If Darwin Met Pasteur and Koch

When I get into arguments on evolution--unfortunately a frequent occurrence in my hometown--I reflexively point to microbes and their impressive ability to evolve new properties literally right before one's eyes (viz. antimicrobial resistance) as incontrovertible evidence of the veracity of evolution by means of natural selection.

I have often wondered how much further mankind's knowledge would be if the genius Darwin had the microbial world to draw from when identifying the earth-shattering facts he did. 

An esteemed group of microbiologists has picked up Darwin's mantle and written a collection of essays that melds Darwinian principles with cutting edge microbiology. The collection is appropriatley entitled Microbes and Evolution: The World Darwin Never Saw. The essays in this book, by making bold new integrations, furthers the philosophy of biology and provides a plethora of ideas to spend hours chewing. 

The essays have varied topics but each illustrates the simple elegance of evolutionary machinery at work on the 3 kingdoms of life (Archae, prokaryotes, and eukaryotes) alike. For an infectious disease physican who hasn't delved enough into "pure" (non-medical) microbiology, the book was a treasure trove.

I highly recommend it.

Is Your Microbiome Giving You a Hangover?

Hangovers are multifactorial events induced by alcohol consumption. The causes include dehydration and hypoglycemia. However,  in light of the results of a fascinating new research study, I wonder if hangovers (like almost everything else) are partly an infectious disease.

What Bala and colleagues at the University of Louisville discovered is that when healthy adults binge drink, they have transiently increased levels of endotoxin--a bacterial product--in their blood. This result is likely due to the effect alcohol has on the barrier functions of the gut which normally keep bacteria from translocating into the blood stream. When these products enter the bloodstream, they set off an inflammatory cascade. 

I wonder what role this inflammation has in the physical symptoms experienced during a hangover. Maybe the oft-reached for ibuprofen and naproxen may actually be dampening the inflammation.

The general lesson I draw is, since we are compromised of more bacterial cells than human, any perturbation of the homeostasis achieved with our microbiome  is likely to have repercussions for our overall health status.

Solving the Riddle of EBV: A Review of Cancer Virus

In Cancer Virus: The discovery of the Epstein-Barr Virus, the book I recently finished, one of the most intriguing anecdotes recounted is how Michael Anthony Epstein attended a lecture by Denis Burkitt. For those who know anything about Epstein-Barr Virus (EBV), the cause of infectious mononucleosis, the importance of these two individuals meeting is obvious as it launched a revolution in virology that lead to EBV being established as the first human tumor virus. 

To recount the major points of the story: Burkitt was a surgeon working in Africa who noticed a peculiar jaw tumor that had specific pathologic findings and a specific geography; Epstein was a researcher working on animal tumor viruses along with Yvonne Barr (see this Youtube clip of her in 2014). The ending of the story is no surprise: EBV was established as a causative factor--when coupled with malaria--in the development of Burkitt's lymphoma. 

Similar stories established EBV's role in nasopharyngeal carcinoma, certain types of Hodgkin's Disease, post-transplant lymphoproliferative disease (PTLD), and HIV-associated CNS lymphomas.

This book, written by EBV researchers Dorothy Crawford, Ingolfur Johannessen, and Alan Rickinson, provides a comprehensive picture of how the science, medicine, and epidemiology were integrated together. The result was a fundamental reshaping of the thinking in virology and oncology. It is obvious that the authors' expertise in the field greatly benefited the historical narrative account they provided. 

Control of tumor viruses through vaccination, as is done with the human papillomavirus (HPV) and hepatitis B virus (HBV), can be viewed as derivative applications stemming from understanding EBV.  For making that giant inductive leap and for their pathbreaking integrations Burkitt, Epstein, Barr, and their many collaborators (who included Nobel laureate Harald zur Hausen as well as Werner and Gertrude Henle) deserve adulation.

CDC Anthrax Exposure: Likely a Contained Biosafety Lapse

Today it was announced that 75 individuals were possibly exposed to anthrax on June 13 while working at the CDC. The exposure is the result of an inactivation procedure not being performed properly. While many questions remain to be answered, a few points regarding anthrax are important to keep in mind:

1. The actual risk of contracting anthrax after an exposure like this is probably very low. As such, of the 75 individuals possibly exposed only 7 are believed to have significant exposures.
2. There is effective post-exposure prophylactic treatment available. Antibiotics such as ciprofloxacin and doxycyline coupled with 3 doses of the vaccine is the recommended regime. 
3. None of the 10,000 exposed in 2001 who were given post-exposure prophylaxis--and poorly complied with it--developed anthrax.

The questions surrounding this exposure will undoubtedly mount as such a biosafety lapse raises serious concerns. However, I do not anticipate that even one case of clinical anthrax will result.

GMO Mosquitoes: The 21st Century Bug Zapper

There are several mosquito-borne diseases that merit a lot of attention in the US. These include dengue, chikungunya, and West Nile Fever. The key to the control of these infections--none of which  are vaccine-preventable--is controlling the mosquito which serves as the vector for human infection. 

Vector-control is a challenging task. Prior to the sermons of fellow Pittsburgher Rachel Carson, which led to bans on DDT use and the collapse of the malaria eradication efforts in the 1960s, mosquito control was achieved using this highly efficacious insecticide. Current vector-control activities employ other compounds targeting mosquito larvae as well as adults. Often, simple efforts such as removing standing water from tires and other household items are highly effective measures. 

A new 21st century approach to vector control that I find very promising is the use of genetically modified mosquitoes. In this approach, pioneered by Oxitec, male mosquitoes are genetically engineered to produce offspring that cannot live outside the laboratory because they require the presence of the antibiotic tetracycline to live. In the wild, when a female mosquito mates with one of these engineered male mosquitoes, the offspring produced will die. Such an activity can substantially reduce vector populations and, therefore, render infection with mosquito-borne viruses less likely. Thus far this approach has been used against Aedes mosquitoes (the vector for chikungunya, dengue, and yellow fever).

Already, this approach has been employed in Malaysia, Brazil, and Panama with great success. Even Florida, recently plagued with dengue, has used this approach.

What I can't seem to fathom is why this measure, which could literally change the landscape in the realm of vector control, is met with derision and fear over tampering with the "fragile ecosystem." Such a reaction completely drops the context. All types of vector control, from bug zappers to DDT to a fly swatter, represent attempts to "tamper" with the ecosystem and are laudable attempts to tame mosquito-borne diseases. Mosquito lives aren't as important as human lives, unless one holds a wickedly egalitarian and nihilistic standard. 

I wonder if these individuals would have counseled against smallpox eradication because of the ecological niche once played by the virus. 

A favorite quote of mine, from Francis Bacon, is applicable here: "Nature, to be commanded, must be obeyed." Viewing nature as a realm able to be shaped and reconfigured by man's mind, while respecting the rules of reality, is what is sorely missing in the minds of those who reflexively oppose the use of these mosquitoes. It is reminiscent of Mary Shelley's panic over the progress of science, which inspired her Frankenstein.