Today, I’d like to share articles published this week that explore developments and discoveries in global health. Drug-resistant strains of bacteria are on the rise, and there is a need for conservation of antibiotics. Genetically-modified mosquitoes are the latest attempt to curb malaria. Scientists have used modified HIV-1 to kill leukemia (really). Medical engineers are developing interesting medical devices for the developing world. Finally, as the UN High Level Meeting on Non-Communicable Diseases starts next week, a quick note on the rising numbers of people living with diabetes.
Drug Resistant Bacteria And Antibiotic Conservation: In The Atlantic this month, Megan McCardle discusses the rise of drug-resistant bacteria in “Resistance is Futile.” We kill off strains of bacteria with antibiotics, leaving a few, usually rarer, strains with a genetic mutation that allows for resistance. The more we use antibiotics, the more prevalent these strains become. Drug-resistant strains are often resistant to other drugs of the same class, and bacteria can and do trade genes, even across species. In the time of globalization and rife air travel, multi- or extreme drug resistance isn’t a great development. It was, however, predicted by Alexander Fleming, who sounded a warning in his Nobel lecture in 1945 that eerily envisions our current predicament:
The time may come when penicillin can be bought by anyone in the
shops. Then there is the danger that the ignorant man may easily underdose
himself and by exposing his microbes to non-lethal quantities of the drug
make them resistant. Here is a hypothetical illustration. Mr. X. has a sore
throat. He buys some penicillin and gives himself, not enough to kill the
streptococci but enough to educate them to resist penicillin. He then infects
his wife. Mrs. X gets pneumonia and is treated with penicillin. As the strep-
tococci are now resistant to penicillin the treatment fails. Mrs. X dies. Who
is primarily responsible for Mrs. X’s death? Why Mr. X whose negligent
use of penicillin changed the nature of the microbe. Moral: If you use peni-
cillin, use enough.
McCardle argues that there must be a global movement to conserve antibiotics, which are “an exhaustible resource…[that should] be treated like an oil field, or an endangered species.” She discusses the problems of the drug marketplace and offers solutions, such as increasing the cost of antibiotics and introducing government controls and partial nationalization of antibiotic prices. As she writes, “We just need to be prepared to face a lot of yelling” from those who are against a bigger government or Big Pharma. Furthermore, such efforts require global buy-in, since an outbreak of a multi-drug resistant strain can travel around the world with a single plane ride, “Contagion“-style. Maybe on a slightly longer time line. McCardle ends by pointing to a potential future: a world where fear of infection outweighs the need for a joint replacement, or where organ transplants and other immune-suppressing procedures carry extra risks. Although her logic makes sense, I wonder how far into crisis we must go to see a global effort to conserve antibiotics, practice infection-eliminating procedures and drug adherence, and create new drugs that will fight new strains. There’s no chance that we’ll begin to address this anytime soon, which puts McCardle (among others) in the unfortunate role of Cassandra. They can say “I told you so” when we’re all living in rubber suits.
Genetically Modified Mosquitoes To End Malaria?: In another Atlantic article, Stephan Faris explores the genetic modification of mosquitoes, which is being studied as a possible malaria eradication strategy. In a lab in Italy, Dr. Andrea Crisanti has developed a way to spread genetic modification from one generation of mosquitoes to the next. These specimens could be genetically modified to cut the rate of malaria transmission, and three approaches are under examination: a trait that makes the mosquito unable to recognize the human scent, a trait that reduces the lifespan of a mosquito so that the malaria parasite cannot breed before it dies with its host, and a trait that kills female mosquitoes in the embryonic stage. There are concerns, of course, about genetic modification and its effects on an ecosystem. Thus far, however, this sounds like it has the potential to be a game-changer for a parasite that infects around 250 million people a year and kills almost a million of them. At the same time, the human race has a bad track record when it comes to churning out seeming miracle cures before realizing that there’s been a mistake. Massive use of DDT to control insect populations comes to mind, as do images of spraying down homes, pools, and school picnic tables with this “harmless” insecticide (as opposed to controlled use in high-risk malaria zones). I’d want to hear more about it before I got on board.
Using HIV Cells to Kill Cancer: Denise Grady of The New York Times reports on the early successes of gene therapy to target and kill chronic lymphocytic leukemia. An HIV-1 cell is deconstructed and combined with DNA from human beings, mice, and cows and viruses that infect woodchucks and cows (the head of the study, Dr. Carl June, called this “truly a zoo”). This artificial virus is then introduced to a patient’s T-cells, which are the cells in the immune system that attack viruses and tumors (and the cells that are infected by HIV). The T-cells become “serial killers” that recognize cancer cells, destroy them, multiply quickly, and remain in the body once the patient is in remission to defend against recurrence. The HIV cell is used as a vector, or carrier, for the other genetic material, since it is especially good at injecting DNA into other cells–“genetic sabotage.” There is no risk of HIV infection with this therapy. Three patients were treated with the genetically enhanced T-cells. For all three patients, this was a last-ditch, experimental attempt to curb or cure their cancer. Two are in full remission and the other is in partial remission. After the T-cells are put into the body, they release a cytokine response, which means flu-like symptoms. For all three, the flu-like symptoms were severe, and it was not understood initially that this was, in fact, a T-cell response to the cancer cells. For the one patient who experienced partial remission, it’s hypothesized that a dose of steroids, given to control his strong cytokine response, may have inhibited the T-cells’ ability to fight off the leukemia. Studies will now examine whether this gene therapy can be used for solid tumors, such as pancreatic cancer. There is, of course, a very long way to go before this is accepted as a routine cancer treatment option, but it does bring hope. I look forward to hearing more about the clinical trials.
“Appropriate” Medical Devices for the Developing World: Anna-Marie Lever of the BBC reviews the efforts of the Institution of Medical Engineers to design medical devices that can be used in the developing world. Lever reports that according to the WHO, three-quarters of medical devices donated to health facilities in the developing world are not used. Furthermore, some high-tech equipment is abandoned when it breaks because there is a lack of repair knowledge. The article and video (see below) discuss a few prototypes, and two in particular stood out to me. A motorcycle with a sidecar mattress/stretcher, complete with retractable roll cage and rain cover, helps get people from remote areas across unpaved roads more comfortably and quickly than a wheelbarrow, hand carried stretcher, or bicycle, and more cheaply than a 4×4. A nipple shield allows mothers living with HIV to more safely breastfeed their babies. These are laudable ideas, though I wonder whether mothers living with HIV would accept another treatment option that may “out” their sero-status: in many places, new mothers won’t use a certain brand of formula because it’s associated with HIV clinics that hand it out for free or they will tear up their clinic ID cards to remain anonymous in the system. The eRanger (the sidecar ambulance) has good potential and should be developed further. Anything that gets the sick and injured to the hospital faster and brings women in before they’ve been in labor for three days is a good invention. To some extent, however, this also evokes the “appropriate technologies” argument: that people in the developing world should not be the recipients of certain devices or should be given devices that are specially-designed (in the West) for their “needs.” Parallel to a thorough design, testing, and community consultation process for newly-invented devices, there should be more efforts to train local people how to use and repair more advanced medical equipment and to improve the health infrastructure, electricity/power supply, and roads of lower-income communities. You can see the eRanger in the BBC video below:
Worldwide Diabetes Figures: The Associated Press (AP) reports that there are now an estimated 366 million people with diabetes worldwide. 4.6 million people die every year of this chronic disease, and health expenditures to fight it cost $465 billion annually. One person dies from diabetes every seven seconds. With the UN HLM on NCDs around the corner, I hope we can see tougher commitments to preventing future diabetes cases and more integration of diabetes prevention and care into standard health care practices.
Finally, today is Park(ing) Day in San Francisco and around the world, another effort to bring greenery to car-infested urban areas. Have a good weekend, and please find a green space in your area in which to celebrate.
Header photo, here, is of Elie Metchnikoff, a pioneering microbiologist who won the Nobel in 1908 for his work on the immune system. Via The Library of Congress, no known copyright restrictions.
