Bordetella pertussis toxin IgG monotest

Whooping cough is a highly communicable, vaccinepreventable disease that lasts for many weeks, presenting high morbidity and a great mortality in some countries; most deaths occur among unvaccinated children. It is typically manifested in children with paroxysmal spasms of severe coughing, whooping, and post-tussive vomiting. Complications include hypoxia, apnea, pneumonia, seizures, encephalopathy, and malnutrition. Whooping cough is a relatively mild disease in adults. It is caused by the bacterium Bordetella pertussis, a small Gram-negative aerobic coccobacillus, which colonizes the cilia of the mammalian respiratory epithelium. Contagion occurs through direct contact with respiratory discharges from infected persons. Specific diagnostic tests include culture, direct immunofluorescence, PCR, and detection of serum ntibodies. While culture is almost 100% specific but little sensitive, direct immunofluorescence lacks both sensitivity and specificity. Serology is widely used for the diagnosis of pertussis in older vaccinated children, adolescents and adults. Yet, the immune responses against infection and vaccination cannot be distinguished. Due to its sensitivity, specificity, and speed, PCR is accepted as a proof of infection in many countries with notification systems. Serological diagnosis should only be attempted in patients with symptoms compatible with pertussis. When the clinical course is not typical and prolonged coughing is the only symptom, confirmation of the diagnosis is required. Measurement of IgGanti- PT is not meaningful in neonates and young infants. Serology can be used for diagnostic purposes only in patients who were not vaccinated during the last twelve months. According to reference laboratories in the EU, ELISA should use purified non-detoxified PT as an antigen, and results should be expressed in International Units per milliliter. Dual sample serology is based on ≥100% increase in antibody concentration. For single sample serology, different cutoff values have been proposed in various countries. The European Centre for Disease Prevention and Control suggests a dual cut-off between 62 and 125 IU/ml. Detection methods based on chemiluminescence have received much attention due to their low background, linearity and wide dynamic range. When coupled to enzyme immunoassays, the signal amplification effect provided by the enzyme enables the design of CLIA (ChemiLuminescent ImmunoAssay) tests with shorter incubation times while keeping or improving their sensitivity.