Delayed Supply of Influenza Vaccine and Adjunct ACIP Influenza Vaccine Recommendations for the 2000-01 Influenza Season FREE

MMWR. 2000;49:619-622

Annual vaccination against influenza is the primary means for minimizing serious adverse outcomes from influenza virus infections. These infections result in approximately 20,000 deaths and 110,000 hospitalizations per year in the United States. ¹ The amount of trivalent inactivated influenza vaccine produced for distribution in the United States has increased substantially; in 1999, four manufacturers produced a combined total of 80 to 85 million doses.

For the 2000-01 influenza season in the United States, lower than anticipated production yields for this year's influenza A(H3N2) vaccine component and other manufacturing problems are expected to lead to a substantial delay in the distribution of influenza vaccine and possibly substantially fewer total doses of vaccine for distribution than last year. A more precise estimate of the vaccine supply will be available as production progresses during the summer. Because many vaccine providers currently are planning their fall vaccination activities, CDC and the Advisory Committee on Immunization Practices (ACIP) are issuing adjunct influenza vaccination recommendations beyond those made by ACIP on April 14, 2000.¹ The adjunct recommendations are specific to the 2000-01 influenza season.

1. Implementation of organized influenza vaccination campaigns should be delayed. Health-care providers, health organizations, commercial companies, and other organizations planning organized influenza vaccination campaigns for the 2000-01 influenza season should delay vaccination campaigns until early to mid-November. The purpose of this recommendation is to minimize cancellations of vaccine campaigns and wastage of vaccine doses resulting from delays in vaccine delivery.

2. Influenza vaccination of persons at high risk for complications from influenza and their close contacts should proceed routinely during regular health-care visits. Routine influenza vaccination activities in clinics, offices, hospitals, nursing homes, and other health-care settings (especially vaccination of persons at high risk for complications from influenza, health-care staff, and other persons in close contact with persons at high risk for complications from influenza) should proceed as normal with available vaccine.

3. Provider-specific contingency plans for an influenza vaccine shortage should be developed. All influenza vaccine providers, including health-care systems and organizers of vaccination campaigns, should develop a provider-specific contingency plan to maximize vaccination of high-risk persons and health-care workers. These plans should be available for implementation if a vaccine shortage develops.

There are no new recommendations for the use of influenza antiviral drugs. The approved usage (i.e., for treatment or chemoprophylaxis), age group, dosage, route of administration, metabolism, and adverse reactions of these agents vary,¹ and all of them require prescription by a physician. Influenza antiviral drugs are useful for controlling influenza outbreaks in specific and circumscribed situations, such as nursing homes. In addition, long-term antiviral chemoprophylaxis of high-risk institutionalized residents or some persons at high risk for complications from influenza might be indicated if vaccine either is unavailable, ineffective (e.g., severely immunocompromised persons), or contraindicated.

However, these drugs are not a substitute for influenza vaccine. Even if an influenza vaccine shortage develops, CDC and ACIP do not support their routine and widespread use as chemoprophylaxis against influenza because this is an untested and expensive strategy that could result in large numbers of persons experiencing adverse effects.

In the United States, 70 to 76 million persons (approximately 35 million persons aged ≥ 65 years; 33 to 39 million persons aged < 65 years with high-risk medical conditions; and 2 million pregnant women) are at high risk for serious complications from influenza infections, including hospitalizations and deaths. The expected delay in influenza vaccine distribution and a possible shortage for the 2000-01 influenza season has raised difficult questions of how to maximize protection against influenza for these persons. One complicating factor is that many vaccine providers must plan their fall vaccination activities now even though the vaccine supply is uncertain. Given the current situation, CDC and ACIP have issued modified recommendations for the 2000-01 season emphasizing the delay of organized influenza vaccine campaigns until November, the continuation of routine vaccination activities during regular health-care visits, and the development of provider-specific contingency plans in case a vaccine shortage should develop. There are additional important points worth emphasizing in addition to these main recommendations:

As new information becomes available, CDC and the Food and Drug Administration (FDA) will issue updates. In the meantime, ACIP and CDC request that persons and organizations planning to administer influenza vaccine, as well as members of the general public, join in these efforts to maximize protection of persons most likely to develop serious and life-threatening complications from influenza. FDA, CDC, ACIP, National Institutes of Health, and vaccine manufacturers will continue to work together to facilitate the availability of influenza vaccine for the upcoming season and to minimize the adverse impact of an influenza vaccine shortage if one should develop. If a substantial vaccine shortage appears imminent, or if the situation warrants, then CDC and ACIP will issue further recommendations.

MMWR. 2000;49:565-568

1 figure omitted

Since 1989, approximately 170 outbreaks associated with recreational water venues (e.g., swimming pools, waterparks, fountains, hot tubs and spas, lakes, rivers, and oceans) have been reported, with almost half resulting in gastrointestinal illness.^1-5 This report summarizes the investigation of an outbreak of gastroenteritis in Florida during 1999. The findings indicated that Shigella sonnei and Cryptosporidium parvum infections caused illness in persons exposed to an "interactive" water fountain* at a beachside park.

During August 23-27, the Volusia County Health Department (VCHD) received reports of three children with S. sonnei infection whose common exposure was play in an interactive water fountain at a beachside park that had opened August 7. To determine risk factors for gastrointestinal illness, VCHD and the Florida Department of Health (FDH) conducted a case-control study among a convenience sample of park attendees, including 34 members of a teenage group that had attended a beach party near the park on August 14 and 52 family members of persons who had reported illness to VCHD. A case of gastrointestinal illness was defined as abdominal cramps or diarrhea (three or more loose stools within a 24-hour period) in a person who visited the park during August 7-27, with illness onset less than 12 days after the visit. Study participants were contacted by telephone and interviewed using a standard questionnaire.

Of 86 park visitors interviewed, 38 (44%) had illness that met the case definition. Onsets of illness occurred during August 15–September 2. The median age of ill persons was 8 years (range: 2-65 years); the median age of well persons was 15 years (range: 5-47 years). Twenty-five (66%) ill persons were male. The most common symptoms reported included diarrhea (97%), abdominal cramps (90%), fever (82%), vomiting (66%), and bloody diarrhea (13%). S. sonnei was isolated by culture of stool specimens from five (36%) of 14 ill persons tested. C. parvum oocysts were identified in stool specimens from two persons by light microscopy using an acid-fast stain. All 38 ill persons, compared with 32 (67%) well persons, had entered the fountain (odds ratio [OR] = undefined; 95% confidence interval [CI] = 4.1-undefined). Other associated risk factors for illness included fountain water ingestion (OR = 52.5; 95% CI = 9.8-377.0) and consumption of food or drink at the interactive fountain (OR = 4.7; 95% CI = 1.6-14.3). As all ill persons entered the fountain, and all but two ingested fountain water, the independence of these exposures was not established.

On August 27, investigators conducted an environmental assessment of the park, a paved area of approximately 2-3 acres adjacent to the beach in Daytona Beach, which included bathrooms, outdoor showers, vending machines, and the interactive water fountain. The fountain used recirculated water that drained from the wet deck/play area floor (no standing water) into an underground reservoir. The volume of recirculated water was 3380 gallons, and the minimum flow rate through the recirculation system was 115 gallons per minute; the turnover rate was 30 minutes, as required by state code for interactive water features. The recirculated water passed through a hypochlorite tablet chlorination system before being pumped back to the reservoir and then to several high-pressure fountain nozzles at ground level throughout the play area. No filtration system had been installed. Investigators identified several potential opportunities for water contamination. The fountain was popular with diaper- and toddler-aged children who frequently stood directly over the nozzles. Chlorine levels were not monitored, and the hypochlorite tablets that deplete after 7-10 days of use had not been replaced after the park opened August 7.

An estimated 4800 persons attended the park during August 7-27, when the fountain was closed by VCHD. The fountain reopened December 12 after several control measures were implemented. First, a cartridge filtration system was installed, and a chlorine monitor was installed to halt fountain operation automatically when residual chlorine levels fall below 3 ppm. Second, a sign was posted advising visitors to shower before entering the fountain and to avoid fountain water consumption. Third, children in diapers were excluded from entering the fountain. No further illness has been associated with the fountain.

P Minshew, Volusia County Health Dept, Daytona Beach; K Ward, MSEH, Z Mulla, MSPH, R Hammond, PhD, D Johnson, MD,'s Heber, DrPH, R Hopkins, MD, State Epidemiologist, Florida Dept of Health. Div of Bacterial and Mycotic Diseases and Div of Parasitic Diseases, National Center for Infectious Diseases; Div of Applied Public Health Training, Epidemiology Program Office; and an EIS Officer, CDC.

This report documents the second recorded outbreak of gastroenteritis associated with an interactive water fountain¹ and highlights the risk for transmitting diarrheal illness in recreational water activities other than a traditional water-filled pool. Outbreaks of gastroenteritis associated with recreational water exposure are recognized with increased frequency.¹ Interactive fountains using recirculating water are new to traditional waterpark amusements (i.e., slides and wave pools). Because these fountains are attractive to diaper- and toddler-aged children, recreational water may be at high risk for contamination by enteric pathogens through overt fecal accidents or rinsing of contaminated bodies in the water.

In this outbreak, S. sonnei and C. parvum were identified in stool specimens from ill persons. Both pathogens have a low infectious dose,^6,7 and C. parvum is resistant to chlorine⁷; however, removal of pathogens may be enhanced by filtration of fecal material from recirculated water. The recirculated fountain water described in this report was unfiltered and inadequately chlorinated, increasing the risk for contamination and disease transmission. The association between illness with S. sonnei and ingestion of recreational water has been described previously.^8,9 The association between illness and consumption of food or drink at the fountain may represent contamination of food and drink by fountain water, or the potential for increased fountain water ingestion among those consuming foods and beverages at the fountain.

Most bacterial outbreaks in recreational water could be prevented if pool and interactive fountain operators maintained mandated chlorine levels at all times and monitored levels more frequently during times of heavy patronage. Although effective chlorination should reduce the risk for S. sonnei transmission, disinfection is not instantaneous, as pathogens may be temporarily sheltered from chlorine when presented as a large bolus of fecal material, resulting in transient contamination. The prevention measures instituted by FDH underscore that water treatment alone does not guarantee illness prevention. The public also should be informed that swimming or playing at recreational water venues is communal bathing and can lead to diarrheal disease transmission when the water becomes contaminated and is swallowed.

To reduce risk for contamination and disease transmission, persons visiting recreational water venues should (1) avoid entering a traditional pool or playing in an interactive fountain if they have diarrhea; (2) avoid swallowing pool or fountain water; (3) practice good hygiene by taking a soap and water shower at home or at the pool, especially after a bowel movement and before entering the water; (4) escort young children to the toilet frequently and clean their bottoms thoroughly before allowing them to resume play;(5) avoid sitting on or over fountain jets because this can increase the risk for water contamination; and (6) take precautions not to contaminate foods or beverages consumed in or near the bathing area with pool or fountain water. Parents should be aware that no diaper (including swim diapers or swim pants) completely prevents stool leakage. If diapered children are to play in waterparks, diapers should be changed immediately after a bowel movement in restrooms where hands and bottoms can be washed thoroughly with soap and water.

Although interactive fountains may not require health department review in some states, waterpark or water attraction operators should recognize that the lack of a pool in these attractions does not necessarily reduce the risk for waterborne disease transmission. States should examine existing regulations for all public recreational water venues and for fountains not intended for interactive water play,¹⁰ and should ensure that all public recreational venues and fountains using recirculated water receive appropriate oversight by public health officials. Additional information for bathers, parents, and pool operators on recreational water safety can be obtained on the World-Wide Web at http://www.cdc.gov/ncidod/dpd/parasiticpathways/swimming.htm.

References: 10 available

*Fountains intended for recreational use, often located at waterparks, as opposed to noninteractive ornamental fountains intended for public display, not recreational use, often located in front of buildings and monuments.

MMWR. 2000;49:585-589

2 tables omitted

Childhood vaccinations have a major impact on the reduction and elimination of many causes of morbidity and mortality among children.¹ Monitoring vaccination coverage levels is necessary to characterize undervaccinated populations and to evaluate the effectiveness of efforts to increase coverage. The National Immunization Survey (NIS) provides ongoing national estimates of vaccination coverage among children aged 19-35 months based on data for the most recent 12 months for each of the 50 states and 28 geographic areas.² This report presents the findings of the 1999 NIS,* which indicate that vaccination coverage among U.S. children aged 19-35 months were at or near record high levels.

To collect vaccination information for all age-eligible children, NIS uses a quarterly random-digit-dialing sample of telephone numbers for each survey area. During 1999, 33,548 household interviews were completed, representing 34,442 children. The response rate for eligible households for the 78 survey areas was 66.3%. Following the interviews and with parental/guardian consent, data accuracy was verified from vaccination providers. Children with provider data were weighted to represent all children surveyed and to account for nonresponding households, changes in natality patterns, and lower vaccination coverage among children in households without telephones.²

In 1999, national vaccination coverage for three doses of any diphtheria and tetanus toxoids and pertussis vaccine (DTP) was 95.9%; for three doses of poliovirus vaccine, 89.6%; for three doses of Haemophilus influenzae type b vaccine (Hib), 93.5%; for one dose of measles-mumps-rubella vaccine (MMR), 91.5%; for three doses of hepatitis B vaccine (HepB), 88.1%; and for one dose of varicella vaccine (VAR), 59.4%.

From 1998 to 1999, national coverage with the combined vaccination series 4:3:1 (four doses of DTP, three doses of poliovirus vaccine, and one dose of measles-containing vaccine) and with 4:3:1:3 (4:3:1 series and three doses of Hib) did not change significantly. Coverage with VAR increased from 43% in 1998 to 59% in 1999.

In 1999, state-specific coverage for the 4:3:1 series ranged from 70% to 91%, and the 4:3:1:3 series ranged from 69% to 91%. For selected urban areas, coverage ranged from 67% to 87% for the 4:3:1 series and from 63% to 87% for the 4:3:1:3 series.

National Center for Health Statistics; Assessment Br, Data Management Div, National Immunization Program, CDC.

National coverage for routinely recommended childhood vaccines has increased substantially since 1993, when the Childhood Immunization Initiative (CII) was implemented by the federal government.³ The findings in this report indicate that national coverage for the recommended vaccines remain at or near record high levels. However, this coverage level cannot ensure protection for children born during or after 1999 even though levels observed in 1999 demonstrate the feasibility of attaining high coverage. Achieving and sustaining the national health objectives for 2010 vaccination coverage and disease-elimination⁴ will require developing a functional vaccine-delivery system. This effort will require collaboration among national, state, local, private, and public partners.

A comprehensive vaccine-delivery system that would achieve and maintain high vaccination coverage levels⁵ and low morbidity in children born during or after 1999 should consist of three components. These components are (1) state- and community-based computerized vaccination registries that include all children from birth, that can identify children needing vaccination, and can recall them for missed vaccinations⁶;(2) ongoing quality-assurance and information-feedback activities⁷; and (3) education programs for parents and health-care providers.

High coverage levels are necessary to maintain and reduce illness, disability, and death associated with vaccine-preventable diseases. Assessment of vaccination coverage levels is an important component of the U.S. immunization program. To maintain the integrity and reliability of the national immunization system, a core surveillance effort that includes immunization coverage levels is essential.⁸ NIS is the primary source of vaccination coverage data among U.S. preschool-aged children.⁵ NIS should continue to characterize at-risk children and evaluate the effectiveness of programs designed to increase coverage.

References: 8 available

*For this reporting period (January-December 1999), NIS included children born during February 1996-May 1998.