Solving medical mysteries in the tropics

Whenever Wong Jin Shyan, M.D. has a trainee, he keeps them motivated by focusing on his favorite task: “I tell them that making a diagnosis is the most fun part, that’s the ‘yay’ moment,” says Wong, who works as a consultant general physician at the Borneo Medical Center in Sarawak, Kuching, Malaysia. Even more rewarding, he says, is being able to make a diagnosis within the first 24 hours of a patient arriving at the hospital. “It’s better for the patient and the hospital.”

In tropical climates like Malaysia, weather plays a huge role in fueling the spread of infectious diseases. Malaysia is regularly flooded during its two monsoon seasons, typically around late May to September and November to March. Stagnant floodwater provides an ideal breeding ground for mosquitos that transmit malaria, dengue and encephalitis—viral diseases that are generally uncommon in the western world.

The flooding also overwhelms wastewater drainage infrastructure, causing sewage to mix with drinking water and leading to outbreaks of bacterial infections, like typhus and leptospirosis, and parasitic infections, like Giardia and Entamoeba.

There are multiple advantages in being able to quickly distinguish a viral infection from other types of illness. For example, parasitic and bacterial infections often require specific treatment, while viral diseases do not. 

Helping curb outbreaks

The lab at the Borneo Medical Center made a breakthrough in rapidly identifying the cause of infectious illnesses when they adopted a modern method for pathogen detection: Real-time PCR panel tests. With the addition of the QIAstat-Dx Respiratory SARS-CoV-2 Panel, QIAstat-Dx Meningitis/Encephalitis Panel and QIAstat-Dx Gastrointestinal Panel to their diagnostic repertoire, diagnoses that previously took days now take less than 2 hours.

Being able to help identify the specific cause of a respiratory infection can make a huge difference for patient’s peace of mind. According to Wong, the coronavirus pandemic set many people in his community on edge. Even those with relatively mild respiratory symptoms, like cough and fever, worry about severe disease and visit the hospital instead of seeing a local doctor.

For individuals with these symptoms, the QIAstat-Dx Respiratory SARS-CoV-2 Panel allows physicians to test for multiple respiratory pathogens simultaneously, while giving them fluids and fever-reducing medications. If a test comes back positive for a viral pathogen, the patient can usually go home the same day.

“The test gives patients the confidence that they can recover at home. It makes parents and patients happier.” The positive detection of a virus also “stops us from overusing antibiotics,” says Wong.

The lab conducts between 150 to 200 molecular diagnostic tests a month.

By collating the results using the QIAsphere app – a platform that enables users to remotely monitor their QIAstat-Dx test status through their personal devices and view on-demand epidemiology reports – hospital physicians can also get a snapshot of the types of pathogens that are circulating in the population, enabling them to not only improve patient treatment, but also help curb infectious outbreaks.

Detecting parasitic infections

Recently, molecular testing helped Wong correctly diagnose a complex case. A patient came to the medical center with COVID-19 symptoms. A molecular diagnostic test helped confirm the diagnosis. Doctors began administering him Paxlovid, an anti-viral to treat the infection.

While in the hospital ward, the patient developed diarrhea – a common side effect of the drug. But the frequency of the patients’ bowel movements made Wong suspect something else might be going on. He tested a stool sample with the QIAstat-Dx GI Panel and helped discover that the patient was also positive for Entamoeba – a gut parasite.

It turned out the patient had been on a camping trip where he was not only exposed to the coronavirus, but also likely infected with the parasite, says Wong. The patient was immediately given the appropriate medicine.

Before bringing the QIAstat-Dx in house, the hospital laboratory would have had to culture microbes from a stool sample, or examine the sample using microscopy. But cultures can take up to two days for a result, if the microbe can be cultured at all. And microscopic analysis of a stool sample for the presence of cysts – a sign of Entamoeba infection – sometimes does not detect them, says Wong.

In addition to Entamoeba, Wong can also now detect Giardia–another parasite that can be particularly difficult to treat in people with compromised immune systems.

Like Dr. House

Another advantage of the QIAstat-Dx system is the ability to later analyze the test result data in bulk through the QIAsphere app, says Wong, and consequently respond to public health needs. QIAsphere helps give the hospital an overview of the pathogens that are circulating in the community. They can see when there is a change in influenza subtype, for example, or a rise in respiratory syncytial virus detections, says Wong.

The information enables the hospital to plan ahead and “strategize.” In the past “we had no data about what is going on.

Now if we start detecting a lot of infections, we can push hard for community vaccination and hopefully blunt the rise in pathogens.” And having hard data helps convince the health community of the need to be proactive, he adds.

Available diagnostic tests, however, don’t cover all of his needs, he says. The laboratory still conducts serology tests in parallel with molecular diagnostic testing to increase the confidence in the test results.

Do the new tests eliminate some of the “fun” in making a diagnosis? Not at all, says Wong. “Since the panels are syndromic, we have to choose which syndrome we are going to test for,” he says.

And there are still many infectious illnesses for which there are no simple diagnostic tests. He frequently encounters tough cases for which multiple types of tests are necessary and even with such tests and imaging, they can still be challenging.

He says: “My job is like Dr. House’s” -  an American-made medical drama TV series about an unconventional and quirky doctor who leads a team of hospital diagnosticians - “minus the friend drama.”