A Moldy Cantaloupe & The Dawn of Penicillin

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For something that grows so carelessly and freely on our fruits and breads, mass producing the white mold and its hidden wonder drug penicillin was devilishly difficult. After Alexander Fleming’s accidental discovery of a bacteria-killing mold contaminating his cultures of Staphylococcus aureus, it languished as a laboratory parlor trick until World War II and the desperate need for treatments to fight bacterial infections became quickly apparent (1).

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2048009/

An image of Alexander Fleming’s original culture of penicillium mold. In his 1929 paper, it is described as a “photograph of a culture-plate showing the dissolution of staphylococcal colonies”. Image: A Fleming. Click for source.

Researchers working at Oxford University in the late 1930s had been able to isolate the penicillin compound and prove demonstrably that it could be used to treat deadly infections but the matter of transforming the spores from kitchen pests to medicinal powerhouses still remained. In 1941, struggling under the relentless blitz of their cities and factories, Britain turned to the United States to develop methods of the industrial manufacturing of penicillin (2).

It would be another fluke – the discovery of a moldy cantaloupe – that would yield a particular strain of mold that could produce prodigious amounts of this “magic bullet” antibiotic. Factories with the expert know-how on man-handling yeast and fungi into yielding their strange fruits  – alcohol distilleries and mushroom factories – were then tasked with the production of penicillin (2). Watch the video below to catch a glimpse of the very beginnings of what would ultimately become a behemoth pharmaceutical industry.

I love this video and all of its unspoken implications. The manufacturing of mankind’s very first antibiotic. The dynamism of an industry on the verge of changing death itself. Women in lab coats, Rosie the Riveter lab gals, toiling away in the molasses and mushroom factories to stop their young men from dying from sepsis (and to help cure those pesky gonorrhea infections!). Watching this video and swayed by the brimming optimism of its narrator, I thought, “By golly, with penicillin we CAN win this war!” And we did – penicillin radically changed the outlook of the war for the Allies, while Germany’s pharmaceutical companies scrambled, frantically trying to find the one strain of mold that would produce penicillin in its required quantities.

We won the war against the fascists but we’ve largely lost the war on microbes. This video will make you fall in love with the once mighty power of antibiotics but our Pyrrhic victory has now brought the battle to hospitals and antibiotic-resistant bacteria have turned against us again. Penicillin is now only effective for a chump change of bacteria and we are swiftly running out of our very best options. Enjoy this video and reflect on our short-lived golden age of antibiotics.

Resources

You can read Alexander Fleming’s paper on his oddball discovery, “On the Antibacterial Action of Cultures of a Penicillium, with Special Reference to their Use in the Isolation of B. influenzæ” published in 1929 in the British Journal of Experimental Pathology, here.

Absolutely fantastic: Fleming’s “germ paintings” using pigmented bacteria.

An ancient Sudanese tribe may have been guzzling penicillin in their beer, the antibiotic a by-product of the fermentation process. Sign this girl up!

Kulturkampf: The German Quest for Penicillin details the history of Germany’s efforts to steal/secure Fleming’s strain of mold and the penicillin arms race with the US and Britain.

References

(1) A Fleming (1929) On the Antibacterial Action of Cultures of a Penicillium, with Special Reference to their Use in the Isolation of B. influenzæ. Br J Exp Pathol; 10(3): 226–236

(2) J Stafford (December 4, 1943) More Penicillin Coming. Science News-Letters. 44(23): 362-4

ResearchBlogging.org
&NA;, . (1930). Antibacterial Action in Cultures of Penicillium, With Special Reference to Their Use in Isolation of Bacillus Influenzas The American Journal of the Medical Sciences, 180 (3) DOI: 10.1097/00000441-193009000-00056

Sex, War & Revolution: The Epidemiology of Gonorrhea in the USA

It’s not often that you encounter a graph and you think, “Wow! My god, that is a spectacular graph!” I have such a graph for you, reader, and it just so happens to be about gonorrhea. I know what you’re thinking: “She can really pick ’em, huh?  Exceptional taste in data presentation.”

Truly though, this graph is a wonderful piece of historical data, a beautiful 2-D chart that plainly illustrates a few of the major social and cultural forces that have occurred in the United States this past century. Namely, the Second World War, the emergence of the Baby Boomer generation and the sexual revolution. This is heavy-duty stuff, people!

Rates of Gonorrhea in the United States, from 1941 to 2010. Image: CDC. Click for Source.

Let’s look at this baby.

From 1941 to 1947, the rates of gonorrheal infection in the American population increased during and after the Second World War. Reported cases reached a peak of roughly 400,000 and fell as soldiers were re-integrated into the American society (1).

American men and women were mighty busy after the war. The United States saw an increased birth rate from 1946 to 1964 that today we view a demographic explosion or “boom” – the Baby Boomers arrived, one of the “largest generations in US history” (2). Gonorrhea laid low during this period, returning to pre-war levels as Americans committed themselves to their new families as well as a revitalized economy and a rapidly changing society.

“You can’t beat the Axis if you get VD!” A public health poster dating from 1942-1945 targeting American soldiers. Blaming women for the spread of these STDs certainly seems unfair but, in the case of gonorrhea, women are largely asymptomatic for the disease whereas men usually suffer symptoms quite acutely. STDs spread easily when people don’t know they’re infected (See: HIV/AIDS crisis.) Image: Public Domain. Click for source.

Twenty odd years later, from the 1960s to the 1970s, those Baby Boomers hit sexual maturity and a massive sexually active population became vulnerable to existing sexually transmitted diseases. This generational coming-of-age coincided with the women’s liberation movement and the sexual revolution, two incredibly powerful cultural forces that, together, triggered profound changes in American sexual mores and behavior (3).

Amidst this slackening of traditional sexual mores and the expansion of social and sexual freedom in this population, oral contraceptives and intrauterine devices (IUDs) fortuitously hit the market. (You see where this is going, right?) An article I dredged up from 1985 dryly states that the “use of non-barrier methods of contraception increased steadily from the early 1960s to the mid-1970s” (4). Indeed – in a very short five years, the number of women taking the Pill increased from nearly zero to 6 million (5). Did the widespread availability of reliable birth control have an effect upon sexual practices?

You bet it did. Both the spirit and the flesh were willing. Surveys conducted in the late ’60s and throughout the ’70s found that the proportion of young women having premarital sex rocketed by 300% compared to a rather measly 50% increase in men (4).

Consulting my epidemiological cookbook for a moment in search of a recipe for a perfect STD epidemic, I see that it calls for one part population explosion, two parts available contraceptives, and a healthy serving of loosening sexual taboos and heightened sense of individualization — be sure to add in increased rates of drug experimentation, if you have any handy in the kitchen. Shake with ice and strain into a martini glass. Serve with the Cuban Missile Crisis, the Woodstock festival and a dude walking on the moon. Will make hundreds of thousands of gonorrhea cases/servings per year (1).

You can see in the graph that the gonorrhea epidemic unquestionably started in the 1960s, increasing in scope until it peaked in 1976. That year, the number of cases diagnosed hit at just over one million (6). It would be near impossible to disentangle the exact effects these macro social and cultural forces – the demographic blip that was the baby boomers, women’s liberation, and contraceptives geared towards women – had on the increasing rates of gonorrhea in this period and on influencing each other. It would be easy to say that women’s lib and contraceptives increased the rate of gonorrheal infection, but really it can only be proven to be a positive correlation.

Certainly, some of the increasing rates can be attributed to the improvement of the surveillance and reporting systems for STDs. Our ability to diagnose them in clinics has become more sophisticated thanks to advances in biotechnology and the rates of gonorrhea increased because our health system got better at detecting asymptomatic, under-the-radar infections.

This is one of three public health posters made by the Health Education Council in the United Kingdom in 1969 emphasizing the importance of contraception. By addressing the taboo of premarital sex, contraception and out-of-wedlock pregnancy, as well as subverting the masculinity of men, they were considered wildly shocking at the time. Image: Health Education Council, United Kingdom. Click for source.

What happened in the mid-1970s that led to the decline of gonorrhea? One of the best explanations is that the numbers of people in the 18-24 age class, a group that has historically always had the highest incidence and prevalence of gonorrhea, began to decline as the Baby Boomer population aged out. Those 76 million people had to move onto their thirties at some point and so, as free love and communal living gave way to what Tom Wolfe famously called the “Me” Decade, they did. Another explanation is that condoms began to be commonly substituted for non-barrier contraceptives, offering a physical barrier against disease transmission (4).

In 1973, the country also got around to implementing a national gonorrhea control program that would both enhance surveillance and diagnosis of the disease. Financed by the CDC, state health departments began providing laboratory services to physicians specifying that all women in the “reproductive age group” should be screened for the disease (7). Why women, you ask? The disease is usually asymptomatic in the ladies and monitoring the infection is one of the best ways to halt transmission. This screening program would eventually lead to detecting a full third of all reported cases of the infection in women from 1973 to 1975 (8). In another 25 years, the gonorrheal rate would crash down to just 74% of its peak rate in 1976, below its pre-war levels.

Today, gonorrhea still remains a significant public problem. It ranks as the second most commonly reported bacterial STD in the States and the CDC estimates that over 700,000 people pick up this infection every year (9). It is a particular scourge in the African-American community, accounting for nearly 70% of all diagnosed cases of gonorrhea (10). Gonorrhea now has ‘Superbug’ status and is now largely resistant to every antibiotic we’ve got left. We will be seeing a lot more of this guy and this graph will soon change again. Americans are still rocking the (sexual) revolution in all its glory and sorrow.

Author’s Note

I’m focusing on the American sexual revolution and women’s liberation here, but the same can most certainly be said for other developed countries in the 1940s to 1970s. For example, the data suggests the exact same epidemiological scenario for England. My apologies to my international readers for this myopic focus on American epidemiology, our data is just so good!

Resources

One of the references I use, see below, is an article on Alternet that is actually an excerpt from the book “Delirium: How the Sexual Counterrevolution is Polarizing America” by Nancy L. Cohen. You can purchase the book here.

Curious about what whopping hell a gonorrheal “Superbug’ will unleash on humanity? The great Maryn McKenna reports on it here, here and here.

Once gonorrhea was exiting the stage, HIV/AIDS was making their big entrance. I wrote about hip-hop and RnB artists singing about HIV and STDs in this article “Let’s Talk About Sex” right here. There’s an included playlist! Listen to it at work and reflect on the global HIV/AIDS crisis! Anyone? Anyone?

References

(1) Cornelius CE. (1971) Seasonality of Gonorrhea in the United States. HSMHA Health Reports. 86(2): 157-60
(2) U.S. Census Bureau. (2011) 2010 Census Briefs: The Older Population: 2010. United States Census 2010 (http://2010.census.gov). Accessed September 21, 2012 here.
(3) Maurer DW. (1976) Language and the Sex Revolution: World War I through World War II. American Speech. 51(1/2): 5-24
(4) Hook EW. (1985) Gonococcal infections. Annals of Internal Medicine. 102(2): 229-243
(5) Cohen NL. (2012) How the Sexual Revolution Changed America Forever. AlterNet (http://www.alternet.org/) Accessed September 21, 2012 here.
(6) Centers for Disease Control & Prevention (2011) Gonorrhea. Sexually Transmitted Disease Surveillance, 2010. Accessed September 21, 2012 here.
(7) Balows A and Printz DW (1972) CDC Program for Diagnosis of Gonorrhea. JAMA. 222(12): 1557-1557
(8) Yorke JA, Hethcote HW and Nold A. (1978) Dynamics and control of the transmission of gonorrhea. Sex Transm Dis. 5(2): 51-6
(9) Centers for Disease Control & Prevention (2012) Gonorrhea – CDC Fact Sheet. Sexually Transmitted Diseases (STD). Accessed September 24, 2012 here.
(10) Centers for Disease Control & Prevention (2011) African Americans/Black. Disparities in HIV/AIDS, Viral Hepatitis, STDs, and TB. Accessed September 24, 2012 here.

ResearchBlogging.org
orke JA, Hethcote HW and Nold A. (1978). Dynamics and control of the transmission of gonorrhea. Sex Transm Dis. DOI: 10.1097/00007435-197804000-00003

Behind Enemy Lines: Cutaneous Leishmaniasis in Returning US Troops from the Middle East

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The Soviet invasion of Afghanistan from 1979 to 1988, by all accounts, did not go as well as they had anticipated. The locals were unsupportive of their efforts against the Mujahideen, the notoriously craggy terrain regularly chewed through soldiers’ boots, the Soviet army was frequently unable to provide suitable equipment, food and water to its own troops, and so on.

Along with these less than encouraging battlefield realities, the Soviet military suffered from a smorgasbord of infectious ills. It is estimated that throughout the nine-year occupation of Afghanistan, the annual attack rate of infectious diseases amongst Soviet troops ranged from a jaw-dropping 53% to 69%. A striking 67% of soldiers required hospitalization for a serious illness (1). Several researchers examining the medical side of the conflict have made the pointed remark that many of the Soviet-constructed hospitals were filled with their own military personnel rather than the Afghani population that they were originally intended for.

Soviet soldiers in Afghanistan in 1988 Image: Unknown. Image: Mikhail Evstafiev. Click for source.

Viral hepatitis and typhoid were largely responsible for disabling troops – there were 115,308 cases of hepatitis and 31,080 of typhoid fever. Another 269,544 cases have been attributed to plague, malaria, cholera, diphtheria, meningitis, shigellosis, amoebic dysentery, pneumonia, typhus, paratyphus and other illnesses. The sheer variety of diseases and magnitude of those infected is astonishing, even to an infectious disease scholar. That’s an impressively multitudinous bacteria-virus-parasite swap meet! I’m trying hard not to imagine Afghanistan as one massive pulsating, sandy petri dish right now. Moving on! Though the origins of these diseases are simple to identify, the logistics of and solutions to preventing them are often more complicated: a consistent shortage in clean drinking water and access to laundered uniforms, poorly enforced sanitation standards, an insufficiently nutritious diet, and the omnipresence of rodents, lice and mosquitoes were responsible for causing the vast majority of diseases (1). These guys were just shipped into the desert and mountains completely unequipped and unprepared for what was lying in wait for them.

That an epidemic can be as worthy an opponent on the battlefield as one’s enemy is not a new concept. Throughout history, from Xerxes to Napoleon to Robert E. Lee, commanders have had to regularly contend with field sanitation and disease prevention and control. Diseases such as typhus, diarrheal disorders, respiratory ills, and infected wounds have oftentimes decided the victor of a conflict. What’s of interest here is that the United States has similarly ventured into Afghanistan and, for the most part, emerged unscathed from the health problems that bedeviled the Soviets. The U.S. military has accomplished a significantly better job of protecting their troops from the Middle East’s endemic infections during Operation Enduring Freedom and Operation Iraqi Freedom.

There is one little nasty buggy and the troubling disease it transmits that is endemic in both Afghanistan and Iraq and that has bested the US military – the sandfly Phlebotomus and the protozoan parasite Leishmania. This disgraceful couple have been around for millennia; it’s thought that the biblical plague of boils described in Exodus 9:9, the “breaking out in sores on man and beast throughout the land of Egypt”, was in fact an epidemic of cutaneous leishmaniasis (2).

Scanning electron micrograph of an adult Phlebotomine sandfly, species unknown. They are known for their hirsute features. Image: Science Photo Library. Source: CVBD. Click for source.

First, the insect. Phlebotomus are biting midges that fly in short hops close to the ground. They sound adorable but alas! Active at twilight and night, the females feed by lacerating the skin and sucking the pooling blood that’s formed from the painful bite. They prefer living in covered, humid areas with organic debris. Sandflies can live both outside and inside human dwellings, though most research seems to find that transmission events occur within the home, as more women and children are infected than men.

And now to the protozoan brute of the matter, leishmaniasis. This is indeed a global parasite, withstanding tropical to temperate climates in more than 100 countries. Southeast Asia and Australasia are the only regions with suitable, supportive climates that have been spared. There are five clinical presentations of leishmaniasis – cutaneous, visceral (kala azar), mucocutaneous, post-kala azar dermal leishmaniasis and diffuse cutaneous leishmaniasis – that may be found throughout these countries and for each presentation several species may be responsible, testifying to the protozoa’s adaptability and expression of unique local flavors.

Cutaneous leishmaniasis (CL), known as “oriental sore”, “Jericho buttons” and “Baghdad boil”, produces painless ulcerative lesions found on the face, arms and legs. It is typically confined to the skin but is also capable of going Four Loko on its host, racing through the lymphatic channels and turning into the deadly visceral leishmaniasis (VL). Not all that common but not entirely unlikely either. There are an estimated 1.5 million ongoing cases of CL with a global prevalence rate of 12 million (3). Ninety percent of all cases of CL occur in just seven countries, in Afghanistan, Algeria, Brazil, Iran, Peru, Saudi Arabia and Syria (4). The WHO has pinpointed Kabul in Afghanistan as the epicenter of CL cases in the world (5).

Transmission of leishmania strongly relies on environmental factors that can support the sandfly – certain kinds of scrub vegetation, an amiable climate as well as a wild or domesticated reservoir host. Dogs, and humans have been found to be the urban reservoirs of leishmania in Afghanistan, though desert rodents may also serve as reservoir throughout parts of the Middle East (6)(3).

In the lower center of the image, a dozen or so Leishmania parasites can be seen infecting a macrophage in the amasitote form. Image: Bushra Moiz. Click for source.

The parasite lives and replicates within the cells of the immune system, specifically the monocytes and macrophages. By hiding away in the immune system’s cells, the very ones responsible for capturing and devouring rogue microbes and parasites, leishmania effectively avoids any immunological confrontation. Using proton pumps and acid phosphatases, the parasite is able to resist degradation by proteolysis, further ensuring its survival within the macrophage. It is for this reason that the disease can be exasperatingly difficult to treat – in many cases, infection can last up to three years. Treating these buggers can also be a long, costly process which may only clear up the clinical disease and not even eradicate the persistent parasite. Current treatments include cutterage or cryotherapy, topical ointments, and local and systemic use of pentavelent antimony which can be rather toxic (7). For a good review of the methods: check out reference (7) below!

Initially, a case of CL innocuously starts as a bug bite that just won’t go away. In time, it develops into a mean-looking, open wet or dry lesion. Size can vary from a few millimeters to several centimeters in diameter. Multiple disfiguring lesions can sprout from the original lesion until a necrotic process ultimately forms and the infection is resolved. Most lesions among Iraqis and Afghanis occur on the face, the part of the body most often exposed in that climate and culture. For this very reason, some communities will deliberately infect children in a discrete region with scrapings from a lesion in an attempt to infect them early on, avoiding disfiguring scars and protecting future marriage prospects. Life-long immunity results from infection, so once you’ve had your dalliance with this protozoa, it’s over.

An unknown soldier based in the Middle East with cutaneous leishmaniasis, dated 1917. Image: Matson Collection. Click for sourece

Of course, the latest American military campaigns in the Middle East have given US troops ample opportunity for intense sandfly exposure (7). And they have been infected. As of 2007, at least 1300 soldiers have been diagnosed with leishmaniasis (mostly CL but a few isolated cases of VL) since deployment to both countries; many speculate that the number may be as high as 2,500, due to underreporting or misdiagnoses by physicians unfamiliar with this exotic disease (8). I’ve been unable to find the latest numbers for 2011 but I can imagine that they’ve added a few hundred to those estimates.

This wasn’t the case during the Gulf War, in which only 32 ground troops contracted CL and VL among 500,000 Western troops (9). Leishmaniasis is rare in northern Saudi Arabia and Kuwait and had not been described as an endemic infection in the locals, expatriate guest workers or any of the Allied troops stationed in the region during World War II. Also, most combat troops were stationed in the open desert rather than in oases or urban areas where the sandfly vector and its rodent reservoirs thrive. They were also deployed in the cooler winter season, a seasonally inopportune time for the sandfly (10).

Prior to the invasion of Afghanistan, the US Defense Intelligence Agency’s Armed Forces Medical Intelligence Center (woof, what a mouthful) anticipated that leishmaniasis might be a problem and called for appropriate provisions to be made – education, insect repellant, bed netting and the like. Overall, the American military has strongly enforced sanitation standards thanks to the existence of a professional non-commissioned officer (NCO) corp with the authority to do so (11). However, military sources have indicated that insect repellant and bed nets were frequently in short supply in the early years, and that many unit commanders failed to emphasize the risk to their troops (8). One paper has reported that 80% of a surveyed 310 infected troops had reported using insect repellents but that a 26% of those had also noted that repellents were occasionally unavailable (7).

Having served nine months in Iraq, Sgt. Eric DiVona awaits treatment for cutaneous leishmaniasis at the Walter Reed Army Medical Center in 2004. Image: AP. Click for source

Soldiers have also had to contend with other tropical delights such as malaria, Q fever, brucellosis but prevention and control measures have largely kept other infections in check among deployed military personnel (12). Overall, the importance of practicing preventative medicine in the military theatre cannot be understated. Fighting conflicts abroad means unavoidable exposure to that country’s climate, geography and attendant health problems. And the most recent conflicts in Afghanistan and Iraq have engendered an attendant destabilization of already weakened public health measures, increased the rate of population migration as well as provoked profound societal insecurity. All of these factors have historically done wonders for the spread and transmission of infectious diseases. I wonder if Franklin D. Roosevelt’s knew how multifaceted his observation that “war is a contagion” really is.

As long as wars and so-called “foreign engagements” continue, it is vital to anticipate the types of health challenges troops should anticipate as well as understand that a soldier’s time overseas can have lasting, multifactorial impacts on their health. Infectious diseases are just one of the many hazards of war. Though they may not factor into war planning, they will be one of the many groups welcoming your invasion and long-term occupation of their home. The Soviets learned the hard way that it’s important to know one’s enemy.

Resources
A really fantastic article, and an important source for this post, about the epidemiological lessons learned in the Soviet-Afghan War.

So, parasites. They have weird life cycles that I find can be a bit tedious to talk about in these articles. Talking about people putting things in their mouth that they shouldn’t and performing  rituals that compromise their health is so much cooler than talking about what insect bit what and which parasite morphed from an amastigote to promastigote, and then traveled from the blood stream to the liver and so on. If you like that kind of stuff, check out this nice graphic from Nature explaining the particulars of leishmaniasis.

For an understanding of how a leishmaniasis diagnosis affects US soldiers, please visit the story “GIs Battle Baghdead Boil” from CBS.

References
(1) Lt Col LW Grau and Maj WA Jorgensen (1997) Beaten by the Bugs: The Soviet-Afghan War Experience. Military Review. 6: 30-7 Download the PDF here.
(2) R.W. Ashford (2000) The leishmaniases as emerging and reemerging zoonoses. Int J for Parasitology. 30(12): 1269-1281
(3) RL Jacobson (2011) Leishmaniasis in an Era of Conflict in the Middle East. Vector-Borne Zoonotic Dis 11(3):247-58. Epub 2010 Sep 16.
(4) Desjeux P et al. (2000) Leishmania/HIV co-infection, south-western Europe 1990–1998. Geneva, World Health Organization. Ref: WHO/LEISH/2000.42 Download the PDF here.
(5) World Health Organization. (Aug 10, 2004) World Health Organization action in Afghanistan aims to control debilitating leishmaniasis. Accessed Oct 5, 2011
(6) MR Wallace, BR Hale, GC Utz, PE Olson, KC Earhart, SA Thornton and KC Hyams. (2002) Endemic infectious diseases of Afghanistan. Clin Infect Dis.  15:34(Suppl 5): S171-207
(7) PJ Weina, RC Neafie, G Wortmann, M Polhemus, NE Aronson. (2004) Old world leishmaniasis: an emerging infection among deployed US military and civilian workers. Clin Infect Dis. 1;39(11):1674-80. Epub 2004 Nov 9.
(8) B Furlow (June 3, 2007) “US Army reports fewer cases of leishmaniasis, but a complex threat persists.EPI NEWS. Accessed: Oct 5, 2011
(9) KC Hyams, J Riddle, DH Trump, JT  Graham. (2001) Endemic infectious diseases and biological warfare during the Gulf War: a decade of analysis and final concerns. Am. J. Trop. Med. Hyg. 65(5): 664–670
(10) KC Hyams, K Hanson, FS Wignall, J Escamilla, EC Oldfield III. (1995) The Impact of Infectious Diseases on the Health of U.S. Troops Deployed to the Persian Gulf during Operations Desert Shield and Desert Storm. Clin Infect Dis. 20(6): 1497-1504
(11) LW Grau and MAJ WA Jorgensen. (1995) Medical Support in a Counter-guerrilla War: Epidemiologic Lessons Learned in the Soviet-Afghan War . U.S. Army Med Depart J. Accessed Oct 17, 2011
(12) NE Aronson, JW Sanders, KA Moran. (2006) In Harm’s Way: Infections in Deployed American Military Forces. Clin Infect Dis. 15;43(8):1045-51. Epub 2006 Sep 14.

This post was chosen as an Editor's Selection for ResearchBlogging.org

Weina, P., Neafie, R., Wortmann, G., Polhemus, M., & Aronson, N. (2004). Old World Leishmaniasis: An Emerging Infection among Deployed US Military and Civilian Workers Clinical Infectious Diseases, 39 (11), 1674-1680 DOI: 10.1086/425747