Incidence of hemoparasitic infections in cattle from central and northern Thailand

Abstract

Background Hemoparasites, such as Babesia spp., Theileria spp. and Anaplasma spp., can negatively affect the health of farm animals resulting in significant losses in production. These losses inherently affect the economics of the livestock industry. Since increases in the severity of vector-borne diseases in the southeast Asian region have been reported, investigations of parasitic epidemiology in Thailand will be necessary to improve the existing parasite control strategies for blood parasitic infections. This study aims to investigate incidences of bovine hemoparasites throughout central and northern Thailand by focusing on areas of high-density cattle populations. Methods Blood parasitic infections among cattle were screened and identified by microscopic examination. Anemia status was then determined by evaluation of the packed cell volume (PCV) of each animal. Furthermore, blood parasites were detected and identified by genus and species-specific primers through the polymerase chain reaction method. Amplicons were subjected to DNA sequencing; thereafter, phylogenetic trees were constructed to determine the genetic diversity and relationships of the parasite in each area. Results A total of 1,066 blood samples were found to be positive for blood parasitic infections as follows: 13 (1.22%), 389 (36.50%), and 364 (34.15%) for Babesia bovis, Theileria orientalis, and Anaplasma marginale, respectively. Furthermore, multiple hemoparasitic infections in the cattle were detected. The hematocrit results revealed 161 hemoparasitic infected samples from 965 blood samples, all of which exhibiting indications of anemia with no significant differences. Sequence analysis of the identified isolates in this study revealed that B. bovis rap-1, four separate clades of T. orientalis msps, and A. marginale msp4 exhibited considerable sequence similarity to homologous sequences from isolates obtained from other countries. Sequence similarity ranged between 98.57–100%, 83.96–100%, and 97.60–100% for B. bovis rap-1, T. orientalis msps, and A. marginale msp4, respectively. Conclusion In this study, the analyzed incidence data of cattle hemoparasitic infection in Thailand has provided valuable and basic information for the adaptation of blood-borne parasitic infections control strategies. Moreover, the data obtained from this study would be useful for future effective parasitic disease prevention and surveillance among cattle.

Tick-borne Pathogen Detection and Its Association with Alterations in Packed Cell Volume of Dairy Cattle in Thailand

“…In this study, the detection of TBPs, specifically samples positive for BTH, T. orientalis, and A. marginale, was associated with significantly lower PCV values. This contradicts the results of previous Thai studies where the differences between the PCV values of cattle positive and negative for T. orientalis were trivial [ 5 , 28 ]. T. orientalis -infected cattle may show normal hematocrit values (24–46%) to as low as 8% [ 30 , 39 ], indicating that positive animals present varying hematologic indices.…”

“…The relatively high detection rates of T. orientalis in the current survey imply that this parasite is the predominant TBP among bovine herds in the sampled areas. The presently recorded T. orientalis overall detection rate (23.40%) was lower than previous surveys that reported 30.1–41.54% across Thailand [ 5 , 6 , 28 ]. The bovine infectious anemia outbreaks associated with the geographical spread of pathogenic T. orientalis have been documented in countries such as Australia, New Zealand, and recently, the USA [ 29 , 30 , 31 , 32 ].…”

“…B. bovis (8.33%) and B. bigemina (10.71%) detection in Lampang in this survey were lower than those reported by Cao et al [ 10 ] and Simking et al [ 11 ] but higher than those observed by Koonyosying et al [ 28 ] and Yoshinari et al [ 36 ]. Current T. orientalis (32.14%) and A. marginale (25%) detection were higher and lower than the detection rates of a previous Lampang survey of 21.05% and 85.53%, respectively [ 28 ]. On the other hand, we observed higher TBP detection rates than a report from Lamphun and lower than those from Nakhon Pathom [ 28 ].…”

“…Current T. orientalis (32.14%) and A. marginale (25%) detection were higher and lower than the detection rates of a previous Lampang survey of 21.05% and 85.53%, respectively [ 28 ]. On the other hand, we observed higher TBP detection rates than a report from Lamphun and lower than those from Nakhon Pathom [ 28 ]. The variances in the reports of TBPs may be attributed to different factors, such as the profiles of the animals (age, sex, breed, etc.)…”

“…We demonstrated the detection of TBPs in dairy cattle from four provinces in northern and western (central) Thailand and recorded higher detection rates in samples from Lampang province. Bovine tick-borne infections have been extensively studied in northern and western (central) parts of Thailand in the past, where researchers reported the aforementioned pathogens in cattle [ 6 , 10 , 11 , 12 , 28 , 36 , 37 ], indicating their endemicity in the localities where they were detected. Studies on bovine TBDs have been performed in Lampang previously.…”