever. Accessed online at hkp://www.cdc.gov Center for Disease Control. 2007. Dipylidiasis. Accessed online at hkp://www.cdc.gov Dipylidiasis. Accessed online at hkp://www.stanford.edu/group/parasites/parasites2003/dipylidiasis/main.htm Luiz, J. and P. Papaiordanou. 2004. Murine Typhus in Brazil: Case Report and Review. Rev. Inst. Med. Trop. S. Paulo 46:283 285. Traub, R., Wisseman C. L, Azad A. F,. 1978. The Ecology of Murine typhus: a crifcal review. 75:237 317.