Table 3

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 infested by previously fed R. rickettsii–infected Amblyomma aureolatum adult male ticks through different feeding periods, Brazil

Guinea pig number	Tick feeding period*	Fever†	Anti-R. rickettsii antibody titers‡	Ear and/or scrotal lesions§
57	1 min	No	<1:64	No
58	1 min	No	<1:64	No
59	3 min	No	<1:64	No
60	3 min	No	<1:64	No
61	5 min	No	<1:64	No
62	5 min	No	<1:64	No
63	10 min	No	<1:64	No
64	10 min	Yes	1,024	No
65	20 min	Yes	1,024	No
66	20 min	Yes	512	No
67	40 min	Yes	1,024	No
68	40 min	Yes	4,096	Yes
69	1 h	Yes	4,096	Yes
70	1 h	Yes	8,192	Yes
71	2 h	Yes	¶	Yes
72	2 h	Yes	512	No
73	4 h	Yes	¶	Yes
74	4 h	Yes	16,384	Yes
75	6 h	Yes	¶	Yes
76	6 h	Yes	¶	Yes
77	8 h	Yes	¶	Yes
78	8 h	Yes	¶	Yes
79	12 h	Yes	¶	Yes
80	12 h	Yes	¶	Yes
81	18 h	Yes	¶	Yes
82	18 h	Yes	8,192	Yes
83	24 h	Yes	8,192	Yes
84	24 h	Yes	16,384	No
85	36 h	Yes	¶	Yes
86	36 h	Yes	¶	Yes
87	48 h	Yes	¶	Yes
88	48 h	Yes	¶	Yes
89	168 h	Yes	16,384	Yes
90	168 h	Yes	¶	Yes

*Number minutes or hours that an infected adult male tick was allowed to feed on each guinea pig before the tick was manually removed from the host. All ticks had previously fed on rabbits for 48 h.

†Rectal temperature >39.5°C during 21 days after tick infestation.

‡ Anti-R. rickettsii IgG endpoint titers determined at 21 days after tick infestation.

§ Ear or scrotal lesions (edema, necrosis) during the febrile period within 21 days after tick infestation.

¶Guinea pig died during the febrile period, before day 21 after tick infestation; its lung 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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