The large blue 4x4 drives slowly over dirt roads, past the herd of emaciated-looking cattle. It’s hot, 104 degrees Fahrenheit in the shade. Two veterinarians from the Cameroonian National Veterinary Laboratory, Lanavet, together with tropical veterinarian Dr. Hermann Unger, employed by a taskforce of the FAO and IAEA, step away from the dusty vehicle and greet the cattle herdsman. The reason for the meeting is serious: animal epidemics are spreading across the Cameroonian savannah, including goat plague (Peste des Petits Ruminants, PPR), which wipes out whole populations of goats and sheep, or foot-and-mouth disease, which spreads primarily among cattle.
Underlying conditions facilitate the spread
The vets are trying to identify the affected herds in order to isolate these and be able to prevent epidemics. This is not an easy undertaking in this central African country, as keeping farm animals here means trekking through the barren landscape with the herd for hundreds of miles – migratory movements that dramatically facilitate the spread of animal epidemics.
“The pathogenic organisms are spreading more and more rapidly,” according to Dr. Unger. In Africa, animals are also transported over large distances within a couple of hours by truck – and, consequently, an epidemic spreads. “It’s a case of very large animal populations then”, he says, “as diseases don’t stop at national borders.” A local outbreak can spread like wildfire, especially if government structures are lacking or the turmoil of war makes intervention difficult. For the veterinarians, it depends all the more on diagnosing contagious diseases in the herds as quickly as possible. If the diagnosis takes too long then the herdsmen and the herds move on in their search for fodder for their animals. The opportunity to break the chain of contagion has thus been lost.
Here, on the savanna in northern Cameroon, the nearest laboratory is five or six hours away by car, explains Dr. Unger. The results cannot be obtained until the next day at the earliest. No-one can prevent the livestock from spreading the pathogen in this period. It is also quite possible that the material might not survive transportation in the dust and heat – and the specimens might ultimately be unusable. “That’s a central problem”, says the scientist.
Modern, portable test systems promise aid
However, there is a solution sitting on the little camping-table that the researcher has set up for himself: a small laboratory with a miniature centrifuge, a couple of reagents and a mobile diagnostic device by the German biotech company, QIAGEN.
This handy device which is the size of an office telephone and weighs only about 2¼ pounds, runs on electricity that Dr. Unger sources from the cigarette lighter in the off-road vehicle. In less than an hour, it enables him to perform molecular analyses of animal epidemic pathogens, in conjunction with a laptop!
The device is one of 30 deployed in developing countries across the world, within the scope of a joint FAO / IAEA project. The IAEA is involved in the use and development of nuclear technology, as well as operating biotechnology and veterinary medicine departments. In conjunction with tests specially developed within the framework of the program, the devices can detect viruses and bacteria directly on-site on the basis of their genetic information. Seven animal epidemics can already be quickly diagnosed using the device, including PPR, avian influenza (H5N1) in poultry, and contagious bovine pleuropneumonia (CBPP). Dr. Unger is the scientific head of the three-year project, the objective of which is to gain experience in managing the mobile diagnostic devices. This is the reason that veterinary medicine has come to Cameroon.
After just a year, the matter is clear to the tropical veterinarian: “The process is proving itself. It has been given a positive rating by everyone involved.” The practitioners are not just impressed by the speed of the diagnosis. In Dr. Unger’s and his colleagues’ view, the ease with which the tests are performed, together with the management of the device and the dependability of the results, make the mobile diagnosis platform - a technology with a future. Thanks to the thermal treatment to which the samples are subjected, they are preserved and then able to be used for later tests in the laboratory, which is another advantage for the specialists. More and more tests have already been developed for the on-site diagnosis; the list of animal diseases able to be diagnosed is expanding rapidly and the number of potential applications is growing.
“If it’s a question of infectious disease detection, in most cases, there is nothing better than molecular technologies. The other side of the coin, however, is that these technologies are very sensitive, frequently require an extensive technical infrastructure and so, to a great extent, specialized laboratories are still reserved”, explains Dr. Konrad Faulstich, Director of Strategic Alliances at QIAGEN. “Our vision is to overcome these barriers with the aid of special on-site test systems, and in fact, for a great number of applications in human medicine, agricultural economics and other areas. For some time, we have observed a trend towards decentralization of laboratory structures, which might intensify further due to the miniaturization of available systems and the introduction of new technologies. These kinds of system can play an important role in directly improving the general social and economic framework in developing and emerging countries. As a consequence, we are involved in a range of projects, in which we are developing test systems for application in human medicine, as well as in practical test procedures, such as in veterinary medicine.”
Risk to economies and health
The extent to which animal epidemics can be seen in developing countries can be shown by the example of PPR. The epidemic causes diarrhea, erosive stomatitis, pneumonia and fever in sheep and goats. Around 90 percent of the diseased animals die after a few days. An outbreak, therefore, means an enormous economic loss. In a country like Nigeria, where PPR appears often, the damage amounts to an estimated 1.5 million US dollars annually, equivalent to a loss of 50,000 animals! Meanwhile, the epidemic, first documented 60 years ago, has spread from its original distribution area in West Africa to East Africa, the Arabian Peninsula, and Southeast Asia.
“Bacterial pneumonia” (the veterinary medical term for contagious bovine pleura-pneumonia) is another example. An outbreak of this in Botswana in 1995 caused damage equivalent to around 500 million US dollars. Presently, the epidemic occurs in 26 African countries. “In Africa, this disease is currently spreading. It is regarded as one of the most serious livestock diseases on this continent”, states German scientist, Dr. Joerg Jores, who works at the International Livestock Research Institute in Nairobi. With the support of the German Federal Ministry for Economic Cooperation and Development (Bundesministerium für wirtschaftliche Zusammenarbeit und Entwicklung, BMZ), Dr. Jores, a microbiologist, is researching diagnostic agents for animal epidemics in order to protect the population from the economic and social consequences.
According to Dr. Jores, agricultural livestock is the most important source of food and income, particularly in dry regions south of the Sahara. Cattle and their products are used as foodstuffs. Meat and milk are utilized as bartering objects. Cattle also enhance the social status of their owner. “Because there are no banks in the rural areas, animals are often used as a type of substitute”, says Dr. Jores. Livestock serves to preserve assets. If a herd becomes diseased, this can reduce a peasant farmer to poverty within days – and not just by himself. Affected animals are then subject to a trade prohibition and this can hit a developing country hard in economic terms.
Preventing a global spread
Additionally, animal epidemics are seldom confined to one region, so the battle against the diseases in Africa can also help towards protecting European herds, the German scientist points out. African swine fever, for example, has already advanced into Georgia – and it is not far from there into Western Europe. There is also some concern that a PPR epidemic could find its way into southern Europe via North Africa. “The diseases must be combated where they originate”, says Dr. Jores. This must also be done to protect the population, as a number of animal epidemics, so-called zoonotic diseases, can also infect man.
Dr. Jores sees great opportunities in the FAO and IAEA project to utilize the mobile diagnostic devices for combating animal epidemics. The procedure is so easy to manage that the devices could also be issued to veterinary health assistants in remote areas. Where a case is suspected, the people could then relay the results to distant veterinary laboratories via cell phone, where the results would then be analyzed – and the required measures could be initiated. But that is a long way off.
Back in Cameroon, “If a lethal animal epidemic was rife here, then that would be a catastrophe”, says tropical veterinarian Dr. Unger as he dilutes a cow’s blood sample with a buffer solution in a small test-tube. He points to the herd, “The herdsman has 20 cows. If half of these die off, then he is poor.” In fact, the result that Dr. Unger can see on his laptop screen after a short time is positive with foot-and-mouth disease, according to the findings. In this case, however, the disease is not lethal if the animal can be kept fed and watered, and the farmer concerned does not have to reckon with severe losses. The veterinarians prescribe a five- to six-day period of isolation, so that the disease will not spread into the surrounding area. “He should stay here on-site with his animals while they are isolated”, Dr. Unger explains and hands over another antiseptic.
He smiles. “Sometimes, arresting an epidemic is not difficult at all”, says the expert – “when the diagnosis is available quickly”.