(First published in Greenfields Agricultural Magazine in February 2002)
In 1992, the Department of Agriculture issued Executive Order #12 identifying the six priority diseases on livestock. Foot-and-mouth disease (FMD), hemorrhagic septicemia, hog cholera, New Castle disease, rabies and anthrax became primary concerns because of their commercial implication to humans. With the exception of rabies that is mostly associated with dogs (and dogs are not for human consumption), these diseases inflict damage on cattle, carabao, swine and fowls, man’s animal sources of meat requirement. Except for rabies and New Castle disease, an avian pest terrorizing poultry farms, all the diseases pester the cattle, carabao and swine. Incidentally, rabies was categorized under livestock because of dog’s significance to humans as pet.
One popular offshoot of the September 11 bombing of World Trade Center in New York is the anthrax. It became a scary byword worldwide associated with mails and parcels. Worse, those who consider anthrax a recent discovery have no idea that it is an age-old fatal animal disease.
Once in a while, we hear stories of herdsmen about their cattle who fell flat dead for no reason at all. They would even claim that the cattle were well fed, healthy, and showed no signs of sickness before it died. They prognosticate that the disease may be due to fatigue or by a strange ‘supernatural’ cause.
But if you ask the veterinarians, given the absence of symptoms before the animal’s death, they would say that the anthrax did it. It is so dreadful it can kill cattle in an instant. No forewarning symptoms of the illness can be found whatsoever.
Anthrax is caused by a spore-forming bacterium called bacillus anthracis. Soil-borne, these spores cannot be destroyed easily. It is resistant to boiling for at least 30 minutes. In fact, it can resist desiccation for 24 months. Provided the spores are not exposed to direct sunlight, they can even retain their viability for a much longer period, at least 10 years. Nevertheless, it is possible to annihilate it using strong disinfectants although the attempt would be difficult.
According to Ronello A. Abila, DVD and Chief of National Veterinary and Quarantine Services of the Bureau of Animal Industry, the anthrax disease became a top priority because of its implication to public health. “Once a person eats the meat of an anthrax-infected animal, the person also gets infected with anthrax. This is usually fatal.”
The disease thrives in mountainous areas, mainly because the anthrax spores survive in alkaline soil; lowland is normally acidic. “This is rampant only in Northern Luzon, Ilocos, and Cagayan regions,” says Dr. Abila.
It is most prevalent during summer and in the early phase of the rainy season but the incidence is higher after the flood. The areas where the disease is endemic (called anthrax bed) are surrounded with big bodies of water like rivers, lakes and swamps.
Anthrax spores spread by inhalation, contact, or insect transmission. During rainy season, when the soil is washed out, the spores get in contact animal. “The animal gets it via the surface soil when it eats and starts to graze the area. If there are spores present, then the animal gets infected,” explains Dr. Abila. Incubation period of the spores lasts from one to three days, though it occasionally reaches up to 14 days.
The animal usually dies in one or two days in the acute form of the disease. The sub-acute form of the disease may end in three to five days or longer, concluding to recovery, especially when the animal is prompted treated.
Dr. Abila further adds that the country experiences around two to six anthrax outbreaks in a year.
Symptoms of the Anthrax Disease
The affected cattle experiences high fever and excitement in the initial stage, followed by depression, distressed breathing, staggering and bloating. In the final stage, the cattle experiences swelling in the neck, breasts, flanks, and genitals region. Bloody discharges from the natural body openings and through skin are usually seen. The blood inside the body is dark and tarry, and clotting is poor. Urine is also tinged with blood.
Prevention and Control
1. Call a veterinarian immediately to confirm the cattle’s cause of death.
2. If confirmed, bury or burn the carcass at once.
3. Make sure to layer the carcass with lime before covering it with soil.
4. Should the animal be opened, let the veterinarian take the task. Anthrax may be considered by the “blackish” color of the animal’s blood. Meat from anthrax-infected animal is already “condemned”.
5. Disinfect thoroughly the area where the dead animal is found.
6. Vaccinate promptly the animals in the herd with anthrax spore vaccine.
7. To diagnose anthrax, take blood samples of the animal from the peripheral vessel properly wrapped in a sterile gauze or cotton and send it to Bureau of Animal Industry for laboratory testing.
8. Separate all animals showing high temperature from the herd and give them massive doses of antibiotics.
The bacterium is sensitive to massive doses of penicillin or broad-spectrum antibiotics such as Aureomycin and Terramycin. Sulfadiazine and Sulfamethazine are also effective. High titre antisera is effective in prophylaxis and in therapy.
Should the animal be opened, it should not be done in an open field. This is to prevent the spores from getting into the soil which would cause further outbreaks.
During outbreaks, the infected animal should be isolated and treated. Healthy animals exposed to infection should be vaccinated and observed. Pastures should be rotationally grazed and the whole farm placed in quarantine.
Anthrax in Humans
It is unlikely but some people who are clueless of the disease eat the meat of the animal that died of anthrax, skin the carcass, and use the hide. It is also equally dangerous that some leave in the open any leftover meat since this will play host to more outbreaks.
However, most cases of anthrax in humans may be attributed to people carrying the hides or large pieces of the meat of the infected animal. In these cases, the pathogens enter the human body through cuts in the arms and hands.
The most common symptom of anthrax in humans is the appearance of malignant pustules especially in the arms, neck, face, and shoulder.