Epiglottitis in a 2-year-old child is diagnosed. Among the following options, most commonly Epiglottitis occurs due to infection with:
Ans. is 'c' i.e., Hemophilus influenza From the above given long list of references it must be evident, that this one was tough for us. is H. influenzae still the most common etiological agent of epiglottitis or has it receded back giving place to other agents such as Streptococcus? Harrison, 16/e and Nelson, 17/e, say that - H. influenzae was the most common etiological agent of epiglottitis but because of widespread use of the HIB vaccine, diseases d/t H. influenzae have reduced drastically and "therefore, other agents such as Streptococcus pyogenes, S. pneumaniae, and Staphylococcus aureus, now represent a larger proportion of pediatric cases of epiglottitis." So far fine. But the trouble is that both of them mention this change for US only. Harrison writes - 'After the introduction of Hib vaccine, disease incidence among children in the United States declined dramatically." Nelson writes - "Since the widespread use of the Hib vaccine in the United States, invasive disease due to H. influenzae type b in pediatric patients has been reduced by 80-90%. Therefore other agents, such as Streptococcus pyogenes, S. pneumoniae, and Staphylococcus aureus, now represent a larger proportion of pediatric cases of epiglottitis." Apart from Nelson and Harrison, all other books consulted (mentioned in References above) write H. influenzae to be the most common etiological agent. They also mention that it has reduced considerably in US d/t extensive use of Hib vaccine. CPDT writes - "In published case series, it is almost always caused by H. influenzae type B" O.P. Ghai writes - "H. influenzae type B is the most frequent causative agent." I consulted specifically book by UK authors who also endorse the same fact Furfare and Ameils Textbook of Pediatrics, 6/e p 777 write - "Epiglottitis is caused primarily by H. influenzae type B. The introduction of the conjugate vaccine in the UK in October 1992 has substantially reduced the incidence of epiglottitis, however, there has been a recent resurgence of cases d/t vaccine failure." Also, read these lines from Harrison - "Nevertheless, lack of vaccination or vaccine failure has meant that many pediatric cases seen today are still due to Hib" So we conclude that- in India - H. influenzae in U.S. - Group A Streptococcus in World as a whole - Not sure but I would go for H. influenzae Most common etiological agent of epiglottitis As far as this question is concerned, it is being asked by an Indian institution, so I would go for the most common etiological agent in India (or may be in the world but definitely not in US)
Influenza virus
Staphylococcus aureus
Hemophilus influenzae
Respiratory syncytial virus
Disorders of the Respiratory Tract