Rubella (Rubellas)

Rash of rubella on back (crop)[1]

Rubella is a contagious, usually mild viral infection that is seen most often in children and young adults.


Presentation

The clinical features [7] are largely determined by age, with symptoms being mild or absent in children under 5 years. The peak incidence of the disease is at 15 years. During the prodrome the patient complains of malaise and fever. Mild conjunctivitis and lymphadenopathy may be present. The distribution of lymphadenopathy is characteristic and involves the suboccipital, postauricular and posterior cervical group of lymph nodes. Small petechial lesions on soft palate (Forchheimer spots) are suggestive but not diagnostic. Splenomegaly may be present.

The exanthematous or eruptive phase usually occurs within the first 7 days of the initial symptoms. The rash first appears on the forehead and then spreads to involve the trunk and the limbs. It is pinkish red, macular and discrete although some lesions may coalesce. The rash usually fades by the second day and rarely persists beyond the third day after its appearance.

Congenital rubella syndrome [8] is characterized by the presence of fetal cardiac malformations especially patent ductus arteriosus and ventricular septal defect, eye lesions especially cataracts, microcephaly, mental retardation and deafness. The classic triad consists of sensorineural deafness, ocular abnormalities and cardiac malformations.

Workup

The diagnosis [9] maybe suspected clinically but laboratory diagnosis is essential to distinguish the illness from other viral infections such as Echovirus and drug rashes. Clinically, the rash will appear first on the face and then spread to the rest of the body. The child maybe febrile and may present with posterior cervical lymphadenopathy. Adults and older children may present with coryza, pain in the joints and swollen glands.

Laboratory tests are demonstrated by a rising antibody titer in two successive blood samples taken 14 days apart or by the detection of rubella specific IgM. The virus can be cultured from throat swabs, urine and in the case of intrauterine infection, the products of conception.

Treatment

Treatment is symptomatic and no specific treatment is available. The main goal is to reduce discomfort caused by the symptoms. Symptoms are not severe. Often no treatment is required. Isolation maybe advised especially to pregnant women.

Congenital rubella syndrome has to be managed in such a way to prevent complications. Surgery will be required for cardiac defects and cataract in case of pediatric rubella. If a pregnant woman gets infected with rubella, the risks should be communicated by the medical provider.

Prognosis

The outlook of postnatal rubella is good with full recovery and complications are very rare. Mortality and morbidity rates have reduced with effective vaccination. Possible complications are superadded pulmonary bacterial infection, arthalgia, hemorrhagic manifestations due to thrombocytopenia, encephalitis and the congenital rubella syndrome. Rubella affects the fetuses of 15 to 30% [6] of all women who contract this infection during the first trimester. The incidence of congenital abnormalities diminishes in the second trimester and no ill effects result from infection in the third trimester.

Etiology

The condition is caused by the Rubella virus which is a togavirus that has a single strand of RNA genome and is enveloped by an icosahedral capsid. Humans are the only hosts to this virus. This virus belongs to family Togiviridae and genus Rubivirus. The main route of transmission is the respiratory system and the virus multiplies in the nasopharynx and lymph nodes. It spreads through close contact when a person sneezes or coughs or through direct secretions such as mucus [3].

It spreads similar to the common cold or measles viruses but is not as infectious as them. This virus has a long incubation period varying from 12 to 23 days. The patient is contagious typically one week prior to onset of rash and for a few days after the rash sets in.

This virus has the ability to cross the placenta, affect the developing fetus and prevent the cells from growing. It has teratogenic properties as well. With improved vaccines rubella is extremely rare now as children receive vaccination at an early age. Anyone who has received the vaccine will have permanent lifelong immunity against rubella. Children and especially women who never received vaccination should be careful of infection.

Epidemiology

The virus has a worldwide distribution [4]. It occurs generally in temperate climates, in winter and spring. Prior to vaccination era, epidemics used to occur every 6 to9 years in the United States affecting children between 3 to 5 years of age. Post vaccination no case of rubella has been observed in United States of America [5] since February 2009. As the virus can get reintroduced, vaccination needs to be continued still. Immunization has to be given universally to maintain the herd immunity. Unimmunized travelers stand at a risk of infection. Congenital rubella syndrome was a major cause of concern as it causes deafness and other abnormalities, thus pregnant females who are not immunized are also at a high risk. These women get their infection from contacts who are not immunized at all.

Rubella affects all races and ethnic backgrounds. It is seen to affect women more than men. Complications of rubella are also seen more in females. School going children have a predilection to being infected, especially between the ages of 5 to 9 years, though now it has drastically reduced thanks to availability of vaccines.

An outbreak of rubella is more frequent in developing countries due to unavailability of vaccines. Rubella is now mainly of concern in pregnant females rather than children and men. In case of an outbreak, immunization is recommended irrespective of immune status.

Sex distribution
Age distribution

Pathophysiology

The site of entry for this virus is the respiratory epithelium of the nasopharynx. The aerosol particles of the respiratory secretions carry these viral particles from the infected person to other contacts.

Once the virus enters, it attaches to the respiratory epithelium, spreads via the bloodstream to the surrounding lymph nodes and multiplies in the reticuloendothelial system. This is the initial spread of virus which is followed by dissemination to other tissues that usually commences 6 to 20 days after the onset of infection. The viral load in the body peaks just prior to onset of the rash and then disappears shortly afterwards. Thus, the incubation period usually lasts for 14 to 21 days, a person being contagious seven days prior and four days after the onset of symptoms. The rate of infection is highest just on the day and the day before symptoms appear.

Transplacental transmission usually occurs when there is maternal viral load as a result the fetus cells gets affected. The exact mechanism of feral damage after infection is still not clearly understood. It is suggested that fetal cells infected with rubella virus show reduced levels of mitotic activity as a result developmental defects occur.

Prevention

Prevention of rubella is important. Human immunoglobulin can reduce the symptoms of this mild illness, but does not prevent the teratogenic effects. Several live attenuated rubella [10] vaccines have been used with great success in preventing this illness and have been successfully combined with measles and mumps vaccine (MMR vaccine). WHO recommends a dose at 12 to 15 [11] months followed by booster doses at 4 to 6 years. Due to high levels of morbidity in India, MMR vaccine is first given at 9 months followed by booster doses at 18-36 months followed by 4-6 years. The side effects of vaccination have been dramatically reduced by using vaccines prepared in human embryonic fibroblast cultures (RA27/3 vaccine). Use of the vaccine is contraindicated during pregnancy or if there is a likelihood of pregnancy within 3 months of immunization. Vaccination should be given immediately in postpartum period [12].

Summary

Rubella is an infectious viral disease also commonly known as German measles or three day measles. The causative agent is a spherical enveloped fragile RNA virus that is easily killed by heat and ultraviolet light. The disease can happen sporadically though epidemics are not uncommon. It is characterized by a specific red rash and lasts for one to three days and often goes unnoticed. The rash is similar to measles but both are caused by different viral agents. It is generally a childhood infection which is rarely fatal. It is more of a serious health risk if it affects pregnant females especially in the first trimester, as it can result in miscarriage or severe birth defects. Congenital rubella is the result when the infection is transmitted to the unborn fetus.

Acquired infection occurs through spread of virus via droplets; maximum infectivity occurs before and during the time the rash is present [1]. Rubella is normally a trivial infection, which does not have any carrier state and the reservoir is only the active human cases. The virus [2] gets eliminated rapidly and if persists in infants with congenital rubella, is only a source of concern for spreading infection to other infants and more so to pregnant female contacts.

With widespread immunization, rubella is almost extinct with very few cases. Cases of rubella are nowadays more seen in young non-immunized adults than children.

Patient Information

Rubella is a disease caused by a virus called Rubella virus. It is highly infectious and is also known as German measles or 3 day measles. The patient usually presents with fever, cough, sore throat and skin rashes which are very similar mot measles but both are caused by different viruses. This was earlier a disease of childhood, but with effective vaccination there is a drastic drop in the number of cases. It is now a main concern for pregnant women as if they get infected it can cause severe developmental defects in the unborn child. This results in a condition known as congenital rubella syndrome. This condition requires specialists and surgeries to correct the malformations. Spontaneous abortion and miscarriage are common in pregnant women infected with this virus.

This viral disease is spread through droplet by coughing, sneezing or coming in contact with respiratory secretions of the infected individual. This condition lasts only for 3 days and sometimes goes unnoticed without any treatment as they resolve on their own.

Any pregnant women who gets infected with this virus especially in the first trimester should consult her obstetrician immediately. Immunization is the only way to prevent this disease. Vaccination should be given to all children and child bearing women who have never got any immunization.

Self-assessment

Ask Question


5000 Characters left Format the text using: # Heading, **bold**, _italic_. HTML code is not allowed.

References

  1. Bialecki C, Feder HM Jr, Grant-Kels JM. The six classic childhood exanthems: a review and update. J Am Acad Dermatol. Nov 1989;21(5 Pt 1):891-903.
  2. Cherry JD. Viral exanthems. Curr Probl Pediatr. Apr 1983;13(6):1-44.
  3. Miller E. Rubella reinfection. Arch Dis Child. Aug 1990;65(8):820-1.
  4. CDC. Provisional cases of infrequently reported notifiable diseases. MMWR. January 9, 2009;57(53):1420-1431.
  5. CDC. Reported Cases of Notifiable Diseases-United States, 1972-2003. MMWR. Apr 2005;52(54):73-78.
  6. Dontigny L, Arsenault MY, Martel MJ et al. Rubella in pregnancy. J Obstet Gynaecol Can. Feb 2008;30(2):152-68.
  7. Cherry JD. Contemporary infectious exanthems. Clin Infect Dis. February 1993;16(2):199-205.
  8. Cherry JD. Rubella virus. In: Feigin RD, Cherry JD, eds. Textbook of Pediatric Infectious Diseases. Vol 2. 4th ed. WB Saunders Co; 1998:1922-49.
  9. Morgan-Capner P. Diagnosing rubella. BMJ. Aug 5 1989;299(6695):338-9.
  10. Watson JC, Hadler SC, Dykewicz CA et al. Measles, mumps, and rubella--vaccine use and strategies for elimination of measles, rubella, and congenital rubella syndrome and control of mumps: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep. May 22 1998;47(RR-8):1-57.
  11. Parkman PD. Making vaccination policy: the experience with rubella. Clin Infect Dis. Jun 1999;28 Suppl 2:S140-6.
  12. Wharton M, Cochi SL, Williams WW. Measles, mumps, and rubella vaccines. Infect Dis Clin North Am. Mar 1990;4(1):47-73.

Media References

  1. Rash of rubella on back (crop), Public Domain

Languages