Outbreak Investigation of Sheep pox in District Barkhan, Balochistan, Pakistan

Abstract

During mid-January 2018, significant number of suspected sheep pox cases was reported to Director Animal Health from district Barkhan, Balochistan. An investigation team was deployed after unusual high mortality and complaint of skin lesions accompanied by lacrimal & nasal discharge. The aim of this investigation was to know the magnitude of the disease, identify risk factors and implement preventive measures so as to stop further spread of disease. We defined a sheep pox confirmed case as sheep with fever >40˚C and necrotic skin lesions along with one or more of the following: Papules, nodules anywhere on the body, Mucopurulent nasal discharge, hyperemia, oedema (generalized), swollen eyelids and enlarged prescapular lymph node. By using pre tested questionnaire rates and frequencies were calculated using Epi InfoTM 7 Software. A case control study was conducted in March 2018.  During active case finding, 43 farms qualified as suspected for sheep pox infection with a total infected population of 4050 animals. Of these, infected adult sheep comprised 76% (3081), followed by 24% (969) lambs. The case fatality rate was 33% (1337/4050) with an overall attack rate of 55% (4050/7438). Majority 49% (21) responded that wool shearing within a flock was done, 42% (18) introduced new animals in a flock without prior quarantine but only 5% (2) were aware of isolation and 21% (9) vaccinate the animals. New animals with in flocks (OR: 3.7, CI 1.34 – 10, P value 0.008) and wool shearing (OR: 3.15, Cl 1.24 – 7.9, P value 0.01) were statistically associated with disease spread. Sheep pox outbreak occurred in the area with new animal arrival, low vaccine coverage and breach in biosecurity and sanitary measure. Standard biosecurity and sanitary prophylaxis measures were recommended to control the outbreak.