Disease Control Bulletin: January 2001

Contents

disease control bulletin

HIV REPORTING: A YEAR IN REVIEW

First Statewide HIV Data Released

Since HIV infection became reportable in Vermont in March 2000, many health care providers have responded to the call of reporting new and prevalent HIV cases. As a result of many collaborative efforts, the first preliminary statewide HIV case surveillance data were just released.

A total of 131 prevalent HIV cases were reported through December 2000, representing Vermont residents reported to be living with HIV infection who have not developed AIDS. The majority of cases, 80 percent, are men, and 69 percent of all cases are people between the ages of 20 and 40 years.

vermont prevalence of aids chart

Vermont HIV/AIDS Prevalence Reported through December 2000

There is a growing proportion of new HIV infections in Vermont women and in 20–29 year-olds, based on the percent of reported HIV cases being higher than that of AIDS cases. As with AIDS data, the HIV data show a disproportionately high number of cases among minorities in Vermont. The percent of prevalent HIV cases based on mode of exposure categories are as follows: men who have sex with men 57 percent; non-prescription injection drug use 15 percent; heterosexual contact 11 percent; hemophilia/blood products 4 percent; undetermined/other 13 percent.

The HIV data include people who were Vermont residents at the time of diagnosis. People who were Vermont residents at the time of diagnosis but moved out of state before HIV reporting began in Vermont may not be included. No one who lived in another state at the time of diagnosis but currently resides in Vermont is reported in Vermont data; residence at diagnosis is the national standard used for including cases in analysis.

Why Are the Data Provisional?

Vermont HIV data are provisional due to the short time that the reporting system has been in place and the need to further evaluate the unique identifier reporting system. Currently, all states require confidential name-based reporting of AIDS cases. Nationwide, over three-quarters of the HIV surveillance systems are also name-based. Vermont’s HIV reporting system usesa unique identifier, rather thana name, for each case reported.

Reportability of HIV Infection

HIV surveillance was implemented in Vermont on March 24, 2000. Both prevalent and incident cases are reportable. As with all communicable diseases, patient consent is not required in order to report HIV to the Department of Health. The HIV/AIDS Surveillance Program upholds the strictest confidentiality procedures, and several measures are used to keep patient information secure.

The Reportable Disease Law (VSA Title 18, Chapter 21, Section 1001) states that ifa medical practitioner has reason to believe thata person is sick or has died ofa diagnosed or suspected reportable disease, he or she shall transmita report of the disease within 24 hours. A copy of the Reportable Disease Law is located at http://www.leg.state.vt.us/statutes/statutes.htm, and the Communicable Disease Regulations are found at http://www.state.vt.us/health/regs.htm.

Who Is Required to Report?

Any medical practitioner who refers HIV-positive individuals toa specialist for care is responsible for filing an HIV case report with the Department of Health. Multiple case reports may be submitted to the HIV/AIDS Surveillance System for the same patient’s infection. More than one clinician can be involved in the diagnosis and/or treatment of the patient, and each provider is required to report the case to the Department of Health. To avoid over-reporting HIV/AIDS in published reports, multiple reports for the same individual are compiled and merged into one record.

How to Report

There are four different case report forms used by the HIV/AIDS surveillance system: adult AIDS, pediatric AIDS, adult HIV, and pediatric HIV. Adult forms are used for people aged 13 years and older; pediatric forms are for children 12 years and under. HIV forms are used when a person is known to have HIV infection, but has not developed AIDS.

AIDS forms are used when a person meets the case definition for AIDS, involving a CD4+ T-lymphocyte count of less than 200 cells per microliter and/or the diagnosis of an AIDS-indicator condition. The 1993 Revised Classification System for HIV Infection and Expanded Surveillance Case Definition for AIDS among Adolescents and Adults is located at http://www.cdc.gov/mmwr/preview/mmwrhtml/ 00018871.htm.

If a person has been previously reported with HIV and develops AIDS, a new AIDS case report is required to be filed with the Department of Health.

Laboratory Reporting

Laboratories are covered under the Communicable Disease Regulations, and laboratory findings are used to identify potentially unreported cases of HIV infection in Vermont. The unique identifier and birthdate froma laboratory report is compared with the HIV and AIDS databases to determine ifa case has been reported to the surveillance system. If a match cannot be made, then the medical practitioner who ordered the test is contacted, anda case report is requested.

This laboratory follow-back procedure is used only for quality assurance purposes, to improve completeness of HIV reporting. Laboratories are required to provide fewer case details than are medical practitioners. Many more data items are needed from the clinician to complete the necessary case information for each individual. The surveillance system relies on every provider to submit case reports every time he/ she seesa new HIV or AIDS patient in his/her practice.

How Complete Are the Data?

Completeness of case reporting is one of the most important criteria used for evaluating HIV surveillance systems. With very small counts, it is very difficult to distinguish between random fluctuation and actual health issues. Estimates for low prevalence states such as Vermont are less accurate than higher prevalence states, which poses a challenge when evaluating the completeness of case reporting.

There are two ways of estimating the completeness of HIV reporting, prevalence (people living with HIV infection who have not developed AIDS) and seroprevalence (all people living with HIV regardless of AIDS diagnostic status).

As of December 1998, CDC estimated 223 people were living with HIV infection in Vermont. According to the prevalent cases of HIV infection, 108 people were reported to be living with HIV in Vermont as of December 1998, representing an estimated 48 percent completeness in case reporting. Since retrospective reporting was necessary to capture as many prevalent HIV infections as possible, prevalence is expected to be lower for past years.

CDC estimated that, at the end of 1998, there were 800,000-900,000 U.S. residents living with HIV/AIDS. However, CDC estimated that only two-thirds of these people had had HIV infection or AIDS diagnosed and were therefore able to be reported. Using the proportion of national annual AIDS incidence diagnosed in Vermont, an estimated 267 to 301 individuals were living witha diagnosis of HIV/AIDS in Ver-mont at end of 1998. As of December 1998, 282 Vermont residents were reported to be living with HIV/AIDS. By looking at the number of people reported with HIV infection only, as well as those who had developed AIDS, the Vermont data appear to be complete through 1998 when this method of estimation is used.

Future Plans for HIV Surveillance

The HIV/AIDS epidemic has affected every county of Vermont. With improved surveillance efforts, better targeted resources, and a better informed community, the data from HIV case reporting can be used to better understand the epidemic in our state. This will enable public health officials and others to evaluate the effectiveness of HIV prevention activities, assist in allocating resources, and plan for future prevention and service needs.

The Vermont HIV/AIDS Surveillance Program will continue to work with infectious disease clinicians, laboratories and other health care providers to achieve complete reporting for this infectious disease. The Department of Health will be evaluating the performance of the HIV surveillance system in collaboration with the CDC.

For More Information

To request HIV/AIDS case reporting forms, a copy of the HIV Surveillance fact sheet, or a copy of HIV in Vermont, contact the Vermont Department of Health at (802) 863-7240.

References

  1. CDC. 1993 Revised classification system for HIV infection and expanded surveillance case definition for AIDS among adults and adolescents. MMWR 1992;41:1-19.
  2. CDC. Guidelines for national human immunodeficiency virus case surveillance, including monitoring for human immunodeficiency virus infection and acquired immunodeficiency syndrome. MMW R 1999;48.
  3. CDC. HIV/AIDS Surveillance Update. 2000;12(No.1).
  4. CDC, National Center for HIV, STD, and TB Prevention. Web Site. 2000.
  5. Vermont Department of Health, Surveillance Data Standards Committee. Recommendations for Surveillance Data Standards at the Health Department. 1996.
  6. Vermont Department of Health. HIV/AIDS Surveillance System. 2001.

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Chronic Disease in Vermont: Overview 1998-1999

The six leading chronic disease diagnoses at hospital discharge were related to cardiovascular disease as were the first, third and ninth leading causes of death. Cancers remained Vermont’s second leading cause of death, although they did not appear among the leading chronic disease causes for hospitalizations1. Vermont’s age-adjusted mortality rates (Figure 1) were statistically significantly higher than theU.S. for chronic obstructive pulmonary disease (COPD) 46.3 per 100,000 95% confidence interval (95%CI) [43.8,48.9] and diseases of the arteries, 12.5 per 100,000 95%CI[11.3,14.0] and lower than theU.S. for heart disease, 270.9 per 100,000 95%CI[264.8,277.1] and stroke, 60.2 per 100,000 95%CI[57.3,63.1]2,3.

Vermont has significantly lower age-adjusted hospitalization rates than theU.S. for nine out of 12 leading chronic disease causes (Figure 2)4. These differences are especially marked for coronary atherosclerosis, congestive heart failure (CHF), and stroke (acute cerebrovascular disease). There was no statistical difference between Vermont andU.S. hospitalization rates for heart attacks (acute MI), nonspecific chest pain or osteoarthritis.

In 1999, the crude self-reported prevalence for both hypertension and diabetes was significantly lower for Vermont compared to the U.S. There was no difference in the prevalence of current asthma, myocardial infarction(ever), or stroke (Figure 3). Eleven states reported an arthritis prevalence of 21 percent from 1996-1998, not statistically different from Vermont’s 1999 prevalence of 21.8 percent5.

Stroke prevalence did not differ between the U.S. and Vermont. The stroke hospital discharge rate for Vermont was significantly lower than theU.S. rate, and Vermont’s stroke mortality rate was significantly, although very slightly, below theU.S. stroke mortality rate. Diabetes prevalence and hospital discharge rates were lower than the U.S. and no difference was apparent between the Vermont five-year average diabetes mortality rate and theU.S. rate6.

For more about Vermont’s goals for chronic diseases and risk factors, see Healthy Vermonters 2010 and BRFSS Highlights7,8.

References:

  1. Cancer in Vermont: A report of 1994-1996 cancer incidence data from the Ver-mont Cancer Registry. Vermont Department of Health. Burlington, VT, 1999. <http:/ /www.state.vt.us/health/CancerinVT.pdf>
  2. Age-adjustment standard United States 2000 population.
  3. Comparisons were made of Vermont’s five year average age-adjusted rates (1994-1998) and single year age-adjusted U.S. rates (1996). The 1996 U.S. age-adjusted rates per 100,000 population were 41 (COPD), 10.6 (Diseases of arteries), 288.3 (Heart disease), 63.2 (Stroke). Source: CDC WONDER.
  4. See www.ahrq.gov/data/hcup/hcupnet.htm for methods and for Nationwide Inpa-tient Sample.
  5. Health-related quality of life among adults with arthritis-Behavioral Risk Factor Surveillance System, 11 states, 1996-1998. MMWR 49(17):366-9.
  6. Diabetes in Vermont: A Review of the Data, 1999. Vermont Department of Health. Burlington, VT.
  7. Healthy Vermonters 2010. Vermont Department of Health. Burlington, VT, Sep-tember 2000. <http://www.state.vt.us/health/_admin/pubs/2000/hv2010/ hv2010.htm>
  8. Vermont Behavioral Health Risks Highlights 1998-99. Vermont Department of Health. Burlington, VT. <http://www.state.vt.us/health/_admin/pubs/2000/risk/ behavior1.htm>

^ Rates are age-adjusted to the U.S. 2000 standard population

Figure 2: Vermont Leading Causes for Chronic
Disease Hospitalizations 1996-98 versus U.S. 1997

Age-adjusted rate (U.S. 2000 standard) per 1,000 population

Figure 3: Prevalence of Selected Chronic Diseases in Vermont, 1999

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Measles

Recent experiences with measles in Vermont are a reminder of the importance of having all health care institutions and practices fully prepared to see and treat persons who present with undiagnosed measles. Despite the sharp decline of measles cases in the U.S., cases do continue to occur and exposure could happen at any time. There are unimmunized or under-immunized Vermonters who may be at risk of developing the disease if exposed to unrecognized imported cases. Since 1980, over 4000 refugees and immigrants have entered Vermont with varying and often unknown levels of immunity to all vaccine-preventable diseases. Some persons are non-immune due to not receiving immunization for various reasons. Perhaps one in a thousand may not have developed immunity following two doses of vaccine.

Since 1990, 44 cases of measles have been confirmed in Vermont. Of these, 28 cases were confirmed in 1993, with the majority occurring among children who had received only one dose of MMR vaccine. Since that time, second doses have become the accepted practice. Between 1994 and March, 2001, there have been 10 cases confirmed in Vermont. Six of these cases occurred in people exposed outside of the U.S.

Measles is an acute, highly communicable viral disease that is generally vaccine preventable. Prior to live measles vaccine that was licensed in 1963, measles was an almost inevitable childhood disease. During 1958-1962, an average of 503,282 measles cases and 432 measles-associated deaths were reported each year in the U.S. Stringent immunization programs, especially those associated with requirements for school entry, have decreased the incidence of measles by more than 99 percent. In 1999 a record low of 86 cases were reported in the U.S.

One or more complications occur in 30 percent of measles cases. Measles can result in blindness, deafness, brain and lung damage, and stunted growth and development. Otitis media is the most common complication of measles. Encephalitis is a less common complication but it may cause permanent brain damage. Measles is a major childhood killer in developing countries, accounting for about 900,000 deaths worldwide each year. Deaths have been reported in 1-2 per 1,000 measles cases in the U.S. Pneumonia is the most common cause for death. The disease is more severe and the risk of complications is greater among infants, children under age 3, and adults.

Measles is transmitted by direct contact with droplets from nasal or throat secretions of an infected person or via the airborne route. Measles is communicable from four days before rash onset until four days after the rash starts. In the pre-vaccine era the secondary attack rate exceeded 90 percent. Documentation exists of transmission of infections to persons who enter a room recently vacated by a person with measles. Non-immune people who occupied a space vacated within two hours by a person during the infectious stage of measles are considered exposed.

People who work in medical facilities are at higher risk for acquiring measles than the general public. In the years 1993-1996, for which the most recent data are available,1.8 percent of the reported cases of measles in theU.S. occurred in persons who worked in health care facilities.

The CDC Personnel Health Guideline published in 1998 recommends that all health care personnel have documented immunity to measles. People known or found to be non-immune should be provided with immunization. Exposed personnel who do not have documented immunity to measles should be excluded from duty the fifth day after the first exposure until 21 days after the last exposure.

According to national standards, only those who meet one of the below criteria can be considered immune to measles. Health care facilities may require additional evidence of immunity for those born before 1957.

  1. Those born before January 1, 1957 OR
  2. Those who have received two doses of measles-containing vaccine, with both doses administered > 12 months of age, given at least one month apart OR
  3. Those with serologic proof of immunity (i.e.: IgG antibody)
  4. Those with documentation of physician-diagnosed measles. (Assessment of physician-diagnosed disease may merit further documentation and should be considered ona case-by-case basis only.)

Health care providers should assess the immunization status of their patients and provide immunization as recommended by the Advisory Committee on Immunization Practices (ACIP). When interpreting immunization records from overseas do not assume immunity without unequivocal documentation of receipt of specific vaccines.

Recommendations

  1. Maintaina high degree of suspicion of measles when presented witha patient with fever, cold symptoms and rash. Report suspected cases to the Health Department, so that confirmatory testing can be expedited.
  2. Provide two doses of measles-containing vaccine (preferably MMR) according to the ACIP schedule, the first at 12-15 months of age, the second at4-6 years of age, prior to school entry. Immunize at-risk adults with two doses of MMR given one month apart.
  3. Require that all health care workers in your facility or practice be immune to measles, and maintain a log of employee’s immune status. Health care workers should have documentation of two doses of MMR received after the age of 12 months, at least one month apart OR laboratory evidence of positive measles antibody IgG titers.
  4. Exclude exposed, non-immune people who cannot, or elect not to, receive immunization from the workplace during the incubation period of the disease.
  5. Remove health care workers with active measles from duty and notify the Health Department.

NOTE: Similar recommendations should be followed for health care workers for rubella and varicella.

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Recommended Childhood Immunization Schedule United States, January - December 2001

recommended immunization chart 2001

immunixatons 2001 instructions

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Vermont: Selected Reportable Diseases January 1, 2000 - December 31, 2000*

vermont reportable diseases jan 2000 to dec 2000

Notes:

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Measles in Vermont: Recent Examples

In June, 2000 the Health Department receiveda call from a physician reporting thata child had presented the day before with fever, cough and maculopapular rash. A second child was currently in the office with similar symptoms. At the same time, a nearby hospital reported an infant who had visited the Emergency Room over the previous weekend with irritability and congestion was now at a physician’s office with conjunctivitis, rash and either thrush or Koplik spots.

These findings were consistent witha diagnosis of measles. The three unimmunized children (age 1, 2 and 3 years) were international adoptees and had only arrived in Vermont a few days before. Their measles exposure had clearly occurred outside of the U.S. The diagnosis was confirmed by a positive measles IgM antibody test on June 14, 2000.

Prompt action was necessary to prevent transmission to their contacts. The Health Department initiated intensive investigation of their activities and identified public places they had visited. Over the next few days the investigation and control activities consumed the energies of five state health departments, at least six physician practices, two chiropractic practices, three hospital infection control offices and several businesses and churches. In one emergency room exposure, at least 27 people were identified as being in the facility as a patient or other visitor in the waiting room within two hours of the index case’s visit.

One physician practice identified four health care workers with unknown immunity status. One hospital identified 14 exposed health care workers for whom immunity status was unknown. The hospital estimated the investigation consumed 20-30 hours of staff time to identify patient and staff contacts, determine individual’s immune status, and counsel those at risk. In total, 11 exposed Vermont residents were identified by laboratory testing as being non-immune. Four of the 11 were health care workers who were deferred from the workplace after exposure, missing an average of 12 days of work each.

On February 14, 2001 a report of a positive measles IgM antibody test ina college student was received. This student presented with cold symptoms, fever and atypical rash and hada history of two appropriately-administered MMR’s. This student had attended classes, social functions and visited three health care facilities during the infectious period. The health care facilities had staff records with evidence of measles immunity on file. The student health center had evidence of immunity for more than 99 percent of the student body. Comparison of known contacts to those on the list with immunization exemption made contact investigation swift and complete.

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