Animals ; Animals, Domestic ; China ; epidemiology ; Coinfection ; Coxiella burnetii ; Francisella tularensis ; Tick-Borne Diseases ; epidemiology ; transmission ; veterinary

Ticks are obligate, haematophagous arthropods that are distributed across the world, which may transmit more than 200 pathogens, including viruses, bacteria and parasites. A large number of tick species are widespread in China, and their transmitting tick-borne viral diseases pose a great threat to human health in endemic foci. This review describes the epidemiology of common, emerging and potentially pathogenic tick-borne viruses in China, and recommends the assessment of public health significance and pathogenicity of emerging tick-borne viruses using reverse microbial etiology, so as to provide insights into the management of emerging tick-borne diseases in China.
Animals ; Humans ; Tick-Borne Diseases/epidemiology* ; Ticks/microbiology* ; Viruses/genetics* ; Public Health ; China/epidemiology*

Objective: To understand the epidemiological characteristics of tick-borne infectious diseases (TBID) and the risk factors of severe illness and death in Hubei Province from 2016 to 2021. Methods: Based on the incidence data of fever with thrombocytopenia syndrome (SFTS), tsutsugamushi disease, typhus and other TBID reported during 2016-2021, the epidemiological analysis was conducted. Field investigation results of TBID in areas with high incidence in 2021, logistic regression analysis of population characteristics, epidemiological history and other factors were used to explore the risk factors of severe and fatal cases. In the field vector investigation, free ticks and surface ticks of the host animals in the cases' home and surrounding grassland were monitored and detected. Results: A total of 3 826 TBID cases were reported in Hubei from 2016 to 2021, of which 71.30% (2 728/3 826) were SFTS, 13.04% (499/3 826) were tsutsugamushi disease and 15.66% (599/3 826) were typhus. A total of 44 cases died in 6 years; the fatality rate was 1.15% (44/3 826). In the peak seasons of incidence from May to July, the cases in people engaged in agriculture related work accounted for 84.61% (3 237/3 826). The incidence rate in women was higher than that in men, and the cases aged ≥50 years accounted for 81.02% of the total (3 100/3 826), and the incidence rate increased with age (P<0.001). The TBID cases were distributed in 86 counties and districts in 16 prefectures (municipality). The incidence rates of different areas had significant differences (P<0.05), and there was a certain spatial-temporal clustering and expasion. Bovis microplus and Haemaphysalis longicornis were captured in the field, and the positive rates in host animals and grassland ticks were 10.94% (7/64) and 40.00% (2/5), respectively. Univariate logistic regression analysis results showed that age ≥50 years and leukocyte <2.0×10⁹/L were risk factors for severe illness and death. Conclusions: The TBID reported in Hubei were mainly SFTS, tsutsugamushi disease and typhus. In order to reduce the incidence of TBID, it is necessary to strengthen the prevention and control in women aged ≥50 years and reduce field exposure and tick bites during the epidemic period.
Animals ; Female ; Typhus, Epidemic Louse-Borne ; Scrub Typhus/epidemiology* ; Severe Fever with Thrombocytopenia Syndrome ; Ticks ; Communicable Diseases ; Phlebovirus ; China/epidemiology* ; Tick-Borne Diseases/epidemiology*

OBJECTIVELyme disease and Human granulocytic anaplasmosis are tick-borne diseases caused by Borrelia burgdorferi and Anaplasma phagocytophilum respectively. We have investigated infection and co-infection of the two diseases in the population of forest areas of eight provinces in China by measuring seroprevalence of antibodies against B. burgdorferi and A. phagocytophilum.

METHODSForest areas in 8 provinces were chosen for investigation using whole sampling and questionnaire survey methods. 3 669 serum samples from people in the forest areas were tested for the presence of antibodies by indirect immunofluorescent assay (IFA).

RESULTSSeroprevalence against B. burgdorferi was 3% to 15% and against A. phagocytophilum was 2% to 18% in the study sites in the 8 provinces in China. We also found co-infection of B. burgdorferi and A. phagocytophilum in 7 of the 8 provinces (the exception being the Miyun area in Beijing). The seroprevalence for both B. burgdorferi and A. phagocytophilum was significantly higher among people exposed to ticks than among people who were not exposed to ticks.

CONCLUSIONWe conclude that both pathogens are endemic in the forest areas in the eight provinces, but the prevalence of B. burgdorferi and A. phagocytophilum differs between the provinces.

Adolescent ; Adult ; Anaplasma phagocytophilum ; pathogenicity ; Anaplasmosis ; blood ; epidemiology ; Animals ; Borrelia burgdorferi ; pathogenicity ; Child ; China ; Coinfection ; Female ; Humans ; Lyme Disease ; blood ; epidemiology ; Male ; Middle Aged ; Seroepidemiologic Studies ; Tick-Borne Diseases ; blood ; epidemiology ; Trees ; Young Adult

OBJECTIVETo evaluate the Anaplasma phagocytophilum (A. phagocytophilum), Ehrlichia canis (E. canis), Dirofilaria immitis (D. immitis) (canine heartworm), Borrelia burgdorferi (B. burgdorferi) infections in countryside dogs from Yunnan, Hainan and Anhui provinces.

METHODSSerum samples were collected from 26 dogs in Yunnan, Hainan and Anhui provinces. The samples were tested using a commercial ELISA rapid diagnostic assay kit (SNAP(®) 4Dx(®); IDEXX Laboratories, Inc. U.S.A.). Meanwhile, indirect immunofluorescence assay (IFA) recommended by WHO was conducted to detect IgG to A. phagocytophilum. Two methods were analyzed and compared.

RESULTSThe number of serologically positive dogs for IgG to A. phagocytophilum was only 2 which was from Hainan province and none of the 26 dogs responded positive for E. canis, D. immitis (canine heartworm), and B. burgdorferi by ELISA rapid diagnostic method. The number of serologically positive dogs for IgG to A. phagocytophilum was 13 (50%) by IFA method. Data of the two methods were analyzed by statistical software and the difference was statistically significant (P=0.002).

CONCLUSIONSIt can be concluded that IFA method was more sensitive than ELISA rapid diagnostic method. However, we need conduct further and intensive epidemiology survey on tick-born diseases pathogens including A. phagocytophilum, E. canis, D. immitis (canine heartworm), and B. burgdorferi which have public health significance.

Anaplasma phagocytophilum ; immunology ; Animals ; Borrelia burgdorferi ; immunology ; China ; epidemiology ; Dirofilaria immitis ; immunology ; Dirofilariasis ; blood ; epidemiology ; immunology ; Disease Vectors ; Dog Diseases ; epidemiology ; Dogs ; Ehrlichia canis ; immunology ; Ehrlichiosis ; blood ; epidemiology ; immunology ; Enzyme-Linked Immunosorbent Assay ; methods ; Fluorescent Antibody Technique, Indirect ; methods ; Immunoglobulin G ; blood ; Lyme Disease ; blood ; epidemiology ; immunology ; Tick-Borne Diseases ; epidemiology

OBJECTIVETo study the existence of Ehrluichiosis, lyme disease and tick-borne spotted fever coinfection in some areas in China.

METHODSUsing polymerase chain reaction (PCR), B. burgdorferi sensu lato, spotted fever group (SFG) Rickettsiae and human granulocytic ehrlichia (HGE), Ehrlichia chaffeensis (EC) were detected in ticks and mouse samples collected from Inner Mogolia autonomous region, Heilongjiang province, Beijing and Fujian province.

RESULTS408 Ixodes persulcatus collected from Inner Mogolia autonomous region, HGE and B. burgdorferi sensu lato and SFG Rickettsiae were detected positive, with rates as 6.8%, 7.8%, 45.6%, respectively. 5 (5/408) were coinfection with HGE and B. burgdorferi sensu lato while 1 (1/408) was coinfection with HGE and SFG Rickettsiae. 46 Ixodes persulcatus collected from Helongjiang province were determined positive, with rates as 6.5%, 10.8% and 34.8%, respectively including 1 (1/46) coinfected with HGE and B. burgdorferi sensu lato. 2 of 922 ticks collected from Beijing were detected positive with B. burgdorferi sensu lato. Among 283 groups of Haemaphysalis yeni ticks (3/group) and from 38 rodent samples collected from Ninghua county of Fujian province HCE and B. burgdorferi sensu lato and SFG Rickettsiae were detected. Out of them, 25 groups were positive with EC and the minimal positive rate was 3.8% while 21 rodent samples were positive with EC with a positive rate of 56.4%. 2 ticks and 1 rodent sample were detected positive with EC and spotted fever group.

CONCLUSIONCoinfection of HGE and B. burgdorferi sensu lato or spotted fever group Richi did exist in Ixodes persulcatus collected from Inner Mogolia autonomous region and Heilongjiang province. Coinfection of EC and spotted fever group Richi was found in the ticks and rodents collected from Fujian province.

Animals ; Arachnid Vectors ; Borrelia burgdorferi Group ; isolation & purification ; China ; epidemiology ; DNA, Bacterial ; analysis ; Disease Vectors ; Ehrlichia ; isolation & purification ; Ehrlichiosis ; epidemiology ; Humans ; Ixodes ; microbiology ; Lyme Disease ; epidemiology ; Polymerase Chain Reaction ; Rats ; Rickettsia ; isolation & purification ; Rickettsia Infections ; epidemiology ; Rodentia ; microbiology ; Tick-Borne Diseases ; epidemiology ; Ticks ; microbiology