Typhus primary prevention
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
No licensed vaccines for prevention of rickettsial infections are commercially available in the United States. With the exception of the louse-borne diseases, for which contact with infectious arthropod feces is the primary mode of transmission (through autoinoculation into a wound, conjunctiva, or inhalation), travelers and health-care providers are generally not at risk for becoming infected via exposure to an ill person. Limiting exposures to vectors or animal reservoirs remains the best means for reducing the risk for disease. Travelers should be advised that prevention is based on avoidance of vector-infested habitats, use of repellents and protective clothing, prompt detection and removal of arthropods from clothing and skin, and attention to hygiene.
Primary Prevention
Avoid areas where you might encounter rat fleas or lice. Good sanitation and public health measures reduce the rat population. Measures to get rid of lice when an infection has been found include:
- Bathing
- Boiling clothes or avoiding infested clothing for at least 5 days (lice will die without feeding on blood)
- Using insecticides (10% DDT, 1% malathion, or 1% permethrin)
Vaccine
The first major step in the development of the vaccine was Charles Nicolle's 1909 discovery that lice were the vectors for epidemic typhus. This made it possible to isolate the bacteria causing the disease and develop a vaccine; he was awarded the 1928 Nobel Prize in Physiology or Medicine for this work. Nicolle attempted a vaccine but was not successful in making one that worked on a large enough scale.[1]
Henrique da Rocha Lima in 1916 then proved that the bacteria Rickettsia prowazekii was the agent responsible for typhus; he named bacteria after H. T. Ricketts and Stanislaus von Prowazek, two zoologists who died investigating a typhus epidemic in a prison camp in 1915. Once these crucial facts were recognized, Rudolf Weigl in 1930 was able to fashion a practical and effective vaccine production method by grinding up the guts of infected lice that had been drinking blood. It was, however, very dangerous to produce, and carried a high likelihood of infection to those who were working on it.
A safer mass-production-ready method using egg yolks was developed by Herald R. Cox in 1938.[2] This vaccine was used heavily by 1943.
References
- ↑ Gross, Ludwik (1996) How Charles Nicolle of the Pasteur Institute discovered that epidemic typhus is transmitted by lice: reminiscences from my years at the Pasteur Institute in Paris Proc. Natl. Acad. Sci. Vol. 93, pp. 10539-10540.
- ↑ Nuernberg Military Tribunal, Volume I pp. 508-511