I've often suspected that the pneumonia diagnosis might have been a euphemism. But it seems as though, in the last two decades, the correlation between alcoholism and pneumonia has begun to be more seriously explored.
Not just the general debilitation, weakened immune function, and possible malnutrition contributing to pneumonia, but actual alcohol specific effects that make infection more likely, and outcomes much more serious.
'Recent reports have identified alcoholism to have an important public health impact and cause a substantial loss of lives worldwide. For a long time alcoholism has been identified to favor pulmonary infections. But only in the last 2 decades the alterations induced by ethanol to the complex mechanisms of lung defense have been recognized. Alcohol alters lung defenses on all levels. It is known to favor oropharyngeal colonization by potentially pathogenic bacteria, aspiration by altering the cough reflex, and to decrease ciliary motility and surfactant production. Innate and adaptive immune responses on the systemic and alveolar level are compromised by alteration of cytokines, decreased chemotaxis, and phagocytic activity of alveolar macrophages and neutrophils.'
'In addition to its well-known association with lung infection (i.e., pneumonia), alcohol abuse now is recognized as an independent factor that increases by three- to four-fold the incidence of the acute respiratory distress syndrome, a severe form of acute lung injury with a mortality rate of 40 to 50 percent. This translates to tens of thousands of excess deaths in the United States each year from alcohol-mediated lung injury, which is comparable to scarring of the liver (i.e., cirrhosis) in terms of alcohol-related mortality. Experimental and clinical studies are shedding light on the basic mechanisms by which alcohol abuse predisposes some people to both acute lung injury and pneumonia.'