Bovine Ephemeral Fever(Three Day Sickness)

By

Mujahid Hussain

Hosts

It is a acute arthropod-borne viral disease of Cattle and Water Buffalo that is seen in Africa, the Middle East, Australia and Asia.

Inapparent infections can develop in Cape buffalo, hartebeest, waterbuck, wildebeest, deer, and possibly goats.

Low levels of antibody have been recorded in several other antelope species and giraffe, but the specificity has not been confirmed.

Etiology

Rhabdoviridae => Ephemerovirus => Bovine ephemeral fever virus (BEFV)

BEFV is: Ether sensitive Inactivated at pH below 5 and above 10

BEFV can be transmitted from infected to susceptible cattle by IVinoculation; as little as 0.005 mL of blood collected during the febrile stage is infective.

No transmission by contact or fomites The virus does not appear to persist in recovered cattle, which often have

a lifelong immunity.

Epidemiology

The prevalence, geographic range, and severity of the disease vary fromyear to year, and epidemics occur periodically. During epidemics, onset is rapid; many animals are affected within days or 2–3 wk. Bovineephemeral fever is most prevalent in the wet season (whenconditions favor multiplication of biting insects); it disappears abruptly inwinter.

Morbidity may be as high as 80%. Overall mortality is usually 1–2%.

Clinical Findings

Biphasic to polyphasic fever (40-42°C [104–107.6°F]), shivering, inappetence, lacrimation, serous nasal discharge, drooling, increased heart rate, tachypnea or dyspnea, atony of forestomachs, depression, stiffness and lameness, and a sudden decrease in milk yield.

Affected cattle may become recumbent and paralyzed for 8 hr to >1 wk. After recovery, milk production often fails to return to normal levels until the next lactation. Abortion, with total loss of the season's lactation, occurs in ~5% of cows pregnant for 8–9 mo.

Bulls, heavy cattle, and high lactating dairy cows are the most severely affected, but spontaneous recovery usually occurs within a few days (that’s why called Three Day Sickness). More insidious losses may result from decreased muscle mass and lowered fertility in bulls.

Lesions

Bovine ephemeral fever is an inflammatory disease. The most commonlesions include polyserositis affecting pleural, pericardial, and peritonealsurfaces; serofibrinous polysynovitis, polyarthritis, polytendinitis, andcellulitis; and focal necrosis of skeletal muscles. Generalized edema oflymph nodes and lungs, as well as atelectasis (collapse of an expanded lung), also may be present.

Diagnosis

Diagnosis is based almost entirely on clinical signs in an epidemic. Laboratory confirmation is by:

Serology Virus isolation

The neutralization test and the blocking ELISA are recommended for antibody detection and give similar results. A 4- fold rise in antibody titer between paired sera collected 2–3

weeks apart confirms infection

Treatment & Control

Complete rest is the most effective treatment, and recovering animalsshould not be stressed or worked because relapse is likely.

NSAIDs given early and in repeated doses for 2–3 days are effective. Oral dosing should be avoided unless the swallowing reflex is functional.

Antibiotic treatment to control secondary infection and rehydration with isotonic fluids may be warranted.

Attenuated virus vaccines appear to be effective but should be used onlyin endemic areas. Inactivated virus vaccines have not produced longtermprotection against experimental challenge with virulent virus and cannotguarantee lasting immunity, but they may boost the immunity produced by live virus vaccine.

The efficacy of vector control remains uncertain, because theinsect vectors have not been fully identified.

There is no evidence that people can be infected.

Overview

BEF is an acute infectious arthropod-born non contagious viral disease of cattle and water buffalo characterized by transient fluctuating fever, depression, stiffness, lameness, and rapid recovery.

Etiology: The BEF virus is a single-stranded RNA, ether-sensitive Ephemero virus of the family Rhabdoviridae

Hosts: Clinical disease has only been observed in cattle and water buffalo. All age groups of cattle are susceptible but the disease is more common in age group of 6-24 months

Transmission: BEF virus is transmitted by several species of culicoides and mosquitoes. Viral development in the insect is suspected to be cyclic. Spread by wind-born carriage of vector is possible.

Key Signs: In cattle and buffalo, there is an incubation period 2-4 days and sometimes longer up to 10 days, and the course 3-5 days. Clinical signs include sudden onset of fever (41-42°C) which usually biphasic or polyphasic, shivering, inappetence, depression, lacrimation, serous nasal discharge, salivation, and lactation may decline suddenly or completely in dairy cows. Signs of stiffness and lameness typically occur on the second day of the disease. Some affected cattle may become recumbent and paralyzed for 8 hours to more than 1 week,

Treatment: A palliative treatment is possible with non-steroidal anti-inflammatory for several days as early as possible.

Thanks For Your

Attention!