Through the last article, dr.provet discussed the transmission of T.B from animals to man.let's know more about the clinical signs and prevention measures of tuberculosis in man.
This article will include:
Clinical signs of tuberculosis in man.
Pulmonary tuberculosis in man
Extrapulmonary tuberculosis in man
Skin tuberculosis in man
The effect of bovine mycobacterium on humans.
Prevention and control of tuberculosis in man.
Epidemic measures.
International measures.
Control of infected individuals, contacts and environment.
Preventive measures of tuberculosis in man
Safety by work in the laboratory
Prevention and control of avian tuberculosis.
The local manifestations(symptoms) of the primary infection of tuberculosis in man vary somewhat according to the route of invasion, including
Pulmonary tuberculosis in man
The primary lesion (tubercles) develop in the lungs and tracheobronchial lymph nodes. symptoms include:
Coughing at first dry then becomes later moist cough and expectoration in frequent attacks.
When sputum becomes profuse and mucopurulent, cavitation occurs.
Haemoptysis occasionally occurs as the first symptoms which may vary from streaking of the sputum with blood to Profuse fatal bleeding.
Fever is often not noticed, and when present usually occurs in late afternoon.
Night sweats occur in advanced cases and occasionally in patients with acute exudative involvement.
Pain in the chest of pleurisy type.
Loss of weight is frequent and in advanced cases may be marked.
Extrapulmonary tuberculosis in man
The primary lesion (tubercle) may be in the mouth or tonsils (infection by ingestion) accompanied with an enlargement of the lymph nodes of the neck producing a condition known as "Cervical adenitis" or Scrofula.
Generally, the form of tuberculosis occurring due to ingestion is manifested as tuberculosis of the bones or lymphatic system.
If the tubercle bacilli penetrate the intestinal mucosa, the primary lesions occur in the wall of the intestine and are accompanied by "Mesenteric adenitis" with peritonitis. or without peritonitis.
Skin tuberculosis in man
At the point of invasion develops an ulceration accompanied by yellowish-brown nodules in the skin.
An extensive involvement of the regional lymph nodes.
The effect of bovine mycobacterium on human
It can be recognized that infection of human beings with bovine mycobacteria produces in most instances:
tuberculous cervical adenitis.
tuberculosis of the skin, the peritoneum, or the bones and joints
This bovine type of mycobacteria might affect almost any tissue of the body.
Prevention and control of tuberculosis in man
The prevention and control of tuberculosis in man an be occured by several measures, including:
Epidemic measures
Intensive search for the source of infection of tuberculosis in man, including:
Tuberculin testing of cattle and slaughter of reactors.
Tuberculin testing of persons detecting hypersensitivity.
Persons who have the disease invariably yield positive reactions, which may be very pronounced if the lesion is still active.
Patch testing is usually employed in children for group screening prior to specific individual testing by the intradermal inoculation of tuberculin in the Mantoux test or its modifications Heaf or Jelly test.
Mantoux test:
It consists of the intradermal injection of 0.1 ml of the appropriate dilution of tuberculin usually in the forearm.
The test is positive when there is an area of induration measuring 5 mm in diameter 2-3 days after the injection.
Heaf test:
A multiple puncture spring release gun is used to prick and introduce the previously applied tuberculin into the skin.
A positive reaction may range from 4-6 discrete papules to solid induration.
This test is also usually done on the forearm.
Jelly test :
A tuberculin jelly is applied in the form of a "V" shape in the interscapular area of the back and covered with a plaster.
A control test should be used for comparison.
In a recent comparison of these three tests, in which such factors as sensitivity, case of performance and consistency were compared
only the Mantoux and Heaf tests were shown to be acceptable for large scale epidemiological investigations.
International measures
They are essential control measures of tuberculosis in man, including:
X-ray screening is employed for individuals before migration to other countries.
Sanitary certificate is given to those persons who Mantoux or heaf tested.
Strict quarantine measures by tuberculin testing of all imported cattle, before being introduced to the country.
Control of infected individuals, contacts and environment
These measures include:
Notification or reporting should be done to the local health authorities about the existence of infected persons.
It is an obligatory case report in most counties.
Isolation: a period of sanatorium treatment removes the focus of infection from home.
A!so education of patients about the hygienic essentials of control the disease which increase the chance of recovery.
Concurrent disinfection of sputum and contaminated articles including handkerchiefs or clothing, and eating utensils used by the patients.
patients should be obligated (by training) to cover their mouth and nose during coughing or sneezing.
Specific treatment: Treatment in man is very effective although the period of treatment with antibiotic and antibacterial drugs may last longer than two years.
But most human patients recover completely and return to normal activities.
The major problem with chemotherapy in cases of tuberculosis is the development of antibiotic-resistant strains of organisms.
But in general this can be by using two or more drugs after in combination.
A combination of streptomycin (SM) and para-amino salicylic acid (PAS) or Isoniazid (INH) are successful in treating cases.
Preventive measures of tuberculosis in man:
These measures include:
Vaccination with BCG (Bacillus Calmitte -Guerin) for uninfected persons (Mantouix or Heaf negative)
Especially newly born infants.
It should be borne in mind that active immunization should not be practised in areas of infection to avoid masking of the infection.
Elimination of tuberculosis among dairy cattle through:
periodical tuberculin testing (every 6 month).
Disinfection of infected animal dwellings.
Elimination of reactor animals.
Ensuring safe milk supply through efficient pasteurization or boiling.
Hospital facilities for the isolation and treatment of active cases.
x-ray screening of contact and suspicious persons especially in vets, nurses, medical students, butchers, and milkers.
Public health nursing service for home supervision and to arrange and encourage for examination of contact.
Avoiding inhalation of dangerous silica dust in industry.
Education of the public about the danger of tuberculosis, its mode of spread and methods of prevention.
Safety by work in the laboratory
Also, there are some measures that should be considered inside the laboratories, including:
It is absolutely forbidden to put food or water for human use in the refrigerator of the laboratory.
Disinfection of white coats before washing. The coats should be changed when contaminated with cultures or samples.
The coats should be put off while eating or in the office.
Never touch the eyes, mouth or nose before cleaning and disinfecting the hands
Centrifuge tubes should be handled from their middle length. If broken in the centrifuge, the tube is carefully taken out and thoroughly disinfected.
Condensed water collected at the bottom of the culture bottles (especially positive cultures is very infectious) should be carefully poured off if the cultures are to be sent by post.
Eradication of flies in the laboratory and at the end of the daily work, laboratory tables should be thoroughly disinfected.
Prevention and control of avian tuberculosis
These prevention measures aim mainly to control Mycobacterium avium, including:
Application of intradermal tuberculin test in one wattle while the second is left as a control, and elimination (condemnation) of reactors.
Agglutination test on fresh blood using (Avi test), and condemnation of tuberculous ones.
Thorough boiling of eggs at least 6-10 minutes before consumption.
Thorough washing of vegetables under running water or in endemic areas, disinfection of these vegetables with Kmno4 1% is necessary.
Efficient pasteurization of milk produced by cows and goats, which were associated with tuberculous birds.
Eradication of flies since they are dangerous transmitters of infection to man.