Legionnaires' disease Legion convention in 1976 was high (29 deaths in 182 infected individuals) because the antibiotics used (including penicillins, cephalosporins, and aminoglycosides) had poor intracellular penetration. Mortality has plunged to less than 5% if therapy is started quickly. Delay in giving the appropriate antibiotic leads to higher mortality. The fatality rate of Legionnaires' disease has ranged from 5 to 30% during various outbreaks and approaches 50% for nosocomial infections, especially when treatment with antibiotics is delayed. Hospital-acquired "Legionella" pneumonia has a fatality rate of 28%, and the principal source of infection in such cases is the drinking-water distribution system. Legionnaires' disease
Community-acquired pneumonia monocytogenes" and a variety of mycobacteria. CAP-causing viruses may also be transferred from mother to child; herpes simplex virus (the most common) is life-threatening, and adenoviridae, mumps and enterovirus can also cause pneumonia. Another cause of CAP in this group is "Chlamydia trachomatis", acquired at birth but not causing pneumonia until two to four weeks later; it usually presents with no fever and a characteristic, staccato cough. CAP in older infants reflects increased exposure to microorganisms, with common bacterial causes including "Streptococcus pneumoniae", "Escherichia coli", "Klebsiella pneumoniae", "Moraxella catarrhalis" and "Staphylococcus aureus". Maternally-derived syphilis is also a cause of CAP