Sunday, June 28, 2009

The Pandemic of 2009

The World Health Organization has officially declared a pandemic as a result of the rapid worldwide spread of Influenza A (H1N1), formerly known as swine flu. But that does NOT mean that a lot of people will die. By definition, a pandemic is simply a widespread outbreak of a new human flu virus that spreads rapidly from human to human, causing human illness.

Some flu pandemics cause only mild symptoms and few deaths – others can be quite deadly. The best-known pandemics of the last century were the deadly Spanish flu of 1918 (20-40 million deaths), and the milder Asian flu of 1957 (1-4 million deaths) and Hong Kong flu of 1968 (also 1-4 million deaths). In contrast, the milder seasonal flu that many of us get nearly every year kills “only” about a quarter of a million people each year.

Pandemics are of concern to public health officials (and the public!) because the virus spreads so quickly and because the consequences of the spread cannot always be predicted in advance. Fortunately, it now appears that this pandemic will be no more deadly than the typical seasonal flu that many of us get nearly every year. Most people who become infected with Influenza A (H1N1) are recovering without the need for medical care. But it could have been otherwise, and that’s why health officials were so concerned at first and why they are still watching it closely.

The other flu we worry about is avian flu, also known as bird flu. Avian flu is VERY deadly in the few cases in which it has been caught from birds, but human-to-human transmission is still exceedingly rare.

Wednesday, June 24, 2009

Freeze Your Eggs

Okay, so you’re a woman in her thirties who wants to have children some day but has not yet met “Mr. Right”. What to do? Well, some women have made the decision to freeze some of their eggs before their reproductive clock stops ticking, just in case. The basic techniques are readily available at any fertility clinic; stimulate egg maturation hormonally, harvest some eggs, and then (instead of fertilizing and implanting them) just freeze them.

Worldwide, only about a thousand children have been born from previously frozen eggs. In contrast, over 50,000 babies are born each year in the U.S as a consequence of in vitro fertilization and implantation (Human Biology 5th ed., p. 394). Obviously, the idea of older single women freezing their eggs has not yet caught on. But it just might!

See “Why I Froze My Eggs”, by Rachel Lehmann-Haupt. Newsweek May 11, 2009, pp. 50-52.

Tuesday, June 23, 2009

Steve Jobs' New Liver

It’s not official, but there are reports in the news media that Steve Jobs, CEO of Apple computers, received a liver transplant recently at an undisclosed location in Tennessee (The New York Times, June 23; “A Transplant That is Raising Many Questions”).

Normally, patients who need an organ transplant place themselves on the transplant list of one of eleven regional Organ Procurement Organizations (OPOs) in the U.S. Waiting times can vary. When an organ becomes available the regional OPO offers it to a patient already on its list, with the highest priority given to the sickest patients and those who have been on the list the longest time.

Most patients sign up for the transplant list at only one OPO, because insurance companies will only pay for an organ transplant performed in a person’s “home” OPO. Nevertheless, patients who are willing to pay for the transplant themselves (and with access to a plane so they can get to the hospital within six hours) can increase their odds for a transplant by placing themselves on the transplant lists of several different OPOs simultaneously. No one has said whether or not Mr. Jobs was on more than one list at the time of his transplant, or how long he waited for his new liver.

For a discussion of whether the current organ allocation system is fair, see “How Should We Allocate Scarce Organs?” in Human Biology 5th ed., pp. 368-369.

Thursday, June 18, 2009

Stretching and Sports Injuries

Does stretching before exercise reduce the risk of sports injuries? Many coaches, trainers, and athletes swear that it does, but no one knows for sure because the critical experiment has never been done.

Now researchers are attempting to do the experiment. Sponsored by USA Track & Field (USATF), the researchers are currently enrolling people who run at least 10 miles per week. Participants must agree to be assigned randomly to either the "stretch" or the "no-stretch" group and to adhere to the study protocol for three months. Runners in both groups are expected to report their injuries during the study period.

Runners can apply to be participants at So far several thousand runners have signed up, though not all of them have completed the study protocol and submitted their reports. The results will be made public as soon as enough runners have completed the protocol for there to be a statistically significant difference between the groups, or when enough data has accumulated to show that there is no difference. Ultimately, up to 10,000 runners may be needed.

Runners, this is your golden opportunity to contribute to the advancement of science.

Monday, June 1, 2009

Dwindling Phosphorus Supplies

The world’s supply of phosphorus for agricultural fertilizers is dwindling, according to a recent article in Scientific American. Global reserves are expected to run out in about 100 years unless new reserves are found or better techniques are developed for extracting phosphate from phosphate-rich rock.

As phosphorus supplies decline and as the world demand for agricultural fertilizers grows, we can expect fertilizer price spikes, phosphate shortages, and perhaps even disruption of food production. Countries with large phosphorus reserves such as Morocco will benefit economically. Morocco could be among the wealthiest nations in the world in 50-100 years.