Undiagnosed febrile disease, bovine - Israel: RFI

International Society for Infectious Diseases
<http://www.isid.org>

Date: Wed 13 Sep 2006

Since 4 Sep 2006, an hitherto undiagnosed syndrome has been observed
in cattle herds within the Jordan Rift Valley, which is a small part
of the 6500-km-long Syrian-East African Rift. The affected area
extends from the Arava valley south of the Dead Sea, northwards along
the Jordan river, the Tiberias Lake (Sea of Galilee) and the Huleh
valley; see maps at

and < http://www.un.org/Depts/Cartographic/map/profile/israel.pdf>,
as well as a physical map at


The syndrome seems to be spreading from south to north, affecting, so
far, more than 30 cattle herds, most of them Israeli-Holstein dairy
cattle, several beef cattle farms and feedlots. Most of the affected
animals were older than one year.

Clinical descriptions of affected animals have become available by
the monitoring and reporting system of "Hachaklait," the country-wide
Mutual Society for Clinical Veterinary Services in Israel. As an
integral part of this service, every attending practitioner pays at
least one weekly visit to each farm within his/her practice and is
available, free of additional charge, for visits in emergency situations.

The main clinical signs were:

- Reduced milk production, anorexia, reduced rumination.
- Fever, weakness.
- Clear to purulent nasal discharge, salivation, nasal and lips
redness and scaling, tongue swelling and erosions.
- Conjunctival hyperemia, redness and edema; in some cases petechial
hemorrhages in the conjuctiva.
- Dyspnea, emphysema.
- Stiff gait, lameness, muscle tremors, recumbency.

Different farmers and vets reported different clinical signs; not all
the above clinical signs were seen on the same farm.

Duration of clinical disease: at least a week, still to be defined.

The morbidity has, so far, been 2 to 20 percent, mortality very low.

No cases have been seen in adjacent sheep and goats farms.

Based upon past occurrence of bovine ephemeral fever (BEF) in Israel
in similar geographic regions and during the same season, and in view
of the appearance of recumbency in several cases, initially BEF was
suspected. However, the clinical signs and their duration soon
appeared to differ from those of BEF; consequently, another disease
agent, most probably vector-borne, has to be considered. In fact, the
syndrome manifests clinical symptoms compatible with those described
in the literature as bluetongue or Ibaraki disease in cattle.
Laboratory investigations at the Kimron Veterinary Institute have
been initiated; so far, no results are available. Samples from
affected animals have been sent to the OIE reference laboratory for
bluetongue at the Institute for Animal Health, Pirbright Laboratory,
UK. If BTV is confirmed, its serotype needs to be defined and an
explanation sought for the current absence of clinical cases in sheep
in the affected region in Israel. If no BTV can be confirmed, another
(Orbi?) virus might be involved and should be identified.

A cattle disease with resembling characteristics was observed in
Israel in 1950. As described in the relevant paper (see further), "a
disease, similar to Blue Tongue," initially appeared at the end of
July or the beginning of August 1950, peaking in September 1950,
mainly affecting imported Austrian, American and French cattle. The
majority of confirmed cases were met with in bovines above the age of
6 months and more; none were diagnosed with certainty in calves less
than 2 months old. Generally, the disease was manifested in the
following 3 forms:

a. Typical changes in the oral cavity without dermatitis and lameness;
b. Dermatitis of the skin in the coronary region, with lameness and
hyperemia of the oral mucosa, without necrosis and ulceration;
c. dermatitis and lameness, hyperemia, necrosis and ulceration in the
oral mucosa.

Typical cases lasted 2-6 weeks; a virus was isolated in embryonated
eggs, suspected to be BTV.

Later, cases were seen in sheep as well, and a virus was isolated.
The isolate from sheep was sent to the Onderstepoort laboratory in
South Africa and identified there as a strain of bluetongue virus (BTV-4?).

References:
1. A.Komarov & L. Goldsmit (1951). A disease, similar to Blue Tongue
in cattle and sheep in Israel. Refuah Veterinarith, Vol 8, No 3, 96-100.
2. A. Komarov & D.A.Haig (1952). Identification of a strain of
bluetongue virus isolated in Israel. Jl.S.A.V.M.A. 23 (3), 153-156.

The current manifestation of clinical disease in the susceptible,
sensitive Israeli cattle may be indicative of their possible role as
sentinels for a vector-borne infection which might be circulating
throughout the region. Information on similar or relevant
observations in other countries in the Eastern Mediterranean region
and North-East Africa is requested.