ABSTRACT
Rabies is the only viral disease in which the exact site and time of virus entry are known. There has been intense study into the prolonged and varied incubation period between that entrance and the ultimate central nervous system (CNS) disease, since the efficacy of the preventive procedures used depend on a knowledge of the virus replication, form, and site. The incubation periods in human rabies usually vary from 3 to 12 weeks (Table 1), 1 , 2 although in rare cases they may be as long as years. 3 Interval Between Exposure and Onset of Symptoms in Untreated Persons Dying of Rabies
No. of cases
No. (%) with indicated incubation period (d)
Institute or worker, years
City or county
0–30
31–60
61–90
<90
Comite d’Hygiene, 1862–1872
France
170
38 (22.4)
74 (43.5)
35 (20.6)
23 (13.5)
Nitsch, 1887–1905
Cracow
72
10 (13.9)
23 (31.9)
16 (22.2)
23 (31.9)
Busson, ?–1929
Vienna
35
7 (20.0)
17 (48.6)
9 (25.7)
2 (5.7)
Högyes, 1886–1897
Hungary
210
58 (27.6)
80 (38.1)
46 (21.9)
26 (12.3)
Babes Institute, 1888–1938
Bucharest
290
…(25.2)
…(38.5)
…(18.0)
…(17.7)
Dodero, 1898–1937
North Vietnam
54
21 (38.9)
26 (48.1)
7 (13.0)
… …
Humphrey, 1955–1962
U.S.
18
7 (38.9)
8 a (44.4)
2(11.1)
1 (5.6)
Pasteur Institute, 1930 –July 1963
Coonoor
115
48 (41.7)
45 (39.1)
13 (11.3)
9 (7.8)
Mahidol University, 1971–1977
Thailand
131
48 (36.6)
49 (37.4) b
19 (14.5)
15 (11.4)
Choomkasieh and Wasi, 1979–1986
Thailand
707
502 (70.9)
114 (16.1)
91 (12.9)
Includes one case with possible incubation period of 27 days.
31 to 90 days.
Modified from Dean, D. J., N.Y. State J. Med., 63, 3507, 1963.
