Rubella (German Measles) is a viral childhood infection with low-grade fever, posterior auricular & cervical adenopathy, and maculopapular rash, clinically indistinguishable from measles, dengue, erythema infectiosum, roseola, scarlet fever and other febrile exanthems. It is vaccine preventable.
CASES/YEAR
40 (US); 1,200,000 (Global)
OTHER NAMES
German measles;
INCUBATION
14 days; range of 12-23 days; [Cecil, p. 2171]
INITIAL SYMPTOMS
Low-grade fever; posterior auricular and posterior cervical adenopathy; and maculopapular rash, clinically indistinguishable from measles, dengue, erythema infectiosum, roseola, scarlet fever and other febrile exanthems; [CCDM]
PRECAUTIONS
"To prevent transmission of rubella in health-care settings, patients suspected to have rubella should be placed in private rooms. In addition to standard precautions, droplet precautions should be followed until 7 days after onset of symptoms. Room doors can remain open, and special ventilation is not required." [ACIP, 2011]
COMMENTS
FINDINGS:
The infection is asymptomatic or without fever in up to 50% of cases. Children usually present with the rash, while adults usually have 1-5 days of mild prodromal symptoms (low-grade fever; malaise, headache, cervical adenopathy; rhinitis, and conjunctivitis) preceding the rash. Arthralgia and arthritis are fairly common complications, particularly among adult females. Thrombocytopenia may occur. Encephalitis and hemorrhagic manifestations are rare. [CCDM, p. 527] Adenopathy in postnatal rubella may last for several weeks and commonly affects the posterior cervical, posterior auricular, and suboccipital nodes. The maculopapular rash is not confluent. Fever, if present, usually resolves by the second day of the rash. [PPID, p. 2009]
PREVENTION:
Hospitalized or institutionalized patients should be isolated with care taken not to expose pregnant, non-immune employees. Patients should be excused from school or work for 7 days after onset of the rash. 90% of babies are affected with congenital rubella syndrome (deaf, blind, mentally retarded, etc.) when the mothers are infected in the first 10 weeks of pregnancy. [CCDM, p. 531] "Although birth before 1957 is generally considered acceptable evidence of rubella immunity, a dose of MMR has been recommended for those health care personnel that do not have laboratory evidence of immunity." [Guidelines for Infection Control in Health Care Personnel. CDC. 1998] "Any exposed HCP who do not have adequate presumptive evidence of rubella immunity should be excluded from duty beginning 7 days after exposure to rubella and continuing through either 1) 23 days after the most recent exposure or 2) 7 days after rash appears if the provider develops rubella. Exposed HCP who do not have adequate presumptive evidence of immunity who are vaccinated postexposure should be excluded from duty for 23 days after the most recent exposure to rubella because no evidence exists that postexposure vaccination is effective in preventing rubella infection." [ACIP, 2011]
DIAGNOSTIC
IgM ELISA test; Paired sera; PCR positive before IgM antibodies; A mild disease & difficult to diagnose clinically. [PPID, 2007, 2010] "The only reliable evidence of previous rubella infection is the presence of serum rubella IgG antibody." [ACIP, 2011]
SCOPE
Global; Endemic rubella has been interrupted in the Americas, but the disease is widespread in Africa, the Middle East, and Southeast Asia; Median of 6 imported cases/year from 2013-2015 iin the United States; [CDC Travel]
SIGNS & SYMPTOMS
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>arthralgia
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>fever
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E pharyngitis
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E rhinitis
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G blood in stool
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G liver function test, abnormal
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G nausea, vomiting
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H leukopenia
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H lymphadenopathy
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H splenomegaly
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H thrombocytopenia
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N headache
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O conjunctivitis, acute
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R cough
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S papules or plaques
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S petechiae and ecchymoses
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S rash (exanthem)
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*arthritis
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*encephalitis
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*epididymo-orchitis
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*hepatitis
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*myelitis
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*myocarditis
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*uveitis
ENTRY
Inhalation, Skin or Mucous Membranes (Includes Conjunctiva)
RISK FACTORS
- Care for patients (droplet/airborne)
- Fail to complete immunizations
- Live together in close quarters
- Travel to endemic area
TREATMENT
No specific treatment; [CCDM, p. 531]
REFERENCES FOR CASES/YEAR
1. (US) Published in MMWR 2011 = 4; In 1964-1965, an epidemic produced 12.5 million cases and about 20,000 cases of congenital rubella syndrome. Since 2001, endemic transmission of rubella has been interrupted in the US. [Harrison ID, p. 934] Use correction factor of 10 for reported diseases: 4 X 10 = 40;
2. (Global) 110,000 babies with congenital rubella syndrome (CRS) every year; [Fact sheets from WHO 2013] Reported cases have decreased from 875,000 in 1999, to 120,000 in 2009, and to 22,000 in 2016; [Cecil, p. 2170] Use correction factor of 10 for reported diseases: 22,000 X 10 = 220,000;