Warning: mkdir(): Permission denied in /home/virtual/lib/view_data.php on line 81
Warning: fopen(upload/ip_log/ip_log_2024-08.txt): failed to open stream: No such file or directory in /home/virtual/lib/view_data.php on line 83
Warning: fwrite() expects parameter 1 to be resource, boolean given in /home/virtual/lib/view_data.php on line 84 Study on vector mites of tsutsugamushi disease in Cheju Island, Korea
Study on vector mites of tsutsugamushi disease in Cheju Island, Korea
H I Ree,I Y Lee and M K Cho*
Department of Parasitology, College of Medicine, Yonsei University, Seoul 120-752, Korea.
Abstract
Because no reference on trombiculid mites (Acarina: Trombiculidae) in Cheju Island where tsutsugamushi disease is highly endemic had been available, studies on trombiculid mites in Cheju Island were implemented during the period of August 1991-April 1992, and the results obtained are summarized as follows: (1) The species and numbers of the field rodents collected were 143 Apodemus agrarius chejuensis (92.3%), 11 Crocidura lasiura (7.1%) and 1 Micromys minutus (0.6%). From total 12,075 chiggers harvested, 9 species of 4 genera in Trombiculidae were identified. (2) The predominant species through all seasons was L. zetum (43.3%), followed by L. orientale (27.4%) and L. scutellare (26.6%). However, in autumn when the most cases of tsutsugamushi disease occur, L. scutellare was prominently predominant, having 79.8% of the collected chiggers. (3) Among 1,142 L. scutellare examined for Rickettsia tsutsugamushi by means of IFA test, 6 individuals were found positive showing 0.5% of infection rate. This is the first finding that L. scutellare is the second vector species of tsutsugamushi disease in Korea. (4) Antibody positive rate of A. agrarius chejuensis sera were 31.2% (44/139), and 1 M. minutus serum was also found positive. The seropositive rates by season were not so significantly different.
Table 2 Infestations of chigger mites on field rodents by season in 1991-1992
Table 3 Species and total numbers of chiggers collected during the whole study period
Table 4 Seasonal prevalences of the chigger mites infested on A. a. chejuensis at three fixed study areas (Tongguiri, Kumdog-ri and Ara-1-dong) in Cheju Island
Table 5 Detection of R. tsutsugamushi antigen from internal contents of the chigger mites by means of IFA test
Table 6 Antibody positive rate of Apodemus agrarius chejuensis sera against R. tsutsugamushi in Cheju Island in August 1991-April 1992
References
1.
Asanuma K, et al. Jpn J Sanit Zool 1959;10(4):232–244.
2.
Chang WH, et al. J Korean Soc Microbiol 1989;24(2):185–195.
3.
Dohany AL, Shirai A, Robinson DM, Ram S, Huxsoll DL. Identification and antigenic typing of Rickettsia tsutsugamushi in naturally infected chiggers (Acarina: Trombiculidae) by direct immunofluorescence. Am J Trop Med Hyg 1978;27(6):1261–1264.
4.
Jackson EB, et al. Am J Hyg 1957;66:309–320.
5.
Kim JH, et al. J Korean Soc Virol 1990;20(2):167–176.
6.
Lee BU, et al. Korean J Ecol 1988;11(1):17–28.
7.
Lee HW, et al. J Kor Soc Virol 1990;20(1):63–73.
8.
Ree HI. Korean J Syst Zool 1990;6:57–70.
9.
Ree HI, Lee IY, Cho MK. Determination of the vector species of tsutsugamushi disease in Korea. Korean J Parasitol 1991;29(1):87–92.
10.
Ree HI, Lee HS, Lee IY, Yoshida Y. Epidemiological studies on host animals of tsutsugamushi disease in Korea. Korean J Parasitol 1991;29(2):181–188.
11.
Ree HI, et al. Korean J Zool 1991;34(2):257–264.
12.
Shim JC, et al. Rep NIH Korea 1990;27:121–124.
13.
Shin HK, et al. Rep NIH Korea 1989;26:139–156.
14.
Shirai A, Dohany AL, Ram S, Chiang GL, Huxsoll DL. Serological classification of Rickettsia tsutsugamushi organisms found in chiggers (Acarina: Trombiculidae) collected in Peninsular Malaysia. Trans R Soc Trop Med Hyg 1981;75(4):580–582.
15.
Shirai A, et al. J Trop Med Pub Hlth 1981;12(1):1–6.
16.
Tamura A, Urakami H, Tsuruhara T. Purification of Rickettsia tsutsugamushi by Percoll density gradient centrifugation. Microbiol Immunol 1982;26(4):321–328.