Rubella From Latin meaning "little red"



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Lec.1 Community Medicne Dr.Wijdan

Rubella

From Latin meaning "little red"

Discovered in 18th century - thought to be variant of measles

First described as distinct clinical entity in German literature

Congenital rubella syndrome (CRS) described by Gregg in 1941


Rubella Case Definition:

Acute onset of generalized maculopapular rash, and temperature of > (37.2 °C), and arthralgia or arthritis, lymphadenopathy, or conjunctivitis

Causative agent:

Rubella virus is an enveloped , positive stranded RNA virus classified as Rubivirus in the Togaviridae family.

One antigenic type

Rapidly inactivated by chemical agents, ultraviolet light, low pH, and heat


Epidemiology:

  • Reservoir Human

  • Transmission Respiratory Subclinical cases may transmit

  • Temporal pattern Peak in late winter and early spring

  • Communicability

  • 7 days before to 5-7 days after the onset of rash .
     


Infants with Congenital Rubella Syndrome may shed virus for a year or more.

Occurance:

Before widespread use rubella vaccine, rubella occurred world wide at endemic levels with epidemics every 5-9 years,with most cases occurring in children. The incidence of rubella in the United States has decreased by approximately 99% from the prevaccine era .The risk of acquiring rubella has decreased in all age groups, including adolescents and young adults


In countries where rubella vaccine has not been introduced, rubella remain endemic. In 1999, an estimated minimum of 100000 CRS cases occurred each year in developing countries.


. In the vaccine era , most cases have occurred in young unimmunized adults in outbreaks on college campuses and in occupational settings .Although the number of susceptible people has decreased since the introduction and widespread use of rubella vaccine, recent serologic surveys indicates that approximately 10% of young adults are susceptible to rubella .


Rubella Pathogenesis:

Respiratory transmission of virus

Replication in nasopharynx and regional lymph nodes

Viremia 5-7 days after exposure with spread to tissues

Placenta and fetus infected during viremia

  • .


Rubella Clinical Features:

Incubation period 14 days (range 12-23 days)

Prodrome of low-grade fever

Maculopapular rash 14-17 days after exposure

Arthralgia or arthritis adult female up to 70%

children rare
Thrombocytopenic purpura 1/3000

Encephalitis 1/6000

Neuritis rare

Orchitis rare


Congenital Rubella Syndrome:

Infection may affect all organs May lead to fetal death or premature delivery

Severity of damage to fetus depends on gestational age

Up to 85% of infants affected if infected during first trimester.

Deafness

Cataracts

Heart defects

Microcephaly

Mental retardation

Bone alterations

Liver and spleen damage


  • Rubella Laboratory Diagnosis:

  • Isolation of rubella virus from clinical specimen (e.g., nasopharynx, urine)

  • Positive serologic test for rubella IgM antibody

  • Significant rise in rubella IgG by any standard serologic assay (e.g., enzyme immunoassay)

  • Rubella Outbreak Control Guidelines:

  • Laboratory diagnosis of rubella and CRS

  • Step-by-step guidelines on evaluation and management of outbreak

  • Rubella prevention and control among women of childbearing age

  • Rubella and CRS surveillance


  • Rubella Vaccine:

  • Composition Live virus

  • Efficacy 95% (Range, 90%-97%)

  • Duration of
    Immunity Lifelong

  • Schedule At least 1 dose

  • Should be administered with measles and mumps as MMR or with measles, mumps and varicella as MMRV


  • Rubella Vaccine (MMR) Indications:

  • All infants 12 months of age and older

  • Susceptible adolescents and adults without documented evidence of rubella immunity

  • Emphasis on nonpregnant women of childbearing age


  • MMR Adverse Reactions:

  • Fever 5%-15%

  • Rash 5%

  • Joint symptoms 25%

  • Thrombocytopenia <1/30,000 doses

  • Parotitis rare

  • Deafness rare

  • Encephalopathy <1/1,000,000 doses

  • Rubella Vaccine Arthropathy:

  • Acute arthralgia in about 25% of vaccinated, susceptible adult women

  • Acute arthritis-like signs and symptoms occurs in about 10% of recipients

  • Rare reports of chronic or persistent symptoms


Population-based studies have not confirmed an association with rubella vaccine

MMR Vaccine Contraindications and Precautions:

1- Severe allergic reaction to vaccine component or following a prior dose

2- Pregnancy

3- Immunosuppression.

4- Moderate or severe acute illness.


Vaccination of Women of Childbearing Age:

Ask if pregnant or likely to become so in next 4 weeks

Exclude those who say "yes"

For others

- explain theoretical risks

- vaccinate


Isolation of the hospitalized patients:

For postnatal rubella, droplet precautions are recommended for 7 days after the onset of rash. Contact isolation is indicated for children with proven or suspected congenital rubella until they are one year of age, unless nasopharyngeal and urine culture results after three months of age repeatedly negative for rubella virus.

Preventive Measures:

1. Educate the general public on mode of transmission , and stress the need for rubella immunization, health care provider must be aware of the risks caused by rubella in pregnancy.

2. WHO recommend use of vaccine in all countries where control or elimination of CRS is considered a public health priority.

Two approaches are recommended to prevent the occurrence of CRS:


a) Prevention of CRS only , through immunization of adolescent girls or women in childbearing age.

b) Elimination of rubella as well as CRS through universal immunization of infants and ensuring immunity in women of childbearing age For increased impact men should be vaccinated

Control of patient, contacts and the immediate enviruments

1. Report to local health authority: in countries where rubella eradication is a goal, all cases of rubella and CRS should be reported.

2. Isolation: In hospital, patients with rubella should be managed under contact isolation precautions. Exclude children from school and adult from work for 7 days after onset of rash.

3. Concurrent disinfection: Not applicable

4. Quarantine : Not applicable


5. Immunization of contacts: Immunization of contacts will not necessarily prevent the infection or illness . Passive immunization with IG is not indicated .

6. Investigation of contact and source of infection .

7. Specific treatment : None, only supportive.


Saif AlDeen Adil Kamil



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