Caused by……. Mycobacterium tuberculosis (most commonly) Also M. bovis (from cattle)

Spread by……. Coughing/sneezing – droplet infection M. bovis in meat

Infection Primary infection site is the lungs. Healthy, immunised person will destroy bacteria and will not become ill.

Symptoms Dry persistent cough Coughing up blood Chest pain Breathlessness Fever Sweating Emaciation

History More prevalent in 19 th Century due to nature of spread: –Overcrowding –Poor housing conditions –Hygiene Streptomycin introduced in UK (& developed world) c. 1940s. Incidence dropped sharply. BCG vaccinations in 1950s decreased prevalence further.

History (cont.) Once thought to be eradicated but recent resurgence due to: –M. tuberculosis antibiotic resistance –AIDS –Poor housing/homelessness in inner cities –Complacent partial treatment programmes (esp. USA) In 1995 more people died from TB worldwide than any other disease. 1/3 of world’s population is infected with M. tuberculosis.

EUROPEAN TB NOTIFICATION RATE /

Antibiotic Resistance If just one drug is used, it acts as a selective agent and resistant strains survive. Exacerbated by failure of people to complete course of antibiotics. M. tuberculosis is slow growing so takes months to cure. Better to use 3 or 4 drugs – reduces likelihood of resistance. In 1995 an HIV unit reported an MDR-TB (multiple drug resistant M. tuberculosis ) resistant to FIVE of the major TB drugs.

= Hot spots (at least 4% are MDR-TB) = Outbreaks The Worldwide Problem