Dear Readers: This week we wanted to discuss some important updates on several topics you’ve asked about recently, including the poliolike illness called acute flaccid myelitis, the potentially deadly EEE mosquito virus and vaping lung disease.

-- When we wrote about acute flaccid myelitis (AFM) last summer, the cause of the poliolike disease was a mystery. What was known then was that some children who developed flulike symptoms -- including fever, aches and pains, and congestion -- also experienced loss of muscle control in their arms and legs. They also often developed trouble breathing and swallowing. And a number of children with the illness became paralyzed, and some died.

Although the symptoms and the pattern of onset of acute flaccid myelitis resemble those of polio, the stools of patients with AFM have tested negative for poliovirus, which is an enterovirus. However, a new analysis of available data, published in October in the journal Pediatrics, suggests that a different enterovirus plays a role. Specifically, lab tests point to enterovirus D68, one of more than 100 known non-polio enteroviruses. The connection needs further study, but this is the first real advance since AFM first appeared. With a clearer understanding of the disease, researchers are now able to narrow their focus, and, hopefully, develop medications or a vaccine for the condition.

-- Another topic from last summer is the Eastern equine encephalitis virus. Referred to simply as EEE virus, it’s a potentially fatal mosquito-borne illness. First recognized in humans in 1938, it has been a rare occurrence for people to become infected with the virus. Recently, infection rates have quadrupled to about 30 cases a year, up from an earlier average of seven cases per year. In 2019, 11 people have died as a result of the virus.

Infection with EEE is still rare, but due to the increase in severe cases, health officials are urging everyone to use insect repellants and cover up while outdoors, particularly from dusk to dawn, which is prime time for mosquitoes.

-- The number of people with a serious lung illness associated with vaping continues to grow. The U.S. Centers for Disease Control and Prevention updates statistics weekly. At this time, there have been a total of 1,299 patients in 49 states, plus Washington, D.C., and the Virgin Islands. At least 23 people have died.

The specific cause of the disease is not known, but bootleg products that contain THC are a possible culprit. According to the CDC, close to 80% of patients in the cases it has analyzed so far have reported using products that contain THC. Another study found that 66% of patients had used a black market product. Vitamin E acetate, an additive used as a thickening agent, has emerged as a suspected agent. So have the noxious fumes that are created when the unregulated chemicals contained within a vape cartridge get superheated. Meanwhile, a small but growing number of patients are being hospitalized a second time.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: I prefer to breathe through my mouth at all times. This is due to fairly constant nasal congestion. Am I getting the same amount of oxygen as breathing through my nose?

Dear Reader: The answer is actually a bit more complex than a simple yes or no. Yes, the same amount of oxygen reaches your lungs whether you’re breathing in through your nose or your mouth. But something different happens to that oxygen when you breathe in through your nose, which doesn’t happen when you breathe through your mouth.

Breathing through the nose warms, filters and humidifies the air. Each of these is important to the health of the delicate tissues of the nose, lower airways and lungs.

Nose breathing has another beneficial effect on oxygen once it reaches the lungs, which doesn’t happen with mouth breathing. This is due to nitric oxide, a colorless and odorless gas. It’s produced throughout the body, including by the paranasal sinuses, which are the group of air-filled spaces in the forehead and around the nasal cavity. When you breathe through your nose, the nitric oxide in the paranasal sinuses follows the inhalation through the airways, down into the lungs and into the millions of microscopic sacs, known as alveoli, that supply the blood with oxygen. Research has shown that nitric oxide plays an important role in increasing blood oxygen and improving oxygen absorption by the lungs. Nitric oxide is also a vasodilator, which means that it increases blood flow and lowers blood pressure.

When you breathe through your mouth, the oxygen contained within that inhalation reaches the lungs. However, it gets there without the added health benefits of nitric oxide. It also gets there without the warming, added humidity or filtration provided by the nose. These all occur because a thin layer of moist tissue, known as the mucous membrane, lines the nose. The sticky surface of that membrane -- the mucus -- is quite efficient at capturing airborne particles and preventing them from getting into the lungs. The mucous membrane also contains specialized immune cells and enzymes to neutralize potential pathogens. And it’s lined with tiny hairlike structures, called cilia. These cilia constantly wave and beat and move mucus, along with debris trapped within it, away from the lungs and down into the throat for removal.

We think it’s important for you to learn the reason for your ongoing nasal congestion. It may be due to allergies or infection; it could be a structural problem, like a deviated septum; or it could arise from a blockage, as from polyps. The good news is that allergies respond well to medication, and anatomical blockages can be surgically corrected. Something as simple as those nasal strips, which help keep the nasal canal open, can bring relief. We think it would be wise for you to see your family’s health care provider to learn and address the underlying cause for your ongoing nasal congestion.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: I heard about a guy who tested as drunk but hadn’t had any alcohol. Is that really even possible, or is it some kind of urban legend?

Dear Reader: It certainly sounds like the product of an overactive imagination, but the scenario you’re referring to did happen. According to news reports, a young Chinese man who had moved to Australia to attend college suddenly started getting drunk. The catch was that he swore he hadn’t imbibed any alcohol. Upon returning home to China, the breathalyzer tests he took during subsequent episodes showed a blood alcohol level up to 10 times the legal limit.

In 2014, he became gravely ill and was admitted to the hospital, 10 years after the onset of the mysterious episodes. He was diagnosed with fatty liver disease, in which a buildup of fat in the liver causes inflammation that leads to organ damage. The condition is common in people with chronic alcohol abuse, which outstrips the liver’s ability to manage and clear the resulting toxins from the body.

The Chinese man was eventually diagnosed with auto-brewery syndrome, a rare condition in which the carbohydrates that a person eats or drinks are fermented in the gut and turn into ethanol, also known as grain alcohol. As it turns out, the young man wasn’t drinking alcohol, but he was drinking a lot of fruit juice and eating carbohydrate-rich foods, thus giving the rogue microbrewery in his gut plenty of raw material to work with.

While this case is interesting on its own, it also holds promise for people with nonalcoholic fatty liver disease, or NAFLD. As the name suggests, this is a type of fatty liver disease that occurs in the absence of heavy alcohol use. In NAFLD, inflammation and cell damage can be severe enough to result in fibrosis and scarring, and can even lead to cirrhosis or liver cancer. The cause of NAFLD isn’t known. But recent studies have found that the guts of people with NAFLD were far more likely to contain certain alcohol-producing bacteria than the guts of healthy individuals. This not only opens new avenues of research, but also offers hope for an eventual cure.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)