Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
Infections Associated With Group Childcare
On average, 12.5 million (61%) of the 20.4 million children in the United States who are younger than 5 years of age were enrolled in a regular childcare arrangement during the spring of 2011. Children in group childcare experience increased frequency of certain infectious diseases and amplify outbreaks of illness ( Table 3.1 ). Aggregation of young children potentiates transmission of organisms that can produce disease in other children, adult care providers, parents, and community contacts. As group size increases, so does the incidence of respiratory illnesses; however, once group sizes of 8 or more children are reached, this effect diminishes. Respiratory infections are much more common than gastrointestinal infections, which comprise only 10% of these illnesses. Children newly entered into group childcare are at especially high risk of respiratory tract and enteric infections. However, mothers whose children were enrolled in group childcare before 2.5 years of age reported their children had less frequent respiratory and gastrointestinal tract infections and episodes of otitis media during elementary school years. The relationship between group childcare exposure and development of asthma is complex and influenced by multiple variables such as early childhood exposure to bacterial and viral antigens, environmental triggers, and genetic inheritance. Not surprisingly, studies have produced conflicting results. In a study of two longitudinal birth cohorts, childcare attendance overall demonstrated a protective effect for subsequent development of asthma. However, there was an interaction between childcare attendance and the Toll-like receptor 2 gene status; carriage of the T allele for TLR2/-16934 was associated with protection from asthma, but AA homozygosity was not. An increase in antibiotic use as an attempt to facilitate earlier return to care enhances the potential for emergence of resistant organisms, thus resulting in an increased economic burden to individual persons and society. Despite the challenges of frequent respiratory and gastrointestinal illness exacerbations among children enrolled in group childcare, these arrangements facilitate opportunities for socialization and enable primary caregivers to be employed outside the home.
TABLE 3.1
Infectious Diseases Associated With Group Childcare
| Sites of Infection and Pathogens | Risk Factors and Association With Outbreaks |
|---|---|
| Enteric Infections | Close person-to-person contact, fecal-oral contact, suboptimal hand hygiene and food preparation practices |
| Viral Pathogens Rotaviruses, enteric adenoviruses, astroviruses, noroviruses, hepatitis A virus (HAV), enteroviruses with enteric manifestations Bacterial Pathogens Shigella spp., Escherichia coli O157:H7 Campylobacter spp., Salmonella spp., Clostridioides difficile Parasitic Pathogens Giardia intestinalis Cryptosporidium parvum |
Commonly associated with outbreaks; HAV and rotavirus vaccine preventable
Commonly associated with outbreaksLess commonly associated with outbreaks Commonly associated with outbreaks |
| Respiratory Tract Infections (acute upper and lower respiratory tract infections or invasion from the respiratory tract) Bacterial Pathogens Haemophilus influenzae type b (Hib) Streptococcus pneumoniae Group A Streptococcus |
Aerosolization and respiratory droplets, person-to-person contact, suboptimal hand hygiene Few outbreaks; vaccine preventable Few outbreaks; vaccine preventable; invasive S. pneumoniae caused by serotypes not in vaccine Few outbreaks and low risk of secondary cases Few outbreaks; some serogroups vaccine preventable Increasingly associated with outbreaks in childcare centers and schools; vaccine preventable Occasional outbreaks, usually as a result of contact with an infectious adult care provider Outbreaks rare; oropharynx usual habitat; usually manifest as septic arthritis or osteomyelitis Disease usually caused by same organisms circulating in the community; influenza vaccine preventable in children ≥6 months of age, measles and mumps vaccine preventable in children 12 months of age and older |
| Infections at Multiple Sites Cytomegalovirus (CMV) Parvovirus B19 Varicella-zoster virus (VZV) Herpes simplex virus (HSV) |
Prevalent; asymptomatic excretion with transmission from children to providers Outbreaks reported; risk to susceptible pregnant women and immunocompromised Outbreaks in childcare centers occur; vaccine preventable in children ≥12 mo of age; zoster lesions present low risk of infection Low risk of transmission from active lesions and oral secretions Rarely occurs in childcare centers; vaccine preventable No documented cases of transmission in group childcare No documented cases of transmission in group childcare |
| Skin Infections or Infestations Staphylococcal and streptococcal impetigo Scabies |
Close person-to-person contact Transmission increased by close person-to-person contact with lesions; outbreaks less likely with decreased incidence of varicella infections; methicillin-resistant Staphylococcus aureus (MRSA) infection common Outbreaks in group childcare reported Common in children attending group childcare Tinea corporis and tinea capitis outbreaks associated with childcare |
| Conjunctiva | Outbreaks in group childcare reported with both bacterial and viral etiologies |
Types of Childcare Settings
Quantifying the number of children participating in each type of childcare setting is challenging because of different ascertainment methods used in several data sources. Types of facilities can be classified by size of enrollment, age of enrollees, and environmental characteristics of the facility. Grouping of children by age varies by setting, but in organized care facilities children usually are separated into the following groups: infants (6 weeks through 12 months), toddlers (13 through 35 months), preschoolers (36 months through 59 months), and school-aged children (5 through 12 years). These designations have relevance to the epidemiology of infectious diseases as well as to regulation and monitoring. Licensed childcare in centers and family childcare homes is subject to state regulation; however, the majority of childcare is provided by family members and others in their homes and is not subject to state regulations and monitoring.
The US Census Bureau conducts the Survey of Income and Program Participation (SIPP), which collects information about childcare arrangements for children <15 years of age. In 2011, 51% of children <5 years of age with working mothers were cared for by a relative, 33% were in organized care including center-based care or family childcare homes, 27% had multiple arrangements, and 11% did not have a regular childcare arrangement, with some survey respondents selecting more than one option. It is intuitive, and there are studies supporting, that children in childcare centers have higher incidence of infectious diseases compared with children in family childcare homes ; however, some studies demonstrate higher rates of infection in family childcare homes. This inconsistency may reflect methodologic study differences in ascertainment and reporting or may indicate that young children in centers develop immunity to common infections at a younger age because of earlier exposure to more pathogens.
Epidemiology, Etiology, and Control of Infections
Although most infectious agents can be associated with outbreaks in settings that do not involve childcare, many agents have the propensity to propagate in group childcare (see Table 3.1 ).
Enteric Infections
Enteric viruses are the predominant cause of diarrheal syndromes among children in group childcare. Outbreaks of diarrhea occur at a rate of approximately 3 per year per childcare center and are associated most frequently with organisms that cause infection after ingestion of a low inoculum. These organisms generally are transmitted from person to person and include rotavirus, norovirus, sapovirus, astrovirus, enteric adenovirus, Giardia intestinalis, Cryptosporidium, Shigella spp. , Escherichia coli O157:H7, other Shiga toxin–producing E. coli (STEC), E. coli O114, and enteropathogenic E. coli. These enteric viruses and fecal coliforms contaminate the environment with greater frequency during outbreaks of diarrhea. In a prospective study of acute gastroenteritis in childcare centers, viruses isolated from the stool of children with diarrhea also were detected on environmental surfaces in 45% of outbreaks. The inoculum associated with diarrhea, the attack rates, and the frequency of asymptomatic excretion of organisms for common enteric infections in group childcare are shown in Table 3.2 . Reported attack rates depend on several factors, including methods used for pathogen detection.
TABLE 3.2
Characteristics of Transmission of Enteric Pathogens in Group Childcare
| Organism | Inoculum Required to Cause Diarrhea in Adult Volunteers | Attack Rate in Enrollees (%) | Secondary Attack Rate in Family Members (%) | Asymptomatic Excretion in Enrollees |
|---|---|---|---|---|
| Rotavirus | 18–1000 virions | 50 | 15–80 | Common |
| Enteric adenovirus | Unknown | 40 | Unknown | Common |
| Astrovirus | Unknown | 50–90 | Unknown | Common |
| Calicivirus | Unknown | 50 | Unknown | Common |
| Giardia intestinalis | 10 1–2 cysts | 17–54 | 15–50 | Common |
| Cryptosporidium | 132 oocysts | 33–74 | 25–60 | Common |
| Shigella | 10 1–2 | 33–73 | 25–50 | Uncommon |
| Escherichia coli | 10 8 | |||
| O157:H7 | 29, 34 | Unknown | Uncommon | |
| O114:NM | 67 | Unknown | Uncommon | |
| O111:K58 | 56, 94 | Unknown | Uncommon | |
| Clostridioides difficile | Unknown | 32 | Unknown | Common |
Organisms generally associated with foodborne outbreaks, including Salmonella spp. and Campylobacter jejuni, are infrequently associated with diarrheal outbreaks in group childcare. However, reports of childcare outbreaks of diarrhea in association with ingestion of fried rice contaminated with Bacillus cereus and of norovirus infection in association with frozen strawberries highlight the issue that foodborne outbreaks can occur in group childcare, especially when food is prepared and served at the childcare center.
Spread of diarrheal pathogens from index cases in group childcare to family members has been reported for many enteropathogens (see Table 3.2 ), with secondary attack rates ranging from 15% to 80%. During outbreaks of diarrhea in childcare centers, asymptomatic excretion of enteropathogens also is frequent (see Table 3.2 ). In a 1-year longitudinal study in the Netherlands of serial stool samples collected from children in 29 childcare centers, real-time multiplex polymerase chain reaction (PCR) testing revealed that enteropathogens were present in 78% of fecal samples, 95% of which were collected from children who were asymptomatic. These pathogens included enteropathogenic E. coli (20%), Clostridioides difficile 16%), STEC (2%), Giardia lamblia (4%), Cryptosporidium spp. (1%), norovirus (9%), rotavirus (3%), and others. A point-prevalence evaluation of 230 asymptomatic preschool children attending childcare in southwest Wales and inner London demonstrated a 1% fecal colonization rate with both Cryptosporidium and Giardia spp. The role that asymptomatic excretion of enteropathogens plays in transmission of disease is unknown.
Acute infectious diarrhea is 2–3 times more common in children enrolled in out-of-home childcare than in age-matched children cared for at home. Approximately 20% of outpatient visits for acute diarrheal illness among children younger than 3 years of age are attributable to childcare attendance. In addition, the incidence of diarrheal illness is threefold higher among children during their first month in out-of-home childcare compared with children cared for at home. , ,
Diarrhea occurs 17 times more frequently in diapered children than in toilet-trained children. Higher attack rates among diapered children may represent exposure of a younger, nonimmune cohort. In contrast, in a multicommunity group childcare outbreak of Shigella sonnei, the highest attack rates were noted in rooms where both toilet-trained and diapered children were comingled (14%) compared with rooms with toilet-trained children only (9%) and rooms with diapered children only (5%), despite comparable availability of sinks and toilets. The likely reason for this finding was that the toilet-trained children were acquiring continence, and the diarrhea resulting from their shigellosis made them incontinent. Investigators in North Carolina demonstrated that adherence to proper diapering and hand hygiene practices and use of dedicated food preparation equipment decreased the incidence of diarrheal illness among children and staff in out-of-home childcare centers.
Viral Pathogens
Rotavirus
In the prerotavirus vaccine era, rotaviruses were the most common cause of significant symptomatic diarrhea in children <2 years of age. Person-to-person transmission by the fecal-oral route predisposes nonimmune infants and young children and their childcare providers to rotavirus infection. Because rotavirus can be isolated from human stools for approximately 21 days after illness onset and rotavirus RNA can be detected on toys and surfaces in childcare centers, rotavirus has been associated with outbreaks of diarrhea in group childcare.
Primary prevention of rotavirus in all settings is accomplished with the completion of the rotavirus immunization series. The universal uptake of rotavirus immunization in the United States since 2006 has resulted in a greatly reduced burden of disease and consequently fewer childcare-associated outbreaks. Pediatric rotavirus immunization has also provided indirect protection to adults, with a decline in peak prevalence by nearly 50% in one study. Rotavirus-immunized childcare enrollees can therefore provide indirect protection to rotavirus-nonimmune childcare providers, thus reducing opportunities for person-to-person transmission.
Norovirus
In the postrotavirus vaccine era, norovirus has become the leading cause of acute gastroenteritis in young children. A population-based surveillance study of children <5 years of age with acute gastroenteritis who presented for medical care in three counties surrounding Nashville, Tennessee, Cincinnati, Ohio, and Rochester, New York, in 2009 and 2010 detected norovirus in 278 (21%) of 1295 stool specimens, compared with rotavirus in 152 (12%).
Several features of norovirus facilitate its spread, including the low inoculum required for transmission (approximately 18–1000 virions), asymptomatic shedding that can precede and extend beyond symptom duration (in up to 30% of infections), tolerance to a wide range of temperatures that facilitates persistence on environmental surfaces, and strain-specific immunity. Outbreaks can occur in a variety of settings including childcare centers, long-term care facilities, hospitals, restaurants, and cruise ships. Two epidemiologic studies of norovirus gastroenteritis in Germany and Japan found that genogroup GII strains predominated in outbreaks associated with childcare facilities while these strains were circulating in the community. ,
Hepatitis A Virus
Hepatitis A virus (HAV) infections usually are mild or asymptomatic in children, and outbreaks in childcare centers generally are not recognized until illness becomes apparent in older children or adult contacts. The first outbreak of HAV infection in a childcare center was reported in 1973 in North Carolina, with subsequent outbreaks recognized throughout the United States. Before routine immunization of children with hepatitis A vaccine in the United States, approximately 15% of HAV infections were estimated to be associated with childcare centers. Uptake of universal hepatitis A immunization in children has resulted in markedly reduced outbreaks among children in childcare and elementary school settings, as well as among adults who have contact with children enrolled in childcare centers. ,
Peak viral titer in stool and greatest infectivity of HAV occur during the 2 weeks before onset of symptoms. Since HAV is transmitted by the fecal-oral route, spread occurs more frequently in settings that include diapered children. The mainstays of prevention of HAV infection include maintenance of personal hygiene, hand hygiene, disinfecting procedures, and immunization.
The US Centers for Disease Control and Prevention (CDC) recommends hepatitis A vaccine for all children beginning at 1 year of age, with the 2 doses administered 6–18 months apart. Routine administration of hepatitis A vaccine to staff at childcare centers is not recommended. However, hepatitis A vaccine should be given to unimmunized, immunocompetent people 12 months through 40 years of age as postexposure prophylaxis (PEP). , The CDC advises that vaccine PEP also be administered to all previously unvaccinated staff and attendees of childcare centers or homes when ≥1 HAV infections are identified in children or employees or when an HAV infection is recognized in ≥2 households of center attendees. In centers that provide care only to toilet-trained children, PEP needs to be administered only to unimmunized classroom contacts of the index child. If an HAV infection is identified in ≥2 households, PEP should be considered for members of households with diapered children attending the childcare center. In most situations, hepatitis A vaccination, rather than immune globulin, is preferred for PEP because it induces active immunity and longer lasting protection and is more available. Despite the decline in the incidence of HAV, continued education, training, and monitoring of staff regarding appropriate hygienic practices are essential components of a prevention plan.
Bacterial Pathogens
Escherichia coli
Bacterial pathogens that have the potential to cause severe systemic infections, including E. coli O157:H7 and other STEC strains, have been associated with fecal-oral transmission in group childcare. In an epidemiologic study of non–O157 STEC outbreaks in the United States, 15 (39%) outbreaks occurred through person-to-person transmission, with 13 (87%) of these occurring in childcare centers. In an outbreak of E. coli O157:H7 infection in a childcare center in Bronx, New York, 11 of 45 attendees tested positive for E. coli O157:H7 by stool culture or Shiga-like toxin assay. The original source of the outbreak was not determined; however, multiple sanitary violations were identified, including improper disinfection of diaper changing tables, lack of sanitary distribution of food, and inadequate exclusion of attendees with diarrheal illness. After 2 cases of STEC were identified at a childcare center in Norway, an outbreak investigation found 9 additional cases among the 91 children enrolled and 1 case among the 41 employees; no evidence of common exposures was found, and person-to-person transmission was determined to be likely. Three of the cases were asymptomatic in this outbreak, and in a large surveillance study in the Netherlands, STEC was detected in 2% of stool samples. These findings raise important questions regarding the utility of exclusion policies and screening of asymptomatic contacts.
Shigella sonnei
S. sonnei is one of the most common bacterial causes of diarrheal outbreaks in group childcare, which can then be transmitted to household contacts and communities. Childcare attendance and age <60 months were associated with illness in a community outbreak of S. sonnei among traditionally observant Jewish children in New York City in 2000. Multiple illnesses in a single household were determined to result from intrahousehold secondary transmission. A multicommunity outbreak of more than 1600 culture-confirmed cases in the greater metropolitan area of Cincinnati, Ohio, in 2001 had an overall mean attack rate of 10% among childcare center enrollees. The highest attack rates occurred among newly or incompletely toilet-trained enrollees, and the lowest attack rates were noted among diapered children. The attack rate was 6% among staff members. Secondary transmission was facilitated by poor hygiene practices, including inaccessible handwashing supplies and incomplete diaper disposal practices, as well as through recreational activities involving water. A prolonged multistate increase of shigellosis caused by organisms with similar biochemical and genetic profiles occurred in the South and mid-Atlantic areas in 2001–03. A substantial proportion of infections was associated with group childcare. In 2005, 639 cases of multidrug-resistant S. sonnei were reported in northwest Missouri. A case-control investigation of 39 licensed childcare centers demonstrated that centers with one or more sinks or a diapering station in each room were less likely to have cases, thus reinforcing the importance of environmental design and hygiene. Some state regulations for exclusion require 2 negative stool cultures prior to returning to care after S. sonnei infection, while others require only 1 negative test. An observational study following a shigellosis outbreak in St. Louis, Missouri demonstrated that of 172 people who submitted at least 2 follow-up cultures, the probability that S. sonnei was isolated from a second culture after being isolated from a first follow-up culture result was only 7%. All (100%) of the second cultures from people who had a first negative follow-up culture result were negative for S. sonnei , a finding suggesting that a single negative convalescent culture result is sufficient to document clearance.
Respiratory Tract Infections
Organisms responsible for respiratory tract infections in group childcare are similar to organisms that circulate in the community and include respiratory syncytial virus (RSV), parainfluenza viruses, adenovirus, rhinovirus, coronavirus, influenza viruses, human metapneumovirus, bocavirus, parvovirus B19, and Streptococcus pneumoniae.
Children <2 years of age who are attending childcare centers have an increased number of upper and lower respiratory tract infections, including acute otitis media and pneumonia, compared with age-matched children cared for at home. Approximately 10%–17% of respiratory tract infections in US children <5 years of age are attributable to childcare attendance. , A prospective cohort study following 119 childcare attendees through 24 months of age demonstrated a mean annual incidence of 4 respiratory tract infections per child during the first year of childcare enrollment and 1 per child during the second year of childcare enrollment. One or more viruses were detected by real-time reverse transcriptase polymerase chain reaction (RT-PCR) from two-thirds of the children with respiratory tract infections. Molecular-based diagnostics have increased the yield of virus detection in children with respiratory tract infections. An epidemiologic study of childcare attendees with new-onset respiratory illness detected at least one virus in 84% and multiple viruses in 46% of cases using PCR testing. Children with multiple viruses detected at the onset of illness were less likely to have fever (odds ratio [OR] 0.6; 95% confidence interval [CI], 0.4–0.9) but more likely to have symptoms lasting >7 days (OR 1.9; 95% CI, 1.2–3.14).
A national registry–based study of Danish children from birth to 5 years of age revealed that the first 6 months of enrollment in group childcare among children enrolled at ≤1 year of age were associated with a 69% higher incidence of hospitalizations for acute respiratory tract infections compared with age-matched children in home care. The incidence of hospitalization decreased after 6 months of group childcare enrollment and was comparable with that of children in home care after >12 months of enrollment. A prospective study comparing children enrolled in childcare in the first year of life with those who were not found that childcare attendees had more episodes of physician-diagnosed upper respiratory tract infections and acute otitis media in their first year of life. In addition, although the two groups had similar rates of illness over the entire 6-year study period, childcare attendees had increased visits to their general practitioner and an increased risk of specialist referral. However, children with earlier group childcare exposure are less likely to become ill from 5 to 13 years of age. The risk of acute otitis media is increased among children enrolled in childcare, especially those <2 years of age. In one study, the incidence of otitis media was 1.5 times higher among children enrolled in childcare compared with children at home. Acute otitis media is the most common reason for antibiotic use in children <3 years of age in group childcare. Childcare attendance has been associated with increased risk of recurrent acute otitis media (>6 episodes in 1 year) and chronic otitis media with effusion persisting for more than 6 months. After controlling for the total size of the childcare group for children <12 months of age, the previously established relationship between attending out-of-home childcare and frequent ear infections was reduced from an OR of 3.2 (95% CI, 1.5–6.7) to an OR of 1.34 (not significant; P = .60). Because acute otitis media usually is diagnosed empirically, the relative contribution of bacterial versus viral causes is largely unknown.
Handwashing decreases the frequency of acute respiratory tract infections in childcare. A randomized controlled trial that included training childcare staff regarding handwashing, transmission modes of infection, and aseptic techniques related to nose wiping demonstrated a significant reduction in upper respiratory tract infections among enrollees <24 months of age. A study to assess the potential role of clothing as a source of transmission of human rhinovirus found that clothing worn by teachers is unlikely to facilitate the transmission of rhinovirus in group childcare. Symptomatic teachers are more likely to have rhinovirus in their nasal mucus and on clothing. Because most infectious agents are communicable for a few days before and after symptoms, exclusion of children and teachers based on upper respiratory tract symptoms is unlikely to decrease transmission, and the continued practice of respiratory and hand hygiene is likely to be more effective in preventing spread.
Viral Pathogens
Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2)
In March 2020, the World Health Organization declared SARS-CoV-2, a novel coronavirus, the cause of the worst pandemic in more than a century, resulting in a disease known as coronavirus disease 2019 (COVID-19). In contrast to other respiratory viruses, including influenza virus, younger children are less susceptible and have less severe disease attributed to SARS-CoV-2 than do adults. Complete epidemiologic data in children are lacking and are derived primarily from contact tracing of ill adults. Therefore extrapolation of these incomplete data to group childcare should be done with caution. Current data suggest that children and adolescents acquire SARS-CoV-2 at approximately one-half the rate of adults and susceptibility decreases significantly as age decreases. , The frequency of asymptomatic infection and the transmissibility of SARS-CoV-2 from asymptomatic and symptomatic young children aged 0–5 years to others is unclear.
Outbreaks in childcare centers have occurred in many locales experiencing high rates of community COVID-19. In these cases of near-simultaneous infection, it is often difficult to distinguish the index case from secondary cases and the relative contributions of children to virus transmission. Complicating matters, many childcare centers have incorporated school-age children who are remote learning. These older children interact with younger ones, and there is evidence from household transmission studies that older children (10–18 years old) transmit SARS-CoV-2 at higher rates (19%) than do children 0–9 years of age (5%). In the small number of epidemiologic studies that have specifically evaluated transmission within group childcare, the transmission rate from young children appears to be significantly lower than typical household transmission rates of 10%–12% in two studies , but higher in one small study. These studies in childcare do not provide detailed information about preventive strategies such as mask-wearing by adult caregivers and children. Many state governments track SARS-CoV-2 infections in licensed childcare, and most of these report that infections in adult caregivers exceed those in children, despite children outnumbering adult caregivers. A large study from India demonstrated that children 0–4 years of age transmit SARS-CoV-2 to both children and adults but most commonly to same-aged children. This study demonstrated that 71% of people infected with SARS-CoV-2 do not transmit the virus to others, inferring that virus transmission predominantly is by a small number of “superspreaders.” There has been no published study to date identifying a child as a superspreader in a childcare center.
The gaps in knowledge regarding SARS-CoV-2 and childcare have had a crippling effect on US childcare. Because symptoms of COVID-19 cannot be reliably distinguished from common and harmless viral respiratory infections, symptomatic children, even if only mildly ill, have been excluded, in many situations, until they test negative for SARS-CoV-2. Children who test positive need to be excluded for at least 10 days, and household contacts are required to quarantine for 10 days after the initial 10-day period for the child. Reassuringly, a large national case-control study of childcare workers in the first 3 months of the pandemic under the guidance of mitigation efforts was not associated with an elevated risk of SARS-CoV-2 transmission to childcare providers.
Mask-wearing, hand hygiene, environmental sanitizing and disinfecting, and exclusion of ill children and adults are essential defenses against further spread of both SARS-CoV-2 and other respiratory pathogens in the childcare setting.
Seasonal Influenza
Rates of seasonal influenza are highest among children <2 years of age and older adults, and rates of complications are highest among children of all ages with predisposing or underlying medical conditions. Among preschool-aged children with influenza virus infections, hospitalization rates range from 100 to 500 per 100,000 children, with the highest rates among children <1 year of age. Influenza viruses are spread from person to person primarily through large respiratory tract droplets, either directly or by secondary contact with objects that are contaminated with infectious droplets. Children shed virus for several days before the onset of clinical symptoms and are contagious for >10 days following symptom onset. , Transmission of infections can be increased by close contact among children who are not able to contain their secretions.
Annual vaccination of all people ≥6 months old is the primary method of preventing seasonal influenza infections. A randomized controlled trial conducted during the 1996–97 influenza season in 10 childcare centers in San Diego, California, found that vaccinating children against influenza reduced influenza-related illness among their household contacts. In addition to preventing respiratory tract illness, influenza vaccine prevents acute otitis media among children attending childcare. , , ,
Routine use of intranasal live-attenuated influenza vaccine (LAIV) among healthy children can be cost effective and can be maximized by using group-based vaccination approaches. A prospective study of intranasal influenza vaccine in healthy children 15 through 71 months of age demonstrated clinical and economic efficacy when vaccination efforts were focused on children in group childcare. Vaccinating children has been associated with indirect protection of older people as well. , LAIV was not recommended for administration in the 2016–17 and 2017–18 seasons after concerns regarding decreased effectiveness were noted compared with intramuscular formulations; however, LAIV was reintroduced on a limited basis in the fall of 2018, with increased uptake noted in the 2019–20 .
Mandatory influenza vaccination before childcare attendance can increase immunization coverage and consequently decrease infection. In 2010, Connecticut became the second state, after New Jersey, to require all children 6–59 months of age in licensed childcare programs to receive at least 1 dose of seasonal influenza vaccine annually. Seasonal influenza vaccination rates among children 6–59 months of age in Connecticut increased from 68% in 2009–10 to 84% in 2012–13. Between the 2007–08 and the 2012–13 seasons, Connecticut had the highest percentage of decrease in influenza-associated hospitalization rates compared with nine other sites participating in the CDC Emerging Infections Program, none of which had an influenza vaccine mandate for childcare centers at the time. However, in 2016 there were only four states that had laws requiring influenza vaccine for childcare attendees. In a national sample of licensed childcare centers, only 26% of center directors reported a mandatory requirement. Having a state influenza vaccination law for children also was associated with directors reporting an influenza vaccine requirement for adult caregivers, but only 13% reported this requirement.
Childcare center closure as a strategy to prevent and monitor community spread of influenza was considered during the 2009 H1N1 influenza pandemic. Extrapolating to school-aged children, 58% of families of 402 students in Perth, Australia, who were affected by pandemic-related school closures reported a substantial disruption of daily schedules. Almost one-half of the parents had work absences, and 35% made alternative childcare arrangements. Children affected by the school closures were more likely to report out-of-home activities during the school closure period. Fewer than one-half (47%) of the parent respondents believed that the school closures were an effective response in reducing the potential for community transmission.
You're Reading a Preview
Become a Clinical Tree membership for Full access and enjoy Unlimited articles
If you are a member. Log in here