Experts are warning clinicians and hospitals in the U.S. to prepare to see increased cases of dengue — a tropical, mosquito-borne disease. In the last month alone, two rare, locally-acquired cases popped up in California.
The illness is carried by the Aedes aegypti species, which traditionally has lived in tropical climates like Africa, the Middle East, Asia, Pacific Islands, Caribbean, Puerto Rico, Central and South America and Southeast Asia.
Only a quarter of cases are symptomatic, according to the CDC, but 5% turn into severe dengue, which is life-threatening. The disease is sometimes called "break-bone fever" due to the excruciating pain it can cause.
Right now, across the globe, Bangladesh is seeing the worst dengue outbreak in its history, according to CNN. As of Nov. 20 there were 301,255 confirmed cases with 1,549 deaths caused by dengue this year, NDTV World reported.
For cases in the U.S., travel-acquired dengue infections are much more common than locally acquired cases. But environmental factors continue to warm temperatures in the U.S. making habitats more friendly to the mosquitos.
According to the CDC, to date, most outbreaks in the nation have been small-scale. In addition to the two cases in California, other states that have experienced local spread of the infection in recent years include Texas, Florida, Hawaii and Arizona.
But are U.S. hospitals prepared for a Bangladesh-sized tropical disease outbreak? Could something of that magnitude even occur in the U.S.?
Duane Gubler, ScD, emeritus professor and founding director of the Signature Research Program in Emerging Infectious Diseases at the Duke-NUS Medical School, told Becker's as long as we continue to live with proper infrastructure like insulated houses, windows with screens and air conditioning that it's not likely to become as much of an issue in the U.S. as it could in less well-resourced countries.
It is also not the first time the U.S. has seen cases of dengue, and he said there isn't reason to panic, emphasizing that "the mosquitoes have always been there, and what has happened in recent years is environmental changes that have allowed for the mosquito to expand its distribution."
Hospitals 'will be caught off guard' and children most at risk
Even so, instances of the virus are likely to increase nationwide throughout the next decade and when they do, David Vu, MD, a pediatric infectious diseases specialist at Stanford told Becker's, hospitals might not see it coming.
"To be honest, I think that we will be caught off guard. I think that most of the healthcare systems in the U.S. are trying to prepare for the next pandemic and trying to learn from the most recent one," Dr. Vu said. "We are not well-prepared for tropical diseases. It's not something that is forefront in our minds. So I think that we will be caught off guard and — depending on the type of infection that we're talking about — we will be caught off guard in different ways."
Dengue, he said, is different from some other tropical viruses. It is primarily asymptomatic in most infected individuals, so cases could linger in a community longer without patients seeking treatment. Then, those who do experience severe dengue could eventually strain ICUs because the disease can essentially cause capillary leak syndrome, which requires intense monitoring and intervention to manage, Dr. Vu explained.
But overall, "the overwhelming burden of dengue [infection] is in children. They tend to be the most severely affected or have the most severe infections," Dr. Vu said. "So, I think that it's quite possible for the children's hospitals to bear a disproportionate burden of dealing with severe dengue disease."
Dr. Gubler noted that while cases may begin to increase in time, he doesn't foresee any large-scale issue hitting hospitals soon.
"I don't think we're going to have major epidemics of diseases like dengue and malaria," he said. "We will have cases, but the hospitals shouldn't be inundated or overcrowded with cases. But that being the case, they should still be prepared to diagnose and manage diseases like dengue."
How can hospitals prepare?
Preparing for something before it happens can be difficult, as was the case with COVID-19. However, Dr. Vu is more optimistic about how the U.S. will fare facing dengue and tropical diseases compared to how it fared during the 2020 pandemic.
"One advantage that we have with tropical diseases that we didn't have with COVID, for example, is that these infections are not new. They already exist in other parts of the world," he said. "It just means that we have to learn from areas of the world who have already dealt with such endemic or epidemic diseases. And with that we need to basically recognize that with climate change, diseases that were once infectious threats to certain parts of the world can now affect more of the world."
As such, supporting continuing education and immersive research is one way hospitals can prepare their clinicians, Dr. Vu noted, adding that more emphasis on tropical diseases in medical programs will also become increasingly beneficial.
Dr. Gubler noted that hospitals cannot adequately prepare to tackle outbreaks without a solid foundation of disease surveillance and supporting data — so preparing hospitals will also require preparing public health systems to monitor and report that information.
"It has to be a partnership between the hospitals, the state, local health departments and the state public health laboratory to monitor these diseases," Dr. Gubler said. "They should develop better local surveillance for any number of infectious diseases."
The best way to go about doing this, he said, is for the health departments to work in tandem with the hospitals and clinics in the local area to ensure every party is collecting and/or receiving the information necessary to manage increasing and emerging diseases.