A 14-year-old boy died of anthrax infection, and the epidemic has been reported in many places! How can we prevent infectious diseases of the same level as the new coronavirus?

On August 9, Beijing reported a case of pulmonary anthrax from Weichang Manchu and Mongolian Autonomous County, Chengde City, Hebei Province, who came to Beijing for treatment. On August 15, CCTV News reported a suspected skin anthrax outbreak in Wenshui County, Shanxi Province, and the case has been isolated for treatment. On August 27, the Chinese Center for Disease Control and Prevention reported two confirmed cases of anthrax in Binzhou, Shandong Province. One case was a 14-year-old student who died on August 6; the other was a 35-year-old man who was diagnosed with skin anthrax and has been transferred to an infectious disease hospital for isolation and treatment.

Since August this year, confirmed cases of anthrax have appeared in many places across the country, attracting widespread attention from the society.

What is anthrax? What causes it? What are the symptoms? How can it be prevented?

Infectious diseases of the same level as COVID-19

Anthrax is an acute infectious disease caused by Bacillus anthracis and is a common infectious disease for humans and animals. Clinically, it can be seen in the form of cutaneous anthrax, pulmonary anthrax, intestinal anthrax, meningeal anthrax, and septicemic anthrax. Among them, cutaneous anthrax is the most common, accounting for more than 95% of all cases.

According to the Law of the People's Republic of China on the Prevention and Control of Infectious Diseases, anthrax is a Class B infectious disease, but pulmonary anthrax is managed as a Class A infectious disease. The current COVID-19 epidemic is also a Class B infectious disease (managed as a Class A infectious disease), so anthrax, especially pulmonary anthrax, is at the same level as COVID-19. Therefore, the occurrence and spread of any type of anthrax should attract our attention.

Three ways of transmission of human infection

The pathogen that causes anthrax is called Bacillus Anthracis, which belongs to the genus Bacillus. The bacteria are thick, arranged in bamboo nodes, have no flagella, and are Gram-positive.

Anthrax bacteria are mainly prevalent in herbivorous animals such as cattle, horses, and sheep. Anthrax bacteria can form spores in the external environment. The spores are highly resistant to dryness, high heat, ultraviolet rays, and some commonly used chemical disinfectants, so they can survive for a long time in the external environment such as soil.

Anthrax is not only highly contagious, but also extremely difficult to eliminate. It is also classified as a "level one dangerous biological weapon". When the Japanese invaded China, the notorious Unit 731 once made anthrax into a biological weapon and deployed it on the Chinese battlefield. Some terrorist organizations have also used anthrax to create terrorist incidents. In 2001, a week after the 9/11 terrorist attacks in the United States, someone sent letters containing anthrax to several American news media offices and senators, resulting in 5 deaths and 17 infections.

There are three ways anthrax can be transmitted to humans:

Contact with infected broken skin, direct contact with sick animals and their blood, feces, urine, milk, internal organs and bones, or contact with skin, hair, meat, bone meal, etc. containing anthrax bacteria or spores, usually causes cutaneous anthrax, accounting for more than 95%.

Oral infection is mainly caused by ingestion of contaminated food containing the bacteria, such as air-dried beef that has not been processed by high heat.

Inhalation infection mainly results from inhalation of dust and aerosols contaminated with anthrax spores.

No delay, timely treatment is the key

Symptoms of anthrax infection in humans include:

Skin anthrax lesions are common in exposed areas such as the hands, upper limbs, neck and shoulders. The initial symptoms are unexplained papules or erythema on the skin, similar to mosquito bite-like papules. Most of them have fever symptoms, and then blisters appear, with swelling around them, followed by central necrosis to form an ulcerative black eschar. The pain is not obvious, there is a slight itching sensation, and no abscess is formed. The mortality rate is less than 1% with timely treatment.

Intestinal anthrax can present as acute enteritis or acute abdomen. Acute enteritis may cause nausea, vomiting, abdominal pain, and diarrhea. Acute abdomen patients have severe systemic poisoning symptoms, including persistent vomiting and diarrhea, bloody stools, abdominal distension, and pain, often complicated by sepsis and septic shock. If not treated promptly, it can often lead to death.

Pulmonary anthrax initially presents with "flu-like" symptoms, including low-grade fever, fatigue, malaise, myalgia, and cough, which usually last for about 48 hours. Afterwards, the disease progresses suddenly and rapidly, with respiratory distress, shortness of breath, wheezing, cough, cyanosis, hemoptysis, etc. Coma and death may occur quickly, with a mortality rate of more than 90%.

The key to the treatment of anthrax patients lies in early detection, early diagnosis, and early treatment. Penicillin is the drug of choice for the treatment of anthrax. The treatment of cutaneous anthrax is not difficult. In addition to the use of antibiotics, it only requires simple wound treatment measures. However, any delay may lead to serious consequences. If there is a history of suspected contact with dead animals and related symptoms appear, you must go to a regular hospital as soon as possible and inform the doctor of the history of contact with dead animals so that you can get timely and correct diagnosis and treatment.

The key to prevention is to avoid contact with the source of infection

1. Animals infected with anthrax and dead animals are the main sources of anthrax infection. The most important thing to prevent anthrax is to avoid contact with the source of infection, do not touch, do not slaughter, do not eat, do not buy or sell, and immediately report to the local agricultural and animal husbandry department for handling. Do not privately slaughter or handle dead animals suspected of anthrax. Professionals engaged in slaughtering and fur processing should pay attention to occupational protection to avoid possible infection caused by pathogens through the skin or inhalation.

2. Ordinary people should purchase quarantined beef and mutton products through regular channels and cook them thoroughly. When traveling, try to avoid contact with frozen meat or related products of unknown origin, especially dead animals or livestock. Choose regular places for eating, choose fully cooked food, and maintain good personal hygiene habits.

3. Although anthrax is generally not transmitted between people like influenza or COVID-19, when coming into contact with anthrax cases, you should also pay attention to personal protection and avoid contact with the case's skin exudates and vomit, body fluids and excrement.

4. Anthrax vaccine is used for emergency vaccination. Currently, there are two human anthrax vaccines approved for formal use in the world. One is the anthrax sterile culture filtrate aluminum gel adsorption vaccine (AVA) approved by the U.S. Food and Drug Administration (FDA). It is made by adding aluminum hydroxide or aluminum phosphate adsorption to the culture fluid of the attenuated anthrax strain without capsule and producing toxins. It was approved for production in the UK and the US in 1960 and 1971 respectively. The other is the attenuated live spore anthrax vaccine approved by the former Soviet Union and my country. The current attenuated live spore anthrax vaccine in my country was approved for production in 1960 and is inoculated by skin scratches. It has been used in China since 1961 and is safe for vaccination. Human anthrax vaccine is an emergency vaccination vaccine determined by the national immunization program. It is not widely used in the population. Only when anthrax occurs and may cause an outbreak of the disease, the relevant departments will organize key areas and key populations for emergency vaccination after evaluation.

Author: Yaohuluwa Medical and Biological Science Popularization Group