30/08/06
Scientists at the Institute for Animal Health's Pirbright Laboratory
have shown that the bluetongue virus causing disease in the Netherlands
is serotype 8. This serotype has not previously been identified
in Europe.
The virus had been sent to IAH Pirbright by the European Commission,
as IAH Pirbright is the European Community Reference Laboratory
for bluetongue.
After confirming that the disease in the Netherlands was bluetongue,
the IAH Pirbright scientists worked day and night over the past
week to identify the serotype of the virus. Having eliminated that
possibility that the virus was one of the five serotypes previously
detected in southern Europe (types 1, 2, 4, 9, and 16), they developed
tests for the other 19 types.
The identification of the serotype was done by PCR tests late
on Friday night (25th August). The test involves the gene for protein
VP2 of the virus. VP2 unequivocally specifies the serotype of the
virus. The PCR result was confirmed by sequencing most of genome
segment 2 of the virus, on Saturday (26thAugust).
Professor Philip Mellor, Head of the European Community Reference
Laboratory (CRL) for bluetongue said "The isolation of a bluetongue
virus serotype new to the region, by Professor Peter Mertens' group
at Pirbright, within only eight days of receipt of the first infected
sheep material from the Netherlands, is an astonishing feat." This
was achieved not only by round-the-clock working but also by the
application of modern diagnostic tests that had been developed
at Pirbright. These tests focussed on detecting and sequencing
the genes of the bluetongue virus (BTV). This was much faster than
the older methods used to identify previous BT outbreaks in southern
Europe, which took three to four weeks.
Typing of the virus is important in tracking where the BTV-8 virus
came from. The results show that the Dutch isolate is NOT descended
from vaccine forms of the bluetongue virus that have been used
in many parts of southern Europe including Bulgaria, Italy, Corsica,
Spain, and also in South Africa, in recent years. The gene sequence
data points to an origin in sub-Saharan Africa.
The initial infected sheep material was received from The Central
Institute for Animal Disease Control, CIDC-Lelystad, Wageningen
UR, The Netherlands.
Bluetongue prevention measures stepped
up
Bluetongue disease confirmed in
Belgium and Germany
Both
endemic and new virus strains to blame for bird flu recurrence
Lazonby Working Sheep Dog Sale |