Last week’s column, Spinal Cord Miracle?, was an inspiring story about how scientific progress enabled a man whose spinal cord had been severed to walk again. This remarkable achievement came as a result of the expenditure of millions of dollars and decades of research. While writing that column, I was struck by the starkly contrasting circumstances of the billions of humans whose health is at serious risk due to lack of access to one of our cheapest and oldest technologies: the toilet.
Approximately 2.6 billion people – that’s 37% of us – do not have consistent access to a toilet. About half of that number have to resort to open defecation. This lack of access to sanitation facilities has very serious consequences. Human feces can contain a variety of pathogens, including bacteria, viruses, and parasites, which can cause serious disease and death. For example, every year approximately 1.5 million children per year die from diarrhea stemming from fecal-contaminated water or food, primarily in Africa and Asia.
The most well-known and feared of these diseases is cholera, which is caused by a bacterium called vibrio cholerae. Cholera sickens approximately 500 million people per year and kills more than 100,000. For a healthy adult to become infected with cholera, he or she needs to consume a dose of approximately 100 million vibrio cholerae bacteria. When the bacteria reach the acidic environment of the stomach, the vast majority die. However, some of the bacteria sense the danger and enter a semi-dormant state that helps them to survive and make their way into the intestines.
To continue their journey, the cholera bacteria must now work their way through a layer of mucus which protects the walls of the small intestine. When the cholera bacteria sense that they have become lodged in the mucus, they grow new flagella, hair-like tentacles used for locomotion, which allow them to worm their way through.
Once they make it through the mucus, they discard the flagella and attempt to colonize the lining of the small intestine. In a manner which parallels the process of humans spreading around the globe in the 16th century, this colonization process is a hard-fought war of attrition. In healthy adults, the beneficial bacteria which had been present in the intestine before the invasion will rapidly reproduce to crowd out the invading cholera in a process called competitive exclusion. In a successful competitive exclusion, the cholera will die off and the person will not become ill and will not pass on the disease to others.(1) Children, the elderly, and those already weakened by other illnesses are far less successful in the arena of competitive exclusion.
If cholera is successful in its colonization efforts, it then starts to secrete a toxin which causes irritation and inflammation of the intestinal wall. Inflamed intestinal walls absorb far less water than usual. Thus, the victim ends up with watery diarrhea, the vehicle by which others become infected, and can become severely dehydrated. Severe dehydration can to lead organ failure and, sometimes, death.
I laid out the steps of a cholera infection in order to illustrate how vibrio cholerae, because it has coevolved with humans over the millennia, has developed survival and reproductive strategies which are hyper-specific to its host, us. This hyper-specificity is common to many other pathogens which inhabit our gastrointestinal tracts and which are present in our feces. As a result, the feces of humans represent a far more significant health threat than the excreta of other animals which contain pathogens which are primarily adapted to them.(2) This explains why we avoid using human sewage for fertilizer.
For those of us privileged enough to live here in Chapel Hill, NC, we are protected from deadly pathogens by the sanitization measures employed by our water and sewer company, OWASA.(3) In places such as rural Tanzania, where systems like OWASA’s are not practical, a well-designed pit latrine can do the job. Communities which gain access to and adopt use of pit latrines instead of open defecation experience dramatic reductions in disease and death.
Given that we know that digging holes in the ground and putting a small shack on top will save lives at low cost, it’s tempting to go out into the world and build a few million latrines. And so we did. But when we did, we learned some important lessons. For example, between 1997 and 2000 the World Health Organization installed 1.6 million outhouses in rural India, home to approximately 600 million people who practiced open defecation. A follow-up survey conducted several years later showed that only 47% of them were still in use.
Results like the outhouse project in India helped to teach the international aid community that they needed to adapt their methods to include more community participation. They found that whether it was a well, a latrine, or any other new system, if they involved the community in its design and construction, the communities would use and maintain their new facilities over the long term. While low-tech projects like building toilets get less media attention than medical marvels like repaired spinal cords, they can help many, many more people. So the next time you consider how to allocate your charity dollars, consider groups which engage in community-based sanitation improvements. You will touch many lives.
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1. In this allegory, the Americas are the small intestine, the Native Americans are the resident beneficial bacteria, and the Europeans are the cholera. When Europeans arrived in the Americas, pathogens such as smallpox and typhoid killed 80 to 90% of the native population, which was the primary driver in allowing their colonization to succeed. So one could say that the competitive exclusive efforts by the Native Americans failed.
2. To be clear, this is not to say that the feces of other animals present no threat to us, as they are the source of such pathogens as salmonella and E-coli. Animal feces such as cow manure can be sanitized prior to being used as fertilizer, through proper composting. If the temperature of the compost pile is >104°F, then the pathogens will either die or be deactivated. (At this point, please let it be known for the record that, with a tremendous show of restraint, I managed to not elaborate on why 104°F is the threshold and how it comes into play in other phenomena.)
3. Next time you see an OWASA employee, remember to say thanks.http://chapelboro.com/columns/common-science/toilet-greatest-public-health-invention-ever/
As the popularity of e-cigarettes continues to grow, public health officials across the country and here at home are calling for more research and stricter regulation on their use.
“We really are in the Wild West of e-cigarettes because it has not been regulated at all by the FDA up to this point,” says Melva Fager Okun, Senior Adviser with Prevention Partners, a Chapel Hill-based non-profit focused on healthy workplaces and institutions.
Last week a trio of public health agencies released reports critical of the burgeoning e-cigarette industry. The Centers for Disease Control, World Health Organization and the American Heart Association issued calls for tighter controls on how the products are used, packaged and marketed.
E-cigarettes or personal vaporizers use atomizers to heat a liquid mixture of glycerin, propylene glycol and nicotine that users inhale. Often the mixture is artificially flavored, and Okun says it’s these flavors that have public health advocates especially worried.
“If you look at the over 7,000 flavors that these e-cigarettes come in, you can see they are definitely trying to appeal to youth,” says Okun. “They are candy flavors, they are cookie flavors and they are alcoholic beverage flavors.”
The use of e-cigarettes, called vaping, has skyrocketed in recent years to become a billion dollar industry.
Teens and young adults seem particularly drawn to vaping, as it is often marketed as safer than traditional tobacco. In North Carolina, use of e-cigarettes by teens has risen five-fold in the past two years.
Okun says much of the concern about e-cigarettes stems from evidence that they encourage traditional tobacco use as well. She cites a report from the CDC showing first time vapers were twice as likely to smoke tobacco within the year.
“I see it as a tremendous threat to the good progress that we had been making, and my great concern especially is that youth, who might not have even thought of picking up a cigarette, are now thinking about picking up e-cigarettes.”
The trend has gained ground locally as well. Okun says she’s seen an increase in retail shops selling vaporizers in Chapel Hill and Carrboro.
“I can hardly think of small shopping malls that now don’t have a designated tobacco and vapor product shop. I am very concerned.”
The federal Food and Drug Administration is considering extending its regulatory authority to include e-cigarettes. If that happens, the products will be subject to many of the same restrictions as traditional cigarettes.
In the meantime, organizations like schools, hospitals and businesses are trying to figure out how to regulate the use of e-cigarettes on their premises.
“In hospitals and patient rooms cigarettes have been long gone. Now people are pulling out e-cigarettes and staff is very confused,” says Okun. “It’s taking their time and effort now to address something they haven’t thought about in years, and they’re not sure what to do.”
Prevention Partners is hosting a free educational webinar on the topic of e-cigarettes on September 10. You can find out more here.http://chapelboro.com/news/health/use-rises-public-health-officials-push-e-cigarette-controls/
RALEIGH, N.C. (AP) – North Carolina’s public health director has resigned, 18 months after her appointment.
The secretary of the state’s Department of Health and Human Services announced she accepted Dr. Laura Gerald’s resignation Tuesday, effective immediately. Secretary Aldona Wos gave no reason for the resignation.
Gerald had two titles as state health director and director of the agency’s division of public health. Former Governor Beverly Perdue appointed her in January 2012, when the agency merged its division of public health and office of rural health and community care.
Wos informed division employees Tuesday evening.
Wos says Danny Staley will temporarily serve as the division’s acting director. His title has been deputy director.
Robin Cummings, director of the agency’s office of rural health and community care, will temporarily serve as acting state health director.http://chapelboro.com/news/health/ap-ncs-public-health-director-resigns/
CHAPEL HILL- UNC’s academic year is over, but a pair of Tar Heel graduate students working toward a master’s degree in public health are still hard at work—and they’re preparing to join an effort to combat blindness around the globe.
One of the students, Casey McCormick of Charlotte, says she and fellow grad student Michael Wilson will be flying to Hanoi, Vietnam to work with a program known as Helen Keller International.
“We’re basically taking an already existing program that they’ve developed in a different province of Vietnam and moving it to an urban setting in Hanoi,” she says. “Then we’re kind of pairing that with a nutrition program because when you don’t eat properly, that has a big effect on your eyesight, and they’ve seen that with the younger generations in Vietnam.”
While in Hanoi, McCormick and Wilson will be helping to implement a program known as the ChildSight initiative into Hanoi’s schools. The program will provide free eye exams and glasses to needy children in Hanoi. The Western Asia-Pacific Region, including Vietnam, has the highest rate of far-sightedness in the world, with about 62 million cases.
McCormick says she decided to go on the trip because of its relevance to her chosen line of work.
“I’ve never experienced or been anywhere near Southeast Asia or taken any sort of classes about that region or culture, and I didn’t think it was appropriate to go forth with a global health degree without experiencing all parts of the globe,” she says.
And McCormick says having Wilson on the trip with her will make the trip even more of a learning experience.
“It’s definitely going to allow us to be more confident in the work we’re doing because we’ll have someone next to us who knows what we’re talking about and was in the same classes with us,” she says. “So, we’ll be able to bounce ideas off each other.”
McCormick and Wilson plan to leave for Vietnam on June 2.http://chapelboro.com/news/unc/unc-graduate-students-combat-worldwide-blindness/