Infectious Diseases That Track With War
“Thanks to Penicillin. . . He Will Come Home!"
- From the National WW II Museum
“Wise and humane management of the patient is the best safeguard against infection.”
- Florence Nightingale, founder of modern nursing and hospital epidemiology
Throughout history, far more military personnel succumbed to infectious diseases than to enemy actions. In America, this enduring feature of war was finally reversed in World War II, mainly as a result of major medical advances in prevention (vaccines) and treatment with the new “miracle drug,” penicillin. In this Germ Gems post I briefly review the enormous impact of infectious diseases on the outcomes of wars and on the misery they cause that often spills over to civilian populations.
Conflict epidemiology. Conflict promotes factors such as mass movement of populations, overcrowding, poor sanitation, lack of access to clean water, lack of shelter, poor nutrition, and collapse of public health infrastructure and health services. These factors lead to an increased incidence of infectious diseases among military personnel and civilians alike.
Pathogens across the spectrum (viruses, bacteria, and parasites) thrive under conditions of war and turmoil. As recognition grew that war is a leading cause of illness and death, the discipline of “war epidemiology” or “conflict epidemiology” became a more prominent component of the field of public health.
A landmark in military/medical history. In the American Civil War, uncontrolled infectious diseases caused two-thirds of the approximately 660,000 deaths of soldiers. Infectious diseases prolonged the fighting by as much as two years. Pneumonia, diarrhea/dysentery, and malaria (aka the “Third Army”) were the predominant adversaries. In a 1993 article in Clinical Infectious Diseases, “Infectious diseases during the Civil War: the triumph of the ‘Third Army,” the authors suggest that the American Civil War represents a landmark in military and medical history as it was the last large-scale conflict fought without knowledge of the germ theory of disease.
Viral infections. Smallpox. According to the Fred W. Smith National Library for Study of George Washington, in the first years of the Revolutionary War, Washington and his Continental Army “faced a threat that proved deadlier than the British” –-smallpox. After heavy losses in Boston and Quebec, Washington implemented the first mass immunization policy in American history.
Historians estimate that over the course of several millennia the variola virus—the cause of smallpox—killed more people than all wars combined. Due to an extraordinary global vaccination campaign, the smallpox virus was eradicated in 1980.
Influenza. It was not until 1933 that Influenza A virus was identified as the cause of the massive 1918-1919 flu pandemic. This pandemic occurred at the same time as World War I. Over 1 million U.S. troops participated in that war, and the flu virus killed more troops than any battle.
The second wave of the 1918 flu pandemic coincided with the Meuse-Argonne Campaign—our largest front-line commitment of the war. The National Institutes of Health reports 26,277 American soldiers died from influenza during the campaign, the deadliest battle for U.S. troops. (Vaccines didn’t play a role in curtailing flu virus infections in this war as the first flu vaccine didn’t become available until 1945.)
COVID-19. SARS-CoV-2, the cause of the COVID-19 pandemic, is the latest virus to be added to the list of pathogens fostered by war. In an April 2022 article in Travel Medicine Infectious Diseases, “Russo-Ukrainian war: An unexpected event during the COVID-19 pandemic,” the authors describe a devastating situation that went from bad to worse. Ukraine was already grappling to cope with the pandemic when Russian troops invaded Ukraine on February 24, 2022.. Access to reliable COVID-19 vaccines became even more limited. And to compound the public health threat of SARS-CoV-2, outbreaks of other viral infections, including HIV, measles, and polio, are threatening to unfold.
As discussed in last week’s Germ Gems post, “War on SARS-CoV-2: Year 4 of the COVID-19 Pandemic,” effective and safe vaccines were developed in record time. When Joe Biden recently asked the Defense Department to explore “how and when they would add COVID-19 to the list of vaccinations our armed forces must get,” this provoked a hue and cry by those opposed to vaccine mandates. (Fortunately, their efforts didn’t prevail. And it’s unclear what these anti-vaccination advocates think about the 17 vaccines already mandated by the Department of Defense.)
Bacterial infections. Bacteria belonging to the genus Shigella cause dysentery—diarrhea with bloody stools. In the American/U.S. Civil War, diarrhea and dysentery were the number one killers. These maladies caused a total of 1,528,098 cases in the Union Army with 57,000 deaths.
Another gastrointestinal tract infection that is facilitated by conflicts is caused by the gram-negative bacterium Vibrio cholerae—the etiology of cholera. In this infection, the diarrhea is non-bloody but copious. Severe cholera, without treatment, kills about half of affected individuals. (An untreated person with cholera may produce 10 to 20 liters [3 to 5 US gal] of diarrhea a day.) The principal route of transmission of V. cholerae is by drinking contaminated water.
Cholera was also a major contributor to mortality in the Crimean War of 1853-1856, and in modern times, it reared its ugly head in the war in Syria and in conflict-ridden countries like Haiti, where climate change, poverty, and depleted stocks of cholera vaccine are cofactors. (See the March 24, 2021 Germ Gems post, “Water, water everywhere, but Is It Safe to Drink?”)
Other bacterial infections that are fostered by wars and conflict are tuberculosis (living in close quarters), syphilis (sexual violence and rape), and infections caused by antibiotic-resistant bacteria. (In Europe, the rise in antibiotic-resistant bacteria is being linked to the overuse of antibiotics in Ukraine.)
Parasitic infection. In the American/U.S. Civil War, over 1.3 million cases and 10,000 deaths from malaria occurred in the Union Army, and fully one quarter of all illnesses reported in the Union Army were malarial in character. Confederate soldiers also suffered, although fatalities from the disease were comparatively lower.
Can war ever be good? Although we are all deeply saddened by the onslaught of death and suffering in war-torn countries like Ukraine, Myanmar, and Syria, some analysts have pointed to benefits of armed conflicts. (See the articles in Forbes, October, 2014, “Why War Is Good” and November, 2017, “Is War Good for Economies?)”
In the field of infectious diseases, as I mentioned earlier the development of penicillin was accelerated by World War II. And the field of hospital infection control also emerged because of war, in this case the 19th century Crimean War.
Improbably, if it weren’t for this war the profession of nursing as we know it wouldn’t have emerged. Florence Nightingale, revered as the founder of modern nursing, first gained fame by leading a team of 38 nurses to staff a hospital in Scutari, Turkey that served the British army. Less well known, however, is her mastery of statistics which played a role in the recognition of Florence Nightingale as the founder of hospital epidemiology.