Mumps (Infectious parotitis)

Mumps Acute viral illness Parotitis and orchitis described by Hippocrates in 5th century B.C. Viral etiology described by Johnson and Goodpasture in 1934 Frequent cause of outbreaks among military personnel in prevaccine era Like measles, mumps is an acute viral illness. Hippocrates was the first to describe the clinical picture of mumps in the 5th century BC. In 1934, Johnson and Goodpasture identified the etiologic agent of mumps as a virus. Although mumps was generally thought of as a disease of childhood, it was also a frequent cause of outbreaks among military personnel in the pre-vaccine era. During WWI, only influenza and gonorrhea were more common causes of hospitalization. Outbreaks are still occurring among military personnel. The last one I’m aware of was on board a ship in the western Pacific in 1992.

What is mumps? It is a disease caused by the mumps virus. Who gets mumps? Past infection with mumps makes a person immune to mumps; most people born before 1957 most likely have already had mumps. In addition, people who receive two doses of the mumps vaccine are much less likely to be infected. The greatest risk of infection occurs among older children, adolescents, and adults.

Mumps Virus Paramyxovirus It is a single-stranded RNA virus One antigenic type Rapidly inactivated by chemical agents (formalin, ether, chloroform), heat and ultraviolet light. .

How is mumps spread? Mumps is spread in droplets from the nose or throat of an infected person, usually when a person coughs or sneezes. Mumps can also spread by direct contact with saliva and discharges from the nose and throat of an infected person.

Mumps Clinical Features Incubation period 14 - 18 days Nonspecific prodrome of low-grade fever, headache, malaise, myalgias Parotitis in 30% - 40% Up to 20% of infections asymptomatic May present as lower respiratory illness, particularly in preschool-aged children Mumps is generally a mild disease but may be severe with some unpleasant consequences. The virus has a predeliction for glandular tissues (e.g. parotid glands, ovaries, testes, pancreas) and nerve tissue. It has a 14-18 day incubation period and typically begins with a prodrome of nonspecific symptoms including low grade fever, headache, malaise and myalgias. The typical swollen parotid glands (either unilateral or bilateral) occurs in 30-40% of cases. Up to 20% of infections are asymptomatic while 40-50% of patients may have respiratory symptoms, particularly children younger than 5 years of age who may develop lower respiratory illnesses.

About one in three persons infected with mumps virus do not have any signs or symptoms of illness. The most common signs and symptoms of mumps include fever, headache, and swelling and tenderness of one or more salivary glands. Swelling of the testicles occurs in 20-30% of infected males - this does not usually result in sterility.

Mumps can also cause central nervous system disorders such as encephalitis (inflammation of the brain) and meningitis (inflammation of the covering of the brain and spinal column). Other complications include miscarriage of a pregnancy, arthritis, pancreatic involvement, or deafness. How soon after infection do signs and symptoms occur? Signs and symptoms of mumps usually appear within 18 days after exposure, but may appear any time within 12 to 25 days after exposure.

When and for how long is a person able to spread mumps? Mumps is contagious from three days before until five days after the onset of swelling. What is the treatment for mumps? Supportive care to relieve symptoms may include applying intermittent ice or heat to the affected neck area, and pain relievers. Warm salt water gargles, soft foods, and extra fluids may also help. Avoid fruit juice or acidic foods, since these stimulate the salivary glands, which can be painful.

Mumps Complications CNS involvement 15% of clinical cases Orchitis Pancreatitis Deafness Death 15% of clinical cases 20% - 50% in post- pubertal males 2% - 5% 1 / 20,000 1 - 3 / 10,000 Symptomatic meningitis occurs in up to 15% of patients, usually resolving without sequelae in 3-10 days. Adults are at higher risk for this than children, and males at higher risk than females. Testicular inflammation occurs in up to 50% of postpubertal males. About half of these patients are left with some degree of testicular atrophy but sterility is rare. Pancreatitis only occurs in about 2-5% of patients. No causal relationship between mumps and diabetes has been conclusively demonstrated. Deafness caused by mumps is rare and is usually unilateral. Death is also rare with an average of 1 death from mumps per year from 1996-2000.

Mumps Epidemiology Reservoir Human Transmission Respiratory drop nuclei Subclinical infections may transmit Temporal pattern Peak in late winter and spring Communicability Three days before to five days after onset of active disease Humans are the only natural host for the mumps virus. The virus is transmitted via direct contact (such as saliva or infected droplets on surfaces) or by respiratory droplets and enters through the nose and mouth. Asymptomatic or nonclassical infections can also transmit the virus. Mumps peaks in late winter and spring but can occur year round. Patients are communicable 3 days before to 4 days after the onset of active disease.

During adulthood, infection is likely to produce more sever disease including orchitis. Death attributable to mumps is rare, the estimated case fatality rate is 3.8 per 10000. more than fatalities occur in people older than 19 years of age. Mumps infection during the first trimester of pregnancy is associated with an increased risk of spontaneous abortion.

There is no evidence exists that mumps infection during pregnancy causes congenital malformations. Peak incidence was between January and May Treatment: Supportive Isolation of the hospitalized patient: in addition to standard precautions, droplet precautions are recommended until 9 days after onset of parotid swelling. Control Measures: 1- School and child care : children should be excluded for 9 days from the onset of parotid swelling

2- Care of exposed people: vaccine not effective in preventing infection after exposure. However mumps vaccine can be given after exposure, because Immunization will provide protection against subsequent exposure. .Immunization during the incubation period has no increased risk. Mumps Ig is of no value

Mumps Vaccine: This is generally given as measles-mumps-rubella (MMR) vaccine. MMR is usually given on or after a child's first birthday. A second vaccination is recommended, again in combination with measles and rubella vaccine, at 4-6 years of age. Persons of any age who are unsure of their mumps disease history and/or mumps vaccination history should be vaccinated, especially if they are likely to be exposed.

Mumps Vaccine Composition Live virus Efficacy 95% (Range, 90% - 97%) Duration of Immunity Lifelong Schedule 2 Doses (as MMR) Should be administered with measles and rubella (MMR) As with measles, the mumps vaccine produces an inapparent or mild noncommunicable infection. A single dose has a clinical efficacy of about 95%. The duration of immunity is thought to be more than 25 years, and is probably life-long in most people. The schedule calls for a single dose of mumps vaccine. However, since measles is recommended as a 2-dose series and we now use the combined MMR, children will be getting 2 doses of mumps vaccine as well. There is not much data on the immune response to the mumps and rubella components from a second dose of MMR. However, most persons who do not respond to the first dose of the mumps or rubella components would be expected to respond to the second dose.

Mumps Vaccine (MMR) Indications All infants >12 months of age Susceptible adolescents and adults without documented evidence of immunity As we discussed with measles, all infants should get one dose of MMR on or after their first birthdays followed by a second dose at least 4 weeks later but usually around 4-6 years of age. Susceptible adolescents and adult without documented evidence of immunity should also have at least 1 dose of a mumps-containing vaccine.

Second Dose Recommendations First dose of MMR at 12-15 months Second dose of MMR at 4-6 years Second dose may be given any time >4 weeks after the first dose The second dose is recommended at school entry at 4-6 months of age but may be given as soon as 4 weeks after the first dose. Children who have already received 2 doses of MMR at least 4 weeks apart, with the first dose administered no earlier than the first birthday, do not need an additional dose when they enter school, that is unless mandated by the states or schools.

Second Dose of MMR Vaccine Intended to produce immunity in persons who failed to respond to the first dose (primary vaccine failure) The second dose of MMR is recommended to produce immunity in those 2-5% who failed to respond the first dose. It’s not technically a booster dose, although the second dose may also boost antibody titers in some of those who did respond to the first dose.

What can be done to prevent the spread of mumps? The single most effective control measure is maintaining the highest possible level of immunization in the community. Children with mumps should not attend school, and adults should not work, until five days after swelling began or until they are well, whichever is longer. Measures such as covering coughs and sneezes, washing hands frequently, and not sharing food or eating utensils can also help. A person who may have had contact with a mumps case should be evaluated by their physician.

However High MMR vaccine coverage levels and vaccine effectiveness likely prevented thousands of additional mumps cases (9 out of 10 exposures that may have resulted in infection in 2 dose vaccinees prevented) Incidence relatively low Disease may be modified

Adverse Reactions: febrile seizures, nerve defness,meningitis, encephalitis, rash ,pruritis .orchitis and parotitis have been reported rarely. Precautions and Contraindications: 1- Febrile illness: fever is not contraindication to immunization . However if other manifestations suggest a more serious illness , the child should not be immunized until recovered .

2-Allergies 3- Recent administration of immune globulin: because high dose of Ig can inhibit the response to measles vaccine for longer intervals , MMR immunization should be deferred for a longer period after administration of IG. 4- Altered immunity : patients with immunodeficiency diseases or people receiving immunosuppressive therapy except patients with HIV infection. 5. Corticosteroids: the recommended interval is at least one month after steroids is discontinued. Pregnancy: live – virus mumps vaccine can infect the placenta but the virus has not been isolated from fetal tissue

However conception should be avoided for 28 days after mumps immunization. Out break control : Exclusion of susceptible students from affected schools judged by local public health authorities to be at risk of transmission should be considered.