By Susan Blumenthal, M.D., M.P.A., Laura McCulloch, and Stephanie Heung
Next week, over 40 African heads of state will convene in Washington, D.C. for the first-ever U.S.-Africa Leaders Summit. One important issue that requires attention at the meeting is strengthening the response to infectious diseases including HIV/AIDS, malaria, Ebola and tuberculosis (TB) that threaten lives, economies and national security.
TB is one of those diseases. It is both curable and preventable, yet 5,000 people worldwide still die every day from this illness. Of the 9 million people that acquire TB every year, 3 million of them are "missed" by their community and country's health systems. Therefore, it is critical to apply the best evidence-based practices to reduce the threat of tuberculosis worldwide.
The symptoms of tuberculosis include coughing, chest pain, fatigue, fever, weight loss, chills, night sweats and loss of appetite. The disease can spread when an individual with active tuberculosis (a disease state characterized by actively dividing bacteria) coughs, sneezes, talks or spits, releasing droplets containing M. tuberculosis into the air. If other people inhale these droplets, they may acquire the disease; however, not everyone who inhales them becomes sick.
Thus, two TB-related conditions exist: latent TB infection and active TB disease. Without treatment, individuals with active TB will infect an average of 10-15 people annually. Individuals with latent tuberculosis -- characterized by non-dividing bacteria -- are often asymptomatic and unable to infect others, but they remain at risk of developing active disease if not properly treated. It is estimated that one-third of the world's population currently has latent tuberculosis. On average, 5-10 percent of people with latent TB will develop active TB at some point during their lives. However, people with compromised immune systems due to HIV or diabetes, and people who use tobacco or are malnourished, have a much higher risk of becoming ill.
Two Decades of Progress
Significant progress has been made in the fight against TB since the World Health Organization (WHO) declared the disease a public health emergency in 1993. Over the past two decades, 56 million people have been successfully treated for TB, with an estimated 22 million lives saved. Global TB incidence has decreased, and TB mortality has fallen 45 percent since 1990. As a result, the Stop TB Partnership's target to reduce TB deaths by 50 percent by 2015 is now within reach.
However, much work remains in order to curb the public health threat of TB. Each year, there are still an estimated 7.5 million new TB cases and 1.4 million TB deaths. TB is the third-leading cause of death for women worldwide and kills almost 75,000 children every year.
The Most Challenging Cases: HIV/AIDS Co-Infection and MDR-TB
TB/HIV co-infection poses a significant threat to HIV and TB control efforts. The two diseases form a lethal combination, each accelerating the other's progression. TB is the leading cause of death for HIV-positive people, responsible for one in five deaths among this population group. People who have both HIV and latent TB are up to 50 times more likely to develop active TB than HIV-negative people. In 2012, there were an estimated 1.1 million new cases and 320,000 deaths from TB/HIV co-infection. Sadly, TB testing rates among HIV patients and the use of antiretroviral (ARV) medications in TB/HIV co-infected people remain low.
Furthermore, drug-resistant forms of TB are severely threatening progress. Multidrug-resistant tuberculosis (MDR-TB) is a form of TB caused by bacteria that do not respond to the two most powerful first-line anti-TB medications, isoniazid and rifampicin. MDR-TB is linked to poor treatment adherence and incorrect TB drug usage. There were an estimated 450,000 new cases and 170,000 deaths from MDR-TB globally in 2012.
MDR-TB can be cured through appropriate use of second-line drugs. However, second-line treatment options are limited, significantly more expensive and less accessible than first-line medications. Furthermore, an estimated 9.6 percent of MDR-TB cases have extensive drug-resistant TB (XDR-TB), a form of multidrug-resistant TB for which few effective treatment options are available.
The Social and Economic Impact of TB
Socioeconomic factors are strongly linked to TB, with over 95 percent of deaths from the disease occurring in low- and middle-income countries. Contributing factors to the global variations in TB incidence rates include lack of access to health care services, poor health information systems, lack of community and societal engagement on the issue, and inadequate attention to relevant social determinants of health that can fuel the epidemic. These social determinants of health include economic inequalities, cultural and religious beliefs regarding treatment, lack of education, rapid urbanization, and stigma surrounding the disease.
Contracting TB often results in a devastating financial burden for patients. TB patients in low- and middle-income countries face catastrophic medical expenses that can drain their savings and impoverish their families. Furthermore, 75 percent of TB patients are between the ages of 15-54, often the most productive stage of life. As a result, the average TB patient loses three to four months of work time and over 50 percent of his or her annual income. TB is a financial burden not just for individual patients, but also for the health systems of affected countries. At the current incidence rate, TB is predicted to cost the world's poorest countries an estimated $1 to $3 trillion over the next decade.
TB and poverty are so intertwined that in order to defeat either condition, both problems must be addressed simultaneously. Crowded living conditions in low-income communities increase the risk of spreading contagious diseases like tuberculosis. The spread of TB and poverty creates a vicious cycle, in which the disease exacerbates poverty, which in turn increases the risk of contracting TB. This is of grave concern since 2.4 billion people worldwide live on less than $2 a day.
Though significantly fewer people die from tuberculosis in high-income countries such as the United States, the disease nonetheless remains a health threat in these nations. In 2012, according to the Centers for Disease Control and Prevention (CDC), 9,945 TB cases were reported in the U.S., the lowest recorded number since national reporting began in 1953. However, unless circumstances change significantly, it is estimated that the U.S. will not be able to eradicate TB until at least 2100.
Global Strategies for Fighting Tuberculosis
A successful approach to reducing TB has been Directly Observed Treatment, Short-Course (DOTS), a multi-pronged tuberculosis control strategy. DOTS is best-known for using community workers to deliver and supervise the administration of TB therapy. This strategy has a cure rate of over 80 percent and has been ranked as one of the "most cost-effective of all health interventions" by the World Bank.
This year, the Stop TB Partnership, an international collaboration of governmental and non-governmental organizations, adopted the "Reach the 3 million" slogan for World TB Day. The slogan refers to the 3 million people with TB missed by health systems every year.
In May 2014, the WHO released its global strategy for containing the tuberculosis epidemic. The strategy seeks to accelerate the 2 percent decline in new TB infections each year to a 10 percent annual decline rate.
The WHO targets for 2025 as listed in the WHO global strategy are:
- A 75 percent reduction in TB deaths compared with 2015
- A 50 percent reduction in the TB incidence rate compared with 2015 (less than 55 TB cases per 100,000 population)
- No affected families facing catastrophic costs due to TB
Additionally, in July 2014, the WHO established an action framework to eradicate TB in low-incidence countries. Below are the eight priority recommendations as listed in the report:
- Ensure funding and stewardship for high-quality planning and services.
- Address the most vulnerable and hard-to-reach groups.
- Address special needs of immigrants; cross-border issues.
- Undertake screening for active TB and latent TB infection in high-risk groups and provide appropriate treatment; manage outbreaks.
- Optimize MDR-TB prevention and care.
- Ensure continued surveillance and program monitoring and evaluation.
- Invest in research and new tools.
- Support global TB control.
Addressing the global TB epidemic will require an estimated $4.8 billion a year in the 118 countries eligible for financing from the Global Fund to Fight AIDS, TB and Malaria. However, an estimated $1.6 billion annual shortfall currently exists in funding for disease prevention and control efforts. Filling this funding gap has the potential to provide treatment for 17 million TB patients and save 6 million lives from 2014-2016. Fighting TB is also a smart investment -- each dollar invested in preventing and controlling TB is estimated to yield US$30 in returns through improved health and economic productivity.
Conclusion
Public health interventions have made major progress in fighting TB, with incidence rates significantly declining since World TB Day was first observed 32 years ago. However, much more needs to be done to achieve a TB-free world -- one in which children will have to turn to the history books to learn such a disease ever existed. The elimination of TB worldwide will only be successful if community, regional, national and international partners from all sectors of society join resources and collaborate to implement life-saving solutions. This will require providing development assistance to low- and middle-income countries, prioritizing the eradication of TB in high-income countries, and investing in the discovery of new treatment and prevention strategies. Eliminating tuberculosis is not only a humanitarian imperative, but it is also an economic necessity. Without intervention, TB will continue to devastate lives and communities around the world.
Rear Admiral Susan Blumenthal, M.D., M.P.A. (ret.) is the Public Health Editor of The Huffington Post. She is a Senior Fellow in Health Policy at the New America Foundation and a Clinical Professor at Tufts and Georgetown University Schools of Medicine. She is also Senior Policy and Medical Adviser at amfAR, The American Foundation for AIDS Research. Dr. Blumenthal served for more than 20 years in senior health leadership positions in the federal government in the Administrations of four U.S. presidents including as Assistant Surgeon General of the United States, the first Deputy Assistant Secretary of Women's Health, and as Senior Global Health Advisor in the U.S. Department of Health and Human Services. She also served as a White House advisor on health. Prior to these positions, Dr. Blumenthal was Chief of the Behavioral Medicine and Basic Prevention Research Branch, Head of the Suicide Research Unit, and Chair of the Health and Behavior Coordinating Committee at the National Institutes of Health. She has chaired numerous national and global commissions and conferences and is the author of many scientific publications. Admiral Blumenthal has received numerous awards including honorary doctorates and has been decorated with the highest medals of the U.S. Public Health Service for her pioneering leadership and significant contributions to advancing health in the United States and worldwide. Named by the New York Times, the National Library of Medicine and the Medical Herald as one of the most influential women in medicine, Dr. Blumenthal was named the 2009 Health Leader of the Year by the Commissioned Officers Association and as a Rock Star of Science by the Geoffrey Beene Foundation. She is the recipient of the Rosalind Franklin Centennial Life in Discovery Award.
Laura McCulloch is a junior at Dartmouth College, pursuing a degree in global health and public health policy. She was a Health Policy Intern at the New America Foundation in Washington, D.C.
Stephanie Heung is a senior at Yale University, pursuing a degree in Molecular, Cellular and Developmental Biology. She is a Health Policy Intern at the New America Foundation in Washington, D.C.