After working around the clock, a team of scientists at Erasmus University in Rotterdam led by virologist Ron Fouchier announced on Tuesday (4th March) that the culprit behind the outbreak is a highly pathogenic mutant form of a less dangerous avian influenza. The mutation alters a surface protein of the virus, allowing it to dodge the immune system and infect cells throughout the bird’s body, often resulting in fatal pneumonia. The sudden appearance of the mutant is "very surprising," says Eric Gingerich, an avian pathologist at the University of Pennsylvania School of Veterinary Medicine, because it usually appears only after the less pathogenic form has circulated among poultry for months.
The less pathogenic form of avian influenza is carried at low levels by wild birds. But within crowded chicken farms, the disease spreads like wildfire through drinking water contaminated by virus-loaded faeces. Once the mutation transforms the virus into the highly pathogenic form, most infected birds die, often within days. The Dutch team believes that a duck or goose may be to blame for infecting the chickens, which have suffered up to 80% mortality on the 18 farms believed to be infected so far. Almost 50 farms surrounding the afflicted properties are also slated to be culled.
Although it's extremely rare, avian influenza viruses can spread to humans if they swap genes with the human influenza virus. This rare event is possible in pigs, which are vulnerable to both human and avian influenza. In 1997, such a strain killed six people in Hong Kong.
Like Hong Kong, the Netherlands has a high density of animals, including chickens and pigs. For this reason, and because the Netherlands is the top exporter of eggs in Europe, the Dutch government has moved rapidly with its poultry culling.
Science Magazine
5 March 2003
Original web page at Science Magazine
The following is a report written by the Dutch Minister of Agriculture, Nature Management and Fisheries in response to the outbreak:
Avian Influenza in the Netherlands (Letter to Parliament 3 March 2003)
On 1 March 2003 an outbreak of Avian Influenza occurred in the area around Barneveld in the Gelderse Vallei and in Laren. Minister Veerman of Agriculture, Nature Management and Fisheries reported the situation to the Dutch Parliament in the following letter:
The President
House of Representatives of the States General
Postbus 20018
2500 EA The Hague
Our reference VVA.2003/692
Date 03-03-2003
Re: Avian Influenza in the Netherlands TRC 2003/1662
Dear Mr. President,
I am writing to inform you about the recent outbreak of Avian Influenza in the Netherlands.
On Friday 28 February 2003 at 1700 hours the Animal Health Service (Gezondheidsdienst voor Dieren, GD) of the National Inspection Service for Livestock and Meat (RVV) reported health problems at six poultry farms. These farms were visited that same evening by specialist teams of the RVV. The RVV confirmed a very high death rate among the poultry at the farms. During the evening there were intensive contacts between the services of my Department. Several hours later the decision was made to implement a standstill order in the area around the affected farms. At that time the diagnosis of Avian Influenza (AI) could not be made, as the symptoms could also have pointed to Newcastle Disease (CD) or Infectious Laryngotracheitis (ILT).
On Saturday 1 March 2003 at 0130 hours a 10-kilometre restricted-movement zone was put into force around the affected farms in the Gelderse Vallei, limiting the movement of poultry, poultry manure and eggs within this area. At the same time a ban was placed on gatherings of poultry for the whole of the Netherlands. In addition a ban was placed on the export of poultry and hatching eggs from the Netherlands.
On Saturday 1 March 2003 I decided to extend the movement ban for poultry, poultry manure and eggs to the whole of the Netherlands as of 1200 hours, with the exception of eggs for consumption. The Dutch measures were taken in close consultation with the European Commission, who felt that we had reacted adequately and decisively. It must be noted here that these measures were taken on the basis of only one suspected incident of Avian Influenza. On Saturday 1 March the measures were discussed with the sector, who endorsed our action.
On Sunday afternoon 2 March the first test results from the Central Institute for Animal Disease Control (CIDC) in Lelystad indicated a high-pathogen H7 strain of Avian Influenza. The final result will only be known in two week's time when the official tests required by the EU have been completed. The risks to human health from this form of Avian Influenza are minimal. Nevertheless, in accordance with EU Directive 92/40 EEC for control of the disease and on the advice of the Dutch Food and Non-Food Authority, animal products from the suspect farms dating from 22 February will be recalled wherever possible.
It has been decided that in spite of the fact that the official test results are not yet known, the control procedure will be set in motion according to the contingency plans. This means that the following measures have been implemented:
Poultry to be slaughtered in a 1 km zone around the sources of infection, priority being given to suspect farms.
In a zone of at least 10 km around the sources of infection rules have been put in place under the Regulation on movement restriction areas for poultry 2003 (Regeling Vervoersbeperkingsgebieden Pluimvee 2003), which are the same as measures enforced in surveillance zones.
The RVV has started screening farms in a radius of 3 km around the sources of the infection.
The General Inspection Service (AID) is enforcing the regulation with the help of the police. Approximately 500 personnel are available for this work.
Slaughter and welfare measures
Slaughter has commenced at the suspect farms with the equipment currently available. We are considering whether it would be advisable to have flocks from the other clinically suspect farms in the 1 km zone slaughtered at a slaughterhouse in the area. We are also looking at the possibility of using Danish and Belgian slaughter methods. Because of potential welfare problems, the removal of broilers and day-old chicks outside the 10 km zones is permitted. I will issue a regulation to this effect. I am considering whether this possibility can also be created within the 10 km zones.
Communication
In accordance with the handbook on communication in a crisis, on Saturday morning 1 March a number of activities were undertaken to ensure fast and efficient communication. An Avian Influenza file was opened on the Ministry's Dutch internet site announcing the measures in force and other relevant information. This file will be up-dated as necessary. Moves were also made on Saturday to set up a departmental communications team and a regional communications team. The latter will be housed with the regional crisis team in Garderen.
The LNV-loket, the Ministry's help desk, was opened on Saturday afternoon at 1500 hours. Farmers and others involved can phone this desk for information on Avian Influenza. On Saturday and Sunday hundreds of calls were received from farmers, private individuals, consumers, police, customs officials and feed suppliers.
A page was drafted together with the Dutch Organisation for Agriculture and Horticulture (LTO-Nederland) and placed on Dutch Teletext 461, giving information about the measures and the current situation.
Financial consequences
This Avian Influenza crisis will have financial consequences for both the sector and the Government. The sector will lose an estimated turnover amounting to tens of millions of Euros. In addition, under existing agreements on animal health funds, the sector will pay up to a maximum of EUR 11.4 million towards control costs. The European Union will reimburse half of the costs of compensation and cleansing and disinfection. If the national costs exceed EUR 11.4 million, the Government will finance the remainder.
I will keep the House informed of further developments.
Yours sincerely,
Cees Veerman
Minister of Agriculture, Nature Management and Fisheries
3rd March 2003
