ABSTRACT
Endemic scrub typhus was recently detected on Chiloé Island in southern Chile. We report a series of cases, acquired over a wide geographical range in continental Chile during 2016-2018, demonstrating that this emerging rickettsial infection is also found on the mainland of South America.
Subject(s)
Orientia tsutsugamushi , Scrub Typhus/epidemiology , Scrub Typhus/microbiology , Adult , Aged , Animals , Chile/epidemiology , Female , History, 21st Century , Humans , Immunoglobulin G/immunology , Immunoglobulin M/immunology , Male , Middle Aged , Molecular Diagnostic Techniques , Orientia tsutsugamushi/genetics , Orientia tsutsugamushi/immunology , Scrub Typhus/history , Scrub Typhus/transmission , Vector Borne Diseases , Young Adult , ZoonosesABSTRACT
BACKGROUND: Substantial outbreaks of scrub typhus, coupled with the discovery of this vector-borne disease in new areas, suggest that the disease remains remarkably neglected. The objectives of this study were to map the contemporary and potential transmission risk zones of the disease and to provide novel insights into the health burden imposed by scrub typhus in southern China. METHODS: Based on the assembled data sets of annual scrub typhus cases and maps of environmental and socioeconomic correlates, a boosted regression tree modeling procedure was used to identify the environmental niche of scrub typhus and to predict the potential infection zones of the disease. Additionally, we estimated the population living in the potential scrub typhus infection areas in southern China. RESULTS: Spatiotemporal patterns of the annual scrub typhus cases in southern China between 2007 and 2017 reveal a tremendous, wide spread of scrub typhus. Temperature, relative humidity, elevation, and the normalized difference vegetation index are the main factors that influence the spread of scrub typhus. In southern China, the predicted highest transmission risk areas of scrub typhus are mainly concentrated in several regions, such as Yunnan, Guangxi, Guangdong, Hainan, and Fujian. We estimated that 162 684 million people inhabit the potential infection risk zones in southern China. CONCLUSIONS: Our results provide a better understanding of the environmental and socioeconomic factors driving scrub typhus spread, and estimate the potential infection risk zones beyond the disease's current, limited geographical extent, which enhances our capacity to target biosurveillance and help public health authorities develop disease control strategies.
Subject(s)
Orientia tsutsugamushi , Scrub Typhus/epidemiology , China/epidemiology , Environment , Geography, Medical , History, 21st Century , Humans , Population Surveillance , Risk Factors , Scrub Typhus/history , Scrub Typhus/prevention & control , Scrub Typhus/transmission , Socioeconomic Factors , Spatio-Temporal AnalysisABSTRACT
Scrub typhus in Bhutan was first reported in 2009. We investigated an outbreak of scrub typhus in a remote primary school during August-October 2014. Delay in recognition and treatment resulted in 2 deaths from meningoencephalitis. Scrub typhus warrants urgent public health interventions in Bhutan.
Subject(s)
Disease Outbreaks , Schools , Scrub Typhus/epidemiology , Bhutan/epidemiology , Child , Female , History, 21st Century , Humans , Immunoglobulin G/immunology , Immunoglobulin M/immunology , Orientia tsutsugamushi/immunology , Population Surveillance , Scrub Typhus/history , Scrub Typhus/immunologyABSTRACT
To increase knowledge of undifferentiated fevers in Kenya, we tested paired serum samples from febrile children in western Kenya for antibodies against pathogens increasingly recognized to cause febrile illness in Africa. Of patients assessed, 8.9%, 22.4%, 1.1%, and 3.6% had enhanced seroreactivity to Coxiella burnetii, spotted fever group rickettsiae, typhus group rickettsiae, and scrub typhus group orientiae, respectively.
Subject(s)
Q Fever/epidemiology , Rickettsia Infections/epidemiology , Scrub Typhus/epidemiology , Antibodies, Bacterial/blood , Antibodies, Bacterial/immunology , Child , Child, Preschool , Cross Reactions , Enzyme-Linked Immunosorbent Assay , Female , Fever/epidemiology , Fever/microbiology , History, 21st Century , Humans , Infant , Kenya/epidemiology , Male , Q Fever/diagnosis , Q Fever/history , Q Fever/microbiology , Rickettsia Infections/diagnosis , Rickettsia Infections/history , Rickettsia Infections/microbiology , Scrub Typhus/diagnosis , Scrub Typhus/history , Scrub Typhus/microbiology , SeasonsABSTRACT
This article summarizes the results of study of tsutsugamushi disease in the Primorye and Tadzhikistan, in its epidemiology, diagnosis and biology of the Rickettsia tsutsugamushi. There is also information on the vectors of the disease, rickettsial infection within chiggers and transtadial transmission from larva to nymph, hosts of trombiculids and natural infection with R. tsutsugamushi.
Subject(s)
Orientia tsutsugamushi/isolation & purification , Scrub Typhus/history , Scrub Typhus/microbiology , History, 20th Century , History, 21st Century , Humans , Russia/epidemiology , Scrub Typhus/epidemiologySubject(s)
Rickettsia Infections/history , Europe , History, 16th Century , History, 18th Century , History, 19th Century , History, 20th Century , Humans , North America , Q Fever/history , Rocky Mountain Spotted Fever/history , Scrub Typhus/history , Trench Fever/history , Typhus, Endemic Flea-Borne/historyABSTRACT
The rickettsial disease of man found only in Asia is mite-borne (scrub) typhus, caused by Rickettsia tsutsugamushi. Unique to southern Japan is a little-known human mononucleosis-like disease caused by Rickettsia sennetsu. In 1981 and 1982, there was a remarkable resurgence in the number of reported cases of mite-borne typhus in Japan after some years of virtual absence. Recent studies of R sennetsu have resulted in its reclassification to the genus Ehrlichia, members of which until now have been exclusively pathogens of animals. The historical background of ecologic investigations, in Malaysia and elsewhere, of these two developments suggest directions for future research.
