The Burden of Disease: HIV, TB, Malaria and Hepatitis
The "S" in AIDS stands for "syndrome," which refers to a pattern of illness proceeding from the immune deficiency that develops in the years after a person becomes infected with HIV: the human immunodeficiency virus. Many people have pointed out the semantic illogic of "getting AIDS," that "you can't catch a syndrome," but, despite liberties taken with the name, the illnesses associated with HIV disease are real and deadly. In classical AIDS, the infections that began to appear in otherwise healthy gay men in 1980 were rare in Western medicine. Some, such as pneumocystis carinii pneumonia (PCP), a disease known to strike immune suppressed transplant patients, gave a clue to the underlying damage to immunity. A constellation of other runaway fungal and viral infections -- opportunists that flourished when defenses were low -- quickly joined the list of illnesses that defined the syndrome of acquired immunodeficiency.
The opportunistic infections of HIV disease were easy to recognize because they stood out so starkly against the typical health status of the young, productive middle-class persons who first came to the attention of doctors in California and New York. Eventually, the set of symptoms that prefigured AIDS became well known and the disease was understood to progress along a continuum from primary infection to a terminal stage.
But if AIDS had first appeared among people with poor health and many other problems (and there is evidence that it did) it would not have been so easily discerned. While AIDS allows a number of characteristic infections to cause disease, for most of the people in the world with HIV, these occur on top of endemic infections or health problems that can be deadly in themselves. For too many people in the world, the burden of disease they face is amplified by HIV.
HIV exists in a complex web of interactions with other infections and pathologies. Some venereal diseases, such as herpes and chlamydia, may enhance the likelihood of becoming infected through sexual contact. Other problems, such as addiction and mental illness, also increase the risk of acquiring HIV and other infections, and, for the infected, make care and treatment much more difficult. Chronic poverty, lack of education and inadequate infrastructure may also be considered pathologies that exacerbate and sustain poor health.
Worldwide, each year, about 20 percent of all deaths are caused by infectious disease, with the overwhelming majority of these occurring in resource-poor regions. And about half of these deaths in the developing world are due to tuberculosis, malaria, and HIV. These are diseases that strike poor people and young people disproportionately and help perpetuate poverty by affecting people in the prime of their productive lives. The losses in lack of development, lost opportunities and lost lives due to preventable and curable infectious diseases are incalculable.
HIV is a transmissible infection acquired through sexual contact, during birth, or by contaminated blood, that depletes an individuals immune capacity to fight off deadly infections and some cancers. Nearly 50 million people may be infected with HIV, and HIV disease killed more than three million people last year, with this number set to rise dramatically in the coming decade. An estimated five million people will become newly infected this year, with rates of new infections poised to explode in Asia and Eastern Europe. Currently, about 70 percent of all people with HIV live in sub-Saharan Africa, where the disease mostly affects women, children and young people, most with few economic resources. Treatment is effective but out of reach for most who need it due to cost.
Malaria is endemic in many resource-poor tropical and sub-tropical regions where the Anopheles mosquito thrives, particularly in Africa. Worldwide, as many as 500 million cases of clinical malaria occur each year and over 3000 people die each day -- many of them children in Africa. For people with HIV, especially pregnant women, episodes of acute malaria are complicated and more serious.
Hepatitis B virus (HBV) is responsible for chronic liver infection in 350 million people around the world and is a major contributor to 1.4 million annual deaths from liver disease and cancer. Transmitted by sex, blood or at birth, chronic HBV infection is a long, slow illness that can produce serious liver damage later in life. In the developing world, particularly in Asia, most HBV infections occur in children, with from 50 to 90 percent of those exposed developing chronic infections. Individuals with chronic HBV infection from childhood have a 25 percent lifetime risk of dying from liver disease. In addition, persons with both HIV and Hepatitis B may be more likely to develop serious liver disease than those with HBV alone.
Infection with another liver virus, hepatitis C (HCV) is nearly universal among injection drug users with HIV in the U.S. Worldwide, an estimated 170 million people are chronically infected with HCV. With a long, slow course of progression, many people infected with HCV during the 1970s and 1980s are now experiencing serious liver disease, including cirrhosis and cancer. For those with HIV, liver damage may be more severe and treatment less successful. In the developed world, where death rates from AIDS have plummeted due to antiretroviral therapy, liver disease has emerged as one of the leading causes of mortality in people with HIV.
It's About Partnership
Collectively, these diseases may be responsible for over six million deaths per year, with many more trailing in their wake as the burden on economies and health care capacity becomes overwhelming. Increasingly, the fear that destabilized societies and economies may impact the security of Western nations has stimulated a great deal of rhetoric and an increasing amount of money dedicated to addressing the burden of disease in the world. Hopefully, several emerging global partnerships will be able to direct a coordinated and effective response to these threats as the promised resources become available.
Indeed, there are opportunities to be mined in these overlapping epidemics. Infrastructure in place to deliver TB treatment has been proposed as a platform on which to build a network to provide antiretroviral therapy. The high rate of antenatal clinic attendance in some parts of Africa gives an opportunity to detect HIV and sexually transmitted diseases, forestalling transmission to infants and preventing complications due to malaria.
The Global Fund for AIDS, Tuberculosis and Malaria (GFATM) was established to respond to these intertwining threats and has taken the first tentative steps towards underwriting expanded treatment programs on a country and regional basis. Although commitments to spend $2 billion by 2005 have been made, so far only $150 million has been disbursed. Despite the growing recognition that these diseases are a linked catastrophe, political will by the donor nations has lagged and the GFATM remains underfunded.
The Gates Foundation recently committed $168 million to fighting malaria and has issued challenges to develop affordable tests to diagnose infectious diseases and monitor therapy for HIV. The Grand Challenges in Global Health initiative is a $200 million partnership with the National Institutes of Health to get scientists to address open scientific questions in such fields as childhood vaccines, insect control, nutrition, and new treatments for debilitating latent infections that impede international development.
But the largest world body addressing the multiplicity of disease in the developing world is the World Health Organization (WHO), which, together with the UNs UNAIDS and other partners has launched an ambitious plan to bring HIV treatment to 3,000,000 people who need it over the next two years. While the thrust of this program is to procure drugs and diagnostics and establish guidelines for treating HIV with a restricted list of standard regimens, the necessary expansion of training and capacity improvement in the health care sector to allow ARV delivery is also expected to strengthen the ability to deliver a broader range of health services.
Despite the existence of an effective vaccine for hepatitis B virus, few children in the worlds poorest countries have been immunized. WHO is a leader in the Global Alliance for Vaccines and Immunization (GAVI), another broad-based partnership with the mission of vaccinating as many children as possible against preventable disease, such as hepatitis B.
WHO is also a leading agency in the Stop TB Partnership, a global association of all organizations and individuals working to control and eliminate TB in the world. Stop TB has set a goal of reducing the global burden of the disease by half by the year 2010. The means to accomplish this require a broad commitment from governments and NGOs to "ensure that every person with TB has access to a cure, that vulnerable populations are protected from infections, and that the social and economic damage of TB is minimized."
Roll Back Malaria is another WHO-founded global partnership with a goal of cutting the worlds malaria burden in half by 2010. With a shorter treatment period, effective prevention technology and recent successes in fighting malaria in affected countries, this effort may have the best chance among the large-scale disease initiatives for hitting its marks. Demonstrating success in rolling back malaria on a global scale is seen to be crucial for demonstrating that similar large partnerships for TB and HIV are feasible.
World Health Organization (WHO): www.who.int
This article was provided by Gay Men's Health Crisis. It is a part of the publication GMHC Treatment Issues. Visit GMHC's website to find out more about their activities, publications and services.