Measles

• Measles


  An acute viral infectious disease
• Measles was very common and an important cause of death of under five children in the prevaccine era
• Measles is one of the vaccine preventable diseases
• Though the prevalence and mortality from Measles reduced drastically due to effective vaccination, Measles was responsible for more than 140,000 deaths globally in 2018
• Most of these measles deaths were in children under five years
• Measles virus


  A paramyxovirus of the genus Morbillivirus
• Measles virus is rapidly inactivated by heat, sunlight, acidic pH, ether, and trypsin
• Measles is a human disease and is not known to occur in animals
• Mode of transmission


  Airborne and direct contact
• The virus remains active and contagious in the air or on infected surfaces for up to 2 hours
• It can be transmitted by an infected person from 4 days prior to the onset of the rash to 4 days after the rash erupts
• Pathogenesis


  Measles is a systemic infection
• Pathogenesis of measles


  1. Virus infect and replicate in the respiratory tract

  2. Spread to regional lymphoid tissues and get to systemic circulation (1st viremia)

  3. Further viral replication in regional and distal reticuloendothelial sites after which they get to systemic circulation (2nd viremia)

  4. Infected lymphocytes and dendritic cells transmit measles to epithelial cells and following amplification in the epithelia, the virus is released into the respiratory tract
• Incubation period


  11 to 12 days (7-14 days)
• Stages of measles disease

  • Prodromal stage
  • Rash stage
  • Convalescent stage
• Prodromal stage


  • Lasts 2 to 4 days, with a range of 1 to 7 days
  • First sign is usually a high fever
  • A runny nose, a cough, red and watery eyes, and small white spots inside the cheeks can develop in this initial stage
• Koplik spots


  Present on mucous membranes, are considered to be pathognomonic of measles, occur 1 to 2 days before the measles rash
• Rash stage


  • Rash erupts, usually on the face and upper neck, spreads to the hands and feet over about 3 days
  • Rash lasts for 5 to 6 days, and then fades
  • Initially, lesions blanch (become white or pale) with fingertip pressure, by 3 to 4 days, most do not blanch with pressure
  • The lesions peel off in scales in more severely involved areas
  • The rash subsides in the same sequence of appearance leaving behind a brownish, branny desquamation
• Fever


  • Continues till 2-4 days of the eruptive phase of the disease and subsides
• Other symptoms


  • Epistaxis
  • Posterior cervical lymphadenopathy
  • Anorexia
  • Splenomegaly
• Complications


  • Diarrhea
  • Otitis media
  • Pneumonia
  • Febrile convulsions
  • Myocarditis
  • Encephalitis
  • Blindness
  • Subacute sclerosing panencephalitis
  • Laryngitis
  • Tracheitis
  • Bronchitis
  • Acute appendicitis
  • Mesenteric lymphadenitis
  • Purpura fulminans with or without digital gangrene
  • Guillain-Barre syndrome
  • Cerebral thrombophlebitis
  • Hemiplegia
  • Retrobulbar neuritis
• Severe measles is more likely among poorly nourished young children, especially those with insufficient vitamin A, or whose immune systems have been weakened by HIV/AIDS or other diseases
• Unvaccinated young children are at highest risk of measles and its complications
• Most measles deaths occur in countries with weak health infrastructures
• Case definition


  An acute illness characterized by: generalized, maculopapular rash lasting ≥3 days; and temperature ≥101°F or 38.3°C; and cough, coryza, or conjunctivitis
• Diagnostic methods


  • Demonstration of anti-IgM antibodies in the serum – by enzyme immunoassay
  • Reverse transcriptase polymerase chain reaction (RT-PCR) – (nasopharyngeal aspirates, throat swabs and urine)
  • Viral culture
  • Histopathologic examination of the involved organs reveals pericapillary infiltration of mononuclear cells with or without pathognomonic, multinucleated, Warthin-Finkeldey giant cells
• Full blood count


  Leucopenia with relative lymphocytosis, thrombocytopenia
• Management


  • Supportive care - Bed rest, dim -light, Adequate nutrition, Adequate fluid intake(ORS)
  • Antibiotics (eye and ear infections, and pneumonia)
  • Anticonvulsants
  • Antipyretics
  • Vitamin A supplements – two doses should given 24 hours apart
• Vitamin A supplements can help prevent eye damage and blindness, and also helps to reduce measles deaths
• Prevention


  • Vaccination
  • Administration of vaccine within 3 days of exposure in susceptible individuals
  • If vaccination is not possible, immune globulin 0.50 mL/kg IM (maximum dose, 15 mL) is given immediately (within 6 days), with vaccination given 5 to 6 months later if medically appropriate
  • Isolation of close contacts until 21 days after onset of rash in the last case
• Immune globulin should not be given simultaneously with vaccine