Tuberculosis in Children and Prevention SE Asia by jackie

It has been estimated by the World Health Organisation (WHO) that worldwide there are 490,000 cases of active TB and sickness in children, and 64,000 deaths of children from TB each year.

we are not doctors but bring to you reliable information from sources and give you the link of the source. Please refer to a medical professional if ill or have questions.

at http://www.tbfacts.org/tb-children.ht

How does a child get TB?

A child gets TB in basically the same way as an adult, which is by inhaling TB bacteria which are in the air as a result of being released into the air by someone with active TB. The source of infection for children is usually an adult in their household who has active TB, is coughing and is infectious, although there have also been instances of children being infected in a communal setting such as a school.

Children with TB in South Africa ©WHO/TBP/Gary Hampton

Once the TB bacteria have been inhaled they may reach the lungs, where they can multiply and then spread through the lymph vessels to nearby lymph nodes. The child’s immune response then develops a few weeks after this primary infection. In most children their immune response stops the TB bacteria from multiplying further although there may continue to be a few dormant bacteria.⁵

However in some cases the child’s immune response is not strong enough to stop the multiplication of the bacteria, and TB disease then develops. The risk of progression to TB disease is greatest when the child is less than four years old, and to a lesser extent when they are less than ten years old. There is also a greater risk of progression in children who have a compromised immune system, for example because they are HIV positive.

Children who develop TB disease usually do so within two years of first being infected. A small number of older children develop TB later, either due to reactivation following a period when the TB bacteria have been dormant, or as a result of reinfection.

Some children are at greater risk of getting TB than others and these include:

A child that lives in the same household as a person who has been recently diagnosed with smear positive TB
A child less than 5 years old
A child with HIV infection
A child with severe malnutrition.

Diagnosing TB in children is difficult as children are less likely to have obvious symptoms of TB, and samples such as sputum are more difficult to collect from young children. Even when sputum can be collected, it may have very few TB bacteria in it (paucibacillary smear-negative disease).

As with adults the symptoms of TB depend on the type of TB that the child has. Children usually have pulmonary TB but they develop extra pulmonary TB (disseminated TB) more often than adults. Disseminated TB such as TB meningitis particularly occurs in young children less than 3 years old. Miliary TB is another name for disseminated TB.

In children with pulmonary TB the commonest chronic symptoms are a chronic cough that has been present for more than 21 days, a fever, and weight loss or failure to thrive.

How do you treat TB in children?

In the same way as TB treatment is provided for adults, TB treatment for children involves a child taking a number of different drugs at the same time for several months.

How do you prevent TB in children?

The main way that TB is prevented in children is by the use of the BCG vaccine.

TB can also be prevented in children by diagnosing and treating cases of active TB amongst adults, as it is usually adults, particularly adults in the same household, who pass TB on to children. Children with TB are usually not infectious, and so will usually not pass on TB to either other children or adults.

Estimated WHO Regional TB statistics for 2012
Region	TB Mortality	HIV Positive TB Mortality	Prevalence	Incidence	Population
Africa	230,000	250,000	2,700,000	2,300,000	892,529,000
Americas	19,000	6,400	390,000	280,000	961,103,000
Eastern Mediterranean	100,000	4,200	1,100,000	670,000	616,591,000
Europe	36,000	3,900	510,000	360,000	904,540,000
South-East Asia	450,000	51,000	4,800,000	3,400,000	1,833,359,000
Western Pacific	110,000	4,800	2,400,000	1,600,000	1,845,562,000
Global Total	940,000	320,000	12,000,000	8,600,000	7,053,684,000

Statistics for TB in “High Burden” Countries 2012
Country	TB Mortality	HIV Positive TB Mortality	Prevalence	Incidence	HIV Positive TB Incidence	Population
Afghanistan	11,000	110,000	13,000	13,000	13,000	29,825,000
Bangladesh	70,000	620,000	68,000	68,000	13,000	154,695,000
Brazil	4,900	91,000	5,600	5,600	13,000	198,656,000
Cambodia	9,300	120,000	9,100	9,100	13,000	14,865,000
China	44,000	1,400,000	47,000	47,000	13,000	1,377,065,000
DR Congo	36,000	350,000	36,000	36,000	13,000	65,705,000
Ethiopia	16,000	200,000	15,000	15,000	13,000	91,729,000
India	270,000	3,100,000	300,000	300,000	13,000	1,236,687,000
Indonesia	67,000	680,000	65,000	65,000	13,000	246,864,000
Kenya	9,500	120,000	9,200	65,000	13,000	43,178,000
Mozambique	13,000	120,000	11,000	65,000	13,000	25,203,000
Myanmar	25,000	240,000	23,000	65,000	13,000	52,797,000
Nigeria	27,000	280,000	27,000	65,000	13,000	168,834,000
Pakistan	62,000	620,000	59,000	65,000	13,000	179,160,000
Philippines	23,000	460,000	28,000	65,000	13,000	96,707,000
Russian Federation	19,000	180,000	22,000	65,000	13,000	143,170,000
South Africa	31,000	390,000	25,000	65,000	13,000	52,386,000
Thailand	9,200	110,000	9,800	65,000	13,000	66,785,000
Uganda	4,700	63,000	5,000	65,000	13,000	36,346,000
UR Tanzania	6,100	82,000	6,400	65,000	13,000	47,783,000
Viet Nam	18,000	290,000	30,000	65,000	13,000	90,796,000
Zimbabwe	4,600	70,000	6,000	65,000	13,000	13,724,000
Total for High Burden Countries	780,000	9,696,000	821,000	65,000	13,000	4,432,959,000

Strategies for TB prevention

TB prevention consists of two main parts. The first part of TB prevention is to stop the transmission of TB from one adult to another. This is done through firstly, identifying people with active TB, and then curing them through the provision of drug treatment. With proper TB treatment someone with active TB disease will very quickly not be infectious and so can no longer spread the disease to others. The second main part of TB prevention is to prevent people with latent TB from developing active, and infectious, TB disease.

Anything which increases the number of infectious people, such as the presence of TB and HIV infection together, or which increases the number of people infected by each infectious person, such as ineffective treatment because of drug resistant TB, reduces the overall effect of the main TB prevention efforts. As a result it is then more likely that the number of people globally developing active TB will increase rather than decrease.

There is a vaccine for TB, but it makes only a small contribution to TB prevention, as it does little to interrupt the transmission of TB among adults.

TB prevention – the BCG vaccine

The TB vaccine called Bacillus Calmette-Guerin (BCG) was first developed in the 1920s. It is one of the most widely used of all current vaccines, and it reaches more than 80% of all new born children and infants in countries where it is part of the national childhood immunization programme.¹ However, it is also one of the most variable vaccines in routine use.

The BCG vaccine has been shown to provide children with excellent protection against the disseminated forms of TB, however protection against pulmonary TB in adults is variable. Since most transmission originates from adult cases of pulmonary TB, the BCG vaccine is generally used to protect children, rather than to interrupt transmission amongst adults.

The BCG vaccine will often result in the person vaccinated having a positive result to a TB skin test

TB Treatment as TB prevention

TB drug treatment for the prevention of TB, also known as chemoprophylaxis, can reduce the risk of a first episode of active TB occurring in people either exposed to infection, or with latent TB. It can also reduce the risk of a recurrent TB episode.

For TB prevention the World Health Organisation (WHO) recommends the drug isoniazid should be taken daily for at least six months and preferably nine months.

The main “target” groups for TB treatment for prevention, are those most at risk of progressing from latent to active TB. These include:

Infants and children aged less than 4 years old;
People infected within the previous two years;
People infected with both TB and HIV;
People who have certain clinical conditions, or conditions which compromise their immune system, such as people with diabetes, and people with chronic renal failure.

Isoniazid is a cheap drug, but in a similar way to the use of the BCG vaccine, it is mainly used to protect individuals rather than to interrupt transmission between adults. This is because children rarely have infectious TB, and it is hard to administer isoniazid on a large scale to adults who do not have any symptoms. Taking isoniazid daily for six months is difficult in respect of adherence, and as a result many individuals who could benefit from the treatment, stop taking the drug before the end of the six month period.

At a Paediatric HIV/AIDS conference in Kampala, doctors were unable to agree as to whether children infected with HIV should be given Isoniazid as preventative treatment for TB. Those arguing for the drug treatment as prevention, claimed that in children co-infected with HIV and TB, up to 50% of exposed children ended up developing the disease.²

There have also been concerns about the possible impact of TB treatment for prevention programmes on the emergence of drug resistance. However, a review of the scientific evidence has now shown that there is no need for this to be a concern. The benefit of isoniazid preventative therapy for people living with HIV, and who have, or may have had latent TB, has also recently been emphasized.

Preventing TB transmission in households

Actions to be taken

In order to reduce exposure in households where someone has infectious TB, the following actions should be taken whenever possible:

Houses should be adequately ventilated;
Anyone who coughs should be educated on cough etiquette and respiratory hygiene, and should follow such practice at all times;
While smear positive, TB patients should:
- Spend as much time as possible outdoors;
- If possible, sleep alone in a separate, adequately ventilated room;
- Spend as little time as possible on public transport;
- Spend as little time as possible in places where large numbers of people gather together.

Cough etiquette and respiratory hygiene means covering your nose and mouth when coughing or sneezing. This can be done with a tissue, or if the person doesn’t have a tissue they can cough or sneeze into their upper sleeve or elbow, but they should not cough or sneeze into their hands. The tissue should then be safely disposed of.

Households where someone has culture positive MDR TB

t is not fully known how differences between drug susceptible, and drug resistant TB, as well as HIV status, affect the risk of TB transmission. However it is thought that people with drug resistant TB remain infectious for much longer, even if treatment has been started, and this may prolong the risk of transmission in the household.

In households with culture positive MDR TB patients, the following guidance should therefore be observed in addition to the measures given above.

Culture positive MDR TB patients who cough should always practice cough etiquette (including use of masks) and respiratory hygiene when in contact with people. Ideally health service providers should wear respirators when attending patients with infectious MDR TB in enclosed spaces.;
Ideally, family members living with HIV, or family members with strong clinical evidence of HIV infection, should not provide care for patients with culture positive MDR TB;
Children below five years of age should spend as little time as possible in the same living spaces as culture positive MDR TB patients.

Face masks are different from respirators and can be made from either cloth or paper. A face mask worn by someone with infectious TB can help to prevent the spread of M. tuberculosis from the patient to other people. The face mask can capture large wet particles near the mouth and nose of the patient, preventing the bacteria from being released into the environment. Cloth masks can be sterilized and reused.

Respirators can protect health care workers from inhaling M. tuberculosis in certain circumstances, but they are expensive to purchase and they require specialized equipment to ensure that they fit properly. The use of a face mask does not protect health care workers against TB, and so a health care worker or other staff should not wear a face mask in a household (or indeed in a health care) setting.

Physical measures for TB prevention

Before drug treatment for TB became available, removing TB patients from their homes and putting them in isolation in sanatoria, was the main way of reducing the transmission of TB.

However this policy changed in the vast majority of countries, after studies showed that if patients stayed at home and were treated on an “outpatient” basis, this did not increase the risk of TB amongst the household contacts of the people with TB. This is because drug treatment quickly makes a TB patient uninfectious, and most household contacts who do become infected, will have already become infected before the diagnosis of TB has been made.

So generally there is now no need for people to leave their homes because they have TB. The only exceptions to this is, as described above, when someone has infectious XDR TB, and it is not feasible to isolate them at home. Also people may still need to go into a health care facility because there are complications arising from their condition, or their treatment. Within a health care facility there may be a need for some separation of people as described below, in order to reduce the chances of transmission.

The measures described above also mainly apply to resource poor settings, and the recommendations can be different where more resources are available.