References:
- Global Infectious Diseases and Epidemiology Online Network: Infectious Diseases of the Philippines, 2013 eBook Edition, ISBN 978-1-61755-582-4, by Stephen Berger. Accessed here.
| Agent | VIRUS - RNA. Togaviridae: Rubella virus |
| Reservoir | Human |
| Vector | None |
| Vehicle | Contact Air Transplacental |
| Incubation Period | 16 to 18 days (As early or late as 14 to 23 days) |
| Diagnostic Tests | Viral culture (throat, urine) Serology Nucleic acid amplification |
| Typical Adult Therapy | Respiratory precautions. Supportive |
| Typical Pediatric Therapy | As for adult |
| Vaccines | Rubella Rubella-Mumps Measles-Mumps-Rubella Measles-Rubella |
| Clinical Hints | Maculopapular rash following a one-day prodrome of coryza and headache; post auricular lymphadenopathy; arthralgia and arthritis encountered in adults; severe thrombocytopenia or encephalitis may follow acute infection. |
| Synonyms | Epidemic roseola, German measles, Roda hund, Rode hond, Rode hunder, Rodehond, Rosolia, Roteln, Rubeola (Spanish), Three-day measles |
CDC Case Definition for Surveillance
A case is defined as an illness that has all the following characteristics:
- Acute onset of generalized maculopapular rash
- Temperature >37.2 C if measured
- Arthralgia/arthritis, lymphadenopathy, or conjunctivitis. Arthropathy may occur in as many as 41% of cases.
A “confirmed” case requires either laboratory confirmation or epidemiological link to a laboratory-confirmed case.
- Atypical features may be seen in adults with rubella; i.e., hepatitis, conjunctival hemorrhage, uveitis, retinitis and a high incidence of polyarthritis.
- Rare instances of acute hepatic failure and hemophagocytic syndrome are reported.
Congenital rubella should be suspected if any of the following is present in a newborn infant:
- Cataracts (45% of cases), congenital glaucoma, pigmentary retinopathy
- Congenital heart disease (70%, most commonly patent ductus arteriosus or pulmonary artery stenosis) Both anomalies may appear concurrently in up to 50% of cases.
- Hearing loss (35% to 60%)
- Purpura
- Splenomegaly
- Jaundice
- Microcephaly, mental retardation 11 , meningoencephalitis
- Radiolucent bone disease
- Duodenal stenosis
The chance of fetal defects from a viremic mother is 40% to 90% during the first trimester.
- Infection also increases the risk for spontaneous abortion and miscarriage by 50%.
- The rate of congenital rubella syndrome during epidemics is 0.5 to 2.2 per 1,000 live births.
- 60% of children with CRS have hearing impairment, 45% congenital heart disease, 27% microcephaly, 25% cataracts, 23% low birth weight (< 2,500 grams), 17% purpura, 19% hepatosplenomegaly, 13% mental retardation and 10% meningoencephalitis.
Anterior Uveitis Differential Diagnosis
Anterior uveitis due to Rubella virus is characterized by younger age at onset and a chronic course, typically associated with cataract at presentation.
- Rubella virus has been implicated in the etiology of Fuchs heterochromic iridocyclitis.
- Anterior uveitis due to Herpes simplex and Varicella-Zoster viruses is more common in adults, and often follows an acute course.
- Herpes simplex anterior uveitis presents with conjunctival redness, corneal edema, a history of keratitis, and the presence of posterior synechiae. Anterior chamber inflammation is common with Herpes simplex virus, while vitritis is more common with Rubella and Varicella-Zoster virus.
- Rubella, Herpes simplex and Varicella-zoster viruses are associated with intraocular pressure of more than 30 mmHg and development of glaucoma (18%-30%; P = 0.686).
- Focal chorioretinal scars were present in 22% of Rubella cases, 0% of HSV and in 11% of VZV uveitis cases.