Why should we be concerned about TB and HIV co-infection?

The World Health Organisation (WHO) estimates that 11.4 million people worldwide are infected with both mycobacterium tuberculosis and HIV.
HIV, AIDS and TB are so closely connected that the term “co-epidemic” or “dual epidemic” is often used to describe their relationship. HIV and TB form a lethal combination, each speeding the other's progression.

According the a 2009 update by the World Health Organisation and the Stop TB Partnership, TB remains a leading killer of People Living with HIV responsible for around 10 to 15 percent of all HIV related deaths throughout the world. PLHIV who are infected with TB are 20 to 40 times more likely to develop active TB than people not infected with the virus.
It is not hard to make the case that we are losing the fight against HIV-related TB. Much of the news on the HIV/TB front is going from bad to worse.
For instance, there’s more HIV-related TB today than ever before with an estimated 700,000 new cases of HIV/TB each year— and 85% of the cases are concentrated in Sub-Saharan Africa. Most patients are unlikely to be diagnosed and placed on life-saving treatment.
What are the TB risks for people living with HIV and AIDS?

• HIV weakens the immune system. Someone who is HIV positive and infected with TB bacilli is at much greater risk to develop active TB disease than someone infected with TB bacilli who is HIV negative.

• A person can have latent TB infection for years and usually only 10% of people infected with TB develop TB disease. But if that person’s immune system gets weak due to HIV, the latent TB infection can quickly turn into active TB disease. Also, if a person who has a weak immune system spends time with someone with active TB disease, there is a greater chance that the exposure can lead to infection and can quickly result in the development of active TB disease. Besides this, TB disease also reduces the CD4 count levels and thus can lead to weakening of the immune system.

How serious a problem is TB and HIV co-infection in the public health system?

• TB and HIV co-infection is a very serious public health problem all over the world, but especially in areas with a high burden of TB and HIV such as in sub-Saharan Africa. According to UNAIDS estimates for 2008, around 33 million people were living with HIV. In 2007, there were an estimated 1.37 million new cases of tuberculosis among PLHIV and 456 000 deaths. In Africa, HIV is the single most important factor contributing to the increased incidence of TB in the past decade.

• There were 9.4 million new TB cases in 2008 of which 1.4 million cases were among PLHIV. In 2008, 1.8 million people died from TB. Of these, 500,000 were people living with HIV.

What is the importance of testing for TB?

• All People Living with HIV should be screened by their medical provider for exposure to TB during each visit. If exposure to TB seems likely, the person should be tested to find out if they have latent TB infection. If they have latent TB infection, they need to get treatment as soon as possible to prevent them from developing active TB disease. If they have active TB disease, they must take medicine to cure the disease. Active TB disease can be prevented and cured, even in people with HIV infection.

How is Africa faring?

• More than one in four TB cases are in one country alone: South Africa, with a WHO estimated case rate of 940 per 100,000 — which is higher than the TB case rate of 800 per 100,000 seen in Europe during the Industrial Revolution. In countries with a high HIV prevalence, TB incidence has been steadily increasing since the 1990s, with case rates rising two- to three-fold in a number of southern African countries, although in some countries the rates now appear to be stabilising. (http://www.aidsmap.com/cms1284892.aspx)

• South Africa has experienced terrible outbreaks of extensively drug resistant TB (XDR TB.)  This dates back a couple of years. In 2006, a total of 221 people out of 536 TB patients attending the Church of Scotland Hospital, located in the small town of Tugela Ferry in Kwazulu Natal were found to have multi-drug resistance and of these 53 were diagnosed with XDR-TB (WHO 2006)

• In Zimbabwe, TB is a major public health problem. The country is ranked 17 on the list of 22 high burden TB countries in the world.

• According to the World Health Organization’s (WHO’s) Global Tuberculosis Control Report 2009, Zimbabwe had an estimated 71,961 new TB cases in 2007, with an estimated incidence rate of 539 cases per 100,000 population. It also has the second highest TB mortality rate in the world. The TB-HIV/AIDS co-infection rate is high. According to WHO, nearly 69% of new adult TB patients tested HIV positive. National data suggest the actual estimate is slightly higher, around 80%, and there is increasing HIV surveillance in TB patients.
• In Swaziland Doctors Without Borders say the dual epidemic of TB and HIV is responsible for killing thousands of people every year. According to them, most of the people are dying in the first two months and are not being put on treatment fast enough (http://www.doctorswithoutborders.org/news/article.cfm?id=4061&cat=field-news)
• About 58 percent of TB patients in Swaziland completed their six-month course of treatment last year, falling far short of the 85 percent target recommended by WHO. International guidelines also set a 70 percent detection target for TB, but in Swaziland the case detection rate is below 60 percent. (http://www.aidsportal.org/News_Details.aspx?ID=11836)

What are the difficulties in diagnosing TB in HIV infected people?

• Diagnosing TB in people with HIV infection is often difficult. PLHIV may experience symptoms similar to those of TB patients and when tested for exposure may not react to the standard TB skin test because their immune system does not work properly. Chest x-rays, sputum tests, and physical exams may also fail to show evidence of tuberculosis infection in people with HIV, particularly among people with severe immune impairment.

What are MDR-TB and XDR-TB?

• MDR-TB or multiple drug resistant TB is a TB bacterium that is resistant to Rifampicin (R) and Isoniazid (H), two of the most potent TB drugs currently available.

• XDR-TB or extensively drug resistant TB is TB bacteria that is resistant to Rifampicin, Isoniazid, as well as any quinolone (a drug class) as well as two of the three second-line injectable drugs,(kanamycin, capreomycin, or amikacin).

• Because MDR and XDR need to be treated for a longer period, and because their treatment has greater side effects, it is difficult to treat these forms of TB.  However, if diagnosed and treated appropriately, these conditions can be successfully cured even among PLHIV.

• In 2007, WHO reported an estimated 500 000 new MDR-TB cases. Just over one percent of the patients were receiving treatment  known to be based on WHO’s recommended standards in 2008.

What are the TB targets for 2015?

• According to the UN Millenium Development Goals, the target is to have halted and begun to reverse incidence. The current assessment is that in all WHO regions, countries are slowly moving towards the target with incidence falling.

• The Stop TB Partnership’s target is to halve prevalence and deaths by 2015 in comparison with 1990. The current assessment by the Stop TB Partnership is that WHO Africa is not on target.

What is the current funding situation for TB programmes?

• Funding is nowhere near the $9 billion that The Global Plan to Stop TB: 2006-2015  said was needed for the development of new TB ‘tools’ (such as some of the diagnostics being rolled out). Treatment Action Group went further, recommending that an additional $11 billion be spent on basic science, infrastructure and operational research. Current spending levels would have to increase by fivefold to reach the Global Plan targets.
• The ability of African health care systems to respond to, manage, and contain the growing number of cases of tuberculosis is constrained by limitations of funding, facilities, personnel, drug supplies, and laboratory capacity. Although the President's Emergency Plan for AIDS Relief (PEPFAR) and the Global Fund to Fight AIDS, Tuberculosis, and Malaria have donated large sums of money to help address Africa's health problems, most of the money has been earmarked for HIV, with a lesser focus on tuberculosis. (http://content.nejm.org/cgi/content/full/358/11/1089)

TB in children

• There is not much information on paediatric TB with most of what is documented being based on research before Antiretroviral therapy became available. While most children in the region get the BCG vaccine soon after birth, the BCG vaccine is reportedly not recommended for children with HIV. Because of the difficulty in diagnosing TB in children, many children with HIV or who become HIV-infected post-natally will be vaccinated anyway. Some may develop life-threatening systemic BCG infections. The media needs to talk about how these conditions can be managed in the region.

TB Treatment

• Two main treatment categories are used in, each with its own regimen. The regimens consist of a combination of five first line drugs.
• Treatment is the same for HIV infected people as for non-HIV infected
• There are specific differences between regimens for adults and children in each category
• The main drugs used in hospitals and clinics are isoniazid, pyrazinamide, rimfampicin, streptomycin and ethambutol
• Ethambuol and streptomycin should not be given to children under ten years and to pregnant women
• Trial for TB treatment is discouraged as a first intervention. A definite diagnosis must be made on the basis of history taking and examination.
• The use of only one TB drug (monotherapy) should always be avoided.

What should the media do?

• The media needs to raise awareness about the need to prevent and treat TB. There are simple steps that people can take at household level to prevent TB such as covering one’s mouth when coughing and airing linens and ensuring there is enough ventilation. The media needs to ensure they keep talking about these steps.

• There is need for adequate funding for the world to respond adequately to TB and HIV. The media needs to add its voice to the growing calls for more funds to be channeled towards TB and HIV

• There have been calls for the integration of TB and HIV health services so as to address the challenges posed holistically. The media needs to lobby at country level to ensure that health authorities prioritise this.

• There is need for the media to raise awareness about the importance of testing for HIV and TB. It is increasingly becoming evident that there is need for everyone to know their HIV status and then act based upon their result. If it is negative, a person needs to ensure they practice responsible behavior so they remain negative and if it is positive, they need to get treated and also get screened for TB  

References:

1) WHO/StopTB Partnership 2009 Update
2)  WHO: Fact Sheet - TB/HIV Co-infection and Drug-Resistant TB, 2006
3)  WHO: TB Fact sheet N°104 - Tuberculosis, March 2007
4) SATAMO: factsheet 2008
5) Health Canada: Tuberculosis Fact Sheet – TB and HIV Infection
6) CDC: Questions and Answers About TB, 2005
7)  http://www.who.int/mediacentre/factsheets/fs104/en/
8) http://www.who.int/3by5/en/TBfactsheet.pdfdata.unaids.org/pub/factsheet/2006/tb_hiv_qa.pdf
9) (WHO’s) Global Tuberculosis Control Report 2009
10) www.topbtb.org/globalplan/
11) http://content.nejm.org/cgi/content/full/358/11/1089