Childhood TB was written to enable healthcare workers to learn about the primary care of children with tuberculosis. It covers: introduction to TB infection, the clinical presentation, diagnosis, management and prevention of tuberculosis in children

1. 1
Introduction
to childhood
tuberculosis
Before you begin this unit, please take the TUBERCULOUS INFECTION
corresponding test at the end of the book to
assess your knowledge of the subject matter.
You should redo the test after you’ve worked 1-1 What is tuberculosis?
through the unit, to evaluate what you have
learned. Tuberculosis (TB or TB disease) is a chronic
infectious disease which may involve many
organs of the body, but most often affects
Objectives the lungs. Tuberculosis of the lung is called
pulmonary tuberculosis.
When you have completed this unit you Tuberculosis is a chronic infectious disease.
should be able to:
• Explain what tuberculosis is.
1-2 What causes tuberculosis?
• Describe how TB bacilli are spread.
• Explain the difference between TB Tuberculosis is a bacterial illness caused by
Mycobacterium tuberculosis. These bacteria
infection and tuberculosis.
are also referred to as TB bacilli (tuberculous
• Explain why children are at high risk of bacilli).
TB infection.
• List communities in which tuberculosis
Tuberculosis is caused by TB bacilli.
is common.
• Explain the features of pulmonary NOTE Mycobacterium tuberculosis was
tuberculosis. first described by Robert Koch in 1882.
• List the common forms of
extrapulmonary tuberculosis. 1-3 How are TB bacilli spread?
Tuberculosis is an infectious disease which
results from the spread of TB bacilli from one
person to another. TB bacilli are usually spread

2. 16 CHILDHOOD TB
when a person with pulmonary tuberculosis home. A mother with untreated pulmonary
talks, coughs, spits, laughs, shouts, sings or tuberculosis who is in close contact with her
sneezes. This sends a spray of very small children is a great danger to her children.
droplets from the person’s infected lungs into
Children in close, prolonged contact with
the air (i.e. airborne droplet spread). Live TB
adults who have untreated pulmonary
bacilli in these droplets then float in the air
tuberculosis are at greatest risk. Younger
and may be breathed in by other people. If the
children are more likely to spend most of the
inhaled TB bacilli reach the alveoli they cause
day and night with an adult.
a tuberculous infection of the lung.
1-4 Who usually spreads TB bacilli? Children in poorly ventilated, overcrowded homes
are at greatest risk of infection with TB bacilli.
TB bacilli are usually spread from adults with
untreated pulmonary tuberculosis. Therefore,
a child with tuberculosis almost always has 1-7 Do all children infected with
been in close contact with an adult with TB bacilli develop tuberculosis?
pulmonary tuberculosis (the source of the TB No. Most children infected with TB bacilli
bacilli). It is less common for a child to catch do not develop tuberculosis (TB disease)
tuberculosis from another child as children because their immune system is able to control
usually do not cough up TB bacilli in large the infection and kill most of the TB bacilli.
numbers. Therefore, adults with untreated As a result, the natural immune response
tuberculosis are a danger to children in the protects most children with TB infection from
family or household. progressing to tuberculosis.
It is very important to understand that a child
TB bacilli that infect children are usually spread can only develop tuberculosis if the child is
from an adult with untreated pulmonary first infected with TB bacilli. Furthermore,
tuberculosis. TB infection does not always progress to
tuberculosis (TB disease). Therefore TB
NOTE TB bacilli in unpasteurised or unboiled infection without further progression is not
cows’ milk (Mycobacterium bovis) can be the same as tuberculosis.
drunk and cause infection of the tonsil or gut,
but this is very uncommon in South Africa.
Fortunately most children infected with TB bacilli
1-5 Which children are at greatest do not develop tuberculosis.
risk of infection with TB bacilli?
The progression of TB infection to tubeculosis
Children, especially those under five years of
is more common in children than in adults.
age, who are exposed to large numbers of TB
bacilli.
1-8 Which children with TB infection are at
the greatest risk of developing tuberculosis?
1-6 Which children are exposed to
large numbers of TB bacilli? Children with a weak immune system
are at the greatest risk. In these children,
Children who live in overcrowded,
infection with TB bacilli may progress to
poorly ventilated homes or are exposed
tuberculosis because they have an inadequate
to crowded buses, taxis, schools, crèches
immune system which is unable to control
and spaces where there are adults with
the infection. TB infection caused by large
untreated pulmonary tuberculosis. A child
numbers of TB bacilli is also more likely to
with tuberculosis often has an adult with
progress to tuberculosis.
untreated tuberculosis living in the same

3. INTRODUCTION TO CHILDHOOD TUBERCULOSIS 17
Therefore, both TB infection and progress to The risk of TB infection progressing to
tuberculosis are most common when a child tuberculosis is greater in young children
with a weak immune system is exposed to than in older children or adults. In children
large numbers of TB bacilli. infected under two years of age, the risk is as
high as 50%.
Children with weak immune systems are at
greatest risk of tuberculosis. About 10% of people with TB infection will
develop tuberculosis.
1-9 Which children have weak
immune systems? 1-12 What do you understand by
the incidence of tuberculosis?
Young children under five years, and especially
if under two years, of age have immature The incidence is the number of people with
(weak) immune systems which are unable to tuberculosis per 100 000 of the population per
control severe infections. The immune system year. This is a very useful measure as it allows
can further be weakened in: the frequency of tuberculosis in different
communities or countries to be compared. The
• Children with HIV infection
incidence of a single community can also be
• Children recovering from measles or
compared from one year to the next.
whooping cough
• Children with severe malnutrition
• Children on large doses of oral steroids 1-13 What is the incidence of
tuberculosis in South Africa?
HIV infection is the most important cause of a
weakened immune system. While tuberculosis is uncommon in most
developed countries, it is common in
developing countries such as South Africa
Children with HIV infection have the highest risk where the number of people with tuberculosis
of developing tuberculosis. has increased rapidly in the last few years.
The incidence of tuberculosis in South Africa
1-10 Is TB infection common? was 948/100 000 in 2007. This is high when
compared to developed countries like the
Yes, infection with TB bacilli (Mycobacterium United Kingdom where the incidence of
tuberculosis) is very common, and it is tuberculosis in 2007 was 13/100 000.
estimated that almost 50% of adult South
Africans have been infected. Most infections In South Africa tuberculosis is particularly
take place during childhood. common in the Western Cape and KwaZulu-
Natal. It is estimated that there are 400 new
cases of tuberculosis per 100 000 children
TB infection is common and usually occurs during each year in the Western Cape. In any clinic
childhood. children will make up approximately 15% of
all the cases of tuberculosis.
1-11 How many children with TB NOTE About ten million new cases of
infection develop tuberculosis? TB occur worldwide each year with two
million deaths due to TB. About 300 South
Only about 10% of all people with TB Africans die of TB each day. With the AIDS
infection progress to tuberculosis (TB disease) epidemic this figure is rising rapidly.
during their lifetime. Therefore, TB infection
is far more common than tuberculosis.

4. 18 CHILDHOOD TB
1-14 In which communities is area of inflammation. This is called primary
tuberculosis common? tuberculosis. From the primary infection TB
bacilli spread along the lymphatics to the local
TB is common in poor, disadvantaged
lymph nodes at the place where the main
communities where overcrowding,
bronchi divide into branches (hilar nodes).
undernutrition and HIV infection are
The primary infection in the lung, together
common. Tuberculosis is a disease of poverty.
with the infected hilar lymph nodes, is called
Tuberculosis spreads in any overcrowded
the primary complex. Parahilar and other
living spaces, both at home and in the
mediastinal nodes may also be affected.
community. TB is often transmitted by
a child’s family member, friend or close After six weeks the immune system usually
neighbour. However it may also be caught becomes active and kills most of the TB bacilli
in a public space if there are many untreated in the lung and lymph nodes. As a result, the
patients in the community. primary infection is asymptomatic in most
children and does not cause clinical illness.
Tuberculosis is usually seen in poor communities. Therefore, the primary TB infection usually
heals and does not spread any further, as the
NOTE About 95% of new TB cases and 99% TB bacilli have been contained by the body’s
of TB deaths worldwide are in developing natural immunity.
countries. In developed countries TB is NOTE The primary TB infection in the lung
virtually confined to poor, overcrowded used to be called the Ghon focus.
environments and ethnic minorities.
1-15 Why is tuberculosis an Inhaling TB bacilli into the lung may result in
important disease? primary infection.
Tuberculosis is a major cause of illness and
death in many poor countries. These are 1-17 Can the primary TB infection
preventable deaths, and the large number of cause illness due to spread of the
patients with tuberculosis is a huge drain on infection within the lung?
healthcare resources. Sometimes the primary TB infection is not
controlled by the immune system and the
Tuberculosis is an important cause of illness and child now becomes ill with the signs and
death. symptoms of pulmonary tuberculosis. This is a
common form of tuberculosis in children.
With progression of the primary infection
PULMONARY to pulmonary tuberculosis, the TB bacilli
continue to multiply and an area of
TUBERCULOSIS inflammation develops in the lung and lymph
nodes in an attempt to prevent the TB bacilli
from spreading any further. Often the centre
1-16 What is primary TB infection of the inflamed area becomes soft as the tissues
of the lung? die. These dead cells (caseous material) can
Tuberculous infection usually starts when TB drain into the surrounding tissues.
bacilli are inhaled deep into the distant parts There are a number of different ways that the
of the lungs, called alveoli. During the first six primary TB infection can spread (progress)
weeks of infection the immune system is unable and lead to complications.
to control the TB bacilli, which multiply rapidly
in the alveoli where they cause a small, local

5. INTRODUCTION TO CHILDHOOD TUBERCULOSIS 19
measles, the TB bacilli may start to multiply
The primary TB infection may spread to cause
once more (reactivation) and a local area
pulmonary tuberculosis.
of tuberculous pneumonia will develop.
Therefore, pulmonary tuberculosis due to
NOTE The immune response to TB bacilli
reactivation of dormant TB bacilli may only
is dependent on T lymphocytes.
present years after the primary infection.
1-18 What are the pulmonary complications
of the primary TB infection in the lung? Pulmonary tuberculosis with enlarged hilar
lymph nodes is the commonest form of
• In some children with a weak immune
system, the body is unable to control the
tuberculosis in children.
primary infection in the lung. The TB
bacilli continue to multiply and spread 1-19 What are the pulmonary complications
into neighbouring parts of the lung to of TB infection in the hilar lymph nodes?
cause tuberculous pneumonia. Progression
• TB bacilli may multiply rapidly in the hilar
from the primary infection to pulmonary
lymph nodes, causing the nodes to enlarge
tuberculosis usually takes place rapidly
and compress the bronchus or trachea
within weeks or months and the child
(airway). Clinically this may present as
becomes ill. This pattern of tuberculosis,
wheezing or stridor with either collapse or
together with enlarged hilar nodes, is the
hyperinflation of a lobe or the whole lung.
commonest form of tuberculosis in young
• The enlarged lymph node may rupture
and undernourished children.
into a bronchus spreading large numbers
• Cavitary tuberculosis (‘open tuberculosis’)
of TB bacilli into other areas of the lung.
is usually seen in older children and
This results in widespread tuberculous
adolescents. The area of tuberculous
bronchopneumonia.
pneumonia progresses and breaks down to
form a hole. This occurs most commonly
in the upper parts of the lung and results Enlarged hilar lymph nodes may compress the
in an air-filled cavity containing dead airways causing wheezing.
(caseous) tissue which contains huge
numbers of TB bacilli. This form of
1-20 Why are the lungs the
pulmonary tuberculosis is very infectious
commonest site of tuberculosis?
as TB bacilli grow fast and many TB bacilli
enter the airways. From here they are The lungs are the commonest site of
coughed into the air where they may be tuberculosis as TB infection is usually caused
breathed in and infect the lungs of other by inhaling TB bacilli.
people. Children and adolescents with
cavitary tuberculosis are very infectious 1-21 What is the difference
and can infect other children and adults. between pulmonary tuberculosis
• Damage to the large airways by in children and adults?
tuberculosis can result in bronchiectasis.
• In older children and adults the TB While children usually have lymph node
bacilli often remain dormant (inactive or enlargement with few TB bacilli in the sputum,
‘sleeping’) in the lung for many months or adolescents and adults usually have cavitary
even years after the primary infection. The tuberculosis with destruction of lung tissue and
body has been able to control but not kill large numbers of TB bacilli in their sputum.
all the TB bacilli. If the immune system
later becomes weakened by malnutrition
or another infection, such as HIV or

6. 20 CHILDHOOD TB
NOTE Cavities are formed in adult-type 1-23 Which other organs can be
tuberculosis, usually in the upper lobes or apices involved in tuberculosis?
of the lower lobes of the lungs. This can result in
permanent lung damage and scarring (fibrosis). Although the lung is the commonest organ
infected by TB bacilli, tuberculosis can involve
any other organ of the body. Sometimes
EXTRAPULMONARY more than one organ is infected. The organs
which are most commonly infected via the
TUBERCULOSIS bloodstream in children are:
• The meninges (tuberculous meningitis)
1-22 Can tuberculous infection spread • Bones, especially the spine (tuberculous
from the lung to other parts of the body? osteitis)
• Joints, especially the hip joint (tuberculous
Yes. This spread beyond the lungs is called arthritis)
extrapulmonary tuberculosis: • Intra-abdominal organs such as liver
• Tuberculosis may spread from the lung to and spleen and peritoneum (abdominal
the pleura causing a pleural effusion. tuberculous)
• Infection with TB bacilli can spread NOTE The skin, tonsils, pericardium, bone
from the lung, and especially the hilar marrow, middle ear and genitalia are less
lymph nodes, via the bloodstream (TB common sites of tuberculosis in children.
bacteraemia) to most organs of the body. Tuberculosis of the kidney usually follows
In children the TB bacilli usually spread five or more years after the primary infection
at the time of the primary lung infection. and therefore is uncommon in childhood.
As a result, tuberculosis of other organs
usually presents soon after the primary 1-24 What is disseminated tuberculosis?
lung infection. However, the TB bacilli Tuberculosis involving multiple organs is
may remain dormant in these organs for referred to as disseminated tuberculosis.
many months or years before they start to This follows spread of TB bacilli through the
multiply and cause local tuberculosis. This bloodstream to many organs. If disseminated
reactivation of TB bacilli is usually due to tuberculosis includes widespread infection of
weakening of the immune system. both lungs, it is called miliary tuberculosis.
• TB bacilli can also spread to other lymph This is a very serious illness with a high
nodes via the lymphatics (e.g. from the mortality rate unless diagnosed and treated
hilar lymph nodes up to the cervical lymph early. It usually occurs in young children.
nodes or down to the abdominal lymph
nodes). Lymph nodes in the axilla or groin
may also be involved. However, lymphatic Disseminated tuberculosis is a serious illness
spread is usually to the cervical nodes. with a high mortality rate.
TB infection of lymph nodes is called
tuberculous lymphadenitis.
1-25 Is extrapulmonary
tuberculosis infectious?
Tuberculous bacilli may spread from the lungs Unlike pulmonary tuberculosis, tuberculosis of
to other organs via the bloodstream or the other organs is rarely infectious to other people.
lymphatics.

7. INTRODUCTION TO CHILDHOOD TUBERCULOSIS 21
1-26 Is extrapulmonary tuberculosis mother to cough over her newborn infant.
common in children? TB bacilli do not appear in the breast milk.
Therefore breastfeeding is safe as long as
Yes, extrapulmonary tuberculosis is far more
the mother is on treatment and the infant
common in children than in adults. Cervical
receives prophylaxis.
lymph node enlargement is the commonest
form of extrapulmonary tuberculosis in
children.
CASE STUDY 1
Cervical lymph node enlargement is the A child of six years develops primary TB
commonest form of extrapulmonary tuberculosis infection in her one lung. She remains
in children. clinically well however. When she is weighed
by the school nurse, the mother is reassured
1-27 Can one have a tuberculous that the child is healthy and thriving.
infection more than once?
1. What is the cause of TB infection?
Yes. Previous TB infection does not give
complete immunity to further TB infections. TB bacilli (Mycobacterium tuberculosis).
A child with a healed primary infection can,
months or years later, have another new 2. Why is this child clinically well if
primary infection when they are exposed to she has a primary TB infection?
an infectious case of tuberculosis, especially
Because most children with a primary TB
if their immune system is weakened by severe
infection have no signs or symptoms of
malnutrition or HIV.
illness. Her immune system has controlled
Therefore, pulmonary tuberculosis may be the TB infection.
due to immediate spread from the original
primary infection, reactivation (relapse) 3. Will this child develop tuberculosis?
of an old primary infection which had not
healed fully (latent tuberculous infection), Probably not, as most children are able to
or spread from a new primary infection prevent the spread of TB bacilli from the
(reinfection). In children, spread from the primary infection.
primary TB infection to cause tuberculosis is
most common and usually occurs within two 4. Which children are at greatest
years of being infected (90% within one year of risk of the primary infection
being infected). progressing to tuberculosis?
Children with weak immune systems. These
1-28 Can a mother with tuberculosis infect include young children, malnourished
her infant either before or after birth? children and children with HIV infection.
Yes. During pregnancy TB bacilli in the mother
can be spread via the bloodstream to the 5. How common is TB infection?
placenta. From here the TB bacilli may reach Very common. Almost 50% of adult South
the fetus via the umbilical vessels or may infect Africans have had a primary TB infection
the amniotic fluid and then be swallowed by at some time in their lives, most during
the fetus. Infection during delivery is rare. childhood.
However, the spread of TB bacilli from a
mother to her infant usually happens after
delivery. The greatest risk is for an infectious

8. 22 CHILDHOOD TB
6. How many children with TB 4. Is childhood tuberculosis
infection develop tuberculosis? common in South Africa?
The risk of progression from TB infection to Yes, especially in poor, disadvantaged
tuberculosis during a lifetime is about 10%. communities. Childhood tuberculosis makes
However the risk is higher in children and is up approximately 15% of all the cases at a TB
as high as 50% in children under two years clinic.
of age. Therefore TB infection is particularly
dangerous in young children. 5. What are the pulmonary complications
of primary TB infection in the lung?
CASE STUDY 2 The primary infection in the lung may
progress to tuberculous pneumonia. In older
children and adults this may form a cavity. The
An 18-month-old child lives in an overcrowded grandfather probably has cavitary tuberculosis.
home. During the day he is looked after by
his grandfather who is unwell and has had
6. Are the hilar lymph nodes often
a chronic cough for the past few months.
involved in primary TB infection?
The clinic nurse is worried as the child is
malnourished and recently had measles. Yes. The primary TB infection in the lung
is usually associated with enlarged hilar
1. Why is this child at high lymph nodes. Together they are called the
risk of TB infection? primary complex. The enlarged hilar nodes
can compress a large airway causing wheeze
Because the grandfather probably has or stridor. Further enlargement of the lymph
undiagnosed pulmonary tuberculosis. The nodes may result in collapse or overinflation
house is overcrowded and the child has of a lobe.
prolonged contact with the grandfather. These
factors all suggest that the child is being
exposed to large numbers of TB bacilli.
CASE STUDY 3
2. Why will the TB infection probably
The parents are very worried as their
progress to tuberculosis?
daughter has a lump in her neck which has
Because the child has a weak immune system been diagnosed as tuberculosis. Friends tell
due to his young age, malnutrition and recent them that the diagnosis must be wrong as
measles infection. tuberculosis only affects the lungs.
The child’s age and exposure to large numbers
of TB bacilli will, therefore, increase his 1. Does tuberculosis only affect the lungs?
risk of both TB infection and progress to No. Tuberculosis may affect most organs of the
tuberculosis. body. Tuberculosis outside the lungs is called
extrapulmonary tuberculosis.
3. What other infection may
weaken the immune system? 2. What is the likely cause of
HIV. the lump in her neck?
Tuberculosis of a lymph node (tuberculous
lymphadenitis).

9. INTRODUCTION TO CHILDHOOD TUBERCULOSIS 23
3. What other organs are most THE FIVE MOST
commonly infected with TB?
IMPORTANT ‘TAKE-
The meninges (TB meningitis), bones (TB
osteitis), joints (TB arthritis) and abdominal HOME’ MESSAGES
organs (abdominal TB).
1. Children are infected with TB bacilli after
4. What is disseminated tuberculosis? exposure to someone with infectious
pulmonary tuberculosis.
The spread of TB infection to many organs. 2. Most TB infection in children does not
This is a serious illness with a high mortality progress to disease (tuberculosis).
rate. 3. The children at greatest risk of progression
to disease are children infected when
5. Is extrapulmonary tuberculosis less than two years of age, HIV infected
infectious to others? children, and children with malnutrition.
Usually not. However, extrapulmonary and 4. Pulmonary tuberculosis with enlarged
pulmonary TB may occur in the same patient. hilar lymph nodes is the commonest form
Pulmonary tuberculosis is the most infectious of tuberculosis in children.
form of the disease. 5. Cervical lymph node enlargement is the
commonest form of extrapulmonary
tuberculosis in children.
6. Can a newborn infant be infected
with tuberculosis from the mother?
Tuberculosis can spread from mother to infant
during pregnancy but this is uncommon.
The greatest risk is when a mother with
tuberculosis coughs onto her newborn infant.