See also: 9 May 2003, 25 April 2003, 7 February 2003, 24 January 2003, 17 January 2003, 10 January 2003, 3 January 2003, 29 November 2002, 22 November 2002, 8 November 2002, 1 November 2002, 25 October 2002, 18 October 2002, 4 October 2002

Emergency report

Information received on 11 April 2003 from Dr Peter Fernandez, Associate Administrator, Animal and Plant Health Inspection Service, United States Department of Agriculture (USDA), Washington, DC:

Report date: 10 April 2003.

Nature of diagnosis: clinical and laboratory.

Date of initial detection of animal health incident: 26 September 2002.

Estimated date of first infection: 19 September 2002.

Outbreaks:

Location	No. of outbreaks
El Paso County, State of Texas (in the Western part of the State)	1

Description of affected population: Newcastle disease has been confirmed in backyard birds (164 birds) in El Paso county, Texas, which is outside the current quarantine area.

Quarantined backyard flocks (infected and/or dangerous contacts) by county in Texas: El Paso (9); an additional 15 premises within a 1-km-radius zone around the positive premises are also quarantined and will be depopulated.

The affected establishment in Texas is situated in El Paso county, approximately 25 km east of New Mexico. Due to potential contact with other backyard birds traced to adjacent counties in New Mexico, the adjacent counties of Otero, Dona Ana and Luna in New Mexico have also been placed under State and Federal quarantine while the investigation is under way.

Total number of animals in the outbreak:

species	susceptible	cases	deaths	destroyed	slaughtered
avi	...	...	...	approx. 456	0

Diagnosis:

A. Laboratory where diagnosis was made: National Veterinary Services Laboratories, Ames, Iowa.

B. Diagnostic tests used: virus isolation, the virus was found to have multiple basic amino acids at the fusion (F) protein cleavage activation site: arg. arg. glu. lys. arg* phe, a sequence compatible with that of mesogenic/velogenic pathotypes.

The sequence of the Texas APMV-1 is compatible with its classification as exotic Newcastle disease virus (ENDV). The sequence at the cleavage site of the fusion protein gene is RRQKR/F, which is identical with that found in the CA, NV and AZ isolates of ENDV. The nucleotide sequence of the 180 bp segment flanking the cleavage site is 100% identical with the CA, NV and AZ isolates of exotic Newcastle disease virus.

C. Causal agent: paramyxovirus type-1.

Epidemiology:

A. Source of agent / origin of infection: molecular epidemiology and phylogenetic analysis show the southern California isolate to be very closely related to the exotic Newcastle disease virus isolated in northern Mexico during the outbreak that occurred in that country in 2000.

B. Mode of spread: direct contact, fomites.

C. Other epidemiological details:

- Quarantine and depopulation of the confirmed positive premise (1) and dangerous contact premises (8) have been completed. All 456 birds on these premises were destroyed.

- The State of Texas has placed quarantine orders on all backyard premises within a 1-km radius of the positive premises. All backyard flocks found within the 1-km radius will be depopulated.

- The State of Texas has further issued quarantine for the entire counties of El Paso and Hudspeth.

- To date, no other raised mortality in backyard birds has been documented and there is no evidence of further clinical infection. Epidemiological investigations and intensified surveillance are ongoing to determine if there has been any spread of the disease.

Control measures:

- quarantine of affected backyard premises and dangerous contacts.

- Movement control inside the country.

- Stamping out.

- Screening.

- Zoning.

Note from the OIE Central Bureau: Since this is the first occurrence of Newcastle disease in the State of Texas, within the context of the current epizootic, the OIE Central Bureau has decided to publish the above emergency report despite our previous note (see Disease Information, 16 [4], 24, dated 24 January 2003) to the effect that no further cases of Newcastle disease in the United States of America reported to the OIE within the context of this epizootic would be notified in Disease Information.

Source: OFFICE INTERNATIONAL DES EPIZOOTIES - 18th April 2003