Tuberculosis (TB) is a bacterial infection. Most cases in New Zealand are in people from overseas. When TB progresses from infection to disease it usually affects the lungs but may affect any organ of the body. Children less than five years of age are at highest risk of developing severe forms of tuberculosis, e.g. meningeal TB (infection of the layers over the brain) and miliary TB.
The earliest known cases of tuberculosis (TB) have been discovered in Egyptian mummies dating back to 4000-2000 BC. TB was probably the leading cause of death in Europe and the US in recorded history. Mortality from TB began decreasing with improved socioeconomic conditions, long before drug therapy and use of the BCG vaccine.
The tubercule bacillus was identified in 1882 and led to early disease control strategies, sanatoriums, pasteurisation of cow’s milk, development of BCG vaccines and discovery of anti-TB drugs.
Compulsory notification of TB began in New Zealand in 1940. BCG immunisation was first introduced to New Zealand in 1948. Universal screening and vaccination of 13 year olds was discontinued in the South Island in 1963, was phased out in regions of the North Island in the 1980s, and had ceased by 1990.
Tuberculosis (TB) notification rates in New Zealand have been around 10 per 100,000. Incidence has decreased slightly in recent years to around seven per 100,000.
New Zealand has higher rates of disease in compared to other developed countries. This may be attributed to socioeconomic deprivation and immigration from high-incidence countries. Over two-thirds of all TB cases in New Zealand are in foreign-born individuals.
The highest rates of disease are seen in individuals living in urban areas, particularly Auckland and South Auckland and in people of non-European ethnicity, particularly Pacific People and ‘Other’.
People with tuberculosis may not have any symptoms. When symptoms are present they may include fever, cough, coughing up blood stained phlegm or blood, chest pain, night sweats, weight loss or poor weight gain, anorexia (not feeling like eating) and malaise (tiredness).
|Risk of disease vs. vaccine side effects
||Effects of disease
||Side effects of vaccine
Tuberculosis (TB) is a bacterial infection. When TB progresses from infection to disease it usually affects the lungs but may affect any organ of the body.
- TB usually infects the lungs.
- TB can spread outside the lungs and infect any organ in the body.
- People with TB may not have any symptoms.
- When symptoms are present they may include cough, fever, night sweats, weight loss or poor weight gain, anorexia (not feeling like eating) and malaise (tiredness).
- Later symptoms may include haemoptysis (coughing up blood stained phlegm or blood), shortness of breath, chest pain and altered liver function.
- Children less than five years of age have a higher risk of developing meningeal (infection of the layers over the brain) TB and miliary TB, both severe forms of disease.
- Some tuberculosis strains are resistant to multiple antibiotics and difficult to treat.
- Up to 50% of people with active TB will die from their disease, even with treatment.
- Children with active TB are excluded from school until effective antibiotic treatment has started, compliance with treatment is established and any symptoms have decreased.
Common side effects
- Soreness/pain, redness and/or induration (area of hard inflammation) around the injection site.
- Lymphadenopathy (tiredness and mildly swollen lymph glands)
- Small blister that may become an ulcer/weeping sore.
- Ulceration (weeping sore) at the injection site that may take up to three months to heal.
- Scar at the injection site.
Uncommon side effects
- Lymphadenitis (mild fever and more pronounced swollen lymph glands).
- BCG abcess within a lymph gland.
Rare/very rare side effects
- Osteomyelitis (inflammation of bone).
- Disseminated BCG disease and death (only usually occurs when the BCG is given to a person who is immune compromised).