Tuberculosis Treatment and Prevention

Thursday, October 12, 2006

Botswana: Partnership Battles Tuberculosis And HIV/Aids in Botswana

The sub-Saharan African nation of Botswana is at the epicenter of the worldwide HIV pandemic. About 24 percent of the population between ages 15 and 49 carry the virus--one of the world's highest prevalence rates.

The 2006 Report on the Global AIDS Epidemic, issued by the Joint United Nations Programme on HIV/AIDS in May 2006, reported 18,000 deaths from the disease last year. Deaths of young adults in recent years have left 120,000 orphans, nearly 7 percent of Botswana's population.

AIDS is known as a fatal disease, but the actual cause of death for many victims is tuberculosis (TB), the most frequently occurring opportunistic disease that attacks the weakened immune system of HIV-positive persons. In fact, a study conducted jointly by U.S. Centers for Disease Control and Prevention (CDC) and Botswana researchers has shown that 38 percent of AIDS deaths in Botswana were actually due to TB.

TB-HIV CO-EPIDEMIC

The dual occurrence of TB and HIV infections is known as a co-epidemic. It is a painful burden for this landlocked nation of 1.7 million people, but the Botswana government is recognized for progressive and comprehensive policies to deal with the disease.

Since 1995, Botswana's Ministry of Health and the CDC have collaborated on programs and research to address the AIDS crisis. The partnership, called BOTUSA (pronounced bo-TOO-sah), involves more than 170 international, local, and support staff working to provide technical assistance, consultation, funding, program implementation, and research devoted to prevention, care, support, and surveillance of HIV/AIDS, tuberculosis, and related conditions.

The principal goal of BOTUSA's TB-HIV research is to expand knowledge of the relationship between epidemic tuberculosis and HIV disease in resource-constrained settings to develop better prevention strategies for TB control in Botswana and similar environments.

The major achievement of this more than 10-year-old research collaboration is a preventive therapy program. Using isoniazid, a proven TB preventive therapy, the program is attempting to prevent tuberculosis in up to 60 percent of people living with HIV. The Isoniazid Preventive Therapy (IPT) Programme, the first of its kind to be introduced anywhere in the world, is working to put all persons in the country living with HIV/AIDS on a preventive regimen of isoniazid to keep TB at bay.

Enrollment in the IPT program has also meant that HIV-infected persons are getting better access to care and antiretroviral drugs.

Health officials hoped the isoniazid treatment would provide a better-than-60-percent protection rate and longer lasting protection against active TB, however, so CDC and the Ministry of Health are conducting a trial involving 2,000 people to determine if continuous isoniazid therapy prevents more disease than the six-month course of drug prophylaxis.

RESEARCH AND TRAINING

Along with the latest projects, BOTUSA has produced a significant amount of research that has contributed to the world's body of knowledge about TB in the AIDS era, including surveys of drug-resistant TB, the population's TB infection rate, and the behavior and responses of patients and clinicians living amid a co-epidemic.

BOTUSA also provides more thorough training for Botswana's urban and rural health care workers, an activity that will result in improved disease surveillance, patient screening, and care.

Botswana is also one of 15 target nations receiving assistance under the President's Emergency Plan for AIDS Relief.

The United States has provided funding for purchase of antiretroviral drugs and contributed to the development and implementation of national systems for training, quality assurance, and guidelines applied to clinical delivery of antiretroviral therapy, HIV laboratory, and monitoring and evaluation of antiretroviral therapy.

These contributions have strengthened the success of Botswana's national strategy against AIDS.


Source: United States Department of State (Washington, DC), October 11, 2006


Margaret Davis, MD, MPH is director of BOTUSA, a partnership between Botswana's Ministry of Health and the U.S. Centers for Disease Control and Prevention.

South Africa: TB Programme a Failure Because Patients 'Not Educated'

Government's TB programme is failing because it has not bothered to educate patients about their treatment in the way that HIV patients have been educated.

In addition, R50 000 a month is being wasted in KwaZulu-Natal alone on processing TB sputum tests at Nkosi Albert Luthuli Hospital, the results of which were never claimed by the hospitals and clinics that sent them in.

This is according to Zinhle Thabethe, who works for iTeach, a TB and HIV implementation programme at Edendale Hospital in Pietermaritzburg.

"I have been on antiretroviral drugs for five years and, because I was trained about taking the medication, I have never missed my ARVs even for a day," Thabethe told an international HIV/AIDS workshop in Durban over the weekend.

"But," she added, "I have also had TB three times and have never been told about how the treatment works or even the consequences if I don't finish my course of medication."

Thabethe said that instead of educating TB patients, health workers referred them to Directly Observed Treatment Short-course (DOTS) volunteers who were supposed to monitor them taking their medication.

"DOTS doesn't work. You must teach us patients how to take our TB drugs rather than DOTS-ing us," she said..

Patients living in informal settlements have "no addresses and no DOTS volunteer is going to be able to follow them up if they don't show up for their medication", she added.

DOTS is the cornerstone of government's TB programme. Yet less than half TB patients countrywide are cured at present, while in eThekwini and Msunduzi barely a third of TB patients are being cured.

However, Dr Sibongile Zungu, KwaZulu-Natal's Chief Health Officer, said she found Thabethe's rejection of DOTS while supporting the ARV rollout model to be "contradictory".

"TB patients are told about the disease and the treatment. If they are well enough to be discharged, they are requested to link to a DOTS person that would assist them to take their treatment," said Zungu.

"It can be a DOTS volunteer but it can be anybody. This is just like the treatment buddy that an HIV positive person starting antiretroviral drugs is asked to identify to help them."

Zungu also said that she knew nothing about the R50 000 being wasted on unclaimed TB tests.

"I find that a bit strange as most hospitals are on the intranet and can link up to Albert Luthuli electronically for results. Besides, ordinary TB sputum tests are processed by local hospital laboratories. It is only when a patient is not improving and [drug] resistance is suspected that their sputum is sent to Albert Luthuli to be cultured."



Source: Kerry Cullinan, Allafrica, October 11, 2006

http://allafrica.com/stories/200610110001.html

Friday, October 06, 2006

AIDS, HIV & Tuberculosis (TB)

What is TB?

Tuberculosis (TB) is a contagious disease that kills around 2 million people each year. One-third of the world's population is currently infected with TB and someone is newly infected every few seconds.

What is the relationship between TB and HIV?

TB is the leading cause of death among HIV infected people; the WHO estimates that TB accounts for up to a third of AIDS deaths worldwide.1 When someone is infected with TB, the likelihood of them becoming sick with the disease is increased many times if they are also HIV positive.

What causes TB?

TB is caused by an organism called mycobacterium tuberculosis. These bacteria can attack any part of the body, but they most commonly attack the lungs. TB bacteria are very common in many resource-poor countries and in poor urban 'pockets' of industrialised countries.

The spread of TB

A person can have active or inactive TB. Active TB or TB disease means the bacteria are active in the body and the immune system is unable to stop them from causing illness. People with active TB in their lungs can pass the bacteria on to anyone they come into close contact with. When a person with active TB coughs, sneezes or spits, people nearby may breathe in the TB bacteria and become infected. Left untreated, each person with active TB will infect on average between 10 and 15 people every year.

People can also be infected with TB that is not active in the body. Inactive TB infection is also called latent TB. If a person has latent TB, it means their body has been able to successfully fight the bacteria and stop them from causing illness. People who have latent TB do not feel sick, do not have symptoms and cannot spread TB. In some people TB bacteria remain inactive for a lifetime without becoming active. But in some other people the inactive TB may become active TB if their immune system becomes weakened - for example by HIV. People with inactive TB are also called TB carriers.

TB and HIV positive people

Because TB can spread through the air, the increase in active TB among people infected with both TB and HIV results in:

• more transmission of the TB bacteria
• more people with latent TB
• more TB disease in the whole population.

People with latent TB are increasingly becoming infected with HIV, and many more are developing active TB because HIV is weakening their immune system. People who are co-infected with both HIV and latent TB have an up to 800 times greater risk of developing active TB disease and becoming infectious compared to people not infected with HIV.

People with advanced HIV infection are vulnerable to a wide range of infections and malignancies that are called 'opportunistic infections' because they take advantage of the opportunity offered by a weakened immune system. TB is an HIV related opportunistic infection. A person that has both HIV and active TB has an AIDS-defining illness.

The HIV/AIDS epidemic is reviving an old problem in well resourced countries and greatly worsening an existing problem in resource poor countries. The are several important associations between epidemics of HIV and TB:

• TB is harder to diagnose in HIV positive people
• TB progresses faster in HIV-infected people
• TB in HIV positive people is more likely to be fatal if undiagnosed or left untreated
• TB occurs earlier in the course of HIV infection than other opportunistic infections
• TB is the only major AIDS-related opportunistic infection that poses a risk to HIV-negative people.

What are the symptoms of TB?

Symptoms of TB depend on where in the body the TB bacteria are growing. TB bacteria often grow in the lungs, causing pulmonary tuberculosis. Pulmonary TB may cause a bad cough that lasts longer than 2 weeks, pain in the chest and coughing up of blood or sputum. Other symptoms of TB disease include weakness or fatigue, weight loss, lack of appetite, chills, fever and night sweats.
Inactive TB has no symptoms.

How is TB diagnosed?

TB can be diagnosed by injecting a protein found in TB bacteria into the skin of an arm. If the skin reacts by swelling then the person is probably infected with TB. However, this method is not wholly reliable at detecting TB infections among HIV-infected people because their weakened immune systems often cannot mount a strong enough defence against the injected proteins to cause swelling. It also detects both active and latent TB, meaning the test is not very accurate at diagnosing active TB disease in people who live in areas where TB (and thus latent TB infection) is very common.

Diagnosis of TB in the lungs may be made using an X-ray or sputum test, but again, these may not give a clear indication of active TB infection in HIV+ people, because their immune systems are not strong enough to mount an inflammatory reaction against the bacteria. In cases of extra-pulmonary TB (where the disease is affecting organs other than the lungs), fluid or tissue samples may be tested.

If there is doubt about the diagnosis of TB, a culture of TB bacteria can also be grown in a laboratory. However, this requires specialised and costly equipment and can take six to eight weeks to produce a result.

If the necessary facilities are not available then the TB diagnosis is often based on symptoms.

How is TB treated?

Active TB disease can almost always be cured with a combination of antibiotics. The variety of treatments and drug options depend on the country you are in. A proper combination of anti-TB drugs provides both prevention and cure. Effective treatment quickly makes the person with TB non-contagious and therefore prevents further spread of TB. Achieving a cure takes about six to eight months of daily treatment.

Several drugs are needed to treat active TB. Taking several drugs does a better job of killing all of the bacteria and is more likely to prevent them from becoming resistant to the drugs. To ensure thorough treatment, it is often recommended that the patient takes his or her pills in the presence of someone who can supervise the therapy. This approach is called DOTS (directly observed treatment, short course). DOTS cures TB in 95% of cases, and a six-month supply of DOTS costs as little as $10 per person in some parts of the world.

Can TB be prevented?

There is a vaccine against TB called BCG3, but the vaccine is now very old (it was first used in the 1920s), and tests have found it to be very variable in its ability to protect people from infection in modern settings. When it does provide protection, this generally only lasts for around 15 years. The BCG can also cause false-positive readings on the tuberculin skin test, and if given to HIV+ adults or children with very weak immune systems, it can occasionally cause disseminated BCG disease. This is often fatal.

A drug called isoniazid (INH) can be used as a preventative therapy for those who are at high risk of becoming infected with TB or for those who have inactive TB. People who have inactive TB but are not yet sick can take a course of isoniazid for several months to stop them developing active TB.

The WHO recommends that HIV positive people who have latent TB (but definitely not active TB) should be offered isoniazid preventive therapy as needed.

TB treatment and HIV

It is vitally important for people with HIV to have treatment if they have active TB. This will cure them and prevent transmission to others. Even in settings where antiretroviral drugs are unavailable or inaccessible, it is crucial that the health system is able to offer HIV positive people the simple antibiotics needed for DOTS.
For some people it can be difficult to take drugs for both TB and HIV at the same time. Some anti-HIV drugs can also interact with some TB drugs making the treatment more difficult. It is important that the TB treatment is taken regularly and exactly as the health care provider has advised. If the drugs are not taken regularly, the bacteria can become resistant to the drugs and this can be dangerous.

As one of the first opportunistic infections to appear in HIV-infected people, TB may be one of the earlier signs of HIV infection. Addressing TB offers the opportunity for early HIV intervention. Although treatment of TB can improve the quality of life of HIV positive people and prolong their life, it cannot stop them from dying of AIDS. This is why access to antiretroviral treatment is also vitally important.

Around the world, attempts are being made to improve collaboration between TB and HIV programmes. It is being proposed that everyone diagnosed with TB should be tested for HIV and vice-versa, and that treatment programmes should share facilities and expertise. However, achieving such collaboration is not straightforward:
"The different cultures of the TB and HIV communities raise many challenges in achieving an effective and productive partnership... TB services are geared towards chronic-care services with simple and standardized technical procedures, while HIV/AIDS services are clinically oriented and tend to be more individual-patient-oriented."

What are multi-drug resistant TB (MDR-TB) and extreme drug resistant TB (XDR-TB)?

When a strain of TB is resistant to two or more 'first-line' antibiotic drugs it is called multi-drug resistant TB or MDR-TB. When it is resistant to three or more 'second-line' antibiotics as well, it is classed as extreme drug resistant TB, or XDR-TB. Drug resistance usually arises when TB patients do not or cannot take their medicine as prescribed, and drug-resistant mutations of the TB bacteria are allowed to replicate. People can also catch MDR and XDR-TB from others.

MDR-TB is a serious problem and is very difficult to treat. In normal first-line treatment, patients take the drugs isoniazid and rifampicin (the most effective TB drug available) plus two or three other first-line drugs for around six to eight months. If a person is resistant to isoniazid and rifampicin however, they are said to have MDR- TB, and will need to change to a regime containing newer and often less widely-available 'second-line' drugs. Treatment with second-line drugs can take a very long time, and is usually far more expensive than standard DOTS therapy because most of the drugs are still under patent.

XDR-TB is even more serious. If someone has XDR-TB, it means they are not only resistant to isoniazid and rifampicin, but to three or more of the six available second-line drugs too. This can make it virtually impossible to formulate an effective treatment regime for them. Many people with XDR-TB will die before it is even realised that they have the extreme resistant strain.

In 2006, 53 people in the province of KwaZulu Natal in South Africa were identified as having XDR-TB. 52 of these people died within 25 days of TB being diagnosed. The majority were HIV positive.

Being HIV positive does not of itself increase the chance of drug resistance, but both MDR-TB, and XDR-TB are a serious problem for HIV+ people, whose weakened immune systems mean they are unlikely to fight off TB naturally (often the only hope for those with a resistant strain).

TB and HIV around the world

The importance of TB to the global HIV epidemic is enormous. Tuberculosis is a serious health problem in its own right but it is also the most likely cause of death for HIV positive people. Like HIV, TB has had an uneven impact around the world. In some parts of the world, TB is increasing after almost 40 years of decline. Escalating TB rates over the past decade in many countries in sub-Saharan Africa and in parts of South-East Asia are mainly due to the HIV epidemic.

Between 1990 and 2005, TB incidence rates tripled in African countries with high HIV prevalence. Rates of TB are now rising in the worst affected African countries by around 3% annually. In 2003, Africa accounted for 81% of the estimated 741,000 cases of TB among HIV-positive people worldwide.

The largest number of TB cases occurs in the South-East Asia Region, which in 2004 accounted for an estimated 3 million new cases (one third of the global total). However, the estimated incidence per capita in sub-Saharan Africa is nearly twice that of the South-East Asia, at 356 cases per 100,000 population in 2004. Also, the countries of Eastern Europe are facing a serious epidemic; there were an estimated 166,000 new cases in Russia alone in 2004.

TB is not only a problem in low and middle income countries. For example, there were 14,517 new cases reported in the U.S. in 2004, and in the UK, TB has been dubbed 'the disease that has never went away', with 7,167 new cases reported in England, Wales and Northern Ireland in 2004. Although the UK's national rate is very low in comparison with most of the world, London has become one of the world's TB hotspots. In parts of London, TB rates are ten times the national rate - higher than in some countries of the former Soviet Union. About 10 per cent of people with TB in London are likely to be co-infected with HIV.

Worldwide TB control

The discovery of antibiotic drugs that kill bacteria, was a turning point in TB control. In well resourced countries, TB was previously treated with a special diet and bed rest, usually in a sanatorium. In the late 1950s, it was found that this was unnecessary and TB could be cured with well-supervised antibiotic treatment at home.

Since DOTS was introduced on a global scale in 1991, more than 17 million people have received the treatment. By the end of 2000, all 22 of the countries with the highest number of TB cases, which together have 80% of the world's estimated incident cases, had adopted the DOTS strategy. In total, 183 countries were implementing the DOTS strategy by the end of 2004, and 83% of the global population was living in parts of countries where the DOTS strategy was in place. Around 36% of all diagnosed TB cases were detected and then treated successfully with DOTS in 2003.

However, improved diagnostic methods for detecting the infection are desperately required, as is a more effective vaccine against the disease. New and more potent drugs are also needed to help simplify and shorten treatment, and fight multi-drug resistant TB. The emergence of MDR, and especially XDR-TB, threatens TB control efforts across the globe, including those in well resourced countries. Due to antibiotic supply problems in the late 1970s and early 1980s, MDR-TB is now particularly common in former Soviet Union countries. It has also been found in a large number of cases in China, Ecuador and Israel. Central Europe and Africa, in contrast, have reported the lowest median levels of drug resistance, but the numbers are rising rapidly.

The WHO's leading infectious disease experts estimate there are around 460,000 new cases of MDR-TB worldwide each year. About half of these are among new TB patients, and the other half are among patients who have previously received treatment. There is also new evidence that drug resistant strains are becoming more resistant and unresponsive to current treatments. Some 79% of MDR-TB cases are now "super strains", resistant to at least three of the four main drugs used to cure TB in first-line treatment. The number of these that could also be classed as extreme drug resistant strains is however unknown.

For many years, TB remained relatively overlooked on the global scale, but MDR and XDR-TB, and other problematic issues are now being recognised internationally. In 2006, the Stop TB Partnership launched "The Global Plan to Stop TB"8, an initiative that aims to halve the death rates and prevalence of tuberculosis worldwide by 2015. If successful, the plan will save over 14 million lives, and will pave the way for the ultimate goal of eradicating tuberculosis by 2050. However, much more still needs to be done to acheive this aim, both by directly combatting TB, and by addressing the HIV epidemic that is fuelling its spread.


Source: http://www.avert.org/tuberc.htm