Table 2

Feeding Period Required by Amblyomma aureolatum Ticks for Transmission of Rickettsia rickettsii to Vertebrate Hosts

Danilo G. Saraiva, Herbert S. Soares, João Fábio Soares, and Marcelo B. Labruna

Author affiliations: University of São Paulo, São Paulo, Brazil (D.G. Saraiva, H.S. Soares, J.F. Soares, M.B. Labruna); Bicho do Mato Research Institute, Belo Horizonte, Brazil (D.G. Saraiva)

Main Article

Fever, seroconversion to Rickettsia rickettsii antigens, and ear and/or scrotal lesions in guinea pigs that were exposed to R. rickettsii–infected Amblyomma aureolatum unfed adult male ticks, Brazil

Guinea pig no.	Tick feeding period, h*	Fever†	Anti-R. rickettsii antibody titers‡	Ear and/or scrotal lesions§
33	2	No	<1:64	No
34	2	No	<1:64	No
35	4	No	<1:64	No
36	4	No	<1:64	No
37	6	No	<1:64	No
38	6	No	<1:64	No
39	8	No	<1:64	No
40	8	No	<1:64	No
41	10	No	<1:64	No
42	10	No	<1:64	No
43	12	Yes	4,096	Yes
44	12	Yes	256	No
45	16	Yes	2,048	Yes
46	16	Yes	1,024	Yes
47	20	Yes	512	Yes
48	20	Yes	2,048	Yes
49	24	Yes	2,048	Yes
50	24	Yes	¶	Yes
51	36	Yes	2,048	Yes
52	36	Yes	4,096	Yes
53	48	Yes	¶	Yes
54	48	Yes	8,192	Yes
55	168	Yes	16,384	Yes
56	168	Yes	16,384	Yes

*Number of hours that an infected male adult tick was allowed to feed on each guinea pig before the tick was manually removed from the host.
†Rectal temperature >39.5°C during 21 days after tick infestation.
‡Anti-R. rickettsii IgG endpoint titers determined 21 days after tick infestation.
§Occurrence of ear or scrotal lesions (edema, necrosis) during the febrile period within 21 days after tick infestation.
¶Guinea pig died during the febrile period, before the 21st day after tick infestation; its lung tissue was PCR positive for Rickettsia spp.

Main Article

Page created: August 13, 2014

Page updated: August 13, 2014

Page reviewed: August 13, 2014

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