What are regulations on bovine tuberculosis regarding the Prevention of Terrestrial Animal Diseases in Vietnam?

What are regulations on bovine tuberculosis regarding the Prevention of Terrestrial Animal Diseases in Vietnam?

Pursuant to Section 1, Appendix 19 issued together with Circular 07/2016/TT-BNNPTNT stipulating as follows:

1. Introduction to Tuberculosis

1.1. Disease concept

a) Tuberculosis is a chronic infectious disease of many animal and human species caused by Mycobacterium tuberculosis. When animals get sick, there are often special inflammatory particles called tuberculosis granules in the viscera. There are three types of tuberculosis bacteria:

- Tuberculosis in humans: Mycobacterium tuberculosis causes tuberculosis in humans but can also cause tuberculosis in cows, dogs and cats.

- Tuberculosis in cattle: Mycobacterium bovis causes tuberculosis in cows but can also infect humans, pigs, dogs and cats.

- Tuberculosis in birds: Mycobacterium avium causes tuberculosis in birds in general and poultry; The bacteria can also cause disease in humans and less susceptible pigs and cows.

b) Resistance of bacteria: Bacteria can live for 1 month in moist sputum, for weeks in milk, and for 6 months in dried cattle manure. Bacteria are sensitive to ultraviolet rays and temperature; sunlight kills bacteria in 8 hours; Disinfectants such as 10% formaldehyde, 2% caustic soda and lime powder easily kill bacteria.

1.2. The source of the disease and the route of transmission

a) Infected species: In nature, all species of cattle, poultry, wild animals, birds and humans are infected. However, each animal species is susceptible to one of three different types of TB bacteria: human, bovine and avian. Young animals are often more susceptible than adults.

b) Disease source: In the body of diseased animals, blood, milk and TB-affected organizations all have pathogens. If TB is in the lungs and gastrointestinal tract, then nasal secretions, saliva, and feces contain many pathogens.

c) Route of transmission: The disease can be transmitted directly from sick children to healthy children and indirectly through intermediate factors. Usually bacteria enter the body through the following routes:

- Respiratory tract: Bacteria from the diseased body are excreted through saliva by coughing, sneezing, spitting, etc or in feces. When feces and sputum dry, pathogens stick to dust particles suspended in the air. If a healthy animal breathes it in, they will be infected.

- Digestive tract: The most common are calves and pigs. Breastfed calves with tuberculosis will be infected. If food and water are contaminated with pathogens, healthy animals will be infected.

In addition, the disease can be acquired through the nipple, through the genital tract.

1.3. Clinical symptoms, lesions

a) Clinical symptoms: Bovine TB is commonly seen in the following forms:

- Tuberculosis: This form is common. The most obvious symptom is a cough, at first a dry cough, then a wet cough, and a cough. Animals often develop a cough when they knock on their chest, are chased, drink cold water, lie down or stand up. When coughing, phlegm spits out, but the animal swallows it; sputum may be mixed with pus, blood; sometimes see blood coming out of the nostrils. Cows are thin and weak, their hair is erect, their skin is dry, they are lethargic, they eat less, and their breathing is increasingly difficult. Auscultate and percussion the lung area has diffuse turbidity, puffiness, and wet crackles or metallic sounds.

- Tuberculosis: This form is quite common. If TB is in the lungs, the lymph nodes are also TB. The lymph nodes are swollen into hard lumps, sometimes palpable. The lymph nodes commonly affected by TB are submandibular, salivary, anterior shoulder, anterior femoral, and intestinal lymph nodes.

- Tuberculosis of the breast: Depending on the severity of the disease, the breast or nipple may be deformed. Touching, feel the lumpy tubercles, swollen mammary glands, hard lumps. Milk production decreased markedly.

- Tuberculosis of the digestive tract: Common in the intestines and liver. Cattle have continuous diarrhea, emaciation, mild bloating and digestive disorders.

b) Lesions: usually have 3 forms: tubercle granules, epidermal proliferative mass, and pustules.

- Tuberculosis granules: Depending on the stage of disease development, the symptoms of TB granules are different. Tuberculosis particles are clearly seen in the lungs, mesenteric lymph nodes; At first, the seeds are small and hard, called millet tuberculosis. In the lungs, there are clear limits, gray color, difficult to peel; if there are many seeds, lung manipulation will feel like the lungs are mixed with sand; cut has a creaking sound. This tubercle is called a gray seed. The gray seeds grow to be the size of green peas, corn kernels, the stem is degenerated into yellow bean residue, so it is called yellow seeds. The above seeds enlarge and break, those that do not break are covered by a proliferative organization called fibrous granules.

- Epidermal proliferative mass: Strongly proliferating fibrous seeds, sometimes as big as chestnuts, guava fruit, being chemically or calcified.

- The cluster of pox: In the later stage, the tubercle granules burst, turning the tuberculosis organization into a mass of pox, crushed, dialysis.

What are regulations on diagnostic test of bovine tuberculosis in the prevention of terrestrial animal diseases?

Pursuant to Section 5, Appendix 19 issued together with Circular 07/2016/TT-BNNPTNT stipulating as follows:

5. Diagnosis and testing of diseases

5.1. Diagnosis of bovine tuberculosis by intradermal injection reaction or specimen collection of suspected or diseased tissues in the amount of 10g to 200g and placed in a wide-mouth vial or plastic bag for testing.

5.2. Specimens must be taken, packaged and preserved according to Vietnamese Regulation QCVN 01 - 83: 2011/BNNPTNT issued under Circular No. 71/2011/TT-BNNPTNT dated October 25, 2011 of the Ministry of Agriculture and Rural Development; Specimens must be taken aseptically, stored in cold conditions from 2°C to 8°C and sent to an agricultural laboratory recognized by the competent authority within 24 hours after sampling.

5.3. Diagnostic and laboratory methods: Follow the diagnostic procedures for bovine tuberculosis specified in Vietnamese Standard TCVN 8400-10: 2010.

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