PARAMYXOVIRIDAE

Parainfluenza Virus ssRNA virus enveloped, pleomorphic morphology 5 serotypes: 1, 2, 3, 4a and 4b No common group antigen Closely related to Mumps virus (Linda Stannard, University of Cape Town, S.A.)‏

Clinical Manifestations Croup (laryngotraheobroncitis) - most common manifestation of parainfluenza virus infection. However other viruses may induce croup e.g. influenza and RSV. Other conditions that may be caused by parainfluenza viruses include Bronchiolitis, Pneumonia, Flu-like tracheobronchitis, and Corza-like illnesses.

Laboratory Diagnosis Detection of Antigen - a rapid diagnosis can be made by the detection of parainfluenza antigen from nasopharyngeal aspirates and throat washings. Virus Isolation - virus may be readily isolated from nasopharyngeal aspirates and throat swabs. Serology - a retrospective diagnosis may be made by serology. CFT most widely used.

Management No specific antiviral chemotherapy available. Severe cases of croup should be admitted to hospital and placed in oxygen tents. No vaccine is available.

Respiratory Syncytial Virus (RSV)‏ ssRNA eveloped virus. belong to the genus Pneumovirus of the Paramyxovirus family. Considerable strain variation exists, may be classified into subgroups A and B by monoclonal sera. Both subgroups circulate in the community at any one time. Causes a sizable epidemic each year.

Clinical Manifestations Most common cause of severe lower respiratory tract disease in infants, responsible for 50-90% of Bronchiolitis and 5-40% of Bronchopneumonia Other manifestations include croup (10% of all cases). In older children and adults, the symptoms are much milder: it may cause a corza-like illness or bronchitis.

Infants at Risk of Severe Infection 1. Infants with congenital heart disease - infants who were hospitalized within the first few days of life with congenital disease are particularly at risk. 2. Infants with underlying pulmonary disease - infants with underlying pulmonary disease, especially bronchopulmonary dysplasia, are at risk of developing prolonged infection with RSV. 3. Immunocompromized infants - children who are immunosuppressed or have a congenital immunodeficiency disease may develop lower respiratory tract disease at any age.

Laboratory Diagnosis Detection of Antigen - a rapid diagnosis can be made by the detection of RSV antigen from nasopharyngeal aspirates. A rapid diagnosis is important because of the availability of therapy Virus Isolation - virus may be readily isolated from nasopharyngeal aspirates. However, this will take several days. Serology - a retrospective diagnosis may be made by serology. CFT most widely used.

Treatment and Prevention Aerosolised ribavirin can be used for infants with severe infection, and for those at risk of severe disease. There is no vaccine available. RSV immunoglobulin can be used to protect infants at risk of severe RSV disease.

Measles (Rubeola) Also known as English, 9 Day, Hemorrhagic or Black Measles Measles virus is present in blood, urine, nasopharyngeal secretions in infected individuals Maximum contagiousness occurs during the prodromal (Catarrhal) Stage by droplet spray Contagious 1 to 2 days before until 5 days after onset of the characteristic rash The rash begins on the head and spreads over most of the body in 24 hours in a descending fashion and fades in the same manner. The severity of the illness is related to the severity of the rash.

Measles (Rubeola) Clinical Manifestations: Cough, Coryza, Conjunctivitis Koplik Spots: the pathognomonic gray/white, sand grain size dots on the buccal mucosa opposite the lower molars, which last 12 to 24 hrs. The conjunctiva may reveal a transverse line along the margins of the eye-lid called Stimson Line. The rash phase is often accompanied by high fever (104 to 105* F.) Cervical lymphadenitis, splenomegaly, and mesenteric lymphadenopathy and abdominal pain may be noted. Otitis Media, pneumonia, and gastrointestinal tract symptoms are more common in infants.

Measles (Rubeola) D/D Complications: Clinical Manifestations: Photophobia The constellation of cough and conjunctivitis is fairly diagnostic for measles. Koplik Spots usually are pathognomonic but are not always present at the time of the most pronounced rash. D/D Exanthem subitum, rubella, enteroviral or adenoviral infection, infectious mononucleosis, toxoplasmosis, meningococcemia, scarlet fever, rickettsial disease, Kawasaki syndrome, serum sickness, and drug rash Complications: Otitis Media (Frequently), Interstitial pneumonia, myocarditis and mesenteric adenitis Encephalomyelitis

Measles (Rubeola) Prevention is with live measles virus administered at 9 months, 4 to 5 years, or 11 to 12 years. Infants and neonates are protected by maternal transplacental antibody Infection with the measles virus confers life long immunity The live vaccine is contraindicated in pregnant women, immunodeficient and immunosuppressed children or during a febrile illness

Mumps Mumps are the only known host. Mumps occur worldwide and in spread by direct contact, aerosolization of respiratory secretions, and fomites. It affects both sexes and 85% of the infections occur in persons under 15 years of age. Epidemics are most frequently in the winter and spring. Virus can be isolated from saliva 6 days before and 9 days after the onset of parotid swelling, the illness can be transmitted 1 day before until 3 days after swelling. Incubation period is usually 16-18 days.

Mumps D/D: Prevention: Clinical Manifestations: The onset is characterized by fever, muscle pain, headache, malaise, and pain and swelling of the parotid glands lasting 3 to 7 days. D/D: Salivary Calculus, recurrent paroititis, salivary gland tumors, lymphomas, and cervical adenitis Prevention: Live attenuated mumps vaccine administered at 15 months and 11 to 12 years. Infection confers life-long immunity Transplacental antibodys protect the infant for first 6 months of life.