Bird flu: The full scale of the threat in East Africa
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While countries in the region have been quick to form task forces to control bird flu, and have also responded swiftly to protect their poultry industries, some observers say little has been done to cushion the tourism industry from the likely shocks. Special Correspondent WAIRAGALA WAKABI reports
THOUGH THE VIRUS THAT CAUSES bird flu has not been found in wild birds in Africa, there are concerns among conservation and tourism circles that the bird flu scare could hurt Africa's birding industry, for which East African countries are a popular destination.
At the same time, agencies like the Food and Agricultural Organisation are warning that farming practices prevalent in several African countries – such as using poultry litter as livestock feed – as well as rampant illegal trade in birds, could aid the spread of the highly pathogenic strain of the H5N1 bird flu virus, which can kill humans.
But while scientists continue investigating the role of wild birds in the spread of bird flu, conservationists say the virus is certain to have implications for wild bird conservation. They also say that although the migratory birds are leaving East Africa at the moment, the region must not put its guard down as some birds could bring the virus to the region when they return beginning from late August.
"There should be heightened surveillance of migratory wild birds, with collection of as much ecological information as possible in the case of confirmed outbreaks," says Paul Kariuki Ndang'ang'a, the programme manager in charge of African species at the Nairobi-based Africa office of BirdLife International. He adds that there should be continuous surveillance of poultry and wild birds, and prompt testing whenever any unusual deaths occur.
Agencies like FAO, BirdLife, and tourism groups across Africa have been concerned that scares over the flu could prompt tourists, particularly birders, to stay away from the region. They say that while the threat of bird flu to humans remains minimal, tourists often make decisions that are not entirely based on factual information.
In Africa, bird flu has been reported in Nigeria, Cameroon, Niger and Egypt, which raised the prospects of hard times for East Africa's main birding destinations, even though there has been no trace of the virus in the region. Thousands of wild birds have been tested (both dead and apparently healthy) throughout major migratory bird stopover sites in Mauritania, Tanzania, Burkina Faso, Kenya, Senegal, Botswana and Cote d'Ivoire.
"It is however still important to prevent contact between wild birds and domestic poultry. Some of the outbreaks in Africa have been near important wild bird areas, like the Logone flood plains around Lake Chad," Ndang'ang'a told The EastAfrican.
African resident, non-migratory waterfowl species often have short to mid-range movements in response to droughts – for example movement to coasts from wetlands that dry out – and it is possible that infected wild birds could spread the disease over short distances between countries.
Dr Hazell Thompson Shokellu, a doctor of ornithology and head of BirdLife's African programmes, told The EastAfrican that governments will need to be keen on controlling movements of poultry and poultry products, besides monitoring the migrating wild birds' routes.
THE MAJOR ENTRY AND exit points for the birds include the Strait of Gibraltar, through which birds enter Morocco and proceed through Mauritania to West Africa. These birds mostly fly to and from Europe. Others fly between Sicily and Malta through Tunisia to Algeria, Libya, West Africa via Mali and/ or Central Africa via Chad.
Other birds come to Africa from Norway, Sweden and Russia; while from the Eastern Mediterranean, birds enter Africa through Djibouti and proceed through Ethiopia to East Africa. This route is the main one used by migrating birds to and from Asia.
But the River Jordan to Nile Valley corridor is considered the most significant one for bird migration in the world. It is the main eastern corridor between Europe, Asia and Africa that is regularly used by over a million birds to pass through a series of sites each season.
From this corridor, birds enter Egypt and then fly through Sudan, Uganda, Kenya and Tanzania on to Southern Africa (Malawi, Zimbabwe and South Africa). This route takes birds from central Europe, the Middle East and Central Asia. Sea birds and some shore birds, on the other hand, migrate along the western coastline of Africa beginning from Morocco, through the West African coastline to southern Africa.
While countries in the region have been quick to form task forces to control bird flu, and have also responded swiftly to protect their poultry industries, some observers say little has been done to cushion the tourism industry from the likely shocks. This is despite the fact that tourism is a key income earner for East Africa, and that birding in particular is becoming an important attraction for high-spending tourists.
"Governments must make a really concerted effort to step up surveillance, control poultry movements and stamp out infections if and when they arise," an official of Nature Uganda, a bird conservation agency, told The EastAfrican.
The official said developed countries have pledged substantial international help and funding for avian flu control and these pledges need to be fulfilled. Currently, the shortage of funds is limiting the efforts of countries like Uganda to take adequate measures.
Kenya has banned the importation of poultry and poultry products from areas with confirmed avian flu outbreaks. The country has also set up what the Ministry of Livestock and Fisheries Development calls "an extensive surveillance system that is able to detect and contain any avian flu outbreaks."
Conservationists say better communication is key to reducing the socioeconomic, conservation and tourism impact of H5N1. They add that governments need to provide accurate information on the risk to people. For instance, bird-human transmission is low and close contact, such as for people handling poultry, is necessary for this to happen.
Governments also need to educate people on how they can minimise their risk of infection and how they can reduce their chances of contributing to the spread of the disease.
FAO is recommending that the feeding of poultry manure/ poultry litter should be banned in countries affected by or at risk from avian influenza, even if it is correctly composted, ensiled or dried with heat treatment. The use of poultry litter in livestock feeding is widespread in East Africa and across the continent.
At the beginning of February, the Paris-based World Organisation for Animal Health (OIE) said the deadly strain of bird flu had been found in poultry in northern Nigeria. This was the first time that the disease was detected in Africa.
Birds infected with the H5N1 excrete virus particles in their faeces. Putting untreated faeces from infected birds into fish ponds and on to fields provides a potential new source of infection. Researchers say although recognised as early as 1988, the risks of this practice for spreading influenza viruses remain little investigated.
There are several ways in which H5N1 can be spread within and between countries. Three major potential routes are the movement of infected poultry and poultry products, movement of caged wild birds in trade, and movement of migratory wild birds.
Recent H5N1 outbreaks among wild birds in Europe and the Middle East show that wild birds are capable of carrying the virus over long distances. Experts also say there is need for heightened biosecurity even in indoor poultry operations.
But many questions remain concerning the effects of the virus on wild birds and how effectively they can spread it to other wild birds or to domestic poultry. "Recent outbreaks in India, Nigeria and Egypt originated within the poultry industry. Here, as in most other H5N1 outbreaks, there is strong circumstantial evidence that movements of poultry and poultry products are responsible," BirdLife says.
In the meantime, the scare over the flu is having negative effects on bird conservation. Environmentalists say that in some countries, politicians have called on hunters to wipe out incoming migrant birds. Some governments have reportedly revived plans to drain wetlands, under the pretext of denying waterfowl landing and breeding places.
Nests of birds, such as the Barn Swallow that breeds in close proximity with man, have been destroyed in the mistaken belief that this measure will lessen the risk of contracting bird flu. "None of these measures will control the spread of avian influenza, but will instead put wild birds and other biodiversity in jeopardy," says BirdLife.
ALTHOUGH H5N1 CAN cause serious disease in people, the virus is hard to catch. Transmission from poultry to humans remains difficult, usually involving prolonged and intimate contact, and so far the virus does not seem to spread from person to person. A major concern is that it might evolve into a form that is transmitted easily between people, thereby provoking a pandemic.
In the past 100 years, there have been at least three major pandemics of human influenza A, which killed many people around the world. It is thought that these deadly virus strains arose when bird flu and human influenza viruses came together, possibly in pigs, and reassorted their genetic material.
Continued outbreaks of H5N1 increase the chances of this happening again, especially as the current strain of H5N1 is exceptional in that it can pass directly from poultry to humans, without the intervention of an intermediate host.
The World Health Organisation, FAO and OIE say control of avian influenza in wild birds by culling is not feasible, and attempts at culling would spread the virus more widely, as survivors disperse to new places, and healthy birds become stressed and more prone to infection.
They say culls of wild birds and destruction of their habitat are not appropriate control measures. They are at best ineffective, probably counterproductive and distract people from more suitable interventions. They would also cause much negative environmental impact.
Originating in poultry, the H5N1 virus has caused deaths among wild water birds at several locations in Asia and most recently in the Middle East and Europe. There have also been recent outbreaks in poultry in Africa, India and Europe. In the latter half of 2005, it was widely predicted that wild water birds – thought to be the most likely species to carry the virus – would spread H5N1 to their non-breeding grounds in Southeast and South Asia, Europe, the Middle East, Africa and Australasia.
By February 2006, only a handful of dead wild birds with H5N1 had been discovered in Southeast Asia. These were resident species in Hong Kong, where diseased, illegally imported poultry were also found. No cases of H5N1 had been found among migrant birds in their non-breeding grounds in the Philippines, Japan, South Korea, Australia, New Zealand or Africa.
However, two outbreaks have occurred in poultry in Africa. There is strong circumstantial evidence that the first of these, in Nigeria, was through the illegal importation of poultry (possibly from China or Turkey). The second, in Egypt, originated in and is currently confined to the poultry sector. In India, outbreaks in backyard poultry flocks in mid-February were apparently caused by the supply of infected birds from a commercial hatchery.
By contrast, in Europe and the Middle East, there have been numerous reports of dead wild birds across many countries. These include thousands of birds in Azerbaijan, plus smaller numbers in Bosnia Herzegovina, Bulgaria, Croatia, France, Germany, Greece, Hungary, Italy, Iran, Romania, Slovenia and Turkey.
Ornithologists say their near-simultaneous appearance in these countries is likely to be in response to cold weather in regions further to the east, causing birds to move towards warmer climes. The infected birds could have come into contact with the virus in the Black Sea region, where it is known to have been present in poultry flocks for several months.
Researchers are now warning that the migrating birds that are leaving East Africa at the moment could present a threat once they return, even if the scientists add that poultry and poultry products seem to hold bigger potential for aiding the spread of the virus across Africa.
The first poultry outbreak in Western Europe was at a closed turkey farm in Ain, France. This outbreak, scientists say, shows that bringing poultry indoors may not be effective, by itself, in halting the disease's spread. It is not yet clear how, or when, the virus entered the closed farm and it will be important to follow all lines of inquiry to determine the likely source of the outbreak.
The European incidents clearly demonstrate that wild birds can carry the virus to new sites after infection – at least during the disease's incubation period, which may last several days. Nevertheless, our understanding of the epidemiology of H5N1 in wild birds, and the behaviour of the virus in the wider environment, remains inadequate, according to BirdLife International scientists.
