A Race Between Humans, Dogs, and Worms: Guinea Worm Eradication Setbacks

One of the principles of eradicating a human infectious disease from the planet is that the disease cannot have another host. For example, smallpox only infected humans. It could greatly complicate -- and likely derail -- an eradication effort if, in addition to finding and isolating infected humans, a wily animal species was added to the mix. 

The 2nd human infectious disease on the chopping block is Guinea Worm, or dracunculiasis. This infection, which is caused by an invasive worm which must be meticulously winded out of the body, has been beaten back to just a few African nations and, under the direction of President Carter's center, has been on its last legs (of course, worms don't have legs). The key to preventing infection is to keep those infected with the worm from placing themselves in water sources to prevent the worm from discharging its infectious form into the water in which others drink (filters are also used to prevent ingestion). 

In 2016, there have been just 19 cases in Chad, Ethiopia, and South Sudan. However those 19 cases are not the full picture as they represent a 25% increase over the same period in 2015 (there were a total of 22 cases in 2015). More ominous to me is the discovery that dogs and baboons are getting infected. It's almost as if the worm, sensing its impending annihilation, has pulled out all stops to stave off extinction and jumped into other species in a manner reminiscent of the demon spirit in the movie Fallen. This phenomenon could make it very hard to fully eradicate this pathogen as wild dogs, for example, can easily contaminate drinking water sources and undo the progress that has occurred with human cases.

Of course, it is no accident that the disease persists in only specific countries as the underlying problem is access to safe drinking water untainted by guinea worm. Civilization, then, is the ultimate way to eradicate this disease. If civilizing forces accelerate sufficiently to bring safe drinking water to the Chad, Ethiopia, and South Sudan, the issue of infections in dogs and other animals may not be so pivotal as feared. However, the provision of safe drinking water is a Herculean task and, if it proves unachievable in the near term, the race between humans, a worm, and dogs will carry more import for the human race than the Olympics.

Veterans of the War that Saved the World

Tonight was the dinner jointly organized by the UPMC Center for Health Security and Johns Hopkins University's Bloomberg School of Public Health in honor of DA Henderson, the founder of our center and a former dean of the school. 

It was an extraordinary event and one that I will remember for a lifetime. Sitting in a room of luminaries of public health including Army generals, two former CDC directors, an undersecretary of the Department of Homeland Security, and countless others would be an extraordinary conglomeration for anyone but DA. 

Scattered amongst the attendees were those that worked on the smallpox eradication campaign, DA's pathbreaking achievement that rid the planet of a murderous virus. Listening to these heroes trade stories from the 1960s and 1970s about how they, under DA's guidance and direction, vanquished this virus from remote corners of the planet -- a feat one of them called more important than the moon landing -- was inspirational. I imagine listening to true war stories of military veterans is a similar experience but I would argue the veterans I heard converse tonight are of a different sort: these were the veterans of the only successful war to save mankind from a virus that had killed with impunity until it met DA and with him as their commander-in-chief they saved the world.

Inferno: An Infernal Misconception of Virology and Infectious Disease

Despite my usual inability to pull myself away from a Dan Brown novel or their film versions, the latest of the film installments, Inferno -- which centers on a bioterrorist plan -- was an unfortunate exception. 

The novel version of Inferno was chock full of the trademark Dan Brown literary signatures that I love being immersed in, however its endorsement of the thoroughly debunked Malthusian doomsday prophecy was something that really detracted from the other aspects of the book that I particularly enjoyed, including its indictment of religiously-motivated opposition to birth control.

But, given the topics I gravitate to, I wanted to draw some attention to the actual virus attack scenario that drives the film's plot. NPR has already addressed the veracity of the technical aspects of the fictional virus and I definitely agree with the assessments of the renowned virologists they interviewed.  

A couple of points I want to emphasize:

A virus that kills 95% of the population, as the Inferno virus is alleged to do, would be a very hard feat. As I discussed in my Atlantic piece, the sheer diversity of the human immune response and the fact that humans emerged in a pathogen-laden environment creates an extremely high bar for any microbe to scale. To achieve a 95% kill rate within a matter of week is pure fiction without a true basis in fact. 

Another important aspect that merits comments is the ability of a rogue scientist to synthesize such a virus. Even if one grants that the person possesses all the tacit knowledge required to do such high level synthetic biology and genetic engineering, what properties are required for a 95% kill rate? Should the virus be transmitted via the airborne route, through body fluids, or through contact? Should it be enveloped or naked? What is the trade-off? 

My point is that fictional viruses are the stuff of fiction and should remain there. While a movie like Inferno will draw much-needed attention to the risks of bioterrorism and emerging infectious diseases, hopefully it does so without allowing fantasy virus characteristics to cloud people's conception of where the true risks lie.

Cholera in Haiti: No Respite from Unintended Consequences

Cholera is a disease caused by a tiny bacterium but fully aided and abetted by infrastructure and sanitary deficiencies. This disease which humans (including our 11th president James Polk who suffered a fatal case after leaving office) have battled for centuries, thanks to the steady march of civilization, has ceased to be a threat to many parts of the world. The US, for example, had just 7 cases of cholera reported in the US and all were travel-related. The fact that no secondary spread occurred is testament to the prowess of our sanitary systems. Though our sanitary engineers may have created a fortress which cholera can not penetrate, the rest of the world has not been so fortunate as millions of cases occur annually and approximately 100,000 individuals die at the hands of this ancient foe. 

No discussion of cholera can occur today without mentioning the plight of Haiti. This island nation had successfully dodged cholera during each of the prior 6 pandemics as well as for the ongoing 7th pandemic until 2010. In a tragic example of unintended consequences, the massive aid effort following the 2010 earthquake that brought people from all corners of the globe to Haiti also brought their pathogens, including cholera.

After much controversy it has been definitely established that the cholera outbreak in Haiti -- which has killed 10,000 and created ghost towns -- was delivered to Haiti in the feces of UN troops from Nepal whose defecation patterns seeded a river with the deadly bacterium. After 6 years, Haiti still suffers from cholera and, because of the devastation the earthquake wrought on this nation which had frail infrastructure to begin with, it is difficult to imagine how Haiti can be cholera free ever again. Indeed, the cholera elimination plan spans until 2022. Hurricane Matthew's influence, as detailed in the New York Times, can be expected to be a boon to cholera as feces laden with the bacteria are washed into drinking water supplies. This is another example of how an infectious disease emergency can threaten a nation's national security and accelerate failed state status.

I was in Haiti just after the earthquake and saw a sight of utter devastation where entire hillsides became public latrine, where simple sanitation was non-existent, where overcrowding was the norm--in short a playground for any pathogen. I myself was in the midst of a likely norovirus outbreak that tore through a US government forward operating base. 

There is hope, however, in the fact that cholera ceases to be a threat with the sterilizing effect of just a modicum of civilization not to mention cholera vaccination (a vaccine, manufactured by PaxVax, is now available in the US as well). 

The Antibiotic Era: Required Reading

In the last few weeks antimicrobial resistance has been in the headlines with a frequency that has rarely been seen. The likely explanation is the unprecedented high level meeting convened by the United Nations that focused the world's attention on this public health crisis. To many, antimicrobial resistance seems to be a strictly modern problem with solutions only recently proffered. However, that is far from the truth and Harvard's Dr. Scott Podolsky's latest book The Antibiotic Era: Reform, Resistance, and the Pursuit of a Rational Therapeutics provides a comprehensive historical overview of a medical community grappling with a nascent technology that transformed medicine, the pharmaceutical industry, and the FDA.

This book, which should be required reading for anyone in the field, is the result of meticulous research that not only shows how antibiotics rippled through medicine but also how the entire medical subspecialty of infectious disease developed. The book is full of legendary figures in infectious disease such as Max Finland, Harry Dowling, Ed Kass and many others. 

One of the most valuable aspects of the book, to me, is that I know have a better understanding of how my field developed. I often wonder how physicians, who were once deluged with infections, lost their expertise and the need for a sub-specialty occurred. As Podolosky illustrates, in the post WWII era, civilization caused infectious diseases to recede in the US at the same time scores of new treatments (i.e. antibiotics) were coming to the market and experts who knew the (now rare) bug and the drugs used to treat them were valuable. This scenario culminated in the founding of the Infectious Diseases Society of America in 1963 and subspecialty certification in 1972. 

These early infectious disease physicians were on the vanguard in warning against antibiotic excess, the evolution of resistance, bacterial vs. viral diagnostic dilemmas, and the lure of shotgun empirical treatment approaches to cover all possibilities. Also detailed was the chasm between academic and community medicine ("town vs. gown", which still exists today) in which academic medical centers are ably equipped to use antibiotics judiciously but community hospitals are woefully behind. 

The book has many pearls of historical insight that are too numerous to list. A few of my favorite quotes I think will be sufficient to close with:

The “end” of antibiotics was envisioned almost from the beginning.

Patients are not born into this world with the view that antibiotics are required for common colds. It is learned from their friends who learned it from their doctors when they went, and so forth.