Unusually High Mortality in Waterfowl Caused by Highly Pathogenic Avian Influenza A(H5N1) in Bangladesh.

Mortality in ducks and geese caused by highly pathogenic avian influenza A(H5N1) infection had not been previously identified in Bangladesh. In June-July 2011, we investigated mortality in ducks, geese and chickens with suspected H5N1 infection in a north-eastern district of the country to identify the aetiologic agent and extent of the outbreak and identify possible associated human infections. We surveyed households and farms with affected poultry flocks in six villages in Netrokona district and collected cloacal and oropharyngeal swabs from sick birds and tissue samples from dead poultry. We conducted a survey in three of these villages to identify suspected human influenza-like illness cases and collected nasopharyngeal and throat swabs. We tested all swabs by real-time RT-PCR, sequenced cultured viruses, and examined tissue samples by histopathology and immunohistochemistry to detect and characterize influenza virus infection. In the six villages, among the 240 surveyed households and 11 small-scale farms, 61% (1789/2930) of chickens, 47% (4816/10 184) of ducks and 73% (358/493) of geese died within 14 days preceding the investigation. Of 70 sick poultry swabbed, 80% (56/70) had detectable RNA for influenza A/H5, including 89% (49/55) of ducks, 40% (2/5) of geese and 50% (5/10) of chickens. We isolated virus from six of 25 samples; sequence analysis of the hemagglutinin and neuraminidase gene of these six isolates indicated clade 2.3.2.1a of H5N1 virus. Histopathological changes and immunohistochemistry staining of avian influenza viral antigens were recognized in the brain, pancreas and intestines of ducks and chickens. We identified ten human cases showing signs compatible with influenza-like illness; four were positive for influenza A/H3; however, none were positive for influenza A/H5. The recently introduced H5N1 clade 2.3.2.1a virus caused unusually high mortality in ducks and geese. Heightened surveillance in poultry is warranted to guide appropriate diagnostic testing and detect novel influenza strains.

Identification and epidemiology of a rare HoBi-like pestivirus strain in Bangladesh.

The genus pestivirus of the family flaviviridae consists of four recognized species: bovine viral diarrhoea virus 1 (BVDV-1), bovine viral diarrhoea virus 2 (BVDV-2), classical swine fever virus and border disease virus. A new putative pestivirus species tentatively named as either 'HoBi-like pestivirus' or BVDV-3 has recently been identified in Brazil, Italy and Thailand. Despite reports of serological evidence of BVDV in Bangladesh, the types of the virus circulating in cattle have not been identified. We conducted surveillance in cattle from May 2009 to August 2010 in three government veterinary hospitals to characterize BVDV in cattle of Bangladesh. We tested serum for BVDV using an antigen-capture ELISA. Of 638 cattle samples, 3% (16/638) tested positive for BVDV antigen. The ELISA-positive samples were selected for further molecular detection and characterization of BVDV. Molecular analysis of the partial 5' untranslated region (UTR) nucleotide sequences of BVDV-positive samples identified the rare HoBi-like pestivirus or BVDV-3 virus circulating in cattle of Bangladesh. The identification of this rare HoBi-like pestivirus or BVDV-3 strain in Bangladesh warrants further surveillance to evaluate its impact on livestock production.

The isolation of exotic Newcastle disease (END) virus from nonpoultry avian species associated with the epidemic of END in chickens in southern California: 2002-2003.

During the first 11 months of the 2002-2003 exotic Newcastle disease (END) epidemic in chickens in southern California, a total of 27,688 cloacal and tracheal (oropharyngeal) swab pools and/or tissue pools from 86 different avian species other than chickens and turkeys were submitted for Newcastle disease virus (NDV) isolation and characterization. Fifty-seven specimens (0.23%), representing 12 species of birds and 13 unspecified species, from a total of 24,409 accessions or submissions were positive for NDV. The NDV isolate was characterized as ENDV by real-time reverse transcription-polymerase chain reaction (RT-PCR). Of the 11,486 premises with other avian species, 1599 also had chickens. There were 1900 positive chicken samples from 164 premises, and 56 positive other avian species from 51 premises. Twelve premises had both positive chickens and positive other avian species. All positive other avian species were located on premises either on or within a 1 km radius of known infected premises. In this epidemic, premises with positive other avian species were significantly more likely to have chickens, and were significantly more likely to have positive chickens (OR = 3.7, P < 0.0001).

Evaluation of North American antibody detection tests for diagnosis of brucellosis in goats.

The sensitivities and specificities of 17 antibody detection tests for brucellosis in goats were estimated. Tests evaluated included the U.S. Department of Agriculture (USDA) card test with 8% cell concentration (8%Card), USDA rapid automated presumptive test (RAP), Mexican rose bengal plate tests with 8 and 3% cell concentrations (8%RB and 3%RB), French rose bengal plate test with 4.5% cell concentration (4.5%RB), USDA standard plate test (SPT), USDA buffered acidified plate agglutination test (BAPA), USDA and Mexican rivanol tests (URIV and MRIV), USDA standard tube tests with Brucella abortus and Brucella melitensis antigens (SATA and SATM), serum enzyme-linked immunosorbent assay (ELISA), USDA cold-fixation complement fixation tests with B. abortus and B. melitensis antigens (CFA and CFM), USDA and Mexican milk ring tests (UBRT and MBRT), and a milk ELISA. Test sensitivity was evaluated by using two groups of 10 goats experimentally infected with B. melitensis or B. abortus and monitored for 24 weeks. Specificity was evaluated by using 200 brucellosis-free nonvaccinated goats from 10 California herds. The 3%RB was considered a good screening test because of high sensitivity at week 24 postinfection (90%), ease of performance, and low cost. The cold-fixation CFA and CFM had 100% specificity in the field study and were considered appropriate confirmatory tests. The milk ELISA was significantly more sensitive (P < 0.05) than the UBRT and significantly more specific (P < 0.05) than the MBRT. The milk ELISA also had the advantage of objectivity and ease of interpretation.

Risk factors for brucellosis seropositivity of goat herds in the Mexicali Valley of Baja California, Mexico.

A case-control study was conducted in the Mexicali Valley to identify risk factors for goat-herd seropositivity for Brucella melitensis. Nineteen case herds (> or = 2 positive results with the 8% rose bengal plate test (RBT)) and 55 control herds (zero positive results in RBT), matched for herdsize and geographic location, were enrolled. Conditional logistic regression was used to construct a multivariable model of the odds of seropositivity using variables assessed in a questionnaire administered to goat ranchers. The final model for herd seropositivity included increased risk from importation of goats from other Mexican states, the presence of La Mancha breed does, and the presence of does born outside the herd. Increasing herdsize was also highly significant (p < 0.01). In addition, a significant (p < 0.05) positive association was found between the presence of seropositive dogs (as assessed by RBT) and seropositive goats on the same ranch.

Vaccine-induced canine distemper in European mink, Mustela lutreola.

This report describes vaccine-induced canine distemper virus (CDV) infection in four European mink (Mustela lutreola) induced by the administration of a multivalent, avian-origin vaccine. Clinical signs consisting of seizures, ataxia, facial twitching, oculonasal discharge, hyperkeratosis of footpads, and anorexia developed 16-20 days postvaccination. Conjunctival smears from one animal were positive for CDV antigen by direct fluorescent antibody testing, confirming the clinical diagnosis. The four mink died 16-26 days postvaccination. Gross and microscopic lesions that were diagnostic for CDV infection included interstitial pneumonia, lymphoid depletion, nonsuppurative encephalitis, and dermatitis. Vaccine-strain virus was isolated from tissues of three animals. Cases of vaccine-induced distemper in mustelids using avian-origin vaccine have seldom been reported.

Implementation and evaluation of a strategic parasite control program for captive exotic ungulates.

A parasite control program was designed for greater than 1,200 exotic ungulates maintained in mixed-species enclosures at the San Diego Wild Animal Park. Three strategically-timed anthelmintic treatments were given during 1988-1989, and their success was evaluated by monitoring pretreatment and posttreatment fecal egg counts. Adequate parasite control was achieved for animals in 52 ungulate species, as evidenced by low pretreatment egg counts and the absence of egg-shedding after treatment. However, animals belonging to 11 species in the subfamilies Antilopinae, Hippotraginae, and Caprinae were identified as important targets for more intensive control efforts because they shed either greater than 100 eggs/g of feces before treatment, or greater than 0 eggs/g after treatment, at 2 or more sampling periods. These results and observations were used to generate management recommendations and illustrate how a model parasite control program can be developed for collections of exotic ungulates.