Zia-ur-Rehman
AGRICULTURE is the most central sector of Pakistan’s economy that accounts for about one-fourth of the gross home product, earns about 60% of export profits in primary and managed forms, and provides employment for half of the country’s rapidly increasing labour force. The livestock share increased from less than 30 to 40%. On the other hand, keeping livestock implies another source of risk such as morbidity and mortality of animals. However, the possibility that these losses occur simultaneously with crop damages is not likely to be high except for extreme events such as a severe flood.
Infectious diseases are spread between hosts by a variety of mechanisms, including direct, airborne and vector-borne transmission. Control of animal-to-animal transmission of disease agents is a key concept in infectious disease epidemiology; however, a more practical approach might be to stop the types of contact that lead to spread the disease. In humans, it is often difficult to prevent contacts, particularly with the ease of long-distance travel .However, in livestock and animals, movements can be the subject of legislation or strict controls and there is a real opportunity to reduce disease transmission. The importance of animal movements is, of course, well understood and international regulations exist to mitigate the risks involved. In spite of these regulations, outbreaks occur regularly as a result of both legal and illegal animal movements.
Fascioliosis and fascioliasis are important neglected worldwide diseases of ruminant livestock and humans, respectively. Fasciola spp. not only causes billion of dollar production losses annually in farm animals but are also emerging food-borne zoonoses in humans according to the World Health Organization (WHO), with 2.4 million people infected and over 180 million at risk. The genus Fasciola comprises two important species, Fasciola gigantica and Fasciola hepaticaF. gigantica typically causes disease in tropical regions whereas F. hepatica is present in temperate areas. Overlap between these two species has been seen in subtropical regions, along with the presence of intermediate forms.
In this study, we describe a study using liver fluke parasites collected from cattle, buffalo, sheep and goats slaughtered in three geographically separated abattoirs in the Punjab and Balochistan provinces of Pakistan, with the following aims: (i) to confirm the species identity of recovered Fasciola spp. (ii) to identify the presence of single or multiple genotypes per infection (multiplicity of infection) and (iii) demonstrate the spread of F. gigantica mt-ND-1 haplotypes.
The species identity of liver flukes was confirmed by deep amplicon sequencing. Split and network trees of the mt-ND-1 haplotypes were examined to show the multiplicity of F gigantica infection and the patterns their spread, providing proof of concept for a novel approach to epidemiological studies of fasciolosis and fascioliasis, and validation of parasite control strategies. First time identified the hybrid of Fasciola spp in Pakistan on the basis of deep amplicon sequencing.
—The writer is associated with University of Veterinary and Animal Sciences, Lahore.
