CHARACTERIZATION OF MANGE MITES AND DERMATOPHYTES IN DOMESTIC ANIMALS OF DISTRICT CHITRAL

Abstract

Mange mites and dermatophytes (commonly referred to as ringworm) are major problems in veterinary medicine. In Pakistan, mange infestation is reported in domestic animals at lower elevations but higher altitudes were not explored previously, while in case of animal dermatophytosis data is lacking throughout the country. Therefore, the present study was designed to characterize mange mites and dermatophytes in domestic animals of district Chitral. Five villages (Kuju, Kaghozi, Mori, Baleem and Sorlaspur) of district Chitral were surveyed during summer (June-July 2012) and winter (December 2012-January 2013) for collection of data and skin scrapings. The mange was diagnosed from skin scrapings by microscopic examination of mites. In total, 6007 animals (2753 sheep, 2033 goats, 1087 cattle and 134 dogs) were investigated during the surveys, among them 55 animals (44 sheep (1.59%), 7 goats (0.34%) and 4 dogs (2.98%)) were diagnosed with mange. Psoroptes ovis (sheep) and Sarcoptes scabiei (sheep, goats and dogs) were the two species of mites identified in microscopy from skin scrapings. The risk factor analysis was carried out separately for livestock species (sheep/goats) and dogs through Chi-square. In Kaghuzi and Sorlaspur less infection was observed as compared to other villages (p<0.05). The infection was higher in sheep than goats, and less than one year age group was more susceptible for mange (p<0.05). A clear trend of higher infection in winter and lower in summer was recorded (p<0.05). Gender, herd size, and herd composition were not significant risk factors for mange (p>0.05). The molecular characterization of Sarcoptes scabiei was carried out by using nine microsatellite markers viz, Sarm 33, 35, 36, 37, 38, 40, 41, 44 and 45 specific to Sarcoptes scabiei. These markers were used to genotype xix individual mites from different host species. Sarcoptes mites from dog and lynx of district Chitral, Pakistan were jointly analyzed with mites collected from different hosts during previous studies from six different countries. Eight private alleles were detected in Sarcoptes mites from dogs and one private allele was detected from mites derived from lynx of district Chitral, Pakistan. The Bayesian cluster analysis in STRUCTURE software proposed five populations of Sarcoptes scabiei from studied mites. The results showed the existence of distinct dog and lynx derived Sarcoptes scabiei populations from district Chitral, Pakistan. The study demonstrated high host specificity in Sarcoptes mites and lack of gene flow between mites from different hosts. In order to characterize dermatophytes skin scrapings were analyzed by microscopy and real-time PCR. At microscopy, samples from 18 cows (1.66%), 4 goats (0.20%) and 3 sheep (0.11%) were positive for fungal elements consistent with Trichophyton verrucosum. Real-Time PCR confirmed the results of microscopy that Trichophyton verrucosum being the only dermatophyte involved. The prevalence was lower in summer as compared to winter (p value<0.05). The infection was more prevalent in young animals (< 1year) and mix herds (p>0.05). There was no significant difference in the prevalence of infection in different villages (p>0.05). The gender and herd size had no association with the disease. The significant risk factors in generalized linear model for Trichophyton verrucosum livestock were cattle, young animals (<1 year age group), winter season and mix herds. This study reports for the first time, the presence of Trichophyton verrucosum in livestock of Pakistan. A better knowledge of the animal role in the spread of this fungus to humans may allow the adoption of more efficient control measures and prophylaxis.