National Reference Laboratories for Viral Hemorrhagic Septicemia (VHS) and Infectious Hematopoietic Necrosis (IHN)
Institute of Infectology
The National Reference Laboratory (NRL) is responsible for coordinating and ensuring the diagnosis of Infectious Hematopoietic Necrosis (IHN) and Viral Hemorrhagic Septicemia (VHS) based on the German regulation on fish diseases and the legislation of the European Union. IHN and VHS are notifiable fish diseases. They are included in the list of non-exotic fish diseases as part of „EU Directive 2006/88/EC on animal health requirements for aquaculture animals and products thereof, and on the prevention and control of certain diseases in aquatic animals“. The work of the NRL is based on the “Regulation on fish diseases and regulation on the modification of the regulation on notifiable animal diseases 2008“, which transposes EU directive 2006/88/EC into national legislation. The tasks are fulfilled in close cooperation with the Community reference laboratory (EU reference laboratory) and the regional diagnostic laboratories (mainly state veterinary authorities) of the federal states.
Pursuant to the regulations specified in Directive 2006/88/EC the laboratory carries out epizootiological investigations to determine the cause of various VHS and IHN outbreaks. This is done by genetic analysis of the virus isolates by sequencing of selected genome regions.
An analysis of the extent and structure of aquaculture, data on epizootiology, diagnostics and control of VHS, IHN and other fish diseases, as well as on the extent and results of laboratory investigations on viral fish diseases in Germany based on the data received from the veterinary authorities of the federal states are presented at the annual meeting of the representants of the national reference laboratories for fish diseases of the EU member states.
Main research topics and projects
- Optimization of IHN and VHS diagnostics
- Patho- and immunogenesis of IHN and VHS
- Investigations on VHS (and IHN) immunoprophylaxis
- Development and improvement of solid dosage forms for oral administration of vaccines in trout
Overview of services
Services of the NRL are offered pursuant to the regulations of Council Directive 2006/88/EC on animal health requirements for aquaculture animals and products thereof, and on the prevention and control of certain diseases in aquatic animals.
ANNEX VI of Directive 2006/88/EG: Functions and duties of laboratories
PART II National reference laboratories
1. The national reference laboratories designated pursuant to Article 56 shall be responsible for coordinating the diagnostic standards and methods within their field of responsibility in the Member State concerned. These national reference laboratories shall:
a) undertake to notify, without delay, the competent authority whenever the laboratory is aware of a suspicion of any of the diseases referred to in Annex IV;
b) coordinate, in consultation with the relevant Community reference laboratory, the methods employed in Member States for diagnosing the diseases concerned under their responsibility;
c) assist actively in the diagnosis of outbreaks of the relevant disease by receiving pathogen isolates for confirmatory diagnosis, characterisation and epizootic studies;
d) facilitate the training or retraining of experts in laboratory diagnosis with a view to harmonising diagnostic techniques throughout the Member State;
e) ensure confirmation of positive results of all outbreaks of exotic diseases listed in Part II of Annex IV, and of primary outbreaks of non-exotic diseases listed in that Annex;
f) organise periodic comparative tests (ring tests) of diagnostic procedures at national level with the laboratories designated by the Member States in accordance with Article 57, in order to provide information on the methods of diagnosis used and the results of tests carried out in the Member State;
g) cooperate with the Community reference laboratory referred to in Article 55 and participate in the comparative tests organised by the Community reference laboratories;
h) ensure a regular and open dialogue with their national competent authorities;
i) operate and be assessed and accredited in accordance with the following European Standards account being taken of the criteria for different testing methods laid down in this Directive:
ii) EN ISO/IEC 17025 on „General requirements for the competence of testing and calibration laboratories“;
iii) EN 45002 on „General criteria for the assessment of testing laboratories“;
iiii) EN 45003 on „Calibration and testing laboratory accreditation system – General requirements for operation and recognition“.
2. The accreditation and assessment of testing laboratories referred to in point 1 (i) may relate to individual tests or groups of tests.
Further tasks of the NRL are:
- Testing of commercial diagnostics within the frame of licensing procedures and batch release
- Supply of diagnostics which are not available commercially
- Testing of vaccines for fish at the request of and in consultation with the Paul-Ehrlich-Institut which is responsible for the licensing of vaccines
- Annual report to the Community reference laboratory on epidemiological and laboratory data on diagnosis and control of KHV-I
- Participation in the annual meeting of the representatives of the NRLs of the EU Member States
- Publication of recommendations on the diagnosis of IHN and VHS in the „Official Collection of Methods“ of the Animal Reporting System TSN and the Animal Disease Control Manual
Reference material
- National reference viruses for VHS (Fi13) and IHN (isolate 233) and for IPN (serotypes Sp., Ab., and VR299) for differential diagnosis
- International reference viruses: for VHS and IHN
- Monoclonal antibodies against IHNV and VHSV
- Reference rabbit antisera (origin: Community reference laboratory Aarhus) against VHSV (F38) and against IHNV (F33)
Overview of methods
The methods used by the NRL for detection and identification of IHNV and VHSV are the following techniques described in decision 2001/183/EC:
- Isolation and cultivation of viruses using the fish cell cultures specified in decision 2001/183/EC,
- Identification of IHNV and VHS by means of immunofluorescence test (IFT), preferably by indirect IFT (IIFT) using monoclonal antibodies (mab),
- Identification of IHNV and VHS by means of ELISA using approved commercial test kits,
- Identification of IHNV and VHS by means of serum neutralization test (SNT) using reference antisera (Community reference laboratory).
Further methods which are not yet part of the EU recommendations are:
- Indirect detection by detection of antibodies against IHNV and VHSV using ELISA and serum neutralization test
- Genome detection by means of RT-PCR
- Development and improvement of solid dosage forms for oral administration of vaccines in trout
- Genetic analysis of virus isolates by sequencing of selected genome sections
Relevant legislation
Council Directive 2006/88/EC on animal health requirements for aquaculture animals and products thereof, and on the prevention and control of certain diseases in aquatic animals (Official Journal of the EU No. L328 p. 14)
Commission Decision 2001/183/EC dd. 22 February 2001 laying down the sampling plans and diagnostic methods for the detection and confirmation of certain fish diseases and repealing Decision 927532/EEC. (Official Journal of the EU No. L 56 p. 65)
Regulation on fish diseases and regulation on the modification of the regulation on notifiable animal diseases dd. 22 November 2008 (Federal Gazette I p. 2315)
Regulation on notifiable animal diseases dd. 3 November 2004, last modified by the Second Regulation on the modification of animal disease regulations dd 18 December 2009.
in their latest version