www.elitecme.com | 2019 | INFECTIOUS DISEASE, DISASTER PLANNING & WOUND CARE 27 Rubella, also known as German measles or the “three-day measles,” stems from an infection by a RNA virus classified as a “Rubivirus.” This virus belongs to the Togaviridae family. Rubella is a viral illness that can be serious and may lead to compli- cations, including death. The clinical diagnosis of rubella is unreli- able—as many as half of infections present as “subclinical” or not apparent. The rash associ- ated with rubella often resembles rashes that are caused by other illnesses; this often pre- vents the recognition of the disease. Prior to the licensure and availability of the rubella vaccine in 1969, the disease was common, particularly in young chil- dren. Epidemics were relatively frequent and occurred every six to nine years. The largest number of cases occurred in the spring. In 2004, rubella was officially eradicated in the U.S.; however, it still is present and is transmissible in several global regions. It is estimated that 100,000 infants worldwide are born each year with congenital rubella syn- drome (CRS). Since the elimination of the dis- ease was declared, less than 10 cases occur domestically each year and are contracted primarily through international importa- tion. This represents a 99% reduction in the occurrence of rubella since the era preceding the availability of an effective vaccine product (CDC, 2017-6). HISTORY OF RUBELLA Rubella was long considered to be a vari- ant of scarlet fever (or measles) and was often referred to as “third disease.” It was first considered a separate disease when described in German medical literature in 1814, thus creating the term “German measles.” Hess hypothesized in 1914 that rubella was a viral illness. This hypothesis was confirmed in 1938 by Hiro and Tosaka through the demonstration that the disease could be passed between children with nasal washings obtained from an infected person. The name rubella is derived from Latin, meaning “little red.” In 1941, an Australian ophthalmologist, Norman Gregg, reported the occurrence of congenital cataracts in 78 infants born to mothers who were infected with rubella in the early parts of their preg- nancy. This was the first report of congen- ital abnormalities related to the infection of pregnant women with rubella. Researchers Parkman and Weller first isolated the rubella virus in 1962 (Dawe), which then led to the licensure of the initial rubella vaccine in 1969 (CDC, 2017-6). EPIDEMIOLOGY OF RUBELLA Rubella first became a nationally reportable disease in 1966. The year with the great- est number of reported cases of rubella in the U.S. was 1969 when 57,686 cases were reported, equating to a frequency of 58 cases per 100,000 population. The rubella vaccine was released that same year, which rapidly decreased the number of reported cases. Fewer than 1,000 cases per year were reported by 198: less than 0.5 instances per 100,000 population. Outbreaks of rubel- la occurred in 1990 and 1991 among the Pennsylvania Amish, and then separately in California. The occurrence of rubella outbreaks has steadily declined since then. Record low annual rubella reports occurred in 2003. This prompted the CDC to re-evaluate the preva- lence of rubella in the U.S. The CDC declared rubella to no longer be endemic in the U.S. in 2004. Between 1982 and 1992, there were three main age groups that were experiencing rubella infections: children under five, chil- dren ages five to 14, and adolescents and adults from 15 to 39 years old. Less than 10% of rubella cases occurred in adults over 40. Nevertheless, since the U.S. eradication of rubella in 2004, 60% of rubella cases occurred in persons aged two to 49 years with a median age of 32 years (CDC, 2016-2). SYMPTOMS OF RUBELLA In acquired rubella, the rubella virus is transmitted through the respiratory route; the nasal passages and nearby lymph nodes are thought to be the locations of viral rep- lication. Rubella has an average incubation period of 14 days, although it can range from 12 to 23 days. Symptoms of acquired rubella are commonly mild: as many as half of infections present without symptoms (CDC, 2016-2). Children with rubella often present with rash as their first symptom; however, chil- dren often do not experience early symptoms. Older children and adults often experience a one- to five-day period of symptoms before a rash occurs. These symptoms can be charac- terized by malaise, low-grade fever, swelling of the lymph nodes, conjunctivitis, eye pain when looking up, a rash on the soft palate at the upper back of the mouth, nausea, and upper respiratory symptoms (CDC, 2016-2). The rubella skin rash often occurs 14 to 17 days after exposure. The rash begins on the face and then progresses downward toward the feet over the course of 24 hours. It is often described as a rose-pink, maculopapular rash, characterized by a flat, red area of the skin cov- ered by small bumps, similar to the measles rash. It is occasionally itchy and commonly lasts for three days. The rubella rash begins to fade after the second day and disappears by the end of the third day. This gives rise to the name “three-day measles” (CDC, 2016-2). Swelling of the lymph nodes can begin a week before the onset of rash and can con- tinue for several weeks after the rash’s resolu- tion (CDC, 2016-2). Arthralgia and arthritis, once thought to be complications of rubella, are so frequent in adults that they are now considered to be symptoms of rubella. Arthritis and arthralgia can occur in up to 70% of adult women with rubella, although this symptom rarely occurs in children and adult men. The most com- monly affected joints are the wrists, fingers, and knees. Symptoms in the joints often occur simultaneously or shortly after the rubella rash and can last for up to 30 days. The devel- opment of chronic arthritis due to a rubella infection is rare (CDC, 2016-2). Rubella is considered to be only moder- ately contagious. Its peak transmissibility is at the onset of its rash. It is critical, however, to recognize that viral shedding can occur from seven days before, until five to seven days (or longer) after the rash’s onset. Transmission of the rubella virus can also occur in asymp- tomatic or subclinical patients. Hospitalized rubella patients should be on droplet precau- tions for seven days after the onset of a rash (CDC, 2016-2). SELF-ASSESSMENT QUESTION Answers are listed on the last page of the course. 7. Arthritis and arthralgia can occur in up to ______% of adult women with rubella. |  CONTINUING EDUCATION