Contents

20 Tuberculosis

Key information

Mode of transmission Inhalation of airborne droplets produced by people with pulmonary or laryngeal tuberculosis (TB).

People with latent TB infection and non-pulmonary TB disease are not infectious.
Incubation period Between 2 and 10 weeks from infection to primary lesion or significant tuberculin skin test (Mantoux) reaction.
Period of communicability May be years with untreated pulmonary TB.

Refer to the Guidelines for Tuberculosis Control in New Zealand 20101 (or current edition).
Burden of disease Disseminated and meningeal TB are more common in very young children.

The immunosuppressed, particularly HIV-infected individuals, are more at risk of disease and complications.

The New Zealand burden is seen in foreign-born residents and those in low socioeconomic groups.
Vaccine BCG vaccine an only be administered by an authorised vaccinator with BCG endorsement.

Live attenuated vaccine, which must be reconstituted.

At the time of writing, BCG supply to New Zealand was interrupted by a global shortage.
Recommendations Neonatal BCG vaccine should be offered to infants at increased risk of TB, defined as those who:
  • will be living in a house or family/whānau with a person with either current TB or a history of TB
  • have one or both parents or household members or carers who, within the last 5 years, lived for a period of 6 months or longer in countries with a TB rate ≥40 per 100,000 (for a list of high-incidence countries see the resource: BCG Vaccine: Information for Health Professionals [code HE2204], available at www.healthed.govt.nz)​
  • during their first 5 years will be living for 3 months or longer in a country with a TB rate ≥40 per 100,000.
Contraindications Immunosuppression for any reason, or suspected of being immunocompromised.

HIV-positive or potentially HIV-positive individuals.

Infants of mothers taking anti-tumour necrosis factor (anti-TNF) therapies (eg, infliximab) during pregnancy.

Positive tuberculin skin test or interferon gamma release assay (IGRA).

Generalised infected skin conditions.
Expected responses 90–95% of people develop a local reaction, which may scar within 3 months.

A minor degree of adenitis is normal, not a complication.

Suppurative adenitis may take months to resolve; usually no treatment is required.