Childcare and Communicable Diseases

Epidemiology

Respiratory tract infections and gastroenteritis are the most common diseases associated with childcare. These infections occur in children and their household contacts, as well as childcare workers, and can spread into the community. The severity of illness caused by a given respiratory and enteric pathogen depends on the person's underlying health status, the inoculum, and prior exposures to the pathogen, either by infection or immunization. Hepatitis B virus (HBV) transmission has been reported rarely in a childcare setting. Transmission of hepatitis C virus (HCV), hepatitis D virus (HDV), and HIV has not been reported in a childcare setting. Some organisms, such as hepatitis A virus (HAV), can cause subclinical disease in young children and produce overt and sometimes serious disease in older children and adults. Other diseases, such as otitis media and varicella, usually affect children rather than adults. Several agents, such as cytomegalovirus and parvovirus B19, can have serious consequences for the fetuses of pregnant women or for immunocompromised persons. Because many childcare workers are women of childbearing age, they should be encouraged to discuss possible risks with their physician if they become pregnant. Both infections and infestations of the skin and hair may be acquired through contact with contaminated linens or through close personal contact, which is inevitable in childcare settings.

Respiratory Tract Infections

Respiratory tract infections account for the majority of childcare-related illnesses. Children <2 yr old who attend childcare centers have more upper and lower respiratory tract infections than do age-matched children not in childcare. The organisms responsible for these illnesses are similar to those that circulate in the community and include respiratory syncytial virus (RSV), parainfluenza viruses, influenza viruses, human metapneumoviruses, adenoviruses, rhinoviruses, coronaviruses, parvovirus B19, and Streptococcus pneumoniae.

Upper respiratory tract infections, including otitis media , are among the most common manifestation of these infections. The risk for developing otitis media is 2-3 times greater among children who attend childcare centers than among children cared for at home. Most prescriptions for antibiotics for children <3 yr old in childcare are to treat otitis media. These children also are at increased risk for recurrent otitis media, further increasing use of antimicrobial agents in this population. Studies have demonstrated reductions in both otitis media and antibiotic use subsequent to pneumococcal vaccination implementation. Pharyngeal carriage of group A streptococcus occurs earlier among children in childcare, although outbreaks of clinical infections with this organism are uncommon. Influenza vaccination of younger infants reduces influenza infection and secondary sequelae in both the children and the adults who care for them, in their home and in childcare settings. Following adoption of the acellular pertussis vaccine, increases in clusters and outbreaks of infection caused by Bordetella pertussis have led to the recognition of less durable immunity, with older children and adults serving as reservoirs of infection.

Transmission of these organisms typically occurs through either direct or indirect contact with the respiratory droplets of an infected child. In childcare settings, contamination of surfaces occurs frequently as children mouth toys, drool, and cough or sneeze. Additionally, some respiratory pathogens are spread through large droplets that typically can travel 3-6 ft. However, intimate contact between children is a routine part of the play and care of young children, thus facilitating transmission. The most common surfaces from which airborne droplets can be spread are the hands, so the most efficient form of infection control in the childcare setting is good handwashing.

Gastrointestinal Tract Infections

Acute infectious diarrhea is 2-3 times more common among children in childcare than among children cared for in their homes. Outbreaks of diarrhea, which occur frequently in childcare centers, are usually caused by enteric viruses such as caliciviruses, enteric adenoviruses, and astroviruses, or by enteric parasites such as Giardia lamblia or Cryptosporidium . A dramatic and sustained decline in the burden of rotavirus infection has been demonstrated since introduction of the rotavirus vaccination program in 2006, and this trend is likely reflected in the daycare population as well. Bacterial enteropathogens such as Shigella and Escherichia coli O157:H7, and less often Campylobacter, Clostridium difficile, and Bacillus cereus, also have caused outbreaks of diarrhea in childcare settings. Salmonella rarely is associated with outbreaks of diarrhea in childcare settings, because person-to-person spread of this organism is uncommon.

Outbreaks of hepatitis A in children enrolled in childcare facilities have resulted in community-wide outbreaks. Hepatitis A is typically mild or asymptomatic in young children and often is identified only after symptomatic illness becomes apparent among either older children or adult contacts of children in childcare. Enteropathogens and HAV are transmitted in childcare facilities by the fecal-oral route and can also be transmitted through contaminated food or water. Children in diapers constitute a high risk for the spread of gastrointestinal infections through the fecal-oral route. As such, enteric illness and HAV infection are more common in centers that care for children who are not toilet-trained and where proper hygienic practices are not followed. The most common enteropathogens, such as norovirus and G. lamblia, are characterized by low infective doses and high rates of asymptomatic excretion among children in childcare, characteristics that facilitate transmission and outbreaks.