On 22nd June, ProMed reported on a episode of mortality in migratory birds in the southern part of Zambia. An epidemiologist with the Government of Zambia, later stated that diagnostic procedures had eliminated avian influenza but there was no definitive diagnosis given. Since then there has been no further posting, which gives cause for concern. By Simon Shane
On 22nd June, ProMed reported on a episode of mortality in migratory birds in the Victoria Falls area of the southern part of Zambia adjacent to the border with Zimbabwe. According to a release by the Chief Veterinary Officer of Zambia, Dr. Jack Shoko, diagnostic procedures on the 40 birds (species not stated) was in progress.
Laurie Garrett, affiliated with the US Council on Foreign Relations, in a June 23rd ProMed posting, noted that the migratory flyway from Nigeria terminates in the Victoria Falls region. On 25th June, Dr. Christina Chisemble, an epidemiologist with the Government of Zambia, stated that diagnostic procedures had eliminated avian influenza but there was no definitive diagnosis as to the cause of mortality. Since this date there has been no further posting, which gives cause for concern.
An unofficial statement at a June 28th poultry industry meeting by a Veterinarian affiliated to the Republic of South Africa, National Department of Agriculture confirmed that the specimens provided by the Government of Zambia were “negative for influenza”.
This situation is eerily reminiscent of the lack of transparency demonstrated by a number of nations following the emergence of H5N1 avian influenza. We have been subjected previously to the sequence of “no it isn’t, maybe it is and then yes it is”.
Relevant information concerning specific diagnostic procedures and their results and the status of investigations should be conveyed to the OIE and neighboring countries. There are numerous causes for acute mortality in migratory birds including infections other than influenza, toxicities and exhaustion associated with migration.
The world community and in particular, veterinary authorities in Zimbabwe, Malawi, Mozambique, South Africa and adjoining countries, Madagascar and Mauritius, deserve to know the disposition of this case, which represents a presumptive presentation of HPAI. A positive diagnosis of avian influenza would require intensification of preventive measures in Zambia and Zimbabwe and other nations with significant poultry populations requiring heightened biosecurity or even pre-emptive vaccination.
If the Zambian authorities have either diagnosed influenza or received an indication of the presence of the infection from a reference laboratory, appropriate action should be taken to prevent extension of infection to subsistence and commercial poultry on both sides of the border. Any mortality in migratory birds should be subjected to a structured investigation with surveillance of poultry and free living species in the area concerned. If the mortality in wild birds in this case was due to some other cause, the actual or most probable diagnosis should be declared. Failure to either diagnosis the condition or to communicate findings reflects negatively on the preparedness of veterinary authorities in Zambia.
Deficiencies in response to possible outbreaks of HPAI have profound implications for the entire region.
By: Simon Shane