Version 1.2 FAQs on Mumps in health care setting last updated 24/04/2009 Mumps Outbreak 2009 Questions and Answers for health professionals and health students working or gaining clinical experience in health care settings (Guidance to be used in addition to already prepared guidance on mumps for HCWs from Mumps OCT) Mumps control and prevention‐ general No postexposure prophylaxis for mumps is available. Passive immunisation with immune globulin is not recommended and has no role in outbreak control. Vaccination of exposed individuals does not prevent progression to infection but may prevent future infection. Isolation of cases together with mass vaccination of susceptible people is the most effective method of controlling outbreaks. How infectious is mumps? The number of secondary cases of infection expected to result from an index case of mumps in a fully susceptible population (R0 or basic reproduction number) is 10‐12. By comparison, measles—a notoriously infectious virus—has an R0 of 15‐17. What is the infectious period of a mumps case? Although the virus has been isolated from saliva from 2 to 7 days before parotitis and may persist for as long as 9 days after onset of disease, the maximum infectious period is considered to be from 3 days before to 5 days after symptom onset.(1) Have mumps outbreaks in health care settings been reported? Reports of mumps transmission in health care settings is rare but has been reported in the literature.(2) The fact that mumps transmission in the health care setting is uncommon is most likely a result of the relatively low infectiousness and transmission rate of mumps and the fact that hospitalisation for mumps is relatively uncommon. Prevention of mumps in hospitals or other health care settings and in third level colleges 1. All new HCWs or health students born since 1978 are recommended two doses of MMR* as proof of immunity (see separate guidance note circulated) 2. Exclude all HCWs/health students with active mumps illness from work until at least 5 days after onset of parotitis 3. Irrespective of their immune status, all exposed HCWs/health students should report any signs or symptoms of illness during the incubation period (from 12 until 25 days after exposure) to the Department of Occupational Health or student health service. Staff/students presenting with symptoms considered likely to be caused by mumps infection should be excluded from work. 4. All mumps cases should be isolated and treating HCWs/students should use standard precautions (including respiratory hygiene and cough etiquette) and transmission‐based droplet precautions while caring for patients with mumps. Version 1.2 FAQs on Mumps in health care setting last updated 24/04/2009 *Relevance of year of birth when considering immune status MMR vaccine was introduced in 1988 for young children. In 1992, a recommendation was made to provide this vaccine to all children 10‐14 years of age in the schools. Therefore, many children born in 1978 would have been vaccinated with one dose of MMR in 1992 following this recommendation. Serological studies of children aged 11‐14 years which was undertaken in Ireland in 1991‐1992 demonstrated evidence of measles and mumps antibodies in 95% and 65% of these children respectively. (3) The recommendation that reported serological immunity in those born before 1978 should be considered as a more accurate reflection of immunity than serological immunity in those born after this date may be relatively arbitrary, and may underestimate the immunity of the population born since this date. However, based on age specific incidence rate of mumps infection in Ireland since the outbreak began this cut‐off seems valid, as the highest ASIR in the current outbreak has consistently been in those < 30 years of age. HCWs exposed to mumps‐ recommended action based on risk assessment • Assess mumps immunity status of staff /students that were exposed. Response is dependent on the determined likely immune status of the HCW; • Immune HCWs o HCWs/students who were born before 1978 and have either evidence of two doses of MMR or documented serological immunity to mumps do not need to be excluded o HCWs/students who were born since 1978 and have two doses of MMR do not need to be excluded • Partially vaccinated HCWs/students born since 1978 o HCWs/students who were born since 1978 and have documentary evidence of one dose of MMR should have a second MMR vaccine but do not need to be excluded • HCWs/students born since 1978 with serological result of immunity only and no evidence of MMR vaccination o HCWs who were born since 1978 and have documentation of serological immunity to mumps but no documentary evidence of MMR vaccination, may be considered as possibly non‐immune based on serological result. o However, based on recent experience during mumps outbreak when student nurses with such documented immunity became ill, such documentation may not accurately reflect true immune status. o Therefore, these workers are therefore recommended another dose of MMR, but may continue working in most settings. • Non‐immune HCWs (not vaccinated, or previous serology negative for IgG) o Exclusion may be considered but may not be necessary o These non‐immune HCWs should have an MMR (one or two doses depending on previous vaccination history). Note: Although Occupational Health departments may wish to consider possible exclusion of HCWs who are non‐immune from the 9th day after the first unprotected exposure to mumps through the 26th day after the last exposure(1), there may be limited value in such exclusion in the Irish setting during this outbreak period. This is due to the fact that at there is already Version 1.2 FAQs on Mumps in health care setting last updated 24/04/2009 widespread mumps in the community and the risk of transmission within community settings is already high during this outbreak period. Although nosocomial transmission has rarely been reported in the literature (2), since the upsurge in mumps first began in Ireland in 2004 HPSC is only aware of one report of possible mumps transmission in the health care setting (from HCW‐HCW) (source: personal communication to HPSC). Regarding the risk to immunocompromised populations from infected HCWs, apart from women in the first trimester of pregnancy there is little international evidence to indicate that other immunocompromised groups are at particular risk of mumps complications if infected (1) . What to do when a mumps case (patient) is identified in hospital? • Isolate patients in whom mumps is suspected. Patients with clinical signs and symptoms of mumps illness should be cared for using droplet precautions • Identify exposed staff/students and patients (usually taken as exposure within 3 feet of case without protection [(i.e. face mask]). • Assess immune status of exposed contacts and offer MMR vaccine to those found to be non‐ immune. Serological assessment of immunity of HCWs following mumps exposure Routine serologic testing is not recommended for all healthcare workers already employed but may be useful for evaluating staff who have had unprotected exposure to mumps who do not have other proof of immunity. If serology is to be used to assess the immune status of a healthcare worker after an unprotected exposure, the test should be done as soon after the exposure as possible, HCWs with mumps • Exclude HCWs with active mumps illness until at least 5 days after onset of symptoms. • Identify close work contacts and offer MMR, if appropriate, and health information regarding mumps and advice to contact occupational health department if symptomatic. Protection offered by MMR vaccine and risk of infection Because 1 dose of MMR vaccine is about 80% effective in preventing mumps and 2 doses is about 90% effective, some vaccinated personnel may remain at risk for infection. Therefore, HCWs should be educated about symptoms of mumps, including non‐specific presentations, and should notify occupational health if they develop these symptoms. Last updated 24/04/2009 Version 1.2 FAQs on Mumps in health care setting last updated 24/04/2009 Reference List (1) Updated Recommendations for Isolation of Persons with Mumps. MMWR 57(40), 1103‐1105. 10‐ 10‐2008. (2) Wharton M et al. Mumps transmission in hospitals. Arch Intern Med 1990 150: 47‐49. (3) Johnson H, Hillary IB, McQuoid G, Gilmer BA. MMR vaccination, measles epidemiology and sero‐ surveillance in the Republic of Ireland. Vaccine 1995;13(6):533‐7.