Dogs (Canis familiaris) as sentinels for determining the risk of occurrence of Rickettsia spp. and Anaplasma phagocytophilum in previously undiagnosed areas

Vet Parasitol Reg Stud Reports. 2023 Nov:46:100930. doi: 10.1016/j.vprsr.2023.100930. Epub 2023 Sep 18.

Abstract

Determining the occurrence of Rickettsia spp. and Anaplasma phagocytophilum in municipalities with no case records is important to define surveillance strategies and is essential to reduce lethality in different regions. Therefore, an approach aimed at enhancing surveillance in municipalities with an unknown epidemiological situation was tested, according to the classification suggested by Resolution SMA/SES 07/01/16. Canine sera collected in the annual anti-rabies campaign were submitted to the indirect fluorescent antibody test for Rickettsia amblyommatis, R. belli, R. parkeri, R. rickettsii and A. phagocytophilum. Titers ≥1:64 and ≥1:320 were considered positive for Rickettsia spp. and A. phagocytophilum, respectively. For Rickettsia spp., 61.8% of dogs were seropositive, with 26% positive for more than one species, and 42.3% were seropositive for R. rickettsii. Dogs from the urban area presented 5.16 (CI 1.18; 7.69) times greater odds of seropositivity for R. parkeri (p = 0.037) and 3.39 (CI 1.04; 3.70) times greater odds for R. belli (p = 0.017). Considering the 1:40 cutoff point, 19.1% of dogs were reactive for A. phagocytophilum. Two (1%) dogs in rural areas were positive (titer 1:640). The results indicate all species ever tested in Lavras/MG, since the present study is the city's first report on the subject. According to classifications of the aforementioned Resolution, the results determine that the municipality of Lavras should be considered a "risk area" for Brazilian spotted fever(BSF). The methodology presented is efficient, straight forward to perform and inexpensive for diagnosing a risk situation for BSF and human granulocytic anaplasmosis. Moreover, its use can be applied throughout Brazil and other countries as a public health alert guideline.

Keywords: Anaplasmosis; Brazilian spotted fever; IFA; One health; Public health; Tick-borne infections.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anaplasma phagocytophilum*
  • Animals
  • Dog Diseases* / diagnosis
  • Dog Diseases* / epidemiology
  • Dog Diseases* / microbiology
  • Dogs
  • Humans
  • Rickettsia Infections* / diagnosis
  • Rickettsia Infections* / epidemiology
  • Rickettsia Infections* / veterinary
  • Rickettsia*
  • Seroepidemiologic Studies