Haemaphysalis longicornis (Neumann), the Asian longhorned tick, is a species native to East Asia, but invasive to Australia, New Zealand, and most recently, the United States. It has spread rapidly across the eastern United States after being established in New Jersey in 2017. Aiding this rapid expansion is the ability of this tick to reproduce parthenogenically and feed on diverse host species. In cattle, this tick can cause heavy burdens and act as a vector for the pathogenic hemoprotozoan parasite Theileria orientalis, genotype Ikeda, creating economic losses that impact the cattle industry. Here, we report Asian longhorned ticks, collected from cattle, a dog, and pastures and morphologically identified at the Oklahoma Animal Disease Diagnostic Laboratory as H. longicornis before molecular confirmation through PCR amplification of the cox1 gene. Blood samples from infested cattle were collected and assessed molecularly for the presence of T. orientalis, with no pathogenic DNA detected. This report describes the first record of H. longicornis in Oklahoma and the farthest westward detection of this tick in the United States to date.

Anaplasma bovis is primarily an infectious agent of ruminants, and has most commonly been reported in Asia, the Middle East, and Africa. Although the primary cause of human anaplasmosis is Anaplasma phagocytophilum, humans may rarely be infected by other Anaplasma spp. Human disease attributed to A. bovis has been occasionally reported, including an A. bovis-like agent in the United States. DNA of an A. bovis-like agent has been amplified from humans and the tick Dermacentor variabilis in the central region of the U.S., but larger prevalence studies among potential vectors or reservoir hosts in the U.S. have not been reported. The aim of this study was to evaluate the prevalence of A. bovis-like agent among D. variabilis and cattle in the Southcentral U.S. Previously extracted DNA from adult D. variabilis collected from Oklahoma (n = 38) and Kansas (n = 93), and blood of cattle from Oklahoma (n = 140) were tested by conventional PCR. Overall prevalence of A. bovis-like DNA within ticks was determined to be 3.1% (4/131), and all positive ticks originated from Oklahoma. Overall prevalence in bovine blood was determined to be 0% (0/140). These findings confirm the presence of an A. bovis-like agent, a potentially zoonotic pathogen, among ticks in the Southcentral U.S.; this agent is likely underrecognized and has been detected in parts of the U.S. that lie outside of the established geographic range for A. phagocytophilum. Further investigation and surveillance are necessary to elucidate possible reservoirs of A. bovis in the U.S., further evaluate the burden of human infection, and fully characterize genetic differences between the A. bovis-like agent detected in the U.S. and A. bovis in other regions of the world.

Cytauxzoon felis is a tick-borne protozoan parasite of considerable importance to domestic cats in the United States. Despite high mortality among clinically presenting cats, some cats may either recover from infection, becoming permanent chronic carriers of C. felis, or may not develop disease following exposure. C. felis in healthy (asymptomatic) cats is currently detected by qPCR or through observation of piroplasms in blood smears. The present study aims to compare the prevalence of C. felis in healthy populations of pet and free-ranging cats by using two different diagnostic tests: an indirect ELISA and a probe-based qPCR. Samples, along with demographic information, were collected collaboratively from healthy cats in the states of Oklahoma, Arkansas, and Missouri (USA) in either pet or free-range populations. Significantly more cats were detected to be C. felis positive by the ELISA than qPCR. Of the total of cats tested by ELISA and qPCR, 248 (35.37%) tested ELISA positive but qPCR negative, indicating formation of specific C. felis antibodies in cats with undetectable circulating C. felis DNA. The results of this study provide insights into the occurrence of C. felis in healthy cats that are exposed in the south-central United States and present a useful diagnostic strategy for detecting C. felis.