Bio-Evolution

Bordetella pertussis/parapertussis

Reference
BE-A993
Packaging
25 tests per kit
Nucleic Acid
DNA
CE Marking
yes

 

Bordetella pertussis is the responsible agent of one of the most contagious human infections known as whooping cough. The infection by B. pertussis is associated with characteristic violent coughing fits, respiratory tract stricture and spasms.

 

B. pertussis is a small GRAM-negative aerobic coccobacillus that colonizes the nose and throat lash of infected persons. The toxins produced by B. pertussis paralyze the lash and lead to a respiratory tract inflammation, interfering with pulmonary secretions. The first description of this pathology was made during the 16th century. It was one of the most frequent and severe infantile disease in the USA, associated with a high morbidity and mortality before the introduction of an efficient vaccine. The incidence clearly decreased with the vaccination but re-increase progressively since the early eighties. In France, between 1996 and 2005, the average incidence in infant of less of 3 months of lifetime was estimated to 276/100 000. The most concerned populations are non-vaccinated infant and adolescents and adults whom lost their natural or vaccinal protection. An explication for that outbreak may be the decreased of the vaccinal cover and the B. pertussis adaptation to the immunity induced bay vaccination.

 

Bordetella parapertussis is a bacteria derived from B. pertussis. The infection caused by B. parapertussis induces the same symptoms as B. pertussis, but is generally less severe. B. parapertussis have a specific antigen called Antigen-O, which protect it from specific antibodies for B. pertussis. Thus infection by B. parapertussis is possible in subjects whom alredy developed immunity against B. pertussis.

 

Direct diagnosis of this disease is done by culture on specific medium (Bordet-Gengou or Regan Lowe) only during the two first weeks of infection. Culture’s sensibility is only 50%.

 

The real time PCR is a faster and more sensitive solution that permits the detection of the pathogen agent to 3 weeks after the beginning of the cough. It is actually a test of first choice for the whooping cough diagnosis. Beyond 3 weeks of cough, serological diagnosis is a pertinent alternative to PCR.