Scrub Typhus: Vector Surveillance and its Control
Abstract
Scrub Typhus is an important emerging vector borne disease being reported now in many parts of the country. This is also known as Chigger Borne Typhus or Tsutsugamushi Fever. Scrub Typhus is caused by bacteria called Orientia tsutsugamushi and is transmitted to people through bites of infected chiggers (larval mites). Recently, it has been reported in the state of Mizoram on wide scale. However, the states of Rajasthan, Jammu & Kashmir, Vellore, Sikkim, Nagaland & Manipur, Mizoram, Tamil Nadu, Maharashtra, Kerala, Himachal Pradesh and Meghalaya have also reported cases of scrub typhus. Scrub typhus is an infectious disease that is transmitted to humans from field mice and rats through the bite of mites that live on the animals. This is a rural disease occurring preferentially in spring and in autumn. Scrub Typhus is an occupational health concern for farmers, park rangers, military personnel, geologist, miners as well as oil palm workers. The life cycle of the trombiculid mite is very complex. The duration of mites’ life cycle depends on species and environment, but normally last 2 to 12 months. Trombiculis mites go through a life cycle of eggs, larva, nymph and adult. Mites have a very patchy distribution over small areas because of their special requirements. The nymphs and adults need certain soil conditions for their survival and development while the larvae require host animals, such as wild rats, other small rodents and birds. Suitable habitats are found in grassy fields, shrubby areas, forests, abandoned rice fields and cleared forests. An attempt has been made to describe the tools for mite surveillance and the possible methods of vector control.
References
Jin HS, Chu C, Han DY. Spatial distribution analysis of scrub typhus in Korea. Osong Public Health Res Perspect
; 4(1): 4-15.
Bang HA, Lee MJ, Lee WC. Comparative research on epidemiological aspects of tsutsugamushi disease
(scrub typhus) between Korea and Japan. Jpn J Infect Dis 2008; 61(2): 148-150.
Li T, Yang Z, Dong Z et al. Meteorological factors and risk of scrub typhus in Guangzhou, southern China,
-2012. BMC Infect Dis 2014; 14: 139.
Paris DH, Shelite TR, Day NP et al. Unresolved problems related to scrub typhus: a seriously neglected lifethreatening disease. Am J Trop Med Hyg 2013; 89(2): 301-307.
Kweon SS, Choi JS, Lim HS et al. A community-based case-control study of behavioral factors associated with
scrub typhus during the autumn epidemic season in South Korea. Am J Trop Med Hyg 2009; 80(3): 442-446.
Tilak R, Kunwar R, Wankhade UB, et al. Emergence of Schoengastiella ligula as the vector of scrub typhus
outbreak in Darjeeling: has Leptotrombidium deliense been replaced? Indian J Public Health 2011; 55(2):
-99.
Lee HI, Shim SK, Song BG et al. Detection of Orientia tsutsugamushi, the causative agent of scrub typhus,
in a novel mite species, Eushoengastia koreaensis, in Korea. Vector Borne Zoonotic Dis 2011; 11(3): 209-214.
Park GM, Shin HS. Geographical distribution and seasonal indices of chigger mites on small mammals
collected on the east coast of the Republic of Korea. J Parasitol 2016; 102(2): 193-198.
Yang LP, Liu J, Wang XJ et al. Effects of meteorological factors on scrub typhus in a temperate region of China.
Epidemiol Infect 2014; 142(10): 2217-2226.
Lee IY, Kim HC, Lee YS et al. Geographical distribution and relative abundance of vectors of scrub typhus in
the Republic of Korea. Korean J Parasitol 2009; 47(4): 381-386.
Li T, Yang Z, Dong Z et al. Meteorological factors and risk of scrub typhus in Guangzhou, southern China,
-2012. BMC Infect Dis 2014; 14: 139.
Eung YS, Kim CM, Yun NR et al. Effect of latitude and seasonal variation on scrub typhus, South Korea,
–2013. Am J Trop Med Hyg 2016; 94(1): 22-25.
Blewitt B. Fevers of the typhus group in the Bhim Tal area, Kumaun Hills, U.P. and India. J R Army Med Corps
; 70: 241-245.
Mackie TT. Observations on tsutsugamushi disease (scrub typhus) in Assam and Burma. Trans R Soc Trop
Med Hyg 1946; 40: 15-56.
Sayen JJ, Pond HS, Forrester JS et al. Scrub typhus in Assam and Burma; a clinical study of 616 cases.
Medicine (Baltimore) 1946; 25: 155-214.
Kalra SL, Rao KN. Typhus group of fevers in Jubbulpore area. Indian J Med Res 1949; 37: 373-384
Kalra SL, Rao KN. Typhus fevers in Kashmir State. Part II. Murine typhus. Indian J Med Res 1951; 39: 297-302.
Rosenberg R. Drug-resistant scrub typhus: paradigm and paradox. Parasitol Today 1997; 13: 131-132.
Watt G, Parola P. Scrub typhus and tropical rickettsioses. Curr Opin Infect Dis 2003; 16: 429-436.
Kelly DJ, Fuerst PA, Ching WM et al. Scrub typhus: the geographic distribution of phenotypic and genotypic
variants of Orientia tsutsugamushi. Clin Infect Dis 2009; 48(Suppl 3): S203-30.
Takamura A, Tanaka H, Kawamura A. Tsutsugamushi disease: an overview. University of Tokyo Press, Tokyo,
Japan. 1995.
Traub R, Wisseman CL Jr. The ecology of chigger-borne rickettsiosis (scrub typhus). J Med Entomol 1974; 11:
-303.
Mittal V, Gupta N, Bhattacharya D et al. Serological evidence of rickettsial infections in Delhi. Indian J Med
Res 2012; 135: 538-541.
Wei Y, Huang Y, Luo L et al. Rapid Increase of scrub typhus: an epidemiology and spatial-temporal cluster
analysis in Guangzhou City, Southern China, 2006-2012. PLoS One 2014; 9: e101976.
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