CHICAGO There are two critical factors in the spread and occurrence of infection in day care centers: how many children attend and the turn over rate, said Dennis L. Murray, MD, a professor at Michigan State University in East Lansing, Mich.
Moreover, crowding, direct contact, the opportunity for indirect transmission and lack of toilet training can increase the spread of infection, he said here at the recent American Academy of Pediatrics meeting.
"Infections are fairly common in children enrolled at out-of-home child care," said Murray. "In most instances, the risk of introducing the infectious agent into a child care group is related directly to the agent's prevalence in the community and the number of susceptible children in that group."
The type of infectious agent also affects the course and severity of a particular infection. The mode by which an agent spreads, the infective dose and the agent's ability to survive in the environment all influence the spread of an infection, according to Murray.
He added that frequency of a symptomatic infection or carrier state and the population's immunity to a particular agent are also important factors influencing prevalence of a particular agent within a child care facility. "Transmission also can be affected by practices in the facility related to personal hygiene and environmental sanitation," Murray said.
"Hand washing and environmental sanitation are of utmost importance in limiting the spread of microorganisms," he said.
Otitis media, cytomegalovirus and parvovirus B19 are among the most common infectious problems encountered in child care environments. For example, said Murray, "Children in out-of-home day care experience more episodes of otitis media than children cared for in their own homes."
Murray said the occurrence of otitis media (OM) is greater in child care centers with high population densities. "The risk of consequences of recurrent OM, such as increases in the rate of tympanostomy tube placement, has also been demonstrated to be greater in children attending larger out-of-home child care centers," he said.
Cytomegalovirus (CMV) also occurs more frequently in child care centers, said Murray. "Between 25% and 70% of preschool children cared for in group child care shed CMV asymptomatically," he said.
Because CMV is transmitted easily through both direct and indirect contact, it typically moves from infected children to caregivers and parents. "Studies of CMV antibody conversion among providers," said Murray, "have found annualized conversion rates of 8% to 20%. This compares to a 2% annualized conversion rate for hospital employees."
Although not as prevalent as OM and CMV, parvovirus B19, which often manifests as erythema infectiosum, is of concern because it is most contagious before the onset of illness. "Because of widespread inapparent infections, many adults are at risk of exposure," said Murray.
While Murray recommends that health care providers be cognizant of parvovirus B19 symptoms such as mild respiratory illness and transient arthritis in otherwise healthy adults more than 50% of adults have pre-existing antibodies to fight the infection. "There is a low incidence of effects on the fetus," he said, "so routine exclusion of pregnant women from an out-of-home child care center is not warranted."
Vaccinations are essential for controlling the spread of vaccine-preventable diseases in child care settings. "Maintaining an age-appropriate vaccination policy is critically important for children enrolled in out-of-home child care," Murray said.
Both hepatitis B and varicella vaccinations should be part of a routine vaccination schedule. Child care providers "should be current for all immunizations recommended for adults," Murray said. In addition, providers should consider getting vaccinated for hepatitis A and B, influenza and varicella (if appropriate). Pregnant women and providers should also be current for vaccinations; some physicians suggest pregnant women should be screened for CMV and parvovirus B19 antibodies, he said.
Extra care must be taken in child care settings to reduce the spread of organisms that are resistant to antibiotics. Crowding, ease of transmission and frequent antibiotic use among children have led to increases in antibiotic resistance. "Limit antimicrobial therapy to situations where there is a clear indication and treat for the shortest effective duration," Murray said.
Moreover, Murray added, physicians should report a suspected outbreak of a multi-drug resistant organism to public health authorities in order to minimize transmission of the bacteria.
For more information see:
- Adler, SP. Cytomegalovirus and child care. Evidence for an increased infection rate among day care workers. New Engl J Med. 1989; 321:1290-96
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