ABC of Anthrax

Whenever we talk about the 9/11 incident, the word "chemical attack' comes to mind automatically. Do you remember those days? Switch on either CNN or local news -- Anthrax Scare is a travel companion together with terrorism.

Anthrax is an acute infectious disease caused by the bacterium Bacillus anthracis. The Anthrax spores can survive in soil for years or decades Anthrax most commonly occurs in animals like cattle, sheep, goats or camels. It can also occur in wild animals like antelopes and other herbivores. Humans generally acquire the disease directly or indirectly when they are exposed to infected animals or occupational exposure to contaminated animal products. Control in livestock is therefore the key to reduced incidence. So far there are no recognised cases of person to person transmission.

The disease still exists in animals and humans in South and Central America, Southern and Eastern Europe, Asia, Africa, the Caribbean, the Middle East and certain areas of Australia. We are lucky in Bangladesh that it's free from Anthrax.

The disease's impact on human health can be really distressing. Symptoms of disease vary but usually occur within 7 days. This infection can occur through skin (cutaneous), inhalation (pulmonary) and gastrointestinal. We can be infected with anthrax by handling products from infected animals or by inhaling anthrax spores from contaminated animal products. And also by eating undercooked meat from infected animals.

About 95 per cent of cases are skin type when a spore enters the skin through a cut or an abrasion; may be while handling contaminated wool, hides, leather or hair products from infected animals. Skin infection looks like an insect bite in the beginning but within 1-2 days develops into a vesicle and then a painless ulcer with a characteristic necrotic area in the centre. Doctors may find a swelling in adjacent lymph glands. Initial signs of gastrointestinal type are loss of appetite, nausea or vomiting and fever followed by abdominal pain, vomiting of blood and diarrhoea. Initial symptoms in inhalation type may look like a common cold. After several days, the symptoms may progress to severe breathing troubles and shock. In reality, inhalation anthrax is most dangerous.

All these three types of anthrax are very dangerous if not treated promptly. Anthrax is diagnosed by examining the blood, skin lesions, or respiratory secretions. Vaccines are offered for animals and humans. It is reported to be 93 per cent successful. Anthrax vaccines considered for animals should not be used in humans. Nevertheless their use should be limited to high-risk groups, such as those occupationally exposed and in some military settings. Antibiotic therapy usually results in dramatic recovery of the individual infected with anthrax if given before onset or immediately after onset of illness. Antibiotic therapy may also be used for prophylaxis in asymptomatic patients believed to have been exposed to Anthrax.