Usefulness of laboratory methods in diagnosis of pertussis in adult with paroxysmal cough.

Pertussis is an acute, highly contagious bacterial infection of respiratory system caused by Bordetella pertussis. Principally, disease affects young children, however, recently it is also reported in adoles- cents and adults. Symptoms of pertussis in adults are non-specific, i.e. dry, paroxysmal and protracted cough. Thus, it is rarely diagnosed in this group.
This paper aimed at evaluating the usefulness of the laboratory methods in diagnosis of pertussis in adults based on a case presenting with dry, paroxysmal and chronic cough.
Sputum (collected on 25th January 2013) and paired serum samples (collected on 13th February and 19 April 2013) were tested. Pertussis diagnostics involved culture, in-house PCR, real-time PCR and ELISA.
Sputum culture, using commercial medium Bordetella Selective Medium by Oxoid did not reveal the presence of B. pertussis. Real-time PCR and PCR, however, confirmed the presence of insertion sequence IS481 and pertussis toxin promoter sequence ptx-Pr, markers indicative of B. pertussis infection. Serological testing revealed the high titres of IgA, IgG and IgM antibodies to B. pertussis in the first sample. In the second sample, collected 2 months following the first one, a significant decrease in IgA antibodies was reported.
These data suggest a high usefulness of the laboratory methods in the diagnosis of pertussis in adults with chronic cough. Application of such methods ensures adequate diagnosis of disease, quick introduction of proper treatment and implementation of procedures preventing the spread of infection.

Authors:Piekarska K1, Rzeczkowska M1, Rastawicki W1, Dąbrowska-Iwanicka A2, Paradowska-Stankiewicz I3.
Journal:Przegl Epidemiol. 2014