Mosquito Soldiers: Malaria, Yellow Fever, and the Course of the American Civil War (review)

Mosquito Soldiers is an epidemiological study of the effects of mosquito-borne pathogens on the course of the American Civil War. This is a fascinating topic and given the fact that disease, rather than wounds, caused two-thirds of wartime mortality, it is a valuable addition to the historiography of the time period. Andrew McIlwaine Bell examines the effects of disease not only on the physical health of the fighting forces (and civilians) but the psychological impact as well. Commanders often based the timing and precise geography of military decisions on the South's well-known and feared sickly season. For instance, anxieties about yellow-fever outbreaks influenced the early campaigns along the Texas coast. The main argument, that yellow fever and malaria helped to shape the war, is convincing, but the concrete details of exactly how this played out remain somewhat obscure. The book is most engaging in its specific accounts and anecdotes. Chapter three contains a particularly effective discussion of General Benjamin Butler's sanitation measures following the occupation of New Orleans in 1862. The anticipated epidemic of yellow fever, hoped for on the part of Confederate partisans and much feared by Northerners, never materialized and the Union retained control of the city. The exploration of the effects of disease on the Vicksburg campaign, on both sides, is also quite compelling. In light of the overarching argument, a later chapter on the Peninsular campaign and troop movements in Arkansas is less convincing, although it contains rich description. Disease clearly affected strategic considerations on a local level, but the effects on the larger military situation and outcomes are not as obvious.

Bell shows that disease hit unseasoned northern troops hard early in the war, and this prolonged the conflict by slowing several Union military advances. He also argues that Union medical officers more effectively deployed quinine against rampant malaria infection, whereas Confederate shortages as the war lengthened caused increased suffering. While the book is well researched and full of interesting evidence, it is less completely developed in terms of explicit argumentation and explanation. This is partially the result of more complete Union records and information, making some direct comparisons difficult. However, several questions remain unaddressed, and here the modern medical understanding of both diseases that Bell discusses in his introduction would be instructive. Because people in endemic areas develop partial immunity to malaria, would Union soldiers, a greater percentage of whom encountered malaria for the first time, have suffered more debilitating malarial paroxysms than those of southern soldiers who had already been living with the disease? Did Confederate soldiers experience a growing incidence of disease-related complications as resources dwindled because of the interactions between immunity and nutrition? Did superinfection with many different strains of malaria lead to more virulent symptoms; if so, what larger consequences did this have for both armies?

While the loss of a significant portion of the Confederate medical records complicates such investigations, important questions remain. Furthermore, Bell mentions the Confederate manpower shortage, but he never completely explores the comparative interaction between disease rates and overall (rather than unit-specific) manpower levels. This is one area where concrete Confederate numbers would help. If the Union did have higher malaria-infection rates, when were these differences offset by the North's superior numbers of actual soldiers and potential recruits? Bell mentions several times that many Southerners started the war with natural immunity to these diseases, but he does not fully consider the implications of this disparity for either the individual disease experience or the broader military situation.