Heaf test
Encyclopedia
The Heaf test is a diagnostic
skin test performed in order to determine whether or not a child has been exposed to tuberculosis
. Also known as the Sterneedle test, it is administered by a Heaf gun (trademarked "Sterneedle") which is a spring-loaded instrument with six needles arranged in a circular formation.
Patients who exhibit a negative reaction to the test
may be offered BCG
vaccination. The test is named after F. R. G. Heaf
. Until 2005, the test was used in the United Kingdom to determine if the BCG
vaccine was needed; the Mantoux test
is now used instead. The Heaf test was preferred in the UK, because it was felt that the Heaf test was easier to interpret, with less inter-observer variability, and that less training was required to administer and to read the test. The test was withdrawn because manufacturers could not be found for tuberculin or for Heaf guns.
The Heaf test is used to test for tuberculosis in adolescents
aged around 13–14.
A Heaf gun with disposable single-use heads is recommended.
The gun injects purified protein derivative
equivalent to 100,000 units per ml to the skin over the flexor surface of the left forearm in a circular pattern of six. The test is read between 2 and 7 days later. The injection must not be into sites containing superficial veins.
The reading of the Heaf test is defined by a scale:
Grades 1 and 2 may be the result of previous BCG or avian tuberculosis.
Children who have a grade 3 or 4 reaction require X-ray
and follow-up.
For interpretation of the test, see Tuberculosis diagnosis
.
positive levels done with 10 TU (0.1 mL 100 TU/mL, 1:1000) are
The Mantoux test
is preferred in the United States
for the diagnosis of tuberculosis; multiple puncture tests, such as the Heaf test and Tine test
, are not recommended.
Medical diagnosis
Medical diagnosis refers both to the process of attempting to determine or identify a possible disease or disorder , and to the opinion reached by this process...
skin test performed in order to determine whether or not a child has been exposed to tuberculosis
Tuberculosis
Tuberculosis, MTB, or TB is a common, and in many cases lethal, infectious disease caused by various strains of mycobacteria, usually Mycobacterium tuberculosis. Tuberculosis usually attacks the lungs but can also affect other parts of the body...
. Also known as the Sterneedle test, it is administered by a Heaf gun (trademarked "Sterneedle") which is a spring-loaded instrument with six needles arranged in a circular formation.
Patients who exhibit a negative reaction to the test
Test method
A test method is a definitive procedure that produces a test result.A test can be considered as technical operation that consists of determination of one or more characteristics of a given product, process or service according to a specified procedure. Often a test is part of an experiment.The test...
may be offered BCG
Bacillus Calmette-Guérin
Bacillus Calmette-Guérin is a vaccine against tuberculosis that is prepared from a strain of the attenuated live bovine tuberculosis bacillus, Mycobacterium bovis, that has lost its virulence in humans by being specially subcultured in an artificial medium for 13 years, and also prepared from...
vaccination. The test is named after F. R. G. Heaf
F. R. G. Heaf
Professor Frederick Roland George Heaf was a British physician.He was born in Desborough, Northamptonshire, England. He attended the University of Cambridge and St Thomas' Hospital as a medical student. He followed a career in Public health and became a Professor at the University of Wales in 1949...
. Until 2005, the test was used in the United Kingdom to determine if the BCG
Bacillus Calmette-Guérin
Bacillus Calmette-Guérin is a vaccine against tuberculosis that is prepared from a strain of the attenuated live bovine tuberculosis bacillus, Mycobacterium bovis, that has lost its virulence in humans by being specially subcultured in an artificial medium for 13 years, and also prepared from...
vaccine was needed; the Mantoux test
Mantoux test
The Mantoux test is a diagnostic tool for tuberculosis. It is one of the two major tuberculin skin tests used in the world, largely replacing multiple-puncture tests such as the Tine test...
is now used instead. The Heaf test was preferred in the UK, because it was felt that the Heaf test was easier to interpret, with less inter-observer variability, and that less training was required to administer and to read the test. The test was withdrawn because manufacturers could not be found for tuberculin or for Heaf guns.
The Heaf test is used to test for tuberculosis in adolescents
Adolescence
Adolescence is a transitional stage of physical and mental human development generally occurring between puberty and legal adulthood , but largely characterized as beginning and ending with the teenage stage...
aged around 13–14.
Procedure
A Heaf gun is used to inject multiple samples of testing serum under the skin at once. The needle points are dipped in tuberculin purified protein derivative (PPD) and pricked into the skin.A Heaf gun with disposable single-use heads is recommended.
The gun injects purified protein derivative
Mantoux test
The Mantoux test is a diagnostic tool for tuberculosis. It is one of the two major tuberculin skin tests used in the world, largely replacing multiple-puncture tests such as the Tine test...
equivalent to 100,000 units per ml to the skin over the flexor surface of the left forearm in a circular pattern of six. The test is read between 2 and 7 days later. The injection must not be into sites containing superficial veins.
The reading of the Heaf test is defined by a scale:
- Negative - No induration, maybe 6 minute puncture scars
- Grade 1 - 4-6 papules (also considered negative)
- Grade 2 - Confluent papules form indurated ring (positive)
- Grade 3 - Central filling to form disc (positive)
- Grade 4 - Disc >10 mm with or without blistering (strongly positive)
Grades 1 and 2 may be the result of previous BCG or avian tuberculosis.
Children who have a grade 3 or 4 reaction require X-ray
X-ray
X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...
and follow-up.
For interpretation of the test, see Tuberculosis diagnosis
Tuberculosis diagnosis
Tuberculosis is diagnosed by finding Mycobacterium tuberculosis bacteria in a clinical specimen taken from the patient. While other investigations may strongly suggest tuberculosis as the diagnosis, they cannot confirm it.-Diagnosis:...
.
Other Tests
The equivalent Mantoux testMantoux test
The Mantoux test is a diagnostic tool for tuberculosis. It is one of the two major tuberculin skin tests used in the world, largely replacing multiple-puncture tests such as the Tine test...
positive levels done with 10 TU (0.1 mL 100 TU/mL, 1:1000) are
- 0–4 mm induration (Heaf 0-1)
- 5–14 mm induration (Heaf 2)
- >15 mm induration (Heaf 3-4)
The Mantoux test
Mantoux test
The Mantoux test is a diagnostic tool for tuberculosis. It is one of the two major tuberculin skin tests used in the world, largely replacing multiple-puncture tests such as the Tine test...
is preferred in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
for the diagnosis of tuberculosis; multiple puncture tests, such as the Heaf test and Tine test
Tine test
The Tine test is a multiple puncture tuberculin skin test used to aid in the medical diagnosis of tuberculosis .This test uses a small "button" that has four to six short needles coated with TB antigens...
, are not recommended.