Mumps and Pertussis
On the Lookout for Pertussis and Mumps in Michigan
Michigan Department of Community Health (MDCH) has received increased reports of pertussis and mumps in the state and is advising providers to be vigilant for possible cases of both diseases.
Pertussis
Reported levels of pertussis began to increase in late 2008 and have continued at a pace higher than previously seen in recent years. In 2008, there were 315 cases reported, and in 2009, MDCH is reporting 902 cases. (All 2009 disease totals are still provisional.)
The exact reasons involved in the increase aren’t known, but could involve a number of factors, including better physician recognition and reporting of the illness, especially in adolescent and adult populations who traditionally have not been thought of as pertussis-susceptible.
In 2009, 59% of reported pertussis cases in Michigan were in adolescents and adults.
Experts generally feel that pertussis is more common than reported figures would indicate; often it is an unrecognized and/or undiagnosed cause of prolonged coughing illness.
Research in recent years has determined that immunity -- both that from vaccine and that from infection/disease -- wears off over time; thus there is an important need for booster doses of pertussis vaccine in adolescence and in adulthood.
Other possible factors in the reported increase include:
- the availability of more types of lab tests;
- a true increase in incidence (data suggest there may be a natural cycle of pertussis with peaks of disease every 3-5 years);
- more reporting in recent years from additional reporting sources (e.g. commercial labs); and
- inconclusive or misleading laboratory testing involving false-positive results.
Though it is far less common than it was in the pre-vaccine era, pertussis is probably still an endemic disease in the U.S., especially among adolescents and adults, many of whom have likely lost immunity.
Pertussis vaccines have been available for adolescents and adults since 2005. These are recommended in the form of a Tdap (tetanus, diphtheria, acellular pertussis) booster dose in the adolescent years and for adults to replace the next needed Td (tetanus, diphtheria) booster dose which is given every 10 years. Unfortunately, this vaccine is under-utilized. According to December 2009 Michigan Care Improvement Registry (MCIR) data, 33% (n=87,980) of 11-12 year olds have been vaccinated with Tdap vaccine. Until Tdap vaccine becomes routinely incorporated into primary care for teens and adults, pertussis will remain a problem in these populations.
In fall 2009, new school immunization rules were approved by the Michigan Legislature for the 2010-11 reporting year. One of the newly required vaccines for sixth graders is Tdap. This new requirement will provide an added incentive to providers and parents to assure that this age group is fully protected from pertussis. (Additional information about the new school rules is included in the accompanying article “Changes to School Rules for Adolescent Vaccines”.)
Immunization is the key to preventing pertussis or minimizing its occurrence and its severity. Studies show vaccination may not always prevent the disease but can help make it a milder illness. Children need the full series of pertussis vaccinations.
Immunizing teens and adults also helps to protect the young babies they are in contact with who are too young to have completed the primary series of pertussis vaccine doses.
Health care personnel are also recommended to receive Tdap. As soon as feasible, health care personnel younger than age 65 years with direct patient contact should be given a one-time dose of Tdap, with priority given to those having contact with infants younger than age 12 months.
Infants are at highest risk for severe pertussis disease, complications, and death. Infant pertussis deaths have occurred in recent years in the U.S. Often the source of infection is another family member with an undiagnosed case of pertussis.
Cases of pertussis should be treated with one of the recommended macrolides or other appropriate antibiotic; household and other close contacts should receive appropriate antibiotic prophylaxis. These recommendations are posted online at: www.michigan.gov/immunize > Provider Information > Vaccine-Preventable Disease Investigation Guidelines.
In health care settings, use of droplet precautions is recommended. Suspected cases should be reported to the health department serving the area where the patient resides.
Additional pertussis resources from CDC are posted at: www.cdc.gov/vaccines/vpd-vac/pertussis.
A sizeable outbreak of mumps has been occurring in the northeastern U.S. since the fall of 2009, mostly in New York and New Jersey and involving religious Hasidic Jewish communities and associated schools. Recently some other states have had cases related to this outbreak, including a few cases in Michigan.
Mumps vaccination is a part of the routine childhood immunization series, consisting of 2 doses, the first at 1 year of age and a second prior to school entry, at 4-6 years of age. MDCH is advising providers to ensure all children and adolescents are up to date with 2 doses of mumps vaccine (MMR), which is also indicated for adults born after 1956 if they have no history of mumps disease or immunization.
Health care personnel born after 1956 should have 2 doses if they lack a history of physician-diagnosed mumps disease, a history of mumps vaccination, or laboratory evidence of immunity. Additional recommendations for vaccination of health care personnel are available at http://www.immunize.org/catg.d/p2017.pdf
Persons with suspected mumps should be isolated for 5 days after onset of parotitis and, if they visit a health care setting, droplet precautions should be initiated immediately.
Any suspected mumps case should be reported to the health department in the area where the patient resides.
Mumps
