Section 6 Measles

Introduction of Measles

Measles is an acute respiratory infectious disease caused by measles virus. Measles patients are the exclusive infection source，and human is the only natural host. Measles is highly infectious，which all population is susceptible. Immunity to measles virus after infection is long-lasting.

Before widespread use of measles vaccine，measles is obviously seasonal，with measles cases clustering in late winter and early spring，attacking children under 5 years old predominantly. Measles has typical clinical manifestations and has a high morbidity and mortality.

A big change occurred in the epidemiological characteristics of measles after the widespread use of measles vaccine，such as prolonging epidemic intervals and inapparent cycle，that is to say，the peak flattening，and the age of onset shift behind，and the clinical manifestations become atypical，and morbidity and mortality dramatically decrease.

1. Diagnostic criteria

（1）Symptoms

1） Fever（38℃ or higher）

2） Cough or catarrh in upper respiratory tract，or conjunctivitis.

3） Koplik spots appears in the mucous membranes of the oral cavity the typical maculae in early stage of measles（2-3 days after onset）.

4） Red maculopapular in the skin develop from retro auricular area to entire body，lasting 3 days and displaying typical course.

（2）Epidemiological history

A history of contact to confirmed measles patients，and the incubation period is 6-18 days.

（3）Laboratory data

1） IgM antibody to measles is positive in sera of a person who has not been immunized with measles vaccine in the recent month.

2） Four folds or higher increase occurs in IgG antibody to measles titer between acute-phase and convalescent-phase sera，or antibody to measles in acute-phase sera is negative while sera conversion occurs in convalescent-phase sera.

3） Measles virus is isolated from nasopharyngeal secretion and/or blood，or nucleic acid of measles virus is positive.

2. Major measures dealing with the measles epidemic

（1）Suspected patients and patients：

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

（2）Cutting off the transmission routes：

conducting disinfection by exposure to sunlight，phenol or lysol. Clean ward using wet cleaning and ventilation，and terminal disinfection is needed.

（3）Protection of susceptible populations：

taking personal protection measures such as wearing masks，distancing from measles patients and receiving emergency immunization as early as possible.

麻疹病例流行病学个案调查表（疑似/暴发）

Questionnaire for Measles (Suspects/ Outbreak)

Questionnaire

（本节编者-马钰　本节核对-吴迪）