Tuberculosis – Basic Concepts

Ursula Oxley TB Nurse Specialist

Some epidemiology…

TB rates in persons by age group, England and Wales, 1999 - 2004

UK born

Born abroad

Tuberculosis case reports by ethnic group (%), England and Wales, 1999 - 2004

World-wide epidemiology

• 3 million deaths from TB in 1995

• 95% cases of TB in developing countries.

• 98% of deaths from TB in developing countries.

• 75% of TB in developing countries in 15 - 50 age group.

(WHO guidelines for National Programmes 2nd edition 1997)

When should I suspect active tuberculosis

?

Anyone at high risk for TB and has symptoms of

• Weight loss• Fever,• Night sweats• Anorexia• Malaise• Cough (more than 3 weeks)• Enlarged lymph nodes commonly cervical and

mediastinal

Which people are considered high risk

?

• People born in high prevalence area 40/100,000 population

• Close contacts of a person with active PTB

• Previous or incomplete treatment for TB

• Immunocompromised (HIV, diabetes, chronic renal failure, chemotherapy, malignancy, corticosteroid use, young children)

• Homeless, institutionalised e.g. prison

• Alcohol or intravenous drug users

How should I manage suspected active tuberculosis

?

• Examination• Check contact/travel history• Exclude other conditions• Arrange CXR• Send 3 early morning sputum samples for

culture and microscopy – acid fast bacilli• Ring for advice or refer to TB Specialist

Services at NUH City Campus tel 0115 9628051 even before results are known

• Clinic appointment offered in same or following week

TB : Diagnostic tests…pitfalls

Sputum smear 50-70% +ve in pulmonary TB

Sputum culture 85-90% +ve in pulmonary TB

CXR Rarely, normal even in smear +ve (eg. endobronchial TB )

Heaf/Mantoux 68 – 83% +ve in pulmonary TB

17 – 32% false -ve

Difficulties of treatment and role of the TB Specialist Nurse

COMPLIANCE

TREATMENT COMPLETION

SIDE EFFECTS

How would you diagnose latent TB

?

Screening for latent TB in two instances:• Contact tracing – Specialist TB Service

mantoux/IGRA testing • Immigrant screening at port of entry and then local

referral to TB Specialist service OR at first registration in primary care – refer to TB

Specialist service Recent CXR (last six months) from high risk

countries with incidence < 40/100,000 CXR plus mantoux from high risk countries

< 500/100,000 e.g sub-Saharan Africa Mantoux only in children under 12 and pregnant

women IGRA testing if Mantoux positive* Treatment only offered to the under 35’s

Latent TB / TB infectionTuberculin reaction may be

positive for following• TB disease• Previous BCG• Atypical Mycobacteria • TB infection (Latent TB)

Mantoux test 1

Mantoux test 2

Mantoux test 3

End notes• TB remains a fascinating challenge

• Awareness and early referral to reduce transmission

• Direct referral to Specialist TB Services for advice and appointments tel/fax 9628051

• Choose and book not appropriate

• BCG has only been offered to high risk groups since 2005

Thank you!