Top 5 Infectious Disease Concerns to Watch in 2019

The world of infectious disease is constantly evolving; an infection that is considered a national or global threat one year could be eliminated the next. There is also always the possibility that an unknown pathogen could emerge and wreak havoc on any sector of the population at any given time (that’s why the World Health Organization included Disease X on its 2018 list of Blueprint priority diseases).

Still, clinicians, infectious disease specialists, preventionists, and the larger health care community all have a pretty good idea of which specific pathogens, human behavior patterns, national crises, or risk factors could contribute to the next major outbreak.

Here, after consulting with experts in the infectious disease space, the Contagion® editorial staff has compiled a list of the top 5 infectious disease—both emerging and re-emerging—concerns to monitor in 2019.

#5: Candida Auris

2018’s No. 1 emerging infection to watch out for is a continuing concern in 2019 as well. Candida auris, a type of yeast, is particularly pesky because it is often multidrug-resistant, is outbreak-prone in health care-related settings, and is difficult to identify. There have been nearly 500 cases confirmed in the United States as of December 21, 2018.

“C auris is not easily identified. You need [matrix-assisted laser desorption/ionization-time of flight mass spectrometry] or DNA sequencing,” Tom Chiller, MD, MPH, chief of the Mycotic Diseases Branch, US Centers for Disease Control and Prevention (CDC), told Contagion® earlier this year. “It’s unfortunately easily transmitted. It’s on our skin so it can readily contaminate health care environments. It’s difficult to treat because of the multidrug resistance, and it causes severe infections like invasive candidiasis.”

#4: Vaccine Hesitancy

The growing hesitancy to vaccinate children as a collective behavior is something to watch in 2019, as it could lead to the re-emergence of infectious diseases previously eliminated in the United States.

Contagion® reported in June that several US cities were vulnerable to a measles outbreak because of opposition to vaccination. Indeed, there have been more than 290 confirmed cases of the disease this year in the United States, despite the fact that measles was considered eliminated by the CDC in 2000.

“[Say] an American child who has not been [vaccinated] goes on a trip abroad and acquires measles,” William Schaffner, MD, infectious disease specialist at Vanderbilt University Medical Center, and the former president of the National Foundation for Infectious Diseases, told Contagion®. “They bring it back and then you have an outbreak of measles, a disease that was totally eliminated.”

#3: Antibiotic Resistance

Ask any infectious disease specialist or preventionist what his or her biggest fear is and chances are antibiotic resistance is high on that list.

“Antimicrobial resistance is an important public health threat. Higher rates of antimicrobial resistance have several deleterious effects, and antimicrobial resistance is recognized as a global crisis for which urgent interventions are needed,” David Van Duin, MD, PhD, wrote in the December issue of Contagion®.

The CDC released a comprehensive list of US antibiotic resistance threats in 2013 and is working on publishing an updated list for 2019. Considered the most pressing threats: Clostridium difficile, Carbapenem-resistant Enterobacteriaceae (CRE), drug-resistant Neisseria gonorrhoeae, Methicillin-resistant Staphylococcus aureus (MRSA), and extended-spectrum beta-lactamase producing Enterobacteriaceae, among others.

#2: The Opioid Epidemic

The opioid epidemic could be the culprit of the next major infectious disease outbreak, experts warn. With the rise in drug use-associated infective endocarditis stemming from the use of intravenous drugs, the number of hospitalizations and valve-replacement surgeries has also spiked.

People who inject drugs are also at a higher risk of contracting hepatitis (B, C, and even A) and HIV, and they are also at risk of developing MRSA bloodstream infections or cellulitis at the injection site.

And now clinicians are even tracking the consequences of orally administered opioids.

“There are now good data to indicate that even orally administered opioids have immunosuppressive properties. What we’re seeing now an increase in staphylococcal infections, group A strep infections, pneumococcal and Candida infections related to opioid use,” Dr. Schaffner told Contagion®. “I think that the recognition is going to expand further as more data come in on the immunosuppressive aspect of opioids. [This] will move from a warm to a hot topic in 2019.”

#1: Ebola and Other Hemorrhagic Fevers

The infectious disease community has been particularly focused on the Ebola outbreak in the Democratic Republic of the Congo this year, as confirmed cases topped 500. The current uncontrolled outbreak, the funding gaps that are arising, and the long-term efficacy of the deployed Merck vaccine are sure to keep the Ebola virus at the forefront of the public health discourse in 2019 as well.

Other hemorrhagic fevers are also garnering some public attention. Nigeria experienced its largest Lassa fever outbreak to date this year, which remains a concern. Marburg, a zoonotic disease sometimes referred to as Ebola’s cousin, is also on the radar of infectious disease specialists heading into the new year because of its high fatality rate in humans.