Dear Doctor: It seems like every time I turn on the news someone's freaking out about ticks and mosquitoes. Haven't they always been around? What's with the alarm bells all of a sudden?

Dear Reader: The reason you're hearing so much about ticks and mosquitoes these days is because of a worrisome spike in the number of people becoming infected with the range of diseases these creatures cause. (We can't say "insects" because, while mosquitoes do fall into that category, ticks don't. They're actually arachnids -- like mites, spiders and their larger cousin, the scorpion.) According to a report released by the federal Centers for Disease Control and Prevention in May, the incidence of disease spread by ticks and mosquitoes has more than tripled between 2004 and 2016.

In just 13 years, the number of tick- and mosquito-borne illnesses in the United States has ballooned from 27,388 reported cases in 2004 to 96,075 reported cases in 2016. Even more concerning is the fact that more than half of that increase occurred between 2015 and 2016. And the key word here is "reported." Not every tick- or mosquito-borne illness is identified or gets reported, so the number of people made ill by a tick or mosquito bite is quite likely higher. (The CDC's report also covers fleas, with a total of 89 reported cases of plague over the 13 years of the report.)

Lyme disease accounted for 82 percent of the increase in tick-borne illness, according to the report. A closer reading of a breakout of the data reveals some troubling trends. For example, babesiosis, a malaria-like illness carried by deer ticks, went from zero cases in 2010 to more than 1,900 reported cases in 2016. Anaplasmosis, also caused by a bacterium carried by the deer tick, jumped more than 650 percent, from 875 cases in 2004 to 5,750 cases in 2016. If left untreated, the disease can cause internal bleeding, difficulty breathing, neurological problems and kidney failure.

When it comes to mosquitoes, the report offers both good and bad news. Cases of Zika have gone from zero in 2015 to 41,680 the following year. Virtually all were reported in Puerto Rico, American Samoa and the U.S. Virgin Islands. West Nile virus, meanwhile, which hit a high of 5,674 cases in 2012, dropped by half by 2016. In addition, the CDC reports that nine new germs that are spread by ticks and mosquitoes have been identified since 2004. Scientists say the rise in disease rates, as well as the widening of their geographic scope, is due in part to the warming climate, which expands the pests' habitats. Global trade and travel also play a role.

Our aim here is not to alarm, but to stress the importance of vigilance in protecting yourself and your family. Bottom line: Create a barrier between yourself and the potential threats. That means appropriate clothing to cover you when spending time outdoors, bug repellent for a chemical shield, and regular visual checks of your skin, scalp and clothing. And don't forget about the pets -- a range of excellent meds are available to keep your furry companions tick- and flea-free as well.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: Does Oscillococcinum work as a flu treatment?

Dear Reader: Oscillococcinum is a homeopathic preparation. Unlike the sound of the name, it has nothing to do with bacteria. The product is derived from wild ducks' hearts and livers. In a homeopathic method, that extract is diluted up to 200 times, such that a miniscule amount of the material is in the final product. The belief is that the heart and liver of a wild duck may have influenza virus and that diluting this material may somehow cause an increased immune response to the flu.

But no studies have shown that Oscillococcinum causes any specific alteration to the influenza virus or the immune system.

However, studies have looked at Oscillococcinum for the prevention and treatment of influenza. A 2015 study reviewed six trials. Two trials assessed the use of Oscillococcinum for prevention of influenza and four trials assessed its use for treatment. The two prevention trials, with a total of 327 people, found a 52 percent decrease in influenza risk among those who used Oscillococcinum.

Out of the four treatment trials, two of the trials -- with a total of 796 participants -- found an 86 percent greater chance that symptoms would resolve after 48 hours among those who took Oscillococcinum compared to those who didn't. (This isn't a dramatic difference when you consider the absolute numbers. To be precise, it amounts to a 16.7 percent chance of resolution in the Oscillococcinum group and a 9 percent chance of resolution in the placebo group.) One interesting note is that patients ages 12 to 29 were much more likely to report a positive effect than those over 30.

After three days, however, the difference between the placebo group and the treatment group declined, and by the fourth day there was no difference. Of further note, there was a 39 percent reduction in the use of other influenza medications in the group that took Oscillococcinum.

The two other studies in this review looked at a physician assessment of patients 48 hours after the onset of symptoms, and while there was a mild improvement seen with the preparation, it was not statistically significant.

Note that the authors of the review found multiple flaws in the methodology of the studies and said that the studies were potentially biased. Thus, they were not convinced of the benefits of Oscillococcinum for either the prevention or treatment of influenza.

A 2009 and 2012 review of multiple studies showed a mild benefit toward Oscillococcinum, but these studies also were considered of poor quality, and the authors could not make any conclusion about the benefit of the medication.

As for whether Oscillococcinum works, I know it isn't satisfactory, but the answer is "maybe." Better-quality studies are necessary. One good thing about the prior studies was that there was little difference between the medication and placebo regarding side effects, so if you take it, it should be safe.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: Our 68-year-old father moved to Hilo on the Big Island of Hawaii two years ago. He's not that great about using sunscreen, so my siblings and I always figured skin cancer would be the biggest health threat. But now with the Kilauea volcano, we're way more worried about the toxic fumes. What are they, and are they really as dangerous as the news stories say?

Dear Reader: When your father relocated to the Big Island, he moved to the youngest of the chain of Hawaiian Islands. It's home to Kilauea, which, despite its outwardly quiet demeanor over recent decades, is considered to be one of the most active volcanoes in the world. In fact, according to the U.S. Geological Survey, Kilauea has been in the process of erupting since 1983. This occurs when magma, the mixture of molten or semimolten rock found beneath the earth's crust, makes its way to the surface.

As this happens, ash, steam and various gases dissolved in the magma are released. Among the emissions is sulfur dioxide, or SO2. It's a noxious gas that in certain concentrations is toxic and potentially deadly. Scientists monitoring the current stage of Kilauea's eruption, which as we've seen from news reports is extremely active, report that significant amounts of the gas are emerging from the volcano's various vents and fissures.

Sulfur dioxide is a colorless, nonflammable gas with the acrid odor of a just-struck match. It's a byproduct of the burning of coal and oil at power plants, of smelting copper and, as Kilauea now reminds us, of volcanic eruptions. In small quantities, SO2 is used as a food preservative, as in dried fruit. It's also used to sanitize food containers and fermentation equipment, and as a moisture control agent.

People exposed to the gas near the volcano may experience eye irritation that can become severe, sneezing, coughing and choking, and a burning sensation or even a rash on the skin. Prolonged exposure to SO2 can cause bronchitis and swelling of the upper airways to the point that breathing becomes difficult or impossible. That's because the gas is highly soluble in water and is easily absorbed by the moist environment of the respiratory tract. SO2 gas is bad news for anyone, but the young, elderly and those with breathing issues are at greater risk of serious side effects. This is why residents have been evacuated from the immediate area and have been allowed to return to fetch pets and valuables only when it has been determined that SO2 is at acceptable levels.

Living in Hilo, a safe distance away from the volcanic activity, your father isn't at direct risk from SO2 gas. However, falling ash, as well as a mixture of SO2 and water vapor from fog or rain, known as "vog," can affect air quality across a wide radius. If your dad has any breathing issues, it's possible that they may flare up as the present eruption continues to affect air quality in a wider area. Staying indoors and avoiding exertion can help protect him from the worst of it.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)