Ask the Doctors

Dear Doctor: Can you settle an argument in our family? Ever since the Ebola virus hit the news, my aunt has been using antibacterial products for everything. She even had the kitchen walls coated with antibacterial paint! But from what we're learning in biology, that's not going to help against a virus. Who's right?

Dear Reader: It's true that whenever reports of a dangerous outbreak like Ebola, bird flu or the Zika virus hit the news cycle, sales of antibacterial products spike. People are understandably concerned about their health and safety, and are responding to news reports that can be high in drama but low on important details.

What you're learning in biology is correct. Antibacterial products will have no effect on a virus. In fact, there is growing concern that the overuse of antibacterial soaps, lotions, laundry products, cosmetics and even house paint may cause more problems than it is solving. A bit about that in a moment.

But first, what's the difference between a bacterium and a virus?

A virus, which needs a host to survive, is basically a Trojan horse. It's made up of a protein coat that shields a core of genetic material. Once inside the body, the virus enters a cell and hijacks its biological mechanisms. It forces the cell to turn out thousands of new copies of the virus, which causes the cell to die. These newly minted viruses then go on to attack fresh cells.

Although they cause a host of deadly illnesses, viruses are not all bad. Thanks to their vast numbers and remarkable diversity, scientists believe that viruses have beneficial functions that are not yet understood. In fact, some leading-edge research into cancer is exploring how to harness the unique properties of viruses to formulate new medications, as well as find mechanisms to attack disease cells.

Bacteria, by contrast, are tiny one-celled organisms that can reproduce on their own. The vast majority of them are benign and even helpful, as we're learning in our research into the gut biome. Less than 1 percent of bacteria cause illness in humans. Those that do emit toxins that damage tissue, interfere with important biological pathways and make you sick. Illnesses caused by bacteria include food poisoning, Lyme disease, pneumonia, cholera and dysentery, to name just a few.

Like viruses, bacteria reproduce quickly. Unlike viruses, they can proliferate outside of human cells. That means that good hygiene is the best defense against the spread of bacterial infections.

So how can products that target bacteria be bad?

The problem is that antibacterial products aren't 100 percent effective. The bacteria they leave behind can, over time, develop a tolerance to certain antibacterial agents in the products, a trait known as cross-resistance. Scientists are concerned that this can lead to genetic mutations that will make bacteria immune to antibiotics.

But we have good news.

According to the FDA, plain old soap and water is still the best defense against bacterial contamination. Soap lifts dirt from your hands and, with 30 seconds of scrubbing and a thorough rinse, the bacteria are down the drain.

(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.)

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