Congenital Rubella Syndrome. Name. English 012 Section 35. Professor Paul Marchbanks. September 29, 2005

Transcription

1 Congenital Rubella Syndrome Name English 012 Section 35 Professor Paul Marchbanks September 29, 2005

2 1 Congenital rubella syndrome, by definition, is a group of physical abnormalities that occur in an infant as a result of infection of the mother with the rubella virus. 1 Rubella, which is otherwise known as the German measles, is a virus that spreads throughout the body via the bloodstream. 2 The virus is spread through the air, or by close contact. Most people associate rubella with a rash which spreads over the entire body. There is an inoculation for the rubella virus, but it is only scarcely received in the United States because there is such a low rate of infection throughout the country. Expectant women, or those who may become pregnant, who are traveling outside of the United States may come into contact with this virus, enabling them to transmit it to the fetus. Although infection of the fetus may occur at any time in the pregnancy if the mother becomes infected with rubella, the first trimester is the most critical time. In cases where the mother was infected within the first trimester, eighty percent of the infants were born with CRS. 2 There are various tests that can be performed on the expectant mother and her fetus to make a prenatal diagnosis for congenital rubella syndrome, which would allow for possible abortion and/or treatment planning. One such test is amniocentesis, which is generally performed between the fifteenth and twentieth week of pregnancy. 2 Taking and testing a sample of the fetal blood is also an option, and is done during the second trimester while the fetus is still small in size. 2 Chorionic villus samples (CVS) are also used to biopsy placental cells, usually around the 10 th week of pregnancy. 2 All of these testing options carry a generally low risk of miscarriage related to the test, with fetal blood sampling providing the highest risk at two percent. 2 Amniocentesis is the safest of all these procedures, with only a one-fourth to one-half percent risk of miscarriage. 2

3 2 Infection of the fetus with rubella can result in abortions, miscarriages, stillbirths, and many birth defects. 3 Birth defects that can result from congenital rubella syndrome include cataracts, glaucoma, retinitis, microcephaly, heart defects, mental and motor retardation, seizures, deafness, developmental delay, and various others. These clinical manifestations of CRS can generally be divided into three groups. 2 The first of these are the symptoms that are directly related to the virus, and are seen immediately at birth but are generally not permanent. 2 Some of these symptoms include low birth weight, bone lesions, thrombocytopaenic purpura (otherwise known as blueberry muffin infant, where purplish dots cover the body), and others. The second group of symptoms is developmental defects, some of which may be delayed and only appear as the infant approaches adolescence. 2 Vision and hearing are most often affected in this delayed manner, with deafness, glaucoma, and cataracts some of the most common side effects of CRS. Other defects in this category include cardiac abnormalities and defects in the central nervous system, such as mental retardation. The third category of these symptoms is late onset and permanent. 2 Some of the symptoms include diabetes, mental retardation, growth retardation, learning disabilities, behavioral issues, and others. 2 Also, about six percent of infants born with CRS show signs of autism. 4 The multiple symptoms of congenital rubella syndrome range from very serious and permanent to easily correctable. Children infected with congenital rubella syndrome are affected by their disease other than in purely physical aspects. These children also encounter social, communication, and mobility hindrances due to disabilities caused by CRS. Some social effects of CRS symptoms include behavioral issues, signs of autism, and learning disabilities which could potentially separate the child from their peers. Often these children are placed into special classes, or even special schools, where they are only exposed to children of their same situations.

4 3 Communication skills, such as listening and proper speech, are also impaired due to the deafness that sometimes accompanies CRS. Another major problem facing CRS patients are mobility issues. These are typically due to untreated visual symptoms such as glaucoma and cataracts. Without treatment these symptoms can lead to blindness, which in turn affects the ease with which the patients may be mobile. Due to new breakthroughs in science, as well as more emphasis on sanitary conditions, the number of incidences of rubella have drastically declined, especially in the United States. The availability of the MMR vaccine is also a large factor in the immense decline. Because fewer adults are being infected with this disease, the number of infants of CRS has also been in a steady decline. Between 1970 and 1996, the number of cases of CRS in the US dropped more than 97.4%. 3 Since 2001, rubella and CRS numbers have dropped to an all-time low. Between 2001 and 2004, only four cases of congenital rubella were reported, with only three of the mothers being born outside the United States. 5 Because of the low occurrence of the disease, as well as its rare distribution inside the United States, rubella and CRS are no longer considered a serious threat in America. 5 As is well known, there is no treatment for the actual eradication of the CRS virus in infants, although there are various supportive treatments for individual symptoms. Some of these treatments include surgery to correct glaucoma and/or cataracts, respiratory support, surgery to correct heart defects, vision and hearing screening/ correction, as well as others. 6 Lauren Thompson, 6 months old, was born in March with congenital rubella syndrome. Her mother contracted rubella while on a mission trip to Africa while she was two months pregnant. Lauren was fortunately born with only a few symptoms, mostly symptoms affecting her vision. She experienced some of the initial symptoms, such as a low birth weight, but she was also

5 4 diagnosed with glaucoma. Knowing that glaucoma can cause blindness if left untreated, Lauren s parents began to look into possible treatment options for their daughter. Surgery would be the best option for the treatment of Lauren s symptoms, with a choice between laser surgery and filtering microsurgery. 7 The filtering microsurgery creates a small drainage area, which requires a slight incision. 7 Because of Lauren s young age, laser eye surgery would be a more feasible option, because it requires no incision. This surgery requires only a slight numbing of the eye, and causes very little pain, usually only a small stinging sensation. With laser eye surgery, a laser beam shines a bright light into the eye, clearing up the glaucoma. Benefits of this type of treatment include the reduced amount of pain, a quick recovery time, and only a few low-level risks involved. Generally, patients are able to resume their normal activities, and remain unaffected by natural light by the day following their surgery. Laser treatment involves few risks, those including a possible short-term increase in intraocular pressure (IOP), or the possibility of the IOP becoming too low to keep the eye s normal shape. 7 Although this surgery will not eliminate the possible need for medication to maintain eye pressure, it will reduce the amount of medication needed. 7 This particular treatment for one symptom of congenital rubella syndrome would be very beneficial to Lauren, as well as a useful treatment for all infected infants with glaucoma. It is a relatively inexpensive treatment, which requires no hospital stay, and is relatively easy on the body. Any patient undergoing this surgery should experience few side effects and be able to tell an obvious difference in their sight. Because glaucoma and other vision problems are some of the most common symptoms associated with CRS, this treatment option is widely used and critical to the well-being of CRS infants. This treatment would allow Lauren, as well as many others, the opportunity to see things clearly and to be active in their daily lives. Also, they can

6 5 live without the stigma of being blind throughout their lives, and avoid any social ostracism they could face due to their disability. Congenital rubella syndrome, although now almost eradicated throughout the United States, can lead to serious problems for those few infected. A main goal in the medical field should be to continue its progress in vaccination, as well as promote and expand upon treatments for the symptoms of rubella. Rubella is a disease that can be cured if enough steps are taken, and is a disease whose eradication would greatly benefit the world.

7 6 References Section 1 Medline Plus [Internet]. Bethesda, MD: U.S. National Library of Medicine; [updated 2004 Jan 21; cited 2005 Sept 24]. Available from: 2 Desmond M, Schoub D. In: Newell M, McIntyre J, editors. Congenital and perinatal infections. New York: Cambridge University Press; p A-Z Deaf/Blindness: Chapter 12: Congenital Rubella Syndrome [Internet]. [updated 2002 Sept 17; cited 2005 Sept 24]. Available from: 4 Casalez D, Marlow N. In: Jeffries DJ, Hudson CN, editors. Viral infections in Obstetrics and Gynaecology. London: Arnold Publishers; New York: Oxford University Press; p Achievements in Public Health: Elimination of Rubella and Congenital Rubella Syndrome--- United States, [Internet]. CDC: MMWR Weekly; [updated 2005 March 25; cited 2005 Sept 24]. Available from: 6 emedicine [Internet]. Multiple anonymous sources and authors.[updated 2004 Nov 2; cited 2005 Sept 24]. Available from: 7 Glaucoma Surgery [Internet]. Glaucoma Research Foundation; [cited 2005 Sept 24]. Available from: