For much of history, physicians made disease diagnoses by simply using their senses. What does the skin look like? How do the lungs sound? Do any bodily fluids have a particular smell?
As we have learned more about the nature of diseases and developed more advanced tools, testing has become one of our strongest defenses against outbreaks. International response to deadly diseases like Ebola and Zika relies on fast and reliable testing to identify and treat those who are sick and prevent the spread to protect those who are not.
“Innovations in testing—making it faster, more affordable and more comprehensive—allow us to protect people from diseases that may originate in their own towns or from thousands of miles away," said Dr. Placide Welo, director of the National Program for the Elimination of Cholera and the Control of Other Diarrheal Diseases (PNECHOL). "Testing accelerates progress against both new health threats and those that have devastated mankind for centuries.”
Diseases evolve, necessitating continued innovations as we respond to ever-changing threats. In many cases, gaps in current test availability and accuracy limit our public health response. Developing new diagnostic tests is no simple task, and the CDC Foundation has worked with partners at every step of the process to conduct research, testing and evaluation to create new tests and ensure they are accurate and scalable.
In this initial phase of testing research, researchers seek to answer questions at an often-microscopic level. This often includes studying molecules, called antibody biomarkers, that could indicate the presence of an infection. Once these biomarkers are discovered, the researchers then begin developing tests to identify them from a sample.
Innovations in testing—making it faster, more affordable and more comprehensive—allow us to protect people from diseases that may originate in their own towns or from thousands of miles away.
The CDC Foundation supports this first step in testing research for neglected tropical diseases (NTDs). NTDs are a diverse group of infections, including some dating back thousands of years, that are prevalent in tropical and subtropical countries in Africa, Asia, Central America and South America. NTDs impose an enormous human, social and economic burden—affecting nearly a billion people around the world. Many of the testing methods for NTDs are outdated or inefficient. In the U.S. territory of American Samoa, the mosquito-borne parasitic disease lymphatic filariasis inflicts tremendous disability and illness among impoverished communities, especially those that lack access to basic or adequate resources, like medical care or sanitation.
To help develop rapid and effective tests for NTDs like lymphatic filariasis, the CDC Foundation supports biomarker discovery efforts. Using a novel method called serum epitope repertoire analysis (SERA), which allows scientists to gather complex information from a single specimen, our partners have been able to identify which antibodies are associated with a given infection—essential information for developing accurate tests for each disease.
Neglected tropical diseases prevalent in tropical and subtropical countries and impose an enormous human, social and economic burden.
Research and development of new diagnostic tests ensures we're accurately tracking and responding to diseases.
But creating an effective test is only part of the challenge. Once a test has been developed and trials have confirmed its efficacy, it is then evaluated on a larger scale to see whether it can help departments of health in the U.S. and ministries of health all over the world prevent outbreaks.
One such evaluation is taking place in the Democratic Republic of the Congo (DRC), a country that has experienced multiple cholera epidemics in the past five years. There, the CDC Foundation is working with partners to answer whether expanded use of rapid diagnostic tests (RDTs) can make a difference in early outbreak detection. Associated with seven worldwide pandemics since the 1800s, cholera is spread through contaminated water and food, resulting in an estimated 2.9 million cases and 95,000 deaths per year worldwide.
“Improving the speed of cholera testing can make a big difference in how quickly cases are identified and will also allow for faster outbreak detection and response," said Dr. Placide. "In DRC, these diagnostic tests provide critical and timely data needed to stop outbreaks early, saving lives in DRC and preventing cholera from spreading around the world.”
Cholera spreads through injestion of contaminated water.
The yellow coloring indicates a positive result for the cholera bacteria.
Some diagnostic tests must be done in lab settings—a cost prohibitive option for many areas. For a highly contagious and deadly disease like tuberculosis (TB), screening tests and tools, such as chest x-rays and the tuberculin skin test, are a reliable way to identify who needs treatment without the immediate need for a lab-based test.
In Vietnam, which continues to face a significant TB burden, including approximately 13,800 deaths annually, the CDC Foundation worked with Friends for International TB Relief (FIT) from 2019 to 2023, to expand its mobile chest X-ray screening campaign in Ho Chi Minh City to incorporate latent TB infection testing, giving individuals the information and care needed to prevent the infection from becoming active.
A man stands for a chest x-ray screening for TB.
FIT brought TB information to rural communities, expanding the reach of their screening work.
“We were able to go out into the community and provide access to TB screening to those who might not have otherwise sought out testing, and we were able to diagnose TB which would’ve otherwise been missed,” said Luan Vo, FIT CEO.
In our increasingly interconnected world, diseases have the potential to spread rapidly. The CDC Foundation continues to support initiatives to develop new tests, evaluate tests' effectiveness and address gaps in testing availability to ensure we’re one step ahead of the next outbreak.
Water tap photo courtesy of Gavi/2018/Duncan Graham-Rowe
Cholera pietri dish photo courtesy of Kendra Helmer/USAID
Vietnam photos courtesy of Friends for International TB Relief (FIT)
