Genetic diversity of Newcastle disease virus in Pakistan: a countrywide perspective.

BACKGROUND: Newcastle disease (ND) is one of the most deadly diseases of poultry around the globe. The disease is endemic in Pakistan and recurrent outbreaks are being reported regularly in wild captive, rural and commercial poultry flocks. Though, efforts have been made to characterize the causative agent in some of parts of the country, the genetic nature of strains circulating throughout Pakistan is currently lacking. MATERIAL AND METHODS: To ascertain the genetics of NDV, 452 blood samples were collected from 113 flocks, originating from all the provinces of Pakistan, showing high mortality (30-80%). The samples represented domesticated poultry (broiler, layer and rural) as well as wild captive birds (pigeons, turkeys, pheasants and peacock). Samples were screened with real-time PCR for both matrix and fusion genes (1792 bp), positive samples were subjected to amplification of full fusion gene and subsequent sequencing and phylogenetic analysis. RESULTS: The deduced amino acid sequence of the fusion protein cleavage site indicated the presence of motif (112RK/RQRR↓F117) typical for velogenic strains of NDV. Phylogenetic analysis of hypervariable region of the fusion gene indicated that all the isolates belong to lineage 5 of NDV except isolates collected from Khyber Pakhtunkhwa (KPK) province. A higher resolution of the phylogenetic analysis of lineage 5 showed the distribution of Pakistani NDV strains to 5b. However, the isolates from KPK belonged to lineage 4c; the first report of such lineage from this province. CONCLUSIONS: Taken together, data indicated the prevalence of multiple lineages of NDV in different poultry population including wild captive birds. Such understanding is crucial to underpin the nature of circulating strains of NDV, their potential for interspecies transmission and disease diagnosis and control strategies.

Prevalence of different tick species on livestock and associated equines and canine from different agro-ecological zones of Pakistan.

Ticks are ectoparasites that act as vectors for transmission of various pathogens to wild and domesticated animals and pose a serious threat to human health. Because of the hot and humid conditions in different agro-ecological zones of Pakistan, ticks are abundant and parasitize a variety of animals. The aim of this study was to identify different tick species and distribution on different hosts especially livestock, such as sheep, goat, cattle, buffalo, and camel, and livestock associated canines and equines, such as horse, donkey, and dog, across different agro-ecological zones of Pakistan. The ticks samples were collected and morphologically identified at genus and species level using morphological keys under stereomicroscope. A total of 2,846 animals were examined for the tick infestation, and 408 animals were tick-infested. Eleven tick species belonging to 4 genera were identified: Hyalomma anatolicum, Hyalomma scupense, Hyalomma dromedarii, Hyalomma isaaci, Rhipicephalus microplus, Rhipicephalus haemaphysaloides, Rhipicephalus turanicus, Haemaphysalis cornupunctata, Haemaphysalis montgomeryi, Haemaphysalis bispinosa, and Ixodes kashmiricus. The overall tick prevalence was 14.3%; host-wise infestation rate was 12.2% in sheep; 12.6%, goat; 11.7%, buffalo; 11.7%, cattle; 19.6%, camel; 27.4%, donkey; 23.5%, horse; and 24.3%, dog. Tick infestation of different animals differed on the basis of the zones. Camels showed the highest tick infestation rate in zones 1 and 2 (21.4 and 26.7%, respectively), whereas donkeys showed the highest infestation rate in zones 3, 4, 6, and 7 (25, 39.3, 3.3, and 21.4%, respectively). The infestation rates of Hyalomma and Rhipicephalus were the highest in zone 2 (71.4 and 52.9%, respectively). The infestation rate of Hyalomma was the highest (47.4%) in sheep; Haemaphysalis (46.9%), goat; Rhipicephalus (69.7%), buffalo; Rhipicephalus (62.3%), cattle; Hyalomma (70%), camel; Ixodes (60.9%), donkey; Ixodes (75%), horse; and Rhipicephalus (61.1%), dog. This study showed the diversity and infestation rate of different ticks with respect to their hosts and agro-ecological zones of Pakistan. High tick burdens and infestation rates are responsible for the spread of different tick-borne infections, resulting in loss of animal productivity and posing a threat to animal and human health. Understanding different tick species and their distribution across different zones will be helpful for developing efficient control strategies against different tick born infections.

Tick-borne Diseases in Sheep and Goats in Pakistan: A Systematic Review and Meta-analysis.

BACKGROUND: Ticks are blood-sucking ectoparasites and transmit various types of protozoal, bacterial, and viral diseases in a wild as well as domestic animals and humans globally. Only a few  published reports are avaliable on the prevalence of tick-borne diseases in sheep and goats in Pakistan. AIM AND OBJECTIVE: The aim of this systematic review and meta-analysis was to evaluate the prevalence (2000-2020) of tick-borne disease (theileriosis, babesiosis, Crimean-Congo hemorrhagic fever infection, and anaplasmosis) in sheep and goats in Pakistan. METHODS: A systematic review of articles published in English language (since 2000-2020) was conducted using PubMed and Google Scholar. Diagnostic methods used in the original reference articles were PCR, PCR-RLB, microscopy, and ELISA. RESULTS: The overall prevalence of theileriosis, babesiosis, anaplasmosis, and Crimean-Congo hemorrhagic fever (CCHF) infections was 15.40%, 21.18%, 26.78%, and 11.62%, respectively. The prevalence of anaplasmosis was 22.06% (90/408) in sheep, 21.11% (76/360) in goats, and 40% (120/300) in both sheep and goats with substantial differences (P < 0.001). The prevalence of babesiosis among sheep was 29.88% (104/348) with highly significant differences (P < 0.001), in goats was 29.88% (25/60) with slightly significant differences (P < 0.031%), and in both sheep and goats were 7% (21/300) with highly significant differences (P < 0.001) according to subgroup analysis. The percentage of prevalence of theileriosis was 17.70% (207/1169) in sheep with highly substantial differences (P < 0.001), 4.51% (31/687) in goats with significant differences (P < 0.133), and 25% (125/500) in both sheep and goats with a significant difference among them (P < 0.001). The prevalence of CCHF among sheep was 18.63% (149/800) and 4.63% (37/800) in goats, respectively. The widely used detection method was microscopy (45.56%) followed by ELISA (38.38%), PCR (12.56%), and PCR-RLB (3.48%) test, respectively. This is a comprehensive report on the status of tick-borne disease in sheep and goats in Pakistan. CONCLUSION: Based on our results, among tick-borne diseases anaplasmosis had the highest prevalence rate in sheep and goats. Due to its high prevalence, control measures should be taken to diagnose and prevent it.