ModuleA2Session3

Tuberculosis: HIV-TB Interaction: 

Tuberculosis: HIV-TB Interaction Part A: Module A2 Session 3

Purpose: 

Purpose To learn about HIV and TB co-infection including clinical presentation recommended diagnostic tests/radiology and common findings management treatment

Objectives: 

Objectives Understand the interaction between HIV and TB Describe the clinical presentation of TB and the most important signs and symptoms to look for List the recommended diagnostics and common findings

Objectives, continued: 

Objectives, continued Describe the treatment and management of HIV-positive patients with TB, including drug regimens and how to monitor during treatment Discuss treatment approaches and strategies including directly observed treatment strategies (DOTS) Discuss ART for individuals with TB co- infection

Overview: 

Overview Tuberculosis: HIV-TB interaction and co-infection Most common cause of death in people with HIV worldwide HIV infection increases the likelihood that new infection with M. tuberculosis (due to immune suppression) will progress rapidly to TB disease HIV is the most potent factor known to increase risk of progression from M. tuberculosis infection to disease

Overview, continued: 

Overview, continued Among HIV-infected individuals, lifetime risk of developing active TB is 50%, compared to 5-10% in persons who are not HIV-infected In a person infected with HIV, the presence of other infections, including TB, allows HIV to multiply more quickly. This may result in more rapid progression of HIV infection HIV-related TB can present typical or atypical clinical and/or radiological features. Atypical features are usually found in HIV-infected individuals with severe immunosuppression

Overview, continued: 

Overview, continued Initial signs of TB disease may become apparent at any time during the evolution of HIV-infection Can come well before other manifestations of HIV infection or after patient has become symptomatic May be pulmonary or extra-pulmonary Pulmonary TB is most common form— presentation depends on degree of immunosuppression

Overview, continued: 

Overview, continued With mild immunosuppression: Typical chest x-ray (CXR) findings include: upper lobe and or bilateral infiltrates cavitation pulmonary fibrosis shrinkage Clinical picture often resembles post-primary pulmonary TB (PTB) Sputum smear is usually positive

Slide9: 

Arrow points to cavity in patient's right upper lobe --typical finding in patient with TB

Overview, continued: 

Overview, continued In severely immunosuppressed patient, the features are atypical, resembling that of primary PTB: sputum smear often negative CXR shows interstitial infiltrates especially in lower zones with no features of cavitation and fibrosis CXR may look exactly like that in bacterial pneumonia In the setting of an HIV epidemic, it is not possible to look at a CXR and say that it is or is not TB

Slide11: 

X-ray in a TB patient may look like this one of a patient with confirmed PCP.

Overview, continued: 

Overview, continued Disseminated and extrapulmonary TB is more common in advanced HIV infection because the immune system is less able to prevent growth and local spread of M.tuberculosis. Unilateral or bilateral infiltrates in the lower lobes are seen more often than upper lesions and cavities Most common forms are lymphadenitis, pleural effusion, pericarditis, miliary disease, and meningitis

Clinical Presentation Signs and symptoms : 

Clinical Presentation Signs and symptoms Most important symptoms Cough lasting more than 3 weeks and not responding to usual antibiotic treatment Production of purulent, sometimes blood- stained sputum Evening fevers Night sweats Weight loss 

Diagnostic Tests: 

Diagnostic Tests Microscopic examination of specimen of sputum that has been stained by the Ziehl-Neelsen (ZN) method A PTB suspect should submit three sputum samples for microscopy: Sample 1: On first visit, the patient should provide an on-the-spot sputum sample Sample 2: Give the patient a sputum container to take home for an early morning sample on the following day (day 2) Sample 3: On day 2, when the patient brings sample 2 in, he/she provides another on-the-spot sample.

Diagnostic tests, continued: 

Diagnostic tests, continued An inpatient can provide 3 early morning sputum samples False negative reports: A PTB suspect with 3 negative ZN sputum smears may not have TB at all due to sample being inadequate or faulty smear preparation/interpretation

Diagnostic tests, continued: 

Diagnostic tests, continued Radiology If TB is still suspected despite negative smears, a chest x-ray should be done. Classical pattern is upper lobe infiltrates with cavitation However, no chest x-ray is absolutely typical of PTB patients with HIV infection In severe immunosuppression, the appearance is often atypical, as described above

Treatment: 

Treatment HIV infected patients should be treated according to national guidelines and in cooperation with local authorities such as the district medical officer (DMO) and the district TB supervisor. Aims of treatment To cure the patient of TB To prevent death from active TB or its late effects To prevent TB relapse To decrease TB transmission to others

Treatment, continued: 

Treatment, continued Drug regimens Initial phase—first 2-3 months During the initial phase, there is rapid killing of TB bacilli Three or more drugs are used in combination Infectious patients become non-infectious within about 2 weeks and symptoms usually improve

Treatment, continued: 

Continuation phase-additional 4-6 months Fewer drugs are necessary (usually 2), but longer time These drugs eliminate the remaining bacilli Treatment, continued

Treatment, continued: 

Monitoring during treatment Bacterial monitoring is only possible for patients with smear positive PTB Sputum smear exam should be done as follows At the time of diagnosis At the end of initial phase During the continuation phase—at the end of month 5 On completion of treatment—month 6 or 8 Using chest x-ray as a monitoring tool is unnecessary and wasteful Treatment, continued

Treatment, continued: 

Treatment approaches and strategies Directly observed treatment, short course (DOT) It is difficult to adhere to anti-TB treatment for 6-8 months or more It is also difficult to predict which patients will adhere to self-administered treatment One certain way to ensure patient adherence is through DOT where a trained supervisor watches the patient swallow the drugs Treatment, continued

Basic principles of DOT, continued: 

Basic principles of DOT, continued For patients who need admission, DOT should be started right away and supervised by the nursing staff For patients requiring no admission or for discharged patients, DOT may be supervised by staff of a nearby health facility, a trained community health worker, or a trained family member

Treatment, continued: 

Treatment, continued Directly Observed Treatment Strategy (DOTS) DOTS is a strategy for TB control which aims to detect 70 percent of active TB cases and to successfully treat 85 percent of them. The essential features of DOTS include: Government commitment to sustained TB control activities Case detection by sputum smear microscopy among symptomatic patients self-reporting to health services Directly observed, standardized treatment regimen of six to eight months

Directly Observed Treatment Strategy (DOTS), continued: 

Efficient information systems for monitoring and reporting treatment outcomes A regular, uninterrupted supply of all essential anti-TB drugs Directly Observed Treatment Strategy (DOTS), continued

Slide25: 

Table . WHO Recommended TB treatment regimen for each treatment category:

WHO Recommended TB treatment regimen, continued: 

WHO Recommended TB treatment regimen, continued N.B. Some authorities recommend 7 month continuation phase with daily isoniazid and rifampicin (7HR) for Category 1 patients with various forms of disease: TB meningitis, military TB, spinal TB with neurological signs.   Examples: a. 2 HRZE / 6 HE: This is a common regimen. The initial phase is 2 HRZE. The duration of the phase is 2 months. Drug treatment is daily (no subscript number, e.g., 3, after the letters), with isoniazid (H), rifampicin (R), pyrazinamide (Z), and ethambutol (E). Alternatively, streptomycin (S), isoniazid (H), rifampicin (R), pyrazinamide (Z).   The continuation phase is 6 HE. The duration of the phase is 6 months. Drug treatment is daily, with isoniazid (H) and ethambutol (E).

Slide27: 

WHO Recommended TB treatment regimen, continued

Antiretroviral Therapy for Individuals with Tuberculosis Co infection: 

Antiretroviral Therapy for Individuals with Tuberculosis Co infection WHO Recommendations for ARV Therapy WHO recommends that people with TB/HIV complete their TB therapy prior to beginning ARV treatment unless there is high risk of HIV disease progression and death during the period of TB treatment (i.e., a CD4 count <200/mm3 or the presence of disseminated TB).

Antiretroviral Therapy for Individuals with Tuberculosis Co infection, continued: 

In cases where a person needs TB and HIV treatment concurrently, first line treatment options include ZDV/3TC or d4T/3TC plus either an NNRTI or ABC. Except for SQV/r, PIs are not recommended during TB treatment with rifampicin due to its interactions with the latter drug  Antiretroviral Therapy for Individuals with Tuberculosis Co infection, continued

Table X. Antiretroviral Therapy for Individuals with Tuberculosis Coinfection: 

Table X. Antiretroviral Therapy for Individuals with Tuberculosis Coinfection Situation Recommendation

Prevention: 

Prevention TB Preventive Therapy Evidence shows it is effective in HIV-infected people Can be given to people with HIV who: have been screened to exclude active TB are PPD positive (Mantoux test 5mm) have not been BCG vaccinated have a high TB risk

Prevention, continued: 

Prevention, continued In a setting where it’s not practical to do a PPD skin test, consider TB prophylaxis for the following individuals if they are HIV-infected: Individuals living in population with high prevalence for TB infection (>30%) Health care workers Household contacts of TB patients Prisoners Miners Other selected groups at high risk for acquisition or transmission of TB