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Wild head lice were obtained by combing out adult and instar lice from the uncut hair of school children. Normal body lice were selected from a colony of rabbit-adapted body lice obtained from the United States Department of Agriculture and maintained in the Department of Microbiology for more than 10 yr. Thirty-nine head lice and 60 body lice were fed on a rabbit that had been injected intravenously with a 10% suspension of a yolk sac pool from eggs heavily infected with the Ankara strain of virulent R. prowazeki. Five days after infection, 33 body lice and 16 head lice had survived and were feeding on a volunteer. Between Days 5 and 9, 13 head lice were dead or moribund and all of them were positive by IF for R. prowazeki. The three surviving head lice were also positive. Tests on the 33 body lice showed that 22 were positive for R. prowazeki, including four of the five body lice that survived until Day 15. In summary, head lice can be readily infected with R. prowazeki and disseminate virulent R. prowazeki organisms in their feces. Thus, theoretically, head lice appear to be highly potential as transmitters of R. prowazeki under optimal epidemiologic circumstances.

Guinea pigs in a test group were fed living guinea pig inclusion conjunctivitis (GPIC) organisms classified as Chlamydia psittaci in 60% yolk-sac suspensions as enteric vaccines, while animals in a control group received uninfected yolk sac. Seven test animals and 14 control animals were challenged 11 or 22 days later with 1,000 50% infectious doses of GPIC organisms in either the conjunctiva or the vagina. Evidence of protection from mucosal infection in both sites was noted in test animals. Clinically, the disease was less severe, and microbiologically, lower percentages of mucosal cells were infected. The results suggest that enteric vaccination against mucosal infections of the eye and the genital tract with chlamydial agents is possible.

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