Postinfectious Cough: Infection
The whooping sound is also usually absent in adults. The cough tends to be spasmodic, and occurs more frequently at night and after exposure to cold air; it lasts usually 4 to 6 weeks but can persist for much longer during the convalescent phase. The duration and frequency of symptoms vary widely but are more severe in females and in nonimmunized individuals. In adults and adolescents, it is common to have a nondistinct protracted cough as the only manifestation of pertussis infection. And many individuals never become symptomatic. Clinical and serologic surveys of elderly subjects living independently have shown that between 3.3% and 8% have pertussis infections each year; yet, only 37.5 to 50% of such individuals are symptomatic. natural inhalers for asthma
Both probable and confirmed cases of pertussis infection should be reported to the public health authorities. A clinical case is defined as an acute illness with a cough that is persistent for > 2 weeks and is associated with posttussive vomiting, the typical whooping sound, or severe paroxysms. A confirmed case is one in which B pertussis has been isolated or is a clinical case that has been confirmed by polymerase chain reaction (PCR) or epidemiologic linkage to a confirmed case. A probable case meets the clinical case definition without laboratory or epidemiologic confirmation. The most reliable way to make the diagnosis is by detection of the organism from nasopharynx secretions. However, culturing the organism requires enriched media, and its sensitivity has been reported to be as low as 25 to 50%. PCR is a rapid and highly specific test for Bordetella spp and has a sensitivity as high as 80 to 100%. Although widely used in the United States, PCR assays have not been standardized. A number of serologic studies are available, including IgG and IgA titers of the antibody to PT, filamentous hemagglutinin (FHA), pertactin, and fimbriae. The most generally accepted serologic criterion for diagnosis is the enzyme-linked immunosorbent assay test to demonstrate a significant increase in IgG serum antibody against PT. Paired sera are necessary as nonrising titers may represent past infection or previous immunization.
Category: Respiratory Symptoms
Tags: Bordetella pertussis, pertussis infection, postinfectious cough, postviral cough