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Communicable Diseases Module: 16. Tuberculosis Treatment in Special Conditions: TB in Children, HIV/TB and Drug Resistant TB

Study Session 16  Tuberculosis Treatment in Special Conditions: TB in Children, HIV/TB and Drug Resistant TB

Introduction

In this study session, you will first learn about diagnosis and management of tuberculosis in children and how this differs from the adult (Section 16.1). Section 16.2 discusses what happens with patients who are infected with both TB and HIV — an example of a co-infection — and how this is managed. Finally, in Section 16.3 we look at the situation where patients have TB that is resistant to drugs.

Of all TB cases registered with the National Tuberculosis programme in Ethiopia, up to a fifth occur in children. Children can present with TB at any age, but the most common age is between one and four years. In most cases, TB in children is a result of primary TB (i.e. the first infection) from an infectious adult or older child, unlike cases in adults which are most often due to reactivation of a previous TB infection. The best way to prevent childhood TB is therefore by proper identification of those who may be infected with TB, and treatment of active TB patients in the home and community.

The HIV epidemic has made the position with regard to TB worse by increasing the risk of reactivation of latent TB infection and by facilitating more rapid progression of TB disease. TB can readily be transmitted to both HIV-negative and HIV-positive households and to other close contacts of infectious patients.

Learning Outcomes for Study Session 16

When you have studied this session, you should be able to:

16.1  Define and use correctly all of the key words printed in bold. (SAQ 16.3)

16.2  Describe the key differences in the diagnosis and management of TB in children and adults. (SAQ 16.1)

16.3  Identify the key factors that will help you look after patients with HIV/TB co-infection. (SAQ 16.2)

16.4  Describe the main causes and consequences of drug-resistant tuberculosis. (SAQ 16.3)

16.1  Diagnosis and management of TB in children

In this section, you will learn how to diagnose and treat TB in children and how to follow their progress after treatment. The diagnosis is made at the health centre or hospital and children will be referred to you to continue treatment in the community under your supervision. The families of children who have TB may ask you questions regarding the drugs that their child is required to take, so it is very important to know a little about the major anti-TB drugs, even though you are not the key person involved in diagnosing TB and prescribing anti-TB drugs.

Note that sputum smear-negative, but culture positive patients are also infectious, but to a lesser degree

Very often children who are exposed to a positive contact within their close environment (especially the household), will acquire tuberculosis infection. A close contact is defined as someone living in the same household, or being in frequent contact with a person who is sputum smear-positive for TB. This exposure leads to the development of a primary (the first or original) lesion in the lungs, which is likely to spread to the regional lymph node(s). In the majority of cases, the child’s immunity will control the disease process at this stage. Progression to TB disease occurs more commonly in children under five years of age and in children who are HIV infected (because their immune systems are therefore compromised), or who have had measles, or who are malnourished.

16.1.1  Symptoms of childhood TB

Children with TB develop chronic symptoms in most cases, and TB may be a more acute disease in the presence of HIV infection. The commonest symptoms that parents notice are:

  • Chronic cough: persistent cough (present for more than two weeks) and not improving.
  • Fever: fever of greater than 38°C for 14 days, after common causes such as malaria and pneumonia have been ruled out.
  • Weight loss: documented weight loss or failure to gain weight.
Figure 16.1  A mother suspected of TB coughing and releasing droplet nuclei into the air that could infect other members of the household, particularly children. People with HIV are at greater risk of being infected with TB.

16.1.2  Signs of childhood TB

The clinical picture of pulmonary TB in older children is similar to that of pulmonary tuberculosis in the adult. For older children capable of producing sputum, samples should be collected as for adults. A range of additional physical signs are suggestive of EPTB. These can include swelling over the spine (called a gibbus) and/or an enlargement of the side of the neck, and neck rigidity not responding to treatment with antibiotics. Other signs are abdominal swelling and non-painful enlarged joints. If a child has the symptoms of pulmonary or extra-pulmonary TB, you should refer him or her for investigation.

You should always ask adult TB suspects and patients if there are children in their households. Any child suspected of having TB should be referred for investigation.

The diagnosis of TB in younger children (less than a year of age) can be more difficult. One of the indictors that you should be aware of is contact with a family member or close associate with TB. Another key factor in diagnosis is loss of weight and failure to thrive. One of the problems is that children of this age rarely produce sputum and, as you know, this laboratory test is the main method of diagnosis in adults.

In those cases of younger children where you suspect TB, you must tell the family to take the child to a higher health facility for diagnosis. To make the diagnosis of childhood TB with a fair degree of accuracy, one or more of the tests outlined in Box 16.1 are generally followed.

Box 16.1  Recommended approach for diagnosing TB in children

  • Careful history-taking, including history of TB contacts and symptoms consistent with TB
  • Clinical examination, including growth assessment; where you see failure to grow, especially in younger children, and weight loss, suspect TB and send the child for investigation
  • Sputum examination; children able to produce sputum should submit sputum for examination
  • Chest X-ray; this investigation is relevant for suspected pulmonary TB cases not producing sputum and for extra-pulmonary TB
  • Biopsy for extra-pulmonary TB; this procedure was mentioned in Study Session 14
  • HIV testing; where appropriate, advise the parents of a child TB suspect to agree to an HIV test for the whole family.

16.1.3  Diagnosis of tuberculosis in HIV-positive children

As in adults, pulmonary TB (PTB) is the most common manifestation of TB in HIV-positive children. The diagnosis of PTB in children under four years old has always been difficult, and infection with HIV makes the effective diagnosis of TB in such cases more challenging.

The approach to diagnosing TB in HIV-infected children is essentially the same as for those children who are HIV-negative, i.e. the presence of three or more of the characteristic symptoms indicates a diagnosis of TB. It is especially important to look for chronic symptoms suggestive of TB, and for physical signs that are highly suggestive of TB — including the results of chest X-ray findings (refer to Study Session 14). Children who present with chronic symptoms suggestive of TB also need testing for HIV infection.

16.1.4  Treatment of tuberculosis in children

As you read in Study Session 13, DOTS (Directly Observed Treatment, Short-course) should be used for all children with tuberculosis. Even when drugs are given under DOTS, tolerance of the medications must be closely monitored. Do not rely solely upon the parents of the child to supervise DOTS; you are responsible for monitoring.

Table 16.1 show different categories of TB cases that you are already familiar with, together with the drug treatment regimen required in children (the number of months for each treatment is indicated by the number in front of the bracket containing the drug combination).

Table 16.1  TB diagnostic category and the recommended treatment regimen in children.
TB treatment categoryTB casesRegimen (daily or three times every week)
Intensive phaseContinuation phase
I
  • New smear-positive pulmonary TB
  • New smear-negative pulmonary TB with extensive involvement of lung tissue
  • Severe forms of extra-pulmonary TB (other than TB meningitis)
  • Co-infection with HIV disease
2 (HRZE)4 (HR)
ITB meningitis2 (HRZS)4 (HR)
IIPreviously treated smear-positive pulmonary TB: relapse, treatment after interruption and treatment failure2 (HRZES) followed by 1 (HRZE)5 (HRE)
IIINew smear-negative pulmonary TB (other than in category I). Less severe forms of extra-pulmonary TB2 (HRZ)4 (HR)
IVChronic and MDR-TBSpecially designed standardised or individualised regimens
  • What are the differences in the drug treatment regimens for adults and children for each category? (Hint: compare Table 16.1 and Table 14.3).

  • In general, the treatment of TB in children is similar to that used to treat adults. However, there are some important differences; if you study Table 16.1 very closely, alongside Table 14.3 from Study Session 14, you will notice some differences. For children, the continuation phase in Categories I and III uses isoniazid and rifampicin in combination (HR), and during the intensive phase for Category III, a combination of three drugs is used (isoniazid, rifampicin and pyrazinamide (HRZ)). For cases of TB meningitis in children, streptomycin is used instead of the preferred drug for adults, ethambutal.

16.1.5  Management of TB in HIV-infected children

Children with TB should be screened for HIV; likewise, HIV-positive children should also be investigated for TB. International guidelines recommend that TB in HIV-infected children should be treated using a six-month drug regimen similar to that used for HIV-negative children; however rifampicin should be given for the entire duration of treatment. It has been found in HIV-infected adults that higher relapse rates occur when ethambutol is used in the continuation phase.

16.1.6  Follow-up and referral of children with TB

As a health worker, you will need to do all you can to administer the chosen treatment and ensure that patients adhere to what they have been told to do. Many children with TB can be managed on an out-patient basis. However, some conditions, such as TB meningitis and other types of EPTB where the infection has spread to organs of the body other than the lung, may require hospitalisation, usually for the first two months of anti-TB treatment. If you find cases where children have respiratory distress, TB involving the spinal cord or they develop severe side effects, they should also be referred to a hospital.

At a minimum, follow-up should include an assessment of symptoms, an evaluation of adherence, an inquiry about any adverse events or side-effects, and the weight of the child should be measured. If the child is losing or gaining weight, they should be referred, because it may be necessary to adjust their medication. As with adult patients, children who were smear-positive for TB at the beginning of treatment should be referred for follow-up sputum smear microscopy at two months, five months, six months and eight months. A child who is not responding to TB treatment should also be referred for further assessment and management.

16.2  TB/HIV co-infection

A person not infected with HIV usually has some natural immunity against tuberculosis. However, the HIV-infected person will be more vulnerable to infection because they will have lost some of their natural immunity. This provides the TB bacteria with a favourable environment in which to multiply and bring about the full disease, showing all the common signs and symptoms. Raising awareness of TB/HIV co-infection is an important role for all health workers (Figure 16.2).

Figure 16.2  Poster campaign to raise awareness of TB/HIV co-infection. (Source: Center for Disease Control and Prevention, USA, accessed from: http://apps.nlm.nih.gov/ againsttheodds/ exhibit/ action_on_aids/ new_disease.cfm )

16.2.1  Effect of HIV on tuberculosis

Ethiopia has one of the highest levels of TB/HIV co-infection in Africa. The WHO Global Report of 2008 estimates that in Ethiopia, 40% of TB patients tested for HIV were HIV-positive, while routine data from 1999 EFY (2006/7) estimates that as many as 31% of TB patients were co-infected with HIV.

Health workers should strongly recommend and routinely offer HIV testing to all TB patients and TB suspects, after providing adequate information on the benefits of such testing.

HIV increases the risk of infection with M. tuberculosis, and more importantly, increases the risk of progression to TB disease, and hence the incidence and prevalence of active TB. In addition, the HIV pandemic has led to an increase in the number of patients developing side-effects to anti-TB drug treatment. This has produced an increase in the workload for healthcare providers, which can compromise the quality of service and deplete resources. It has also been found that latent TB infection in HIV-positive persons reactivates at a rate of 10% per year, as opposed to 5–10% over a lifetime for HIV-negative persons. HIV-positive persons are prone to re-infection with new strains of TB from the community, and drug resistance may occur more frequently in TB/HIV co-infections.

16.2.2  Effect of tuberculosis on people living with HIV

TB is the leading cause of illness and death among people living with HIV (PLHIV). It increases the occurrence of other infections, increases the rate at which HIV progresses, and influences antiretroviral therapy (ART) in various ways. Late diagnosis and delayed treatment of TB contributes to increased death rates in PLHIV.

A new strategy for tuberculosis control in high-HIV prevalence populations has been developed and the various approaches are summarised in Box 16.2.

If an HIV-positive patient develops symptoms of TB, it is essential you encourage them to seek treatment and refer them to a treatment facility.

Box 16.2  New strategies for dealing with TB/HIV co-infections

Activities directed against TB control are:

  • Intensified case finding (look actively for TB suspects and investigate for TB)
  • Treatment of TB cases (reduces risks of transmission)
  • Isoniazide Preventive Therapy (IPT) for patients who are HIV-positive but do not have an active TB infection. This is also recommended for children in contact with active pulmonary TB and children investigated for TB but found to be normal. This treatment prevents progression of TB infection to active disease.
  • BCG vaccine, given to children at birth. It is a modified ‘live’ vaccine for the prevention of severe forms of TB (TB meningitis, disseminated TB) which usually occur in childhood. It is one of the vaccines in Ethiopia’s Expanded Programme of Immunization (EPI).

    BCG vaccination is described in the Immunization Module.

Activities directed against HIV (and therefore indirectly against tuberculosis) are:

  • Safer sexual practices (e.g. use of condoms) to prevent transmission of the virus
  • STI (sexually transmitted infection) treatment to reduce the risk of transmission of HIV
  • Cotrimoxazole Preventive Therapy (CPT) prevents development of other opportunistic infections
  • Antiretroviral therapy (ART) to suppress HIV multiplication and increase natural immunity against TB infection.

All of these topics are covered in detail in the Study Sessions on HIV/AIDS in Part 3 of this Module

16.2.3  TB classification in HIV-positive patients

Classification of TB for those individuals who are also HIV-positive differs slightly from the classification categories described in Study Session 14. They are all category I patients, but can be further classified into one of three revised sub-categories. This revision was introduced by the WHO in 2009 and you will need to be aware of these revised categories for registration and the follow-up of patients with both diseases. The revised sub-categories are listed below:

  • a.Smear-positive pulmonary tuberculosis (one or more sputum smears found to be positive for TB bacteria)
  • b.Smear-negative pulmonary tuberculosis
  • c.Extra-pulmonary tuberculosis.

16.2.4  Diagnosis of TB in HIV-positive patients

The following methods are used for diagnosis of TB in HIV patients; whenever you suspect patients having both diseases you need to send them for investigation.

Clinical examination

Pulmonary tuberculosis is the most common manifestation of tuberculosis in adults infected with HIV. Tuberculosis occurs at various stages of HIV infection, with the clinical pattern correlating with the patient’s immune status and could broadly be classified as early and late presentation. If a patient presents during the early stages of HIV-infection, the symptoms of TB are usually similar to those seen in non-HIV patients. However, if the patient comes at a late stage of HIV-infection, the presentation of TB is similar to primary TB, or it may spread to different organs. The clinical features in pulmonary TB are generally similar in HIV-infected and HIV-negative patients. However, cough and spitting of blood are reported less frequently by HIV-infected patients.

Sputum examination

Most HIV-positive pulmonary TB patients are sputum smear-positive. However, the proportion of smear-negative tests is much greater in HIV-positive than in HIV-negative TB patients, especially in the late stage of HIV.

Chest X-ray in HIV-positive patients

If the sputum smear remains negative, chest X-ray can be of additional value in diagnosis. However, the appearance of the X-ray may not be typical for TB. Diagnosis of TB in the HIV-infected patient is difficult.

HIV-positive patients who you suspect may have extra-pulmonary TB should be referred.

Diagnosis of smear-negative TB in HIV patients

Important diagnostic methods have been developed recently by the WHO. This was necessary because HIV-positive patients were presenting with a cough of two to three weeks duration and then on investigation with sputum microscopy were found to be TB negative. However, if the symptoms and clinical state still strongly suggest TB, such patients are to be divided into the ambulatory ill (which means they could walk) and the seriously ill.

The adult patient will be classified as seriously ill if one or more of the following danger signs are present:

  • Unable to walk unaided
  • Respiratory rate over 30 breaths per minute
  • Fever of more than 39°C
  • Pulse rate of over 120 heart beats per minute.

A patient classified as seriously ill on this basis should immediately be referred to a higher level health facility. When immediate referral of this type is not possible, the following measures should be undertaken in the nearest health facility with the necessary equipment and trained staff:

Sputum microscopy: at least two sputum specimens should be taken and examined, one of which should be an early-morning sputum, produced after an overnight sleep. One positive smear will be sufficient to classify a patient as a smear-positive case if the patient is HIV-positive, or if there is strong clinical suspicion of HIV infection.

HIV testing: HIV testing should be routinely offered along with sputum examination in HIV-prevalent settings for patients presenting with cough of two to three weeks’ duration. A person with an unknown HIV status (e.g. because of unavailability of HIV test kits or refusal to be tested) can be classified as HIV-positive if there is strong clinical evidence of HIV infection.

16.2.5  Prevention and management of TB among PLHIV

  • Isoniazid preventive therapy (IPT): IPT is given to HIV patients after investigation where there is no evidence of TB. It is given for six months; you are expected to follow those patients on IPT for adherence and possible side-effects.
  • Cotrimoxazole preventive therapy (CPT): It is well-documented that administration of CPT decreases illness and deaths among HIV-infected TB patients. Cotrimoxazole is given for this category of patients and to all HIV-positive TB patients.
  • Sometimes TB drugs and ART can produce adverse reactions that may worsen or cause new infections. Patients should be advised to continue their medication and report any problems.

Treatment of TB in PLHIV: When patients with TB/HIV are treated with anti-TB drugs and ART, problems related to the medication regimen may result. This group of patients therefore needs frequent follow-up and support; you should be alert for possible side-effects and prepared for early intervention and referral.

16.3  Drug-resistant TB and multi-drug resistant TB

The emergence of resistance to anti-tuberculosis drugs, and particularly of multidrug resistant-TB (MDR-TB) arises when TB bacteria develop resistance to rifampicin and isoniazid. MDR-TB has become a major public health problem in a number of countries and an obstacle to effective global TB control. When a patient has TB with bacteria that are no longer sensitive to one or more anti-TB drugs, for instance isoniazid, using this antibiotic will not be helpful. Other drugs (known as second-line drugs) have to be used instead of the first-line drug regimens.

A good TB control programme — especially with regard to patient follow-up and adherence, will not generate much drug resistance. Resistance to TB drugs usually occurs as a consequence of inadequate treatment, be it irregular, too short or too weak. Resistant TB bacteria can be transmitted to other people like any other form of TB.

16.3.1  Drug sensitivity testing (DST)

Drug sensitivity testing (DST), performed in a reference laboratory, is the only means by which resistance to anti-TB drug(s) can be confirmed. DST involves growing TB bacteria and treating the culture with one or more anti-TB drugs and seeing if the bacteria are killed or not. If the bacteria are not killed by giving the drug(s), they are considered resistant.

Table 16.2 makes the point that there are three sources for the development of drug resistance. The first and most important category reflects shortcomings by health providers — they can give an inadequate drug regimen, or the wrong guidelines, or they can fail to treat correctly through lack of training and a poor monitoring system. The second category is related to the drugs themselves — they can be of poor quality, in short supply or they can be poorly stored. The last factor contributing to the development of drug resistance relates to the TB patients themselves, and reflects factors such as poor adherence, lack of information about the disease and the influence of social barriers, any one of which can result in patients discontinuing the drugs.

Table 16.2  Causes of inadequate anti-tuberculosis treatment contributing to development of MDR-TB.
Healthcare providersDrugsPatients

Inadequate regimens

Inappropriate guidelines

Non-compliance with guidelines

Absence of guidelines

Poor training

No monitoring of treatment

Poorly organised or funded TB control programmes

Inadequate supply

Poor quality

Unavailability of certain drugs (stock-outs or delivery disruptions)

Poor storage conditions

Wrong dose or combination

Inadequate drug intake

Poor adherence (or poor DOT)

Lack of information

Lack of money (no treatment available free of charge)

Lack of transportation

Adverse side-effects

Social barriers

Poor absorption of drugs

Substance dependency disorders

Treatment of MDR-TB is more complicated and takes longer than treatment of TB that is not resistant to the first-line drugs. In Ethiopia, the management of MDR-TB is currently available only at St Peter Specialized TB hospital, but there are plans to expand provision to other regions. As a health worker, the most significant way in which you can help now and in the years ahead is to do all you can to ensure that patients adhere to their treatment, in order to increase the number of cured cases and reduce the incidence of drug-resistant TB.

Summary of Study Session 16

In Study Session 16, you have learned that:

  1. Children are usually infected with TB by an adult or an older child with sputum smear-positive PTB, often a family member.
  2. The best way to prevent childhood TB is therefore by proper identification and treatment of infectious patients, but diagnosis can be difficult for younger children not able to produce sputum.
  3. The DOTS strategy is applicable to all patients with TB, including children and those with TB/HIV co-infection.
  4. TB is a leading cause of morbidity and mortality, and the spread of HIV has increased the TB epidemic in Ethiopia. HIV increases risk to infection with M. tuberculosis, the risk of progression to TB disease, and the incidence and prevalence of TB.
  5. All patients diagnosed with TB should be encouraged to undergo counselling and testing for HIV, and all HIV-positive patients should be screened for TB.
  6. Sputum smear microscopy remains the main method to confirm a diagnosis of pulmonary TB, including in HIV-positive patients. It also helps in identifying infectious patients so that transmission can be stopped.
  7. Most of the time, drug-resistant TB is due to inadequate treatment, poor adherence to drug regimens, poor quality or insufficient drugs, and lack of training of healthcare providers in drug prescribing, monitoring and follow-up.
  8. For all TB patients, do all you can to ensure adherence to drug regimens, which will reduce the prevalence of TB, including the drug-resistant forms.

Self-Assessment Questions (SAQs) for Study Session 16

Now that you have completed this study session, you can assess how well you have achieved its Learning Outcomes by answering these questions. Write your answers in your Study Diary and discuss them with your Tutor at the next Study Support Meeting. You can check your answers with the Notes on the Self-Assessment Questions at the end of this Module.

SAQ 16.1 (tests Learning Outcome 16.2)

When do you suspect tuberculosis disease in children?

Answer

You suspect tuberculosis disease in children for one or more of the following reasons:

  • a.Presence of contact history with TB suspect or TB case in the family.
  • b.Chronic symptoms of TB – a cough for more than two weeks, fever, and sweating, decreased weight and decreased appetite.
  • c.Presence of a risk factor like HIV infection, malnutrition, after measles etc.

SAQ 16.2 (tests Learning Outcome 16.3)

A 32-year-old male patient was diagnosed with HIV three months ago; he was started on ART 10 weeks ago. He presented with cough productive of whitish sputum and low grade fever of one month duration. What will you do for this patient and what advice would you give him and his family?

Answer

This HIV patient should be suspected of having tuberculosis or other infections that occur at the late stage of HIV. You should refer the patient for possible TB diagnosis, including clinical evaluation, sputum examination and chest X-ray.

Advise him not to stop taking his ART drugs, or cotrimoxazole (CPT). You should also advise screening of family members for TB, as well as for HIV.

SAQ 16.3 (tests Learning Outcomes 16.1 and 16.4)

What is multidrug resistant-TB (MDR-TB)?

Answer

Multidrug resistant-TB (MDR-TB) is active TB involving M. tuberculosis organisms that are resistant to at least isoniazid and rifampicin, the two most powerful anti-TB agents.