see BCG. [A. L. C. Calmette (1863–1933) and C. Guérin (1872–1961), French bacteriologists]
A pre-vaccination tuberculin test is necessary in all age-groups except newborn infants, and only those with negative tuberculin reactions are vaccinated. Complications are few and far between. A local reaction at the site of vaccination usually occurs between two and six weeks after vaccination, beginning as a small papule that slowly increases in size. It may produce a small ulcer. This heals after around two months, leaving a small scar. (See IMMUNITY; TUBERCULIN.)... bcg vaccine
Age Disease and mode of administration
3 days BCG (Bacille Calmette-Guerin) by injection if tuberculosis in family in past 6 months.
2 months Poliomyelitis (oral); adsorbed diphtheria, whooping-cough (pertussis)1 and tetanus2 (triple vaccine given by injection); HiB injection.3
3 months Poliomyelitis (oral); diphtheria, whooping-cough (pertussis)1 and tetanus2 (triple vaccine given by injection); HiB injection.3
4 months Poliomyelitis (oral); diphtheria, whooping-cough (pertussis)1 and tetanus2 (triple vaccine given by injection); HiB injection.3
12–18 months Measles, mumps, and rubella (German measles)4 (given together live by injection).
(SCHOOL ENTRY)
4–5 years Poliomyelitis (oral); adsorbed diphtheria and tetanus (given together by injection); give MMR vaccine if not already given at 12–18 months.
10–14 females Rubella (by injection) if they have missed MMR.
10–14 BCG (Bacille Calmette-Guerin) by injection to tuberculin-negative children to prevent tuberculosis.
15–18 Poliomyelitis single booster dose (oral); tetanus (by injection).
1 Pertussis may be excluded in certain susceptible individuals.
2 Known as DPT or triple vaccine.
3 Haemophilus in?uenzae immunisation (type B) is being introduced to be given at same time, but di?erent limb.
4 Known as MMR vaccine. (Some parents are asking to have their infants immunised with single-constituent vaccines because of controversy over possible side-effects – yet to be con?rmed scienti?cally – of the combined MMR vaccine.)
Recommended immunisation schedules in the United Kingdom... immune system
These people include health workers, contacts of people who have tuberculosis, and immigrants (including children) from countries with a high rate of tuberculosis.
Infants born to immigrants in this category are immunized, without having a tuberculin test, within a few days of birth.
The vaccine is also recommended for children aged 10–14 years for whom the test is negative.... bcg vaccination
The symptoms depend upon the site of the infection. General symptoms such as fever, weight loss and night sweats are common. In the most common form of pulmonary tuberculosis, cough and blood-stained sputum (haemoptysis) are common symptoms.
The route of infection is most often by inhalation, although it can be by ingestion of products such as infected milk. The results of contact depend upon the extent of the exposure and the susceptibility of the individual. Around 30 per cent of those closely exposed to the organism will be infected, but most will contain the infection with no signi?cant clinical illness and only a minority will go on to develop clinical disease. Around 5 per cent of those infected will develop post-primary disease over the next two or three years. The rest are at risk of reactivation of the disease later, particularly if their resistance is reduced by associated disease, poor nutrition or immunosuppression. In developed countries around 5 per cent of those infected will reactivate their healed tuberculosis into a clinical problem.
Immunosuppressed patients such as those infected with HIV are at much greater risk of developing clinical tuberculosis on primary contact or from reactivation. This is a particular problem in many developing countries, where there is a high incidence of both HIV and tuberculosis.
Diagnosis This depends upon identi?cation of mycobacteria on direct staining of sputum or other secretions or tissue, and upon culture of the organism. Culture takes 4–6 weeks but is necessary for di?erentiation from other non-tuberculous mycobacteria and for drug-sensitivity testing. Newer techniques involving DNA ampli?cation by polymerase chain reaction (PCR) can detect small numbers of organisms and help with earlier diagnosis.
Treatment This can be preventative or curative. Important elements of prevention are adequate nutrition and social conditions, BCG vaccination (see IMMUNISATION), an adequate public-health programme for contact tracing, and chemoprophylaxis. Radiological screening with mass miniature radiography is no longer used.
Vaccination with an attenuated organism (BCG – Bacillus Calmette Guerin) is used in the United Kingdom and some other countries at 12–13 years, or earlier in high-risk groups. Some studies show 80 per cent protection against tuberculosis for ten years after vaccination.
Cases of open tuberculosis need to be identi?ed; their close contacts should be reviewed for evidence of disease. Adequate antibiotic chemotherapy removes the infective risk after around two weeks of treatment. Chemoprophylaxis – the use of antituberculous therapy in those without clinical disease – may be used in contacts who develop a strong reaction on tuberculin skin testing or those at high risk because of associated disease.
The major principles of antibiotic chemotherapy for tuberculosis are that a combination of drugs needs to be used, and that treatment needs to be continued for a prolonged period – usually six months. Use of single agents or interrupted courses leads to the development of drug resistance. Serious outbreaks of multiply resistant Mycobacterium tuberculosis have been seen mainly in AIDS units, where patients have greater susceptibility to the disease, but also in developing countries where maintenance of appropriate antibacterial therapy for six months or more can be di?cult.
Streptomycin was the ?rst useful agent identi?ed in 1944. The four drugs used most often now are RIFAMPICIN, ISONIAZID, PYRAZINAMIDE and ETHAMBUTOL. Three to four agents are used for the ?rst two months; then, when sensitivities are known and clinical response observed, two drugs, most often rifampicin and isoniazid, are continued for the rest of the course. Treatment is taken daily, although thrice-weekly, directly observed therapy is used when there is doubt about the patient’s compliance. All the antituberculous agents have a range of adverse effects that need to be monitored during treatment. Provided that the treatment is prescribed and taken appropriately, response to treatment is very good with cure of disease and very low relapse rates.... nature of the disease tuberculosis has
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