Why quarantine for measles is critical…and quarantine for Ebola was not

Measles has come to the happiest place on Earth. As of this writing, a total of 32 cases of measles have been linked to Disneyland visits that took place between December 17th and 20th. About 75% of the cases identified to date were not vaccinated, either because they chose to forgo vaccines or because they were too young, and at least 6 have been hospitalized.

A measles outbreak is a public health disaster, which can cost into the millions of dollars in health resources. You can be sure that public health workers in California and beyond are working overtime trying to identify cases, educate those who were possibly exposed about how dangerous measles can be, and implement practices so that those who may have been exposed to measles don’t further put others at risk. This includes avoiding public places, and practices such as calling ahead to a doctor’s offices so possible cases can be ushered into private rooms rather than languishing in the waiting room. A clinic in La Mesa recently closed because of a potential measles exposure. An unvaccinated South Pasadena woman, Ylsa Tellez, received a quarantine order after her younger sister was diagnosed with measles. Tellez is fighting the order and “taking immune-boosting supplements” instead.

Why such extreme measures on the part of public health?

Measles is highly contagious. It’s spread by air, and so contagious that if an infected person enters a room, leaves, and an unvaccinated person enters the room hours later, they still can contract measles. Remember a few months back, when that figure was circulating showing that Ebola wasn’t particularly easy to spread? Well, measles very much is. The basic reproductive rate for Ebola is around 2, meaning on average each infected person will cause an additional 2 infections in susceptible individuals.

And what’s the reproductive number for measles?

Eighteen. Eight. Teen. I’m not exaggerating when I say that it is literally one of the most contagious diseases we know of.  On average, if you have 10 susceptible individuals exposed to a measles patient, 9 will end up getting sick.

How do we break the cycle of transmission? Vaccination is one way–if one has been vaccinated for measles, chances are very low (but not zero, because nothing is perfect) that they will contract measles. Beyond vaccination, the next-best intervention is to keep those who are infected away from everyone else. The way we do this is by quarantining them.

In public health terms, quarantine specifically refers to the separation of individuals who have been exposed to an infectious agent, *but are not yet ill themselves,* from the rest of society. That way, they’re unable to spread the infection to others. Quarantine makes the most sense when individuals can transmit the infection before they realize they’re sick, which is exactly the case with measles. Infected individuals can spread the virus fully 4 days before the characteristic rash starts to appear, and continue to spread it for another 4 or so days after the rash begins—potentially infecting a lot of people. The problem is, like Ylsa Tellez, they’ll feel fine while they’re out there in the general population. They don’t even have to be coughing or sneezing to spread it (symptoms which can appear prior to the rash)—they can just be breathing (something many of us like to do on a regular basis), and still contaminate their environment with the measles virus.

The difference in transmissibility also makes measles a very different situation from Ebola. Public health officials almost universally condemned quarantine for Ebola exposures, for two reasons: 1) Ebola wasn’t highly transmissible, and  isn’t airborne like measles is; and 2) because Ebola isn’t efficiently transmitted until late in the infection when the patient is very ill and likely bedridden. Quarantining Ebola patients was a political stunt, not a public health necessity.

This is why states have the legal authority to enforce quarantine for infectious diseases: it reduces the risk that asymptomatic, potential disease-spreaders will act as “Typhoid Marys” (another asymptomatic, deadly-disease-spreader), which is in the public interest. And while unvaccinated Tellez feels “attacked” and her mother thinks people are being “not nice” when they demand that Tellez submit to quarantine, their choice not to vaccinate has already put many others at risk of disease and, and is resulting in the quarantine of many other exposed individuals as well. In the 2011 Utah measles outbreak, 184 were quarantined and thousands of contacts traced, at an expense of approximately $300,000. The Disneyland outbreak has already spread into 4 states (California, Utah, Washington, and Colorado). Quarantine is one of our tools to stem the epidemic. In our recent outbreak among Ohio Amish, most willingly submitted to quarantine, and over 10,000 doses of the MMR vaccine were administered. Quarantine is undoubtedly a difficult prospect to face, but perhaps if Tellez and others had been vaccinated in the first place, they, and we, wouldn’t be in this situation.

Guest post: Will new FDA guidelines reduce threat from superbugs?

Guest post by Tim Fothergill, Ph.D.

In January of this year the British Chief Medical Officer urged her government to add  threat posed by superbugs to the official list of “Apocalypses to Worry About” along with catastrophic terrorist attacks and massive flooding. With typical British understatement, its actual name is the National Risk Register of Civil Emergencies but a very stark picture was painted of a post-antibiotic world in which routine operations, such as hip replacements, could prove fatal. In September, The Centers for Disease Control in the US issued a similar statement which estimated that 23,000 people die every year in the US from antibiotic resistant infections. So what is it that has Dame Sally Davies and so many others so worried?

“Superbug” is a term used to describe bacteria which are resistant to many common antibiotics which are used to treat infection. Resistance to these drugs makes treatment more difficult and has increased mortality rates. As resistance to individual antibiotics becomes more prevalent the number of deaths is only set to increase, especially because there is a dearth of research into new antibiotics. Antibiotics are used medically in the short term, so don’t offer the same kind of return on investment for the pharmaceutical companies as drugs for chronic diseases or long-term treatments, such as anti-depressants or hypertension medications. Even more worryingly of all is that strains of potentially deadly infectious bacteria, such tuberculosis have already been identified that are resistant to every potential drug.

Against this background the FDA’s announcement of a plan to phase out the agricultural use of antibiotics is very welcome. Many animals raised for human production are fed antibiotics as a matter of course to boost growth rates. The animals are not suffering from infection, but the drugs can help them grow faster, resulting in a more efficient production of meat for the market. For most drugs, there is a mandatory withdrawal period during which the animals are fed no antibiotics so that they will clear out of the meat prior to slaughter. However, the antibiotics can impact the food supply and human health in other ways. Not only is there concern about meat contaminated with resistant bacteria but the standard agricultural practice of using animal waste as fertilizer only increases the risk of releasing resistant bacteria into the environment contributes to the spread of resistance. This is of particular concern if the land fertilized in this manner is subsequently used to grow food crops that are typically consumed raw. Previous recalls due to bacterial contamination have included spinach and cantaloupe melons. The potential for harm would only have been greater if these cases had involved superbugs, but this possibility is becoming more and more likely. Resistant bacteria that are spread onto crops via animal manure fertilizer have been demonstrated to not only persist in the soil but to also pass the genes for antibiotic resistance onto other species. As we have no control over this genetic transfer it is quite possible that they spread to even more pathogenic species.

The FDA’s proposal to limit antibiotics in cattle feed would seem like good news then. However, the most significant caveat with this plan is that it is voluntary and as such is dependent on the cooperation of the drug producers and farmers. Two of the largest antibiotic producers, Zoetis and Elanco, have indicated that they will no longer labelling their products as suitable for growth promotion. Any subsequent use of these antibiotics for growth promotion would be “off-label” and something that the FDA can and does regulate. However, as with all regulation the devil will be in the details. We do not know yet what the change in labelling will actually say. If their new label can be interpreted in such a way that cattle are still regularly fed antibiotics then nothing will have been achieved.

For example, in Denmark they found that after introducing a ban on antibiotic use for growth promotion in cattle that the quantities of antibiotics actually increased. Animals no longer fed a sub-therapeutic level of antibiotic became more susceptible to infection and thus need therapeutic treatment more often. At first glance this might seem as if little has changed but antibiotics taken at therapeutic levels for the prescribed duration will result in fewer occurrences of resistance to the antibiotic in question. Anybody who has been told by their doctor to ensure that they take the full course for an infection will know this. By reserving antibiotic use for therapeutic use only, where it is needed in greater quantities to fight infections, not only will there be fewer superbugs released into the environment, but the drug companies will stand to increase their sales. This might explain their willingness to cooperate with these proposals. Their other option would be to switch production to antibiotics which are not regarded as being important for human health (such as the ionophores) as these are not covered by these new proposals. However, this is something that would presumably involve some cost to them.

It is also worth comparing the timescale for voluntary phase-out (three years) with the length of time it would take the FDA (presumably in collaboration with the USDA) to implement a strategy for an obligatory regulatory framework, which might have more teeth in terms of enforcement, but which is not yet on the table. The FDA has many admirable qualities but turning on a dime is not one of them. This process would take at least that long if not longer. What we do not know at this point is whether there are plans for the FDA to pursue such mandatory regulation if this voluntary arrangement is found not to be working. Such efforts would presumably require specific budgeting and it seems unlikely that this will happen any time soon given the current state of Congressional deliberations on budget matters. Another possible mandatory option would be Louise Slaughter’s PAMTA bill which is currently with the Health Subcommittee.

If our goal is to reduce the spread of antibiotic resistant bacteria from agriculture then the FDA plan may in fact be the best option, and it is certainly better than doing nothing. Mandatory regulation seems unlikely at this point. However, accountability is still vital to the success of this voluntary agreement. What form could this accountability take? The FDA must be prepared to state publicly if insufficient progress is being made. Also, it is to be hoped that increased demand from major chains like Chipotle, McDonalds and KFC will help. If they were to make this demand then cattle production would change at a much faster pace than that proposed currently. This means that consumers are in a position to contribute by choosing to support suppliers of meat produced in a way consistent with these new guidelines.

********************

Tim Fothergill, Ph.D. is a microbiologist with over a decade of experience in researching the mechanisms for the spread of antibiotic resistance. This interest has led him to the intersection of antibiotic resistance in bacteria and policy, where his is now looking at the implications and consequences of legislation and regulation around antibiotic use. As a result, he has become concerned that the threat posed by overuse of antibiotics needs to be taken more seriously. But it’s not all doom and gloom: his interest in instrumentation and general microbiology extends to brewing his own beer.

 

HIV In-Home Testing Kits: Increased Awareness or Increased Problems?

Fifth of five student guest posts by Jonathan Yuska

The saying, “The more you know, the more you can control,” is no more meaningful than when used in the context of HIV detection and prevention. Public health advocates endlessly stress the need for knowing one’s status; and one would assume that any way in which the most amount of people can be tested would be beneficial for the population1. The Food and Drug Administration shared this same idea when they overwhelmingly approved the first ever over-the-counter (OTC) HIV testing kit in 20052; which in theory, sounds like a promising way to reduce the possible 350,000 HIV cases that remain undiagnosed in this country3. Though, some medical staff are still weary of this type of diagnostic method for reasons such that it breaks the linkage between the patient and long-term care. The debate on whether HIV testing should be—shall we say—left only to the professionals or put in the hands of everyday citizens is only just beginning; though, here are some points you may want to consider when making your own opinion on HIV home testing.

The OraQuick ADVANCE is one example of an in-home testing kit that provides the user with an accurate (sensitivity of 99.3% and specificity of 99.8%) and rapid means of HIV detection with nearly no invasiveness. In just 20 minutes and a swab of the mouth, individuals who may have been living their entire life unaware they are HIV positive, now can take that knowledge as empowerment to manage their health safely and finally receive the appropriate care they may desperately have needed. Supporters of in-home kits believe it offers a choice of what to do with the knowledge of being diagnosed and dismisses possible stigmatizations associated with being tested since testing can be done in the privacy of one’s own home. Proponents also feel that HIV home testing may become the new norm before engaging in intimacy and suggest testing kits come in boxes of two so partners can test each other4. The OTC HIV testing kits are hoped to slow down the more than 40,000 new infections3 that occur every year in the United States; though, some that believe kits such as OraQuick will make little difference in reducing the HIV infection crisis in the populations that need it most.

The HIV home testing kit is hoped to attract those at highest risk including young, low-income and education, non-white males who neither frequent medical care facilities nor are tested regularly on their HIV status5. Surveys conducted by the National Center for Health Statistics have shown that 79% of persons in these types of populations would indeed use home HIV tests if available; though, when participants in the survey were told the price of testing kits was $40, the approval rate of the kits dropped to 40%2. This raises some speculation on whether OTC kits will actually access these sorts of populations without first lowering the price to purchase them.

Rather than accessing those at highest risk, some naysayers anticipate the tests will predominantly appeal only to those “worry well” or hypochondriac individuals who continually test negative or new couples that want to verify their HIV statuses before sexual intimacy begins. Though, what one does with the knowledge of having tested negative for HIV is still under question. It may be seen that negative results actually promotes more risky sexual behaviors—since they were able to “get away” with it in the past—such as having intercourse without protection. This sort of risky behavior may expose the individual to a whole host of other sexually transmitted diseases2.

Issues with the proper usage of kits may also pose a problem in accurately diagnosing those who have been recently infected with HIV which could lead to false-negative results. Individuals participating in unsafe practices may be unaware of the 8-week “window period” needed for in-home tests to detect HIV antibodies (human antibody component is needed to determine HIV status in at-home tests [RNA tests commonly used by clinics can detect HIV within 9 to 11 days post infection]) and unwittingly spread their infection to others6.

False-positive results from in-home tests may also cause a great deal of damage to the validity of proven HIV detection methods as well as the likelihood of individuals to repeat HIV testing after receiving highly upsetting untrue news. False positive outcomes from tests are most common in populations with a low occurrence of disease in the first place—like in HIV—where the occurrence of unknown cases is roughly 0.2%. The ability to perfectly detect such a small percentage of people infected even with a test that is highly sensitive and specific is extremely unlikely and the predictive value of the test will be noticeably low2.

Lastly and most obviously is the disconnect from care that occurs from in-home diagnostic kits. Public testing focuses on linking HIV-positive patients with counseling and treatment; though, when this diagnosis is done in private, a person’s anxiety may force them to exile where they never seek treatment and may even contemplate suicide1. It is important to note that diagnosing patients is only half of the battle, linking them to the appropriate care is the other half—something home testing inherently does not do.

“The more you know, the more you can control” is a saying that is at the heart of reducing the amount of HIV transmissions person-to-person by knowing one’s status. HIV home testing kits such as OraQuick sounds like a promising way to reduce the number of transmissions since they are quick and convenient for the user, but whether these tests will actually reach those individuals who are at greatest risk is doubtful. At home kits may also promote risky behaviors, increase the numbers of false-positives and –negatives, and deteriorate the linkage to care that is vital to those with new diagnoses.

Will in-home HIV testing kits be the assistance needed in decreasing the HIV transmission concern—some professionals are questionable. Now after reviewing the facts on HIV home testing, what is your stance on the subject?

Sources:

1. Chesney, Margaret A., and Ashley W. Smith. “Critical Delays in HIV Testing and

Care.” American Behavioral Scientist. Apr. 1999. 17 Feb. 2013             <http://abs.sagepub.com/content/42/7/1162.short>.

2. Walensky, Rochelle P., and David Paltiel. “Rapid HIV Testing at Home: Does It Solve

a Problem or Create One?” Annals of Internal Medicine (2006): 459-562.

3. Fleming, P. L. “HIV Prevalence in the United States, 2000.” Feb. 2002. 18 Feb. 2013

<http://stdpreventiontraining.jhmi.edu/docs/Fleming%20et%20al_HIVPrev_Seattle_CROI_2002.pdf>.

4. McNeil, Donald G. “Another Use for Rapid Home H.I.V. Test: Screening Sexual

Partners.” The New York Times. 5 Oct. 2012. 18 Feb. 2013 <file:///Users/ska020/Desktop/Another%20Use%20for%20Home%20H.I.V.%20Test%20-%20Screening%20Partners%20-%20NYTimes.com.webarchive>.

5. Phillips, Kathryn A. “Potential Use of Home HIV Testing.” The New England Journal

of Medicine. 11 May 1995. 18 Feb. 2013 <http://www.nejm.org/doi/full/10.1056/NEJM199505113321918>.

6. “Possible Exposure to HIV?” How long it takes to test HIV positive after infection.

Stop AIDS Project. 18 Feb. 2013 <http://stopaids.org/resources/possible-exposure-hiv/time-it-takes-test-positive>.

Obstetric fistula as a neglected tropical disease

Mahabouba*, age 14, was sold into a marriage as a second wife to a man 50 almost years her senior. Raped and beaten repeatedly, she ended up pregnant, finally succeeding in running away 7 months into her pregnancy. Fleeing to the nearby town, she found that the people there threatened to return her to her husband, so she ran back to her native village in Ethiopia. However, her immediate family no longer lived there. An uncle eventually took pity on her and provided her with housing. When Mahabouba went into labor, lacking resources, she tried to deliver her baby herself. Her pelvis was still too small for the baby’s head to pass through, and she ended up in obstructed labor for 7 days before a birth attendant was finally called in to assist. By this point, the tissue of between the baby’s head and Mahabouba’s pelvis had become necrotic due to lack of blood flow. The baby was stillborn and Mahabouba had developed a fistula–a hole had formed between the tissue in her vagina and her rectum. She had no control of her waste elimination, and couldn’t even stand up due to damage to her nerves.

Her uncle wanted to help her, but the common belief was that women who experienced such tragedies were cursed by God. She was moved to a hut at the edge of the village and left to fend for herself against circling hyenas. Eventually, still unable to use her legs, she crawled to another village searching for help. Found by a missionary, she was taken to the Addis Ababa fistula hospital. The damage to her body was too severe to completely fix, but she received a colostomy which allowed her to at least live in society, and eventually she became a nurse’s aide at the hospital.

Mahabouba’s story, on the grand scale of things, is a success story. It’s estimated that up to 3.5 million women currently suffer from fistulas, with somewhere from 50,000 to 130,000 new cases each year–and most of them go untreated. Because many of these happen in rural areas lacking health care providers, it’s difficult to get at exact numbers, and there is little push to obtain them. A woman quoted in Kristof and WuDunn’s “Half the Sky,” an Australian gynecologist who has worked in Ethiopia for more than 30 years, notes that women with fistulas “are the women most to be pitied in the world…They’re alone in the world, ashamed of their injuries. For lepers, or AIDS victims, there are organizations that help. But nobody knows about these women or helps them.”

A new paper aims to change that. Out today in PLoS Neglected Tropical Diseases, Dr. L. Lewis Wall of Washington University in St. Louis argues that obstetric fistula should be included among the neglected tropical diseases (NTDs), which currently include a variety of infectious conditions. NTDs typically are present in warmer climates, and they disproportionately affect the “bottom billion” of the world’s population–the poorest of the poor. They also lack attention from the research community, particularly when it comes to funding priorities.

Though obstetric fistula isn’t an infectious disease, it certainly fits the other parameters for a NTD. “The emphasis on infectious diseases has meant that other important forms of morbidity and mortality have been neglected,” explained Wall via email. “Surgical services are not high on the list of most public health interventions and infectious disease specialists and public health workers are, in general, ill-equipped to deal with surgical issues or obstetric issues. This would mean focusing attention on a huge category of human need that is also neglected as are the traditonal NTDs and could mean a significant uptick in funding for programs to deal with maternal health generally, and obstructed labor/obstetric fistula particularly.”

Indeed, history has shown that obstetric fistulas are fairly easy to prevent and treat, given the proper medical personnel and training. Once common in the United States (the Waldorf-Astoria hotel in Manhattan sits on the site of the first fistula hospital in the U.S.), Wall points out that they are now rare enough here that they merit case reports in the medical literature. Why are they so uncommon? Primarily, very few women in the U.S. are so unattended in childbirth that they would go days in labor without intervention. Rather, most would have a Cesarean section to remove the baby and thus the fistula wouldn’t develop in the first place. Access to this intervention is severely lacking in women in developing countries. “The Cesarean rate in the United States is over 30% (for various reasons) but in many African countries, the rate is less than 1%; well below the 6% needed to meet minimal maternal health needs,” points out Wall.

For women who do develop fistulas, surgical treatment has a high success rate–and is cheap. One of the tragedies of obstetric fistula is that the surgery to treat the injury in many cases costs only around $420–for less than the cost of a fancy TV, you could give a woman back her life. Still, that’s far above what most women in developing countries can afford to pay. Furthermore, even if every woman could afford treatment, “the surgical capacity to treat current fistula cases is woefully inadequate; probably only 10,000 cases per year, with 3-10 times that many new cases,” says Wall.

Unfortunately, there are painfully few treatment centers in developing counties. In addition to the facility in Ethiopia, Dr. Wall is also one of the founders of the Danja fistula center in Niger, which opened its doors earlier this year. There are others scattered throughout continent, but given the rarity of surgical expertise and the frequency of obstetric fistula, the need far outpaces the personnel available. Nevertheless, early attention and surgical intervention are both needed. Wall notes, “The most important thing is identifying prolonged labor and intervening before a fistula develops. There are pilot studies using village health workers to identify women who do not delivery in a timely fashion and to route them to centers for more advanced obstetric care, but these are few and far between. There are programs to train emergency medical technicians who can perform Cesarean sections without being fully qualified doctors; there has been some success with this. With rare exceptions, however, fistula surgery requires surgical skill, long training and experience, so healthcare systems must develop the capacity to perform this kind of work, even when patients are not popular or wealthy enough to ‘pay’ for services.”

While obstetric fistula mirrors many other NTDs, there is one way it is also unique–it affects women solely, and particularly very young women (age 12-14) whose bodies have not developed enough to safely bear children. Maternal health is already a sorely underfunded area of research. Every day, even in 2012, 800 women die from causes related to pregnancy and childbirth, and 99% of those are in developing countries, particularly in rural areas. A midwife working in Ethiopia and quoted in “Half the Sky” lamented, “If this happened to men, we would have foundations and supplies coming in from all over the world.” The inclusion of obstetric fistula into the umbrella of NTDs could open up new funding streams and awareness, and bring us one step closer to this goal.

_____________________
*Mahabouba’s story is told in “Half the Sky” by Nicholas Kristof and Sheryl WuDunn, pages 93-97, as well as in this New York Times article. Other women’s stories can be found at this site.

Works cited and further reading

Wall, LL (2012). Obstetric Fistula Is a “Neglected Tropical Disease” PLoS Neglected Tropical Diseases, 6 (8) Link

Kruk et al. (2007) Economic evaluation of surgically trained assistant medical officers in performing major obstetric surgery in Mozambique. BJOG.

White et al. (1987) Emergency obstetric surgery performed by nurses in Zaïre. Lancet.

Wilson et al. (2011) A comparison of clinical officers with medical doctors on outcomes of caesarean section in the developing world: meta-analysis of controlled studies. BMJ.

Kristof and DuWunn (2009). Half the Sky: Turning Oppression into Opportunity for Women Worldwide. Knopf, New York.

Raw milk. Raw deal?

This is the sixth of 16 student posts, guest-authored by Anna Lyons-Nace. 

Natural…unprocessed…raw.  These terms are often used by consumers, nutritionists and health experts to denote the most healthful, high-quality food options available for consumption. However, when pertaining to the recent increasing trend in raw milk consumption, can consumers be confident that they are choosing the safest and most healthful option?  Statistical data and health studies would suggest otherwise.

Before we delve into the discussion any further, we should first establish what is considered raw milk and what is not raw.  Raw milk is considered any animal milk, most often from cows, sheep and goats, which is not pasteurized, but still utilized for human consumption. Keep in mind that raw milk can also be used for producing other dairy products such as cheese and yogurt. Raw milk may also undergo a straining process, but it is otherwise unprocessed.  Sources of raw milk are typically local farming operations.  In fact, the interstate sale of raw milk for direct consumption has been prohibited in the U.S. by federal law since 1987, due to safety concerns regarding shelf life and disease risks.  However, there are many states that allow the intrastate sale of raw milk, while a few states prohibit it completely.  This means that the vast majority of what we see in our local grocery stores will have undergone the process of pasteurization, which will be clearly stated on the label.  Pasteurization involves heating the milk to very specific temperatures for short time frames in order to kill potentially harmful germs. Pasteurization was introduced in the U.S. during the first part of the 20th century, at a time when millions of people were contracting life-threatening illnesses such as typhoid, diphtheria and tuberculosis, often through milk consumption. Applying the simple process of pasteurization, along with other health advances, led to a dramatic decline in such diseases, and is considered a major public health triumph.  Decreasing or eliminating potentially harmful microbes through pasteurization, not only makes the product safer for consumers, it also increases shelf life.

So why is raw milk becoming a sought after commodity for many consumers?  This can probably be attributed to such things as a general increase in societal demand for whole, natural and sustainable food products; as well as the perceived benefits of the milk itself. Raw milk drinkers claim that the unpasteurized product is higher in nutrients, protective enzymes and immune boosting probiotics, and can help treat a variety of ailments from asthma to gastrointestinal disorders. Supporters also claim that pasteurization is the cause of milk allergies and lactose intolerance.  It is important to note that these claims remain largely unsubstantiated by published scientific studies.  In many cases these claims have been categorically refuted by direct scientific evidence.  The Food and Drug Administration (FDA) frankly states that “research shows no meaningful difference between the nutrient content of pasteurized and unpasteurized milk”.  Science has also shown that most enzymes of concern by advocates are not altered by pasteurization. For those with allergy concerns, medical experts and research agrees that it is the proteins naturally present in milk (both raw and pasteurized) that are the cause of allergic reactions to milk and have no relationship to the pasteurization process.  In regards to lactose intolerance, it needs to be understood that lactose intolerance is a genetic error of metabolism that some people are born with, and there is lactose present in both raw and pasteurized milk.  So unfortunately for the lactose intolerant, raw milk is not the solution. As for probiotics, milk does not naturally contain probiotics; so if they are detected in the raw milk they are likely from another source such as air exposure or fecal contamination.  But the good news is that we as consumers have many, safer options for experiencing the benefits of probiotics, including yogurt with active cultures and over the counter supplements.

Now that we have explored some of the common myths surrounding raw and pasteurized milk, it is most important to discuss the reality of the risks involved with raw milk consumption. Real world case studies, as well as research by such reputable organizations as the Centers for Disease Control and Prevention (CDC) and the FDA, consistently show that the risks of raw milk consumption far outweigh any real or perceived benefit. A 13 year study by the CDC showed raw milk and raw milk products are 150 times more likely to cause a disease outbreak than are pasteurized dairy products. These risks come in the form of a long list of disease causing germs that can contaminate dairy products, and are the reason that pasteurization was instituted in the first place. Some of the more significant contaminants that can be present in raw milk include such pathogens as Salmonella, E. coli, Listeria, and Campylobacter.  These pathogens can cause a variety of symptoms, but most commonly produce gastrointestinal illness such as vomiting and diarrhea that can range from mild forms to fatal illnesses. The most vulnerable to becoming sick from drinking raw milk include babies, young children, those with weakened immune systems and pregnant women. But “healthy” people can become ill as well, and there are many documented cases. Data collected by the CDC from 1998-2009 documented 93 disease outbreaks due to raw milk and raw milk product consumption.  These outbreaks caused 1,837 illnesses, 195 hospitalizations, and 2 deaths.  It is important to note that for every case that is reported and diagnosed, there are many illnesses that go unreported, which means these case numbers in reality are certain to be much higher.  The most recently reported outbreak occurred in Oregon this past April.  The outbreak involved 19 people, 15 of which were children, with 4 of the children ending up in the hospital undergoing treatment for kidney failure.  Eleven of the cases were confirmed to have been caused by a very dangerous strain of E. coli that was traced back to a dairy farm that supplied the families with raw milk. In reflecting on outbreaks such as these, it is important to remember that these illnesses are preventable.   But hopefully, these sad cases will also serve to educate us as consumers, so that we can make informed and healthy choices for ourselves and our families.

References

  1. Langer AJ, Ayers T, Grass J, Lynch M, Angulo FJ, Mahon BE. Nonpasteurized dairy products, disease outbreaks, and state laws-United States, 1993-2006. Emerg Infect Dis. 2012 Mar;18(3):385-91.
  2. Oliver SP, Boor KJ, Murphy SC, Murinda SE. Food safety hazards associated with consumption of raw milk. Foodborne Pathog Dis. 2009 Sep;6(7):793-806. Review.
  3. Centers for Disease Control and Prevention, Trying to Decide about Raw Milk? Last Updated March 7, 2011, http://www.cdc.gov/foodsafety/rawmilk/decide-raw-milk.html (Accessed June 5, 2012)
  4. Centers for Disease Control and Prevention, Raw Milk Questions and Answers, Last Updated March 22, 2012, http://www.cdc.gov/foodsafety/rawmilk/raw-milk-questions-and-answers.html (Accessed June 5, 2012)
  5. Milk Facts, Heat Treatment and Pasteurization, http://milkfacts.info/Milk%20Processing/Heat%20Treatments%20and%20Pasteurization.htm (Accessed June 8, 2012)
  6. Food and Drug Administration, Raw Milk Misconceptions and the Danger of Raw Milk Consumption, Last Updated November 1, 2011, http://www.fda.gov/Food/FoodSafety/Product- SpecificInformation/MilkSafety/ConsumerInformationAboutMilkSafety/ucm247991.htm (Accessed June 5, 2012)
  7. Food and Drug Administration, Questions & Answers: Raw Milk, Last Updated November 1, 2011 http://www.fda.gov/food/foodsafety/product-specificinformation/milksafety/ucm122062.htm (Accessed June 5, 2012)
  8. Food Safety News, 19 Ill with E. Coli in Oregon Raw Milk Outbreak, Last Updated April 21, 2012, http://www.foodsafetynews.com/2012/04/post-5/ (Accessed June 5, 2012)
  9. International Association for Food Protection, Raw Milk Consumption: An Emerging Public Health Threat? Last updated 2012 http://www.foodprotection.org/events/other-meetings/3/iafp-timely-topics-symposium-raw-milk-consumption-an-emerging-public-health-threat/10/speaker-presentations/ (Accessed June 6, 2012)
  10. International Association for Food Protection, Nutritional Straight Talk on Raw and Pasteurized Milk, last updated 2012 http://www.foodprotection.org/files/timely-topics/TT_02.pdf (Accessed June 6, 2012)

 

 

Climate change and public health

I rarely write about climate change. As much as it’s been hashed out amongst climate scientists, and even many of the former “climate skeptics” have now changed their tune, I readily accept that climate change is happening, and is happening largely due to human activities. More importantly for my field, climate change is also having effects on human health in a number of different ways, from the movement of insect vectors into new areas, to warming of the seas leading to more extreme weather conditions, to the loss of coral reefs and the freshwater that these reefs protect from the surrounding oceans. It’s an immense field, and it seems that every time I turn around, another paper is published detailing the public health effects of climate change.

Luckily for me, many of these examples have been carefully documented in a recent book by Paul Epstein and Dan Ferber, Changing Planet, Changing Health. Epstein was a maverick in this field, trained as a physician who had carried out global health research in several African countries. In his previous position helping to run the Center for Health and the Global Environment at Harvard, he led research into a variety of areas in tropical medicine, including the role of climate in disease epidemiology. Unfortunately, as I was finishing up this book last night, the New York Times reported that Dr. Epstein passed away at the age of 67. This is a huge loss to the field, but work in this area will certainly continue, and we’re likely to only see more connections between disease and global warming in the coming years and validation of his passions and ideas.

“Changing Planet, Changing Health” is deceptively expansive. It’s a mere 300 pages before notes and index, but it takes you on a journey investigating the movement of mosquitoes in Africa, cyanide in Honduras, soybean rust in Illinois, pine beetles in Colorado, and even flooding in Cedar Rapids, Iowa. And yet, the book never felt disconnected to me–Epstein & Ferber manage to draw the myriad climate-associated threads together into a well-woven tapestry, and fluidly move from one topic to another. They also discuss what needs to be done to curb this destruction in the last chapter.

Of course, the last chapter is also one of the toughest. While climate change is harming our health in a thousand different ways every day, there’s still denial in many circles that it’s even happening, and none of the solutions to curb it are easy. Furthermore, too many people still see it as “just a polar bear problem” rather than something that actually makes a difference in their lives. This needs to change. Epstein and Ferber succeed in making climate change personal: something everyone who eats and breathes should be concerned about.

On the value of pseudonyms

Our new Scienceblogs overlords sure have great timing with their new pseudonymous blogging rules. For those who haven’t run across that yet, National Geographic has decided to eliminate pseudonyms and force everyone with a blog remaining here (which is already dwindling) to blog under their real names. Meanwhile, out here in the real world, there’s a new unfortunate case study (short version: “EpiGate”) showing how blogging under one’s real name can lead to serious threats and potential loss of employment, among other things.

I blog under my own name (obviously), but if I were starting out now, I probably wouldn’t make that choice again. There are a lot of things I would love to write about on here, but can’t–or won’t–for a variety of reasons. For one, I’m untenured and would like to stay gainfully employed, and ideally even promoted and tenured this academic year, so it’s difficult for me to talk about some of the more “slice of life” stuff on here. Even talking about being a woman in science and balancing work and personal issues (oh, there are so many stories I could tell there…) is kind of walking a fine line. I don’t necessarily want people who google me for my science to come across posts on my kids’ latest exploits, or various personal drama that might make for great blog posts, but also make it weird for external reviewers trying to fairly evaluate me, for instance. Second, I don’t enjoy being harassed. Long-time readers will note that it’s rare that I write about HIV denial, even though that was such a main topic of this blog once-upon-a-time that it even culminated in a journal article. It’s just tiring to be harassed personally by deniers–and even moreso to have my colleagues and administration bullied.

And this is just what’s happened to my colleague, EpiRen. He managed to tick off an online bully; said bully then called EpiRen’s superiors, who gave him a choice between his blogging and his employment. Not surprisingly, EpiRen eventually ended up pulling his public blog and Twitter feed, to the detriment of anyone who wanted a good source of public health information on the internets.

There’s an active discussion regarding the differences between blogging science as a scientist, and blogging as a journalist under one’s real name. A journalist’s job is to write for the public; a scientist’s, honestly, is not–and so if National Geographic is serious about wanting to keep good scientists in their lineup (and others have noted that, truly, they likely don’t give a shit), their decision to disallow pseudonymous blogging is shooting themselves in the foot. There are many valid reasons why a scientist may not want to be publicly identified on their blog–does that really make the information any less valid? Does NG really think that someone who may carry out experimental work with animals, and discuss animal research on their blog using a ‘nym, would really choose their blogging hobby over their livelihood and–potentially–their family’s safety? There are animal rights and anti-vaccine extremists to worry about; Carl Zimmer even points out recent threats aimed at Chronic Fatigue Syndrome researchers who have reached conclusions that some patients didn’t like or agree with. Who can blame many scientists for wanting badly to share their work and insights with the general public, but doing so in a way that disassociates those posts from their “real life” identity?

These things aren’t just theoretical. HIV denier Andrew Maniotis showed up, unannounced, at my work office one day a few years ago. The recently-arrested “David Mabus” showed up at an atheist convention. While using a pseudonym doesn’t always protect you–certainly many pseuds have been outed by those willing to do the detective work–it at least offers you some measure of protection from threats, both online and off.

NG claims to have listened to reasons for blogging under a pseudonym, but have made this decision as a way to “establish best practices” in the industry. Well, I call shenanigans. They’re freaking National Geographic–they can set the curve, and establish best practices by allowing (hey, even encouraging!) quality pseud bloggers. After all, would Carl Zimmer and Ed Yong be any less awesome if they were instead known as ParasiteGuy and RocketMan?

“The Fever” by Sonia Shah

Malaria is one of mankind’s most ancient scourges. A century after the discovery of its cause, various species of the parasite Plasmodium, humanity still remains in its deadly grip in many areas of the world. Malaria is estimated to have caused 225 million illnesses and almost 800,000 deaths in 2009, making it one of the top infectious disease killers. Many of these deaths occurred in children under the age of five.

Shah traces the history of malaria from the introduction of the parasite into the human population to modern-day controversies about malaria treatment, research, and funding. It’s a fast-paced read; informative but never dry. Indeed, Shah makes much use of metaphor; sometimes, to the detriment of the scientific narrative, in my opinion. However, that’s more of a minor issue to me.

Shah begins the book with an anecdote about her own childhood as an American visiting her relatives in India; sleeping under a bed net while her cousins sleep in the open, fearing mosquitoes, and India, and being ashamed of her fears. She notes later that, when her family hears she is writing a book about malaria, they ask her why–to them, it seems as silly as writing a book about the common cold. Shah notes this several times throughout the book–for example, explaining that many in malaria-endemic regions, people would rather use their bednets for fishing than to protect from mosquitoes, so while programs which deliver such nets can tout high numbers of bednets distributed it doesn’t necessarily mean that everyone who receives one is using them correctly.

Indeed, much of the book is spent discussing the limitations and missteps of anti-malarial programs, past and present, from issues of mosquito resistance to pesticides, to parasite resistance to chemotherapy. Another repeated thread is political will, or lack thereof, in anti-malarial programs, and the ping-pong that is played by many funding agencies. When programs demonstrate success and malaria is reduced, there is little will to continue such programs–which may be hampered in any case by the emergence of resistant mosquitoes or parasites. It’s a messy business, and today’s programs don’t seem to be much better off than those carried out in the previous century.

Shah’s book is a thoughtful read for anyone interested in global health–not only for the history of Plasmodium‘s detection and eventual proof as the cause of malaria (after many false starts), but also for the thoughtful descriptions of global health programs carried out by outsiders throughout the decades, and possible ways to change these and avoid repeating the mistakes already made by predecessors.

The Epidemic: Typhoid at Cornell

In the United States, we tend to take our clean drinking water for granted. Even though there are periodic concerns which bubble up about pharmaceuticals or other chemicals in our water supply, we typically believe–with good reason–that we have little to fear when it comes to contamination from microbes. Our drinking water, while far from perfect, is heads and shoulders above what it once was–something many of us forget or have never realized. There have been notable breakdowns, such as the 1993 outbreak of Cryptosporidium in Milwaukee that sickened over 400,000 individuals, but these days such events are few and far between.

This hasn’t always been the case. In the early 1900s, the safety of the water supply even in many large U.S cities wasn’t monitored, and there were no standards in place to guarantee that individuals receiving pumped water wouldn’t be made ill by it. This is the setting for David DeKok’s new book, “The Epidemic,” detailing a 1903 outbreak of typhoid fever (caused by Salmonella enterica serovar Typhi) in Ithaca, New York, that hit at least 512 homes in the town and left 82 dead, including 29 Cornell students. It’s estimated that 10 percent of the populace was sickened, one of the last of the major typhoid outbreaks in the U.S.

The book begins with a description of those behind Ithaca’s water supply back in the day. It was an ugly mess of local businessmen and members of Cornell’s Board of Trustees, who unwittingly set the outbreak in motion with the 1901 sale of Ithaca Water Works to local businessman William Morris. Morris was a Cornell alum, a lawyer and entrepreneur who had previously invested in power companies. He had agreed to buy the Water Works only as a side deal that provided him with his main interest, Ithaca Gas Light Company. The deal was financed in part by Cornell University, with some of Morris’s buddies on the Board of Trustees greasing the deal.

Morris had never run a water company before and while others in town had suggested adding in a filtration plant upon Morris’s purchase of the company, Morris ultimately refused, and began construction on a huge new dam. For this, he hired Italian workers–from an area of Italy where typhoid was still endemic. This was prior to the discovery of the carrier state for typhoid, so while the workers appeared to be quite healthy, at least one of them was unwittingly spreading the deadly organism. Coupled with the atrocious state of the dam construction site–including limited access to outhouses, so workers urinated and defecated near the creek where they were working–this assured that Six Mile Creek would be contaminated, and a good portion of Ithaca’s water supply along with it.

Soon, the cases started to roll in. From January 1903 until May of that year, they piled up even as students began to flee the campus, sometimes unknowingly taking their infection home with them to family members. What followed was a mess of blame-gaming and politicking, with no one taking responsibility and officials contending that the very victims of the outbreak were responsible by being careless about what they ate and drank. Even well into the epidemic, the need for boiling contaminated water was debated and put aside as students and townfolk were dying. Indeed, a letter from late February 1903–well into the epidemic–shows that university officials were still denying they carried any blame, or even that their students were drinking contaminated water.

DeKok uncovers a story that will make anyone interested in public health seethe in anger, and yet it’s one that can–and does–still happen today, as the good ol’ boys’ network and corporate interests trump the health of the populace. Our drinking water is much improved, but corporations are still allowed to pollute with little more than a slap on the wrist. Sadly, DeKok recounts how Morris’ wealthy friends ended up protecting him from any kind of fallout, while Andrew Carnegie came through and donated enough funds to cover medical and funeral bills for the affected students. Finally, in an ironic turn of events, DeKok also notes how Morris’ companies evolved over the years into the General Public Utilities Corporation, which ran the Three Mile Island nuclear power plant.

“The Epidemic” is a story of an outbreak that, with just a bit of foresight and concern for the public good over private profits, could have been prevented entirely. It sadly mirrors many public health controversies that still thrive today. For instance, one passage notes that any government funding for the water works was fear-mongered as “socialism,” a platform that could have come from our current Republican leadership. It’s a tragic reminder that we don’t always learn from our mistakes, and while our water may be safer today than in 1903, public health still gets trampled on by private industry. Will we ever learn?