Airplane Cabins and Your Health

30 08 2012

Do you remember SARS (Severe Acute Respiratory Syndrome)? It popped up in China in 2002 and spread to more than 25 countries before we could blink.

PKIDs landed a group of disease prevention educators in China just as the world became aware of this outbreak that would rapidly become an epidemic. It was coincidence, of course. The trip had been planned for months.

But, our proximity to the SARS outbreak was a reminder to us of how efficient air travel is at spreading germs.

In 2009, there were 2.5 billion airline passengers and that number is expected to increase to 3.3 billion by 2014. That’s a lot of sneezing, coughing, and just plain touching of armrests, overheads, and other surfaces going on in small spaces.

Dr. Alexandra Mangili and Dr. Mark Gendreau wrote a piece for the Lancet in 2005 that talks about the mechanics of disease transmission in an airplane. It’s very good, if you have a few minutes to read it.

They explain air flow patterns and how much air is recirculated (50% and that’s through filters). Turns out, air does not flow the length of the plane, but rather in sections or pockets along the width of the plane. Still an efficient method of disease transmission for airborne and large droplet transmission, but not the only way germs are spread onboard.

According to the article, the most common infections on aircraft have been via the fecal-oral route through contaminated food, although that has diminished in the last few years, possibly due to prepackaged food products and more care in the prepping and handling of food.

Mosquitos, a common vector for diseases such as dengue and malaria, often hitch rides on airplanes. Mangili and Gendreau point out that, “Many cases of malaria occurring in and around airports all over the world in people who had not travelled to endemic areas, known as airport malaria, is evidence that malaria-carrying mosquitoes can be imported on aircraft.”

The cabins of airplanes cannot be thoroughly disinfected between flights. Many times, a plane lands, passengers disembark, and more passengers are seated within 30 minutes. Think of all the droplets of goo left behind that the cleaning crew cannot remove, and the many surfaces that can’t be disinfected.

Keeping one’s hands clean throughout the flight will go a long way toward preventing transmission, and staying up-to-date on your vaccinations for your home country and your destination. As for masks, the authors say, “Although masks play a crucial part in infection control in health care settings, their use is unproven in disease control within the aircraft cabin.” But they do recommend masking and isolating someone suspected of having SARS.

The CDC has quite a bit more to say about air travel and travelers’ health in general, if you’re looking for more details.

How do you prevent infections during air travel? What do you do to protect yourself? We’d love to hear! Please share your tips in the comment section.

By Trish Parnell
Image courtesy of WHO

The Numbers of Malaria

9 02 2012

Seems strange now, but malaria used to be considered a cure for neurosyphilis and, in certain young people, a cure for psychiatric disorders. The belief that malaria cured neurosyphilis was so strong that, in the 1920s, a Nobel Prize was awarded to Julius Wagner-Jauregg for the therapy.

Times changed. The therapy fell out of favor and we moved on. Now we consider malaria to be the scourge that it is and the battle to end it is on all fronts.

To better understand the scope of this parasitic disease, the Bill and Melinda Gates Foundation recently funded a look at new data and the implementation of new computer modeling which allowed researchers to look at malaria over a thirty-year span.

Findings indicate the death rate from malaria in 2010 was twice as high as we thought. The World Health Organization (WHO) originally estimated 655,000 deaths, but worldwide there were actually 1.24 million deaths from malaria.

This number is a drop from a high of 1.82 million deaths in 2004, so, although the current number is high, the good news is death rates from malaria are falling. It’s hard to look at a number so large and call it anything like good news, but from a public health perspective, it is.

I’ve seen malaria in the form of a convulsing, vomiting, feverish young woman being cared for by her increasingly scared and desperate husband. It is not an infection for which we can take a couple of aspirin and wake up refreshed.

The numbers infected are huge. The CDC estimates there are three to five hundred million cases each year with, as noted above, over a million deaths.

We all know that one person actually can make a difference. Do you want to do something? World Malaria Day is coming up in April. Start now, figure out what you and your friends would like to do, and do it. You can find ideas and resources on World Malaria Day’s website.

By Trish Parnell

Image courtesy of YoHandy

Genetically Modified Mosquitoes: The End of Malaria?

30 08 2010

Every year on this planet, malaria kills roughly one million people, many of them children. Scientists are trying to change that number.

Given that malaria is transmitted by the mosquito, which only lives about a month, shortening the mosquito lifespan could reduce the number of infections.  At least in theory.

Dr. Michael Riehle and his staff at the University of Arizona have been busy engineering a GM (genetically modified) mosquito. They’ve shortened the lifespan of the mosquito without modifying its essential functions, and this could change the lives of people who live with the threat of malaria on a daily basis.

The bugaboo is that genetically modifying insects, plants, and animals can result in unintended consequences.  There are scenarios that can’t be tested in a laboratory environment, or anticipated in the wild.    For instance, what if the GM mosquito, unable to transmit malaria due to a shortened life span, is the perfect vector for transmission of some other disease?

In the U.S., numerous exotic species have been introduced accidently—and intentionally. Many have become invasive species.  The kudzu vine, the Japanese beetle, the snakehead fish, pythons, and the elm bark beetle are a few in a long list of  species that have endangered indigenous plants, fish and animals because they have no natural predators in their new habitat.

Today we have GMOs (genetically modified organisms), including bacteria, plants and animals, that have been highly successful in the lab advancing medical research.

GM plants have been used in the fields and the foods we eat since the early 1990s.   Staple crops like corn, soy beans, and tomatoes are some GM crops.  Have there been ramifications?  Are there health implications?  Can we even identify the products that are genetically modified?

Just recently, GM canola plants, which are pesticide-resistant, have been found cross-pollinating in the wild with weeds.  The repercussions are not yet known.  Meanwhile, genetically engineered sugar beets, responsible for 50 percent of our sugar, have been tabled due to a federal court ruling.

Various GM lab animals and GM crops and livestock are on the docket for FDA review.  There is the potential for benefit, but there is also concern.

Currently there is nothing stopping someone from introducing these GM mosquitos, which could be the answer to many prayers, or a possible “frankenfish.”

There are proponents and opponents in the GM debate.  On which side do you land?

It’s the Mala Aria That Kills You

22 02 2010

Bad air or “mala aria,” as the Italians first called it a few centuries ago, kills over a million people every year—mostly children.

Worldwide, there are about 250 million cases of malaria each year and half of the humans on the planet continue to be at risk of infection.

Symptoms of malaria made the medical texts of ancient China almost 5,000 years ago, and King Tut was most likely helped to his death by malaria.

Malaria certainly has its bona fides as a scourge of humanity.

Egyptologist Dr. Zahi Hawass led the recent studies that found an “…important result of the DNA studies was the discovery of material from Plasmodium falciparum,  the protozoon that causes malaria, in the body of Tutankhamun. Medicinal foodstuffs (i.e., drugs to fight fever and pain) found within the tomb support the team’s contention that the young king suffered from a severe malarial infection.”

After thousands of years, science has won a few battles but the war goes on.

The current goal is to increase access to prevention and protection methods, such as drugs for treatment, protective netting, and indoor spraying, with the hope that this will greatly reduce malaria cases and deaths.

None of this gets to the core problems of that blasted mosquito and the rotten parasite that uses the mosquito as transportation to get to humans. Turns out the parasite doesn’t even hurt the mosquito, as it so obviously does humans.

The hope is that the increased access to prevention/protection can be kept up long enough for scientists to discover ways to eliminate the core problems.

World Malaria Day is 25 April. Buy a net for a kid.  The net is cheap and the child’s life is priceless. Who knows, this child who lives because of the net you buy may grow up to be the scientist who discovers a cure for malaria.

Wouldn’t that be something.