Section 16 Pertussis

Introduction of Pertussis

Pertussis is an acute respiratory infectious disease caused by bordetella pertussis. Human is the exclusive infection source spreading this disease via droplets. Although all populations are susceptible to this disease，children younger than 5 years old，especially younger than 1-year-old，are the most predominant sufferers. Immunity to this disease following natural attack is enduring and second time of infection with this disease is rare. At present，morbidity and mortality of pertussis have dramatically decreased，with children younger than 9 years old accounting for 90%，and babies younger than 1-yearold accounting for 1/3. Pertussis usually occurs in the spring，reaching a peak during May to July. Nowadays this disease has lost explicit epidemic cycle.

Pertussis is characterized in its typical form by paroxysms of coughing，very short duration and dozens of times without inspiration，followed by a long-drawn inspiration，or “whoop，” repeating the above for several times and ending with expulsion of violent vomiting. The whooping cough occurs several times or dozens of times every day and often at night. The patients usually do not get fever. In severe cases edema may develop in face and eyelid，ulcer may occur in glossodesmus and conjunctiva may bleed. This stage can last 1 week-2 months，often 2-6 weeks.

1. Laboratory diagnose

（1） White blood cell count dramatically increases with lymphocyte cells accounting for above 50%.

（2） Positive isolation of bordetella pertussis from sputum or laryngopharyngeal secretion.

（3） Four folds or higher increase in serum agglutinating antibody titer between acute-phase and convalescent sera

2. Major measures dealing with pertussis

（1）Suspected patients and patients：

early discovery，early diagnosis，early reporting，early isolation，and early treatment.

（2）Cutting off transmission routes：

conducting disinfection by exposure to sunlight，phenol or Lysol. Clean ward using wet cleaning. Terminal disinfection is not necessary.

（3）Protection of susceptible populations：

taking personal protection measures such as wearing masks，distancing from measles patients. Emergency immunization is prohibited.

百日咳流行病学个案调查表

Epidemiological Questionnaire for Cases of Pertussis

Questionnaire

（本节编者-马钰　本节核对-吴迪）