Anthrax is a serious infectious disease caused due to gram-positive, rod-shaped bacterium known as Bacillus anthracis. It occurs naturally in soil and commonly infects domestic and wild animals worldwide. People can get sick from anthrax if they come into contact with infected animals or contaminated animal products. Anthrax can cause severe diseases in both humans and animals.
There is no evidence that anthrax is transmitted from person to person, but it is possible that anthrax can become contagious through direct contact with skin lesions or through contact with a contaminated object (fomite). Usually, anthrax bacteria enter the body through a skin wound. You can also become infected by eating contaminated meat or breathing in the spores.
Signs and symptoms, depending on how you are affected, may include skin rashes, vomiting, and shock. Immediate treatment with antibiotics can cure most anthrax infections. Inhalation anthrax is more difficult to treat and can be fatal. Anthrax is rare in the developed world. However, the disease remains a concern because the bacteria have been used in bioterrorism attacks in the United States.
Signs and symptoms
Symptoms usually appear within seven days of exposure, although in some cases the incubation period is considerably longer.
Cutaneous anthrax starts as a raised area on the skin that itches (pruritic papules). Usually, it occurs on exposed areas, most often on the arms and hands followed by the face and neck. It resembles an insect bite. The area enlarges and within a day or two becomes an ulcer, surrounded by small blisters filled with fluid. A characteristic dark, crusty patch on the affected area of skin later forms and, after a few weeks, begins to loosen and eventually fall off, leaving a scar. The course of these events is so characteristic that physicians familiar with the disease often miss the diagnosis, although it is rare.
Gastrointestinal anthrax can present as either intestinal or oropharyngeal disease. Symptoms of intestinal infection include fever, nausea, abdominal pain, vomiting, and anorexia. As the disease progresses, vomiting of blood, bloody diarrhea, toxemia, shock, and bluish discoloration of the skin and mucous membranes (cyanosis) may occur. Symptoms of the oropharyngeal disease may include fever, sore throat, difficulty swallowing (dysphagia), accumulation of fluid in throat tissues (edema), and swollen lymph nodes.
Inhalation anthrax usually begins with one to three days of fatigue, low-grade fever, and a dry cough. These symptoms, typical of a mild upper respiratory tract infection, may be accompanied by pain or a feeling of heaviness in the chest and just below the chest. After this relatively mild onset, there will be periods of more severe illness characterized by high fever, elevated pulse and respiratory rates, profuse sweating (profuse diaphoresis), and difficulty breathing (dyspnea).
Anthrax in Victoria
In Victoria, outbreaks of anthrax in animals occur periodically in the southern regions and along the Murray and Goulburn rivers. Sometimes a person is affected. The illness usually develops within two to seven days of exposure.
Humans can become infected with anthrax by handling infected animal products or by breathing in anthrax spores from infected animal products. Anyone who works with livestock or their byproducts — such as armorers and dairy workers, tanners, veterinarians, and farmers — is most likely to be exposed.
How do people get infected with anthrax?
People become infected with anthrax when the spore enters the body. When anthrax spores enter the body, they can become “activated.” The bacteria can then grow, spread throughout the body, produce toxins, and cause serious illness.
It can happen when people breathe in spores, eat food or drink water contaminated with spores, or get spores in a cut or scratch on the skin. In the United States, it is very rare for people to become infected with anthrax. Certain activities can also increase a person’s chances of becoming infected.
Causes
Anthrax is primarily a disease of animals, certain herbivores such as cattle, goats, and sheep. These diseases are caused by contact with anthrax spores, which are present in the soil around the world. Rare cases when humans are infected usually occur when people come into contact with infected animals through their occupations. When people eat undercooked meat or other products from infected animals. It is more likely to occur in developing countries, although imported animal products from these countries may pose a risk.
Human infection sometimes results from contact in industrial environments. In the United States, there have been occasional incidents in industrial settings, for example, processing contaminated animal fibers such as goat hair.
People who work in agricultural jobs can also get infected. These infections usually occur in people who have had direct contact with animals infected with or who have died from the disease.
Cutaneous anthrax occurs when the spores come into contact with skin that is broken as a result of a cut or injury. Gastrointestinal results from eating undercooked or raw meat from animals infected with the disease. Inhalational occurs as a result of breathing in (breathing in) spores.
There have been no confirmed cases of person-to-person transmission of this disease through the skin, gastrointestinal tract, or inhalation. For this reason, it is considered unnecessary to vaccinate or treat family members, friends, or co-workers who become ill with anthrax unless. It is possible that they are infected. have been exposed from the same original source.
Different types of anthrax infection
Anthrax can affect different parts of the body, including:
- Cutaneous anthrax – The skin is the most commonly affected part of the body, accounting for about 95% of cases. The skin becomes itchy and then develops into a sore that turns into a blister. The blister may break and bleed. Within two to seven days, the ruptured blister becomes a sunken, dark-colored, or black rash that is usually painless. Death is rare with appropriate antibiotic treatment. The mortality rate for untreated cutaneous anthrax is 5-20%.
- Pulmonary anthrax – is a rare lung infection that can occur when bacterial spores are inhaled. At first, the infection looks like a mild upper respiratory tract infection, such as a cold or the flu. The person’s health deteriorates rapidly over the next few days, with severe breathing difficulties and shock. Without treatment, the mortality rate is 70% to 80%. In many cases, pulmonary anthrax is fatal even with treatment.
- Intestinal anthrax – Very rare in developed countries. It occurs if a person eats undercooked meat from an infected animal, usually one that has died on a farm. If the infection spreads to the blood (septicemia), the death rate is between 25% and 60%.
Diagnosis
Your doctor will ask you what kind of work you do, among other questions, to determine your chances of being exposed to this disease. He or she will first want to rule out other, more common conditions that could be causing your signs and symptoms, such as the flu (influenza) or pneumonia.
Test
You may have a rapid flu test for a quick diagnosis of a case of influenza. If the other tests are negative, you may have more tests to look specifically for anthrax, such as:
- Skin testing. A sample of fluid or a small tissue sample (biopsy) from a suspected lesion on your skin can be tested in a laboratory for signs of cutaneous anthrax.
- Blood tests. You may have a small amount of blood that is checked in the laboratory for anthrax bacteria.
- A chest X-ray or computerized tomography (CT) scan. Your doctor may order a chest X-ray or CT scan to help diagnose inhalation anthrax.
- Stool examination. To diagnose gastrointestinal anthrax, your doctor may check your stool sample for anthrax bacteria.
- Spinal tap (lumbar puncture). In this test, your doctor inserts a needle into your spinal canal and removes a small amount of fluid. A spinal tap is recommended any time doctors suspect systemic anthrax – other than cutaneous anthrax – because of the possibility of meningitis.
Treatment
Which single antibiotic or combination of antibiotics, and the length of treatment, will be most effective for you depends on how you got infected with anthrax, your age, your overall health, and other factors.
Since the 2001 attacks in the United States, researchers have developed antitoxin treatments—raxibacumab and siltuximab—for inhalation of this disease. Instead of going after the bacteria that cause the disease, these drugs help eliminate the toxins that cause the infection. Anthrax immunoglobulin can also be used to neutralize toxins. These drugs are given in addition to antibiotics and are available to doctors through the US Centers for Disease Control and Prevention.
Some cases of injection anthrax have been successfully treated with surgical removal of the affected tissue. Although some cases of this disease respond to antibiotics, advanced anthrax cannot be inhaled. By the later stages of the disease, the bacteria have often produced more toxins than drugs can remove. Along with antibiotics, people with this disease can be treated with intensive supportive care, including ventilators, fluids, and drugs to tighten blood vessels and increase blood pressure.