A first report on prevalence of caprine theileriosis and its association with host biomarkers in Southern Khyber Pakhtunkhwa, Pakistan

Seasonality, epidemiology and phylogeny of Theileria ovis with a note on hematological and biochemical changes in asymptomatic infected goats from Pakistan

Caprine theileriosis, caused by Theileria ovis is a serious production issue, especially in the areas that depend on goats and sheep for milk, meat, and other economic benefits. Pakistan has a large goat population, but few reports have been documented from this country regarding PCR-based detection of T. ovis. The molecular prevalence of T. ovis, on a seasonal basis, in various goat breeds enrolled from Muzaffar Garh district of Punjab in Pakistan was determined from October 2018 to September 2019. In this study, 1084 goat blood samples were screened for the detection of T. ovis DNA through PCR-based amplification of 18S rRNA gene. Out of 1084 goats, 12 (1.11%) were infected with T. ovis. The parasite prevalence varied with the sampling seasons (Chi square test, P = 0.008), and the parasite prevalence was highest in goat blood samples collected in summer (2.39%) followed by winter (1.88%). DNA sequencing and BLAST analysis confirmed the presence of T. ovis, and the amplified isolates from the 18S rRNA gene of T. ovis were found to be highly conserved during phylogenetic analysis. Young goats (Fischer exact test, P = 0.022) were found more infected with T. ovis during the winter season. Infected goats had elevated white blood cell counts (Two-sample t-test, P = 0.04), blood urea nitrogen to Creatinine ratio (Two-sample t-test, P = 0.02) and decreased serum Creatinine (Two-sample t-test, P = 0.001) as compared to T. ovis negative goats. We report a relatively low molecular prevalence of T. ovis in goats from the Muzaffar Garh district. However, it is recommended that control measures to eradicate T. ovis infection in goats in this area should be taken.

Clinical, hematological and molecular evaluation of piroplasma and Anaplasma infections in small ruminants and tick vectors from Kurdistan province, western Iran

Tick-borne haemoparasite infections are a major challenge in small ruminant (SR) production across tropical areas. The present study evaluated the prevalence of Theileria, Babesia and Anaplasma in SRs and their tick vectors and estimated the association between pathogen prevalence with clinical hematological findings among SR populations in Kurdistan province, western Iran. In total, 250 blood samples and 250 tick species (one per animal) were collected from SR populations, along with clinical and hematological examinations. Microscopy of blood smears and molecular analysis were performed to detect potential infection with Theileria, Babesia and Anaplasma. Moreover, haemoparasites were explored in the isolated ticks using semi-nested PCR. Based on microscopy, the prevalence of Theileria, Anaplasma and Babesia infections was 91.2%, 23.2% and 2.4%, respectively. Semi-nested PCR analysis of blood samples demonstrated 86.8%, 78.8% and 14% prevalence for T. ovis, A. ovis and B. ovis, respectively. Dermacentor marginatus and Rhipicephalus turanicus were predominant isolated tick vectors from SR, while D. marginatus was the most contaminated tick in all investigated counties. There were, also, a statistically significant association between the estimated molecular prevalence rates with semi-yellow conjunctiva (A. ovis), body temperature (T. ovis and A. ovis), heart rate (T. ovis and B. ovis), mean white blood cell count (T. ovis and A. ovis), mean red blood cell count (T. ovis and B. ovis), as well as mean corpuscular volume, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration in all haemoparasite infections. Future studies are recommended to reveal the epidemiology of such infections in SRs in Iran.

Molecular Detection and Differentiation of Different Theileria Species in Naturally Infected Goats Using Nested PCR-RFLP: A First Report from Northern India

PURPOSE

Theileriosis is an economically important tick-borne pathogen with a serious impact on livestock health and productivity. Despite the fact that bovine theileriosis has been widely investigated, there exists a paucity of information on these infections in small ruminants, especially in India. The present study was carried out to detect and differentiate different Theileria spp. in goats using nested PCR RFLP.

METHODS

Blood samples and ticks were collected from 405 goats in various agro-climatic zones of Haryana state, India. The blood samples were screened by microscopy, nested PCR-RFLP, and sequence analysis. The nested PCR-RFLP was performed with four restriction enzymes viz., Hpa II, Bsh 1285I, Hae II and Rsa I. Six nested PCR amplicons with different RFLP patterns were sequenced and submitted to NCBI (OM666861, MZ220430, OM666628, MZ220437, OM666637, OM721806).

RESULTS

Microscopy revealed 18.27% (n = 74) infection with Theileria spp., while 33.58% (n = 136) of blood samples were confirmed positive by nested PCR. Out of 136 positive samples, 43.38% (n = 59), 11.02% (n = 15) and 20.58% (n = 28), were positive for T. ovis, T. lestoquardi and T. luwenshuni (Theileria sp. China 1), respectively. Mixed infection was detected in 25% (n = 34) cases. Based upon Hpa II digestion pattern, 13 samples with T. lestoquardi and T. ovis, and 21 samples with T. ovis and T. luwenshuni were detected. Sequence study further confirmed their identity. The majority of ticks collected from goats were identified as Rhipicephalus spp., Hyalomma anatolicum and Hemaphysalis spp.

CONCLUSION

This study represents the first confirmed molecular report of goats infected with T. ovis, T. lestoquardi, and T. luwenshuni from northern India.

Tick-borne haemoparasitic diseases in small ruminants in Pakistan: Current knowledge and future perspectives

Livestock industry is an essential part of Pakistan’s economy, and a variety of ruminants (including sheep and goats) are reared for the increasing demand of milk, meat and hide products. Haemoparasitic illnesses such as theileriosis, anaplasmosis, and babesiosis are a significant health risk for small ruminants in our country. Information regarding distribution patterns, the tick species involved and effective strategies to control tick-borne diseases (TBD) in goats and sheep of Pakistan is limited. To this end, it is required to assess the present rank of TBDs in small ruminants of Pakistan with a note on their vector ticks in order to control and identify the gaps in the knowledge of TBDs. This will recommend areas for future research and will add to the understanding of these diseases and will draw attention to the need for better-quality tools for the diagnosis and control of TBDs in small ruminants of Pakistan.

Molecular identification of Theileria species in naturally infected sheep using nested PCR-RFLP

Ovine theileriosis is an important tick-borne haemoprotozoan disease of sheep in tropical and subtropical regions, causing severe productivity and economic loss. There is a paucity of information related to molecular studies of ovine theileriosis from India. The present study identified different Theileria spp. in naturally infected sheep using nested PCR-restriction fragment length polymorphism (nPCR-RFLP). Blood samples and ticks were collected from 204 sheep in different agro-climatic zones of Haryana state, India, during the tick active season. Microscopic examination of thin blood smears revealed 33.3% (68/204) infections with Theileria spp., while 44.6% (91/204) of blood samples were positive by nPCR assay. Different Theileria spp. were identified based upon RFLP patterns using four restriction enzymes: Hpa II, Bsh 1285I, Hae II and Rsa I. Out of 91 positive samples, 50.5% (46/91), 23.08% (21/91), 11% (10/91) and 2.2% (2/91) were positive for T. ovis, T. lestoquardi, T. luwenshuni (Theileria sp. China 1/Theileria sp. China) and T. annulata, respectively. Mixed infection was detected in 13.2% (12/91) of cases. Based upon HpaII enzymatic digestion pattern, two samples with T. lestoquardi and T. annulata, nine samples with T. lestoquardi and T. ovis and one sample with T. ovis and T. annulata were detected. The presence of these Theileria spp. was further confirmed by sequence analysis. The majority of ticks collected from sheep were identified as Rhipicephalus spp. followed by Hyalomma anatolicum and Hemaphysalis spp. The present investigation depicts the first comprehensive molecular report of naturally infected sheep with T. ovis, T. lestoquardi, T. annulata and T. luwenshuni from northern India.

Epidemiology, Distribution and Identification of Ticks on Livestock in Pakistan

Background: Ticks are ectoparasites that transmit a variety of pathogens that cause many diseases in livestock which can result in skin damage, weight loss, anemia, reduced production of meat and milk, and mortality. Aim: The aim of this study was to identify tick species and the distribution on livestock hosts (sheep, goat, dairy cattle, and buffalo) of Punjab, Khyber Pakhtunkhwa Province and Islamabad from October 2019 to November 2020. Materials and Methods: Surveillance was performed to calculate the prevalence of ticks on livestock. Tick prevalence data (area, host, breed, gender, age, and seasonal infestation rate) was recorded and analyzed. Results: A total of 2080 animals were examined from selected farms, and, of these, 1129 animals were tick-infested. A total of 1010 male tick samples were identified to species using published keys. Haemaphysalis punctata, Haemaphysalis sulcata, Hyalomma anatolicum, Hyalomma detritum, Hyalomma dromedarii, Hyalomma excavatum, Hyalomma marginatum, Hyalomma rufipes, Rhipicephalus decoloratus Rhipicephalus microplus, and Rhipicephalus sanguineus were collected from goats, sheep, buffalo, and cattle. The overall rates of tick infestation on livestock were 34.83% (buffalo), 57.11% (cattle), 51.97% (sheep) and 46.94% (goats). Within each species, different breeds demonstrated different proportions of infestation. For cattle breeds, infestation proportions were as follows: Dhanni (98.73%), Jersey (70.84%) and the Australian breed of cattle (81.81%). The Neeli Ravi breed (40%) of buffalo and the Beetal breed (57.35%) of goats were the most highly infested for these species. Seasonally, the highest prevalence of infestation (76.78%) was observed in summer followed by 70.76% in spring, 45.29% in autumn, and 20% in winter. The prevalence of tick infestation in animals also varied by animal age. In goats, animals aged 4–6 years showed the highest prevalence (90%), but in cattle, the prevalence of ticks was highest (68.75%) in 6 months–1-year-old animals. 1–3 years old buffalo (41.07%) and 6 months–1 year sheep (65.78%) had the highest prevalence rate. Females had significantly higher infestation rates (61.12%, 55.56% and 49.26%, respectively) in cattle, sheep, and goats. In buffalo, males showed a higher prevalence (38.46%) rate. Conclusions: This study showed tick diversity, infestation rate, and numerous factors (season, age, and gender of host) influencing tick infestation rate in different breeds of cattle, sheep, goats, and buffalo in Punjab Province, Khyber Pakhtunkhwa Province, and Islamabad, Pakistan. Higher tick burdens and rates of tick-borne disease reduce production and productivity in animals. Understanding tick species’ prevalence and distribution will help to develop informed control measures.

Molecular Epidemiology and Characterization of Theileria in Goats

The study was carried out to determine the prevalence and associated risk factors of theileriosis in goats of Chattogram district, Bangladesh. Molecular characterization of circulating Theileria in this area was also undertaken. A total of 400 samples were collected from goats of different breeds, ages and sex with relevant information of rearing and management. The prevalence of theileriosis was 8.50% (34/400) by polymerase chain reaction though all of those samples were test-negative by microscopic examination. Among different risk factors season, breed and tick infestation were found to be significantly (p ≤ 0.05) associated with the prevalence of theileriosis in goats. Serous nasal discharge and swollen lymph nodes were determined to be significant clinical signs. The Theileria spp. detected in the present study closely resemble isolates which were previously detected in Myanmar and China. Further large scale epidemiological studies are required to identify the circulating species and responsible vectors, which would facilitate control measures for this disease in Bangladesh.

Systematic Review of Ticks and Tick-Borne Pathogens of Small Ruminants in Pakistan

Ticks and tick-borne diseases (TTBDis) are a major constraint to the health and production of small ruminants in Pakistan. Despite being the subject of intermittent studies over the past few decades, comprehensive information on the epidemiology and control of TTBDis is lacking. Herein, we have systematically reviewed the current knowledge on TTBDis of small ruminants in Pakistan. Critical appraisal of the selected 71 articles published between 1947 to 2020 revealed that morphological examination had been the most widely used method for the identification of TTBDis in Pakistan. Tick fauna comprise at least 40 species, mainly belonging to Haemaphysalis, Hyalomma and Rhipicephalus. The prevalence of ticks is the highest in summer (June–September) and it is also higher in goats than sheep. Anaplasma, Babesia and Theileria spp. are the major tick-borne pathogens (TBPs), and their prevalence is usually higher in sheep than goats. Spatio-temporal distribution, genetic diversity and control of ticks and TBPs of small ruminants as well as the competence of tick vectors for various TBPs remain to be explored. Therefore, coordinated and focused investigations are required to fill knowledge gaps in these areas to maximise the health, production and welfare of small ruminants and minimise economic losses associated with TTBDis in Pakistan.

Molecular verification of transplacental transmission of Theileria lestoquardi in goat

Ovine and caprine malignant theileriosis (OCMT), a critical condition in small ruminant production, causes lethal infections. In September 2016, a total number of 400 goats of Marghoz breed (the largest population of goat breed in Iran), in northwest of Iran, were examined for approximately 25 pre-partum abortions and 7 goats' mortality for a period of 3 days. A dead goat and her aborted fetus were brought into the Urmia Veterinary Hospital for further diagnostic investigations. The microbiological assessments including direct microscopical examination of the vaginal discharges and placentome with respect to the differential staining (Gram's staining method), conventional pure culturing, fetal abomasal contents, and the liver were negative. Microscopic examinations of blood smears of the goat and the fetus revealed characteristic of Theileria spp. piroplasms and impression smear samples from goat liver and fetal spleen were positive for Theileria Koch blue bodies. DNA analysis was performed using PCR technique and specific primers derived from the nucleotide sequences of 18S rRNA gene of T. lestoquardi; following extraction from blood samples, placentome, goat liver, and spleen of the fetus. The amplified DNA was sequenced afterwards and the corresponding sequence was registered under GenBank accession number MG208059. The sequence alignment showed that the products of PCR had a homology of 99% to known T. lestoquardi sequence registered under accession numbers of KY352037.1, KC778786.1, and JQ917458.1 in the GenBank. To our knowledge, this is a report demonstrating molecular verification of T. lestoquardi transplacental transmission in a neonatal kid of Marghoz breed of goats, its feasible role in induction of perinatal deaths and abortion in goat flocks.