Buffalopox

Ashok Boora, Sarita Yadav, KP Singh

Buffalopox (BPX) is a contagious viral zoonotic disease primarily of domestic buffalo (Bubalus bubalis) characterized by disseminated pustular skin lesion mostly on the skin of udder, teat, medial aspect of thigh, inguinal region, base and inner surface of ear and eye. Disease occurs in two forms namely mild and severe. Lesions are localized in mild form whereas in severe form, which is uncommon, lesions are generalized. The secondary bacterial infection leads to concurrent otitis, conjunctivitis, mastitis as a complication of disease imposing significant economic losses in terms of reduced milk yield up to 50-80% in addition to reduction in working capacity of draft animal.

Etiology

BPX virus is classified in the family poxviridae under the genus Orthopox virus. It is still debatable whether BPXV is a buffalo adapted Vaccinia Virus (VACV) used by Edward Jenner in 1798 for vaccination against human smallpox or original virus.

Transmission

Infection is carried from animal to animal through close contact with lesion, contaminated milker’s hand, milking machine (teat cup) and mechanical transmission by biting flies.

Symptoms

Incubation period of the disease is 2-5 days. Typical pock lesions with raised edges on the skin of udder, teat, medial aspect of thigh, inguinal region, base and inner surface of ear and eye. The lesion passes through five stages during the course of the disease as follows:

Stage I – Roseolar stage (diffuse redness on the skin)

Stage II – Papular stage (elevated hard area on skin)

Stage III – Vesicular stage (exudate enters in raised area)

Stage IV – Pustular stage (pus formation)

Stage V – Desquamative stage (crust or scab formation)

Course of the disease is two to three weeks.

Distribution

Since first reported in 1934 in Lahore (India), disease has been reported mainly  sporadically and occasionally in epidemic form from various states of India including Haryana, Uttar Pradesh, Madhya Pradesh, Tamilnadu, Maharashtra, Karnataka, Andhra Pradesh, Gujrat and Rajsthan. Outbreaks have been recorded from many parts of the world including Egypt, Indonesia, Italy and Indian subcontinent.

Zoonotic Importance

BPX is an infectious Zoonotic disease primarily affecting the buffaloes and occasionally human and cows. In humans, disease is characterized by fever, axillary lymphadenopathy malaise and localized pock like lesions on hand, finger, face and legs. Incubation period in humans, 3-19 days, is comparatively longer than buffaloes.

Treatment and control

BPX is a self-limiting disease with a course of two to three weeks but the secondary bacterial infection leads to productive losses in terms of mastitis.

  • Segregation of affected and in contact animals from apparently healthy animals.
  • Separate arrangement for milking of infected animals by separate attendants.
  • Cleaning of pox lesions with potassium permanganate (1:1000) to inactivate the virus.
  • Topical application of antiseptic ointment like boric acid (1:10) or broad spectrum antibiotic ointment on lesion to curtain secondary bacterial infection.
  • Use of teat dips/ antiseptic lotion.
  • Treatment is symptomatic without any specific therapy.

Collection of sample

Scab/ crust, skin scrapings and vesicular fluid in sterile 50% buffered glycerol saline (pH7.4) with added antibacterial and antifungal antibiotics like penicillin, neomycin, polymixin and mycostatin. Keep sample on ice or frozen refrigerated packs in an insulated box for transportation to laboratory. Store the samples at -20 to -70 c for future use. Collect Paired sera samples (4ml) at a gap of 21 days, 1st at the onset of disease and 2nd after recovery from the disease.

Diagnosis

  1. a)Clinical sign: Typical pock like skin lesions.
  2. b)Laboratory confirmation of agent:
  • Virus isolation: Embryonated chicken egg inoculation through chorio- allantoic membrane (CAM) route or characteristic cytopathic effect (CPE) on Vero cell lines.
  • Electron microscopy: Brick shaped Virion.
  • Serological test to detect specific antigen and antibody against BPXV:
  1. Counter immuno-electrophoresis (CIE)
  2.  Serum neutralization test (SNT)
  3. Agar gel immuno diffusion (AGID)
  4. ELISA
  • Molecular techniques: Polymerase chain reaction (PCR)