Browsing by Author "Buckle K"

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    Detection of Foot-and-Mouth Disease Virus in the Absence of Clinical Disease in Cattle and Buffalo in South East Asia
    (Frontiers Media S.A., 2021-07-23) Buckle K; Bueno R; McFadden A; van Andel M; Spence R; Hamill C; Roe W; Vallee E; Castillo-Alcala F; Abila R; Verin B; Purevsuren B; Sutar A; Win HH; Thiha M; Lwin KO; Khounsy S; Phonthasy S; Souriya V; Keokhamphet C; Arzt J; Ludi A; Mioulet V; Capozzo AV
    Foot-and-mouth disease virus (FMDV) is widespread throughout much of the world, including parts of South East Asia. Surveillance is often limited in endemic areas, relying predominantly on passive outbreak reporting. As part of the World Organisation for Animal Health (OIE)'s South East Asia and China Foot-and-Mouth Disease Project (SEACFMD), field sampling was performed to help understand evidence of widespread virus exposure observed in previous studies. Serum and dry mucosal swabs were collected to evaluate the presence of FMDV RNA on the nasal, oral, and dorsal nasopharyngeal mucosal surfaces of 262 healthy cattle (n = 84 in Laos; n = 125 in Myanmar) and buffalo (n = 48 in Laos; n = 5 in Myanmar) immediately following slaughter in three slaughterhouses. Swabs and serum were tested by the OIE/FAO World Reference Laboratory for foot-and-mouth disease (WRLFMD) using pan-serotypic real-time reverse transcription-PCR (rRT-PCR) and serum was evaluated using the FMD PrioCHECK non-structural protein (NSP) ELISA. In total, 7.3% of animals had detectable FMDV RNA in one or more of the three sites including 5.3% of nasopharyngeal swabs, 2.3% of oral swabs, and 1.5% of nasal swabs. No FMDV RNA was detected in serum. Overall, 37.8% of animals were positive for NSP antibodies, indicating likely past natural exposure to FMDV. Results were comparable for Laos and Myanmar, and for both cattle and buffalo, and were not significantly different between age groups. Detectable FMDV RNA present on the oral and nasal mucosa of clinically-healthy large ruminants in Laos and Myanmar demonstrates the importance of sampling asymptomatic animals as part of surveillance, and may indicate that subclinical infection plays a role in the epidemiology of FMD in these countries.
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    Investigation of post-vaccinal canine distemper involving the Rockborn-like strain in nine puppies in New Zealand
    (Taylor and Francis Group on behalf of the New Zealand Veterinary Association, 2025-04-09) Gulliver E; Taylor H; Eames M; Chernyavtseva A; Jauregui R; Wilson A; Bestbier M; O’Connell J; Buckle K; Castillo-Alcala F
    Case history: This report details investigations into nine cases of neurological disease and/or sudden death in 8–13-week-old puppies between 2021 and 2024. Aside from two pairs of littermates, cases were unrelated. The puppies had an onset of clinical signs 9–23 days following at least one “on-label” dose of a commercially available quadrivalent vaccine containing live attenuated canine distemper virus (CDV). Clinical findings: Eight of the nine cases displayed signs typical of “classic distemper,” including seizures, circling, tremors, hypersalivation, progressive neurological deficits, pyrexia, and/or respiratory and gastrointestinal signs. Pathological and molecular investigations were undertaken in eight cases. Mononuclear/lymphohistiocytic encephalitis or meningoencephalitis with or without neuronal intranuclear inclusion bodies was present in seven cases. Five cases had bronchopneumonia. Other lesions included poliomyelitis, necrotising enteritis and myocardial necrosis or myocarditis. PCR for CDV was positive on tissues from seven cases, and immunohistochemistry for CDV was positive on neural tissues in six cases. Whole genome sequencing of PCR amplicons demonstrated a Rockborn-like strain with 99.9% homogeneity between samples from four cases and a vial of vaccine. Diagnosis: Based on the combination of case history, pathological findings, molecular test results and/or whole genome sequencing, a diagnosis of post-vaccinal canine distemper was confirmed in six cases and presumed in two. Clinical relevance: Outbreaks of canine distemper have been stemmed by widespread vaccination starting in the mid-twentieth century. Consequently, confirmed cases of natural CDV have not been reported in New Zealand since an outbreak in the 1980s, and CDV is considered a “notifiable organism” as per the Biosecurity Act 1993. This is the first case series to report genomic investigation of post-vaccinal canine distemper in New Zealand puppies and highlights a rare adverse event associated with routine vaccination. Our results suggest that puppies with neurological, respiratory and/or gastrointestinal disease with an onset within 6 weeks of vaccination with live attenuated CDV should be reported and investigated accordingly.