Koi herpesvirus disease outbreak: Input for the implementation of a surveillance program in South Tyrol - Italy.

A severe episode of high and abnormal mortality was observed in the population of Cyprinus carpio of Lake Caldaro (South Tyrol, Italy) in summer 2016. The diagnostic investigation carried out led to the identification of Koi Herpesvirus (KHV) as the etiologic agent. Following this disease outbreak and its socio-economic consequences, the local authorities, in agreement with the local Fishing Association, decided to implement a surveillance program for the achievement of KHV-free health status (Category I) in the Province, in accordance to the Implementing Decision (EU) 2015/1554. The selected area was a defined geographical compartment (the Monticolo lakes compartment, South Tyrol, Italy), which is located near Lake Caldaro, where the Koi Herpesvirus disease (KHVD) outbreak had occurred. This area is of particular interest because it supplies other water bodies with juvenile C. carpio individuals; with the achievement of a KHV-free health status, South Tyrol could possibly become independent in the breeding of this fish species. Suitable samples were collected and processed during a two-year period in order to detect the presence/absence of KHV. The same samples were tested for other viruses that can affect carp, namely spring viraemia of carp (SVCV) and carp edema virus (CEV). According to the results, the authors conclude that the Monticolo lakes area should be classified as KHV-free, as no sample has tested positively for the presence of this specific virus (KHV).

Achievements of an eradication programme against caprine arthritis encephalitis virus in South Tyrol, Italy.

Small ruminant lentivirus infections in goats affect both production and animal welfare. This represents a threat to the qualitative and quantitative growth of goat farming, recently observed in mountainous regions such as the Autonomous Province of Bolzano - South Tyrol (Italy). To monitor and eradicate the caprine arthritis encephalitis virus in this goat population, a compulsory eradication campaign was launched, based on a strict census of small ruminants and yearly serological testing of all animals, followed by the consequent culling of seropositive individuals. The campaign succeeded in completely eliminating cases of clinical disease in goats, while drastically reducing the seroprevalence at the herd as well as individual animal level. The serological outcome of the introduced control measures was determined using commercially available ELISA kits, demonstrating their suitability for use in this type of campaign, aimed at reducing seroprevalence as well as clinical manifestations of these infections. However, this clear success is diminished by the failure to achieve a complete eradication of these viruses. The reasons leading to the observed tailing phenomenon and the occurrence of new infections in already sanitised flocks are discussed and implementation of further measures are proposed.

[Retrospective evaluation of data over five years of the BVDV prevention program using ear notch samples from the autonomous province of Bolzano (Italy)]. / Retrospektive Auswertung von Daten über fünf Jahre BVDV-bekämpfungsprogramm mittels Ohrgewebeproben in der Autonomen Provinz Bozen (Italien).

In 2005 the Autonomous Province of Bolzano implemented a BVD-Virus control programme by testing all newborn calves for Bovine Viral Diarrhoea Virus (BVDV) antigen by analysing ear notch samples. In eradication programs between November 2005 and October 2010 a total of 344,108 newborn calves were ear notch sampled and analysed for BVDV by an antigen ELISA detecting the E(rns) (HerdCheck BVDV Antigen/Serum Plus, Idexx Laboratories, Switzerland). The tissue samples were collected during calf ear tagging (within the first 20 days of life) using two sampling devices (TypiFix-System, Agrobiogen GmbH [Germany] and Allflex [France]). 0.4% (1400) of the collected samples showed a positive result, and of these, 583 calves were subjected to a follow-up examination, analysing the samples again by ELISA as well blood samples by Reverse transcriptase-PCR. Blood samples were also collected from the dam, if still present on the farm by the time of sampling. These results suggest that a BVDV control programme testing all newborn calves sampled for BVDV antigen by analysing an ear notch sample in principle is practicable. However, due to the low positive predictive value (75%) of the E(rns)-ELISA used, not all persistently infected calves can be detected.