Disease Control Bulletin: July 2002

Contents

disease control bulletin

Heat-Related Illness

As summer approaches, we enter the time of year whenheat-related emergencies are more likely to be encountered. While Vermont does not commonly experience the oppressive heat that sometimes results in heat-related illness, some people remain at risk and need to take simple precautions to avoid such problems.

Types of Heat Emergencies

There are four types of heat-related illness:

These four conditions are progressive in severity and usually heat stroke is the only one considered life threatening.Heat stroke can lead to shock, brain damage, organ failure and death.

Epidemiology of Heat-related Illness

The lack of a standardized method of defining a heat-related illness or death makes it difficult to obtain definitive statistics on morbidity or mortality. Nevertheless, the occurrence of heat waves has provided researchers with opportunities to delineate factors that appear to be related to heat illness. Anyone exposed to excessive heat is at risk, but factors associated with increased risk include:

Heat-related deaths for the United States, when plotted according to age, have a skewed, concave distribution. The average annual rate of heat-related deaths for infants and children under age 4 is 0.3 per 1,000,000 population. The rate drops to less than 0.05 for 5 to 9 year-olds (the lowest rate of any age group) and then increases steadily with age. Among people age 55 to 64 the average annual death rate is slightly greater than 1 per 1,000,000 population. That goes up to about 1.5 for people age 65 to 74 and greater than 3 for people age 75 to 84. For those over age 85, the rate is almost 5 per 1,000,000, a risk almost 100 times as great as the risk for 5 to 9 year-olds.

Mortality estimates for heat stroke vary widely. Rates as low as 0 percent fatalities have been reported in small case series. Rates as high as 70 percent have also been reported, however. Survival appears to be strongly linked to patient age, health status and timeliness of treatment.

Patients who experience heat stroke related to exertion seem to survive more often than those with classical heat stroke. Interpretation of this information is difficult since exertional heat stroke occurs more often in the young and classical heat stroke in the old and infirm. Additionally, young patients are more likely to collapse when witnesses are present. The elderly and disabled population is more likely to be alone, sometimes making prompt discovery and intervention impossible.

Information regarding sequelae is limited. The available data suggest that hepatic damage is almost universally present in heat stroke, but fortunately does not typically lead to permanent dysfunction. Renal damage, too, is common, particularly when there is hypotension or myoglobinuria. Diarrhea, though it occurs frequently, is a transient phenomenon.

Pathophysiology

Heat cramps, which tend to occur after exercise as the victim is relaxing, seem to be related to salt deficiency.

Heat syncope occurs when heat causes the blood vessels to the skin to dilate. Combined with the pooling of blood which occurs from standing, this movement of blood out of the central circulation causes decreased blood to the vital organs and results in a faint.

Heat exhaustion is due to severe dehydration and electrolyte loss. Generally, it results from strenuous activity in a hot, humid environment. Fluids are lost through perspiration and breathing and electrolytes might become imbalanced. Patients often experience cramps, headache, fatigue, nausea and vomiting. They may appear listless, with pallor of the skin and profuse sweating. There can be altered mental status, lack of coordination, and diffuse weakness. The treatment for minor symptoms is to provide a cooler environment and begin rehydration. For more severe symptoms, medical attention should be sought.

Heat stroke is the catastrophic life-threatening condition that results when the body is no longer able to regulate temperature. The greatly elevated body temperature begins to effect body tissue damage and leads to organ system dysfunction. The cells of the body, having been unable to cope with rising temperature are taxed to the limit and begin to fail. Body temperatures of 104 degrees Fahrenheit or higher are typical.

In heat stroke, changes in organ systems, including the nervous system and brain occur, the onset is often sudden and the level of consciousness is altered. In addition to symptoms similar to heat exhaustion, there may be confusion, delirium or coma and seizures. Eventually, the cardiovascular system fails. Spontaneous hemorrhage can occur. Within a short amount of time, the liver is affected, the kidneys begin to fail, and the respiratory system is overwhelmed.

Presentation and Management

Heat cramps commonly present with symptoms of muscle cramping, profuse sweating, thirst and fatigue. Management of a patient with these symptoms includes movement to a cool or shady environment. Give sips of cool water or other commercially available electrolyte replacement fluids every 15 minutes. Cool wet cloths applied to the skin with fanning will help maintain or lower elevated body temperatures. Avoid alcohol rubs and do not apply ice directly to the skin. Avoid further exercise until the patient is symptom free and ambient temperatures are cooler.

Heat syncope is often associated with extended periods of standing in a hot environment and fluid loss. The patient presents as a typical faint. Prevention includes avoiding long periods of standing in hot environments and maintaining adequate hydration. Treatment includes cooling as previously described. Manage the patient’s airway and elevate the legs until the patient is fully conscious and alert. Give nothing by mouth until the patient is conscious and alert.

Heat exhaustion may progress from heat cramps to include symptoms of headache, light-headedness/dizziness, weakness, nausea or vomiting, cool moist skin, and dark urine. Management remains as previously described with special attention to monitoring the patient for progression to heat stroke.

Heat stroke is a life threatening condition that requires prompt medical intervention. A person with heat stroke will present with signs and symptoms that may include: very high body temperature (above 104° F); irrational behavior or confusion; hot, dry skin (might be moist if the person has been exercising); rapid, shallow breathing; weak, rapid pulse; seizures; and unconsciousness. Call 911 immediately. Control the patient’s airway and begin body cooling by removing clothing, applying cool moist cloths to the body, and fanning. Cold packs in the armpits, groin and neck areas might improve cooling. Administer oxygen and secure IV access, if possible, pending definitive medical management.

In caring for a patient with a heat-related illness, there are several things to avoid:

Prevention

The best management of heat-related illness is prevention. There are several common sense steps that can reduce the likelihood of problems.

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HIV/AIDS Surveillance: Frequently Asked Questions

What is HIV and AIDS surveillance and why is it conducted?

HIV and AIDS surveillance is the process of collecting, analyzing, and interpreting data about individuals infected with HIV or diagnosed with AIDS. Information derived from these data assist in the development of programs to prevent infection with HIV and to plan and evaluate treatment and support programs for Vermonters living with HIV and AIDS.

HIV surveillance, which is relatively new in Vermont, has become increasingly important in recent years as treatment advances such as antiretroviral therapy slow the progression of HIV infection to AIDS. People are living longer with HIV, which means that AIDS data alone cannot give us a reliable estimate of the HIV epidemic or trends in HIV transmission. HIV surveillance data will help the Vermont Department of Health more effectively target our HIV prevention efforts in Vermont and help us support treatment for people infected with HIV.

How long has HIV and AIDS surveillance been conducted in Vermont?

AIDS surveillance in Vermont began in 1982, when AIDS was added to the list of Reportable Diseases and Syndromes in theVermont Department of Health’s Communicable Disease Regulations, which were adopted and are periodically updated pursuant to 18 V.S.A. § 1001. HIV was added to the list in 2000.1

What data are collected?

HIV and AIDS surveillance data include date of birth, gender, county of residence, date of diagnosis, and other information. HIV case reports collected by the department use a unique identifier code made up of certain letters of the person’s name and certain digits of the person’s Social Security number. A specific name and number will always generate the same unique identifier; the unique identifier, however, cannot be converted back to reveal the name from which it was created. AIDs cases are reported to the Department of Health by name; names are necessary to assure complete and non-duplicated information regarding cases of reportable diseases.

What are the sources of HIV and AIDS data?

The Vermont Department of Health collects information about HIV and AIDS cases from Vermont laboratories and health care providers and from other states. In Vermont, separate forms are used to report AIDS cases and HIV infection. Routine surveillance practices are used to eliminate duplicate cases at both the state and national levels.

Vermont health practitioners are required to report both incident (newly diagnosed) and prevalent (previously diagnosed) cases of AIDS, including patient names and other identifying information that is kept confidential and privileged by law.

HIV reporting is more complicated because some tests are performed anonymously.

The HIV unique identifier code also is used by the department to record information provided by other states about Vermont HIV positive cases. (Thirty-four states and territories currently require confidential name-based reporting for confirmed HIV infection.2 Only a few states other than Vermont use code-based HIV reporting systems. All states require the reporting of diagnoses of AIDS confidentially by name to their respective health departments.)

Why is it important to report someone who has progressed to AIDS if this person has already been reported with HIV infection?

Knowing how HIV infection progresses to AIDS among HIV-positive Vermonters will help the department and its service providers to direct appropriate services to populations in need. Additionally, reporting is required under Vermont laws and regulations.

Should a case of HIV infection or AIDS detected in Vermont be reported to the Health Department even if it already has been reported in another state?

Yes. Such reporting is required by Vermont law and is necessary to assure completeness of reporting.

For more information about HIV and AIDS surveillance or to obtain reporting forms, please contact HIV/AIDS Surveillance, Vermont Department of Health, 802-863-7240 or (in Vermont) 800-640-4374.

References

  1. Centers for Disease Control and Prevention. Guidelines for national human immunodeficiency virus case surveillance, including monitoring for human immunodeficiency virus infection and acquired immunodeficiency syndrome. MMWR 1999;48(RR-13).
  2. Centers for Disease Control and Prevention. HIV/AIDS Surveillance Report. 2001; 13(No.1): 36-37.

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Microbial Etiology of Chronic Diseases

Microbes are known to cause a wide range of infectious diseases. Such a disease could have an acute course, as in meningococcal meningitis or a chronic course, as intuberculosis. Some microbes, such as poliovirus (paralysis)or Chlamydia trachomatis (trachoma), have long been associated with chronic conditions following acute infectiousdisease. Although as long as 100 years ago there had beenspeculation that cervical cancer was related to sexually transmitted infections, microbes have not generally beenassociated with the more common chronic diseases such ascardiovascular disease, cancer and chronic respiratory diseases.

We now know that microbes can be linked to a growinglist of chronic diseases not previously thought to have an infectious etiology. New technologies, along with somelandmark scientific reports over the last few decades, have opened up the possibility in the minds of many medicalscientists that many chronic diseases might have microbial links.

For example, today in the United States approximately oneout of seven cases of cancer has a microbial etiology. Amongthe cancers with a clear infectious agent link are stomach cancer (Helicobacter pylori), cervical cancer (human papilloma virusor HPV), liver cancer (hepatitis B and C viruses) Burkitt’slymphoma (Epstein Barr virus) and Kaposi’s sarcoma (herpesvirus 8). Scientists have established that these microbialagents are necessary but not sufficient to cause these types ofcancer. Other factors, such as genetics and the environment, influence the ultimate development of specific cancers.

Determining whether a specific chronic disease isassociated with one or more microbial agents is a complex challenge. Some of the factors that limit the ability of scientiststo make these connections include: biotechnologicallimitations, lack of plausible explanations for pathogenic mechanisms, multiple organisms or possibly multifactorialmechanisms which are required to cause disease, andinadequate animal models. The basic biological mechanisms by which we develop chronic diseases are still poorlyunderstood and the means by which microorganisms could influence those mechanisms are understudied.

Koch’s postulates, developed in the late 1800’s require the ability to isolate an agent and an animal to causally link microorganisms and disease However, in order to determine the link between a microorganism or combination of microorganisms and a specificchronic disease, scientists need to utilize additional branches of science including epidemiology, immunology, molecular biology and genetics. Microbiologists and epidemiologists will have to collaborate on long-term population-based studies. Ever more sophisticated techniquesto measure the presence of not just fastidious microorganisms but also their antigenic components or even their uniquegenetic sequences will have to be combined with immunologicstudies. Some investigations will also involve the indirect evidence of microbial etiology by demonstrating that antimicrobial therapy has a protective or even therapeutic effect with respect to certain chronic diseases. Finally, thesearch for animal models will have to continue. We knowthat many of the early studies with respect to viral cause of cancers were performed in animals. That same effort will haveto be applied to the study of the possible microbial etiologyof such chronic diseases as cardiovascular disease and respiratory disease. Finally, scientists and the public will needto overcome skepticism about the infectious etiology ofchronic diseases.

chronic diseases or conditions with well established associations with microbes. for more info contact the dept of health

chronic diseases or conditions with strong associations with microbes for more info contact the dept of health

chronic diseases or conditions with potential associations with microbes, for more info contact the dept of health

Resources:

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The Alphabet Soup of Hepatitis: A Quick Guide to Diagnosis and Testing

Hepatitis A, hepatitis B, hepatitis C, and hepatitis non-ABC are reportable infectious diseases in Vermont. Each is diagnosed based on clinical and laboratory criteria. Hepatitis B and hepatitis C can present as acute or chronic illness. Several blood tests are available to establish accurate diagnoses.

Hepatitis A

Acute hepatitis A, caused by the hepatitis A virus (HAV), is usually a fairly straightforward diagnosis in adults. The clinical picture includes malaise, anorexia, nausea with or without vomiting, fever, and jaundice, plus dark-colored urine and light-colored stools. Children can present with similar symptoms, but are often asymptomatic while potentially infectious. Liver function tests (serum aminotransferases) are elevated. Laboratory diagnosis of acute hepatitis A is made with a positive hepatitis A IgM antibody test. False positive results are very uncommon and can occur in the presence of a positive rheumatoid factor. A positive hepatitis A IgG antibody represents past infection or response to hepatitis A vaccination.

Immediate reporting of an individual with acute hepatitis A allows the Vermont Department of Health to investigate the case and 1) determine a possible source of the infection, 2) identify other related cases, and 3) recommend disease control measures, including immunoglobulin and/or hepatitis A vaccination for contacts. Hepatitis A can be acquired by eating foods that have been contaminated with HAV; contamination might have occurred at the source of the food, e.g., in seafood caught in waters contaminated with infected sewage, or during food preparation, e.g., by an infected food service worker. Hepatitis A can also be transmitted through sexual practices involving oral-fecal exposure. Vaccine to prevent hepatitis A is recommended for children in specified endemic areas (none in Vermont), for travelers to developing countries, and for individuals with chronic liver disorders, including chronic hepatitis B and chronic hepatitis C.

Hepatitis B

Acute hepatitis B, caused by the hepatitis B virus (HBV), presents a clinical picture just like that of hepatitis A in adults; children with acute hepatitis B display symptoms as well. HBV is transmitted through blood and blood products, shared intravenous drugs and drug paraphernalia, and through sexual intercourse. Injection drug users and individuals with multiple sex partners, including men who have sex with men, are at increased risk for acquiring hepatitis B.

Chronic hepatitis B occurs when, for reasons not yet understood, an individual who has contracted acute hepatitis B is unable to clear the HBV. This occurs in 5 to 10 percent of patients, especially those in whom initial HBV infection was asymptomatic. Continued infection damages the liver, resulting in fibrosis and cirrhosis and greatly increased risk for the development of hepatocellular carcinoma. Individuals with chronic hepatitis B infection can transmit the infection to a susceptible contact via blood products, sharing of intravenous drugs/drug paraphernalia, and sexual intercourse. Children born to women with acute or chronic hepatitis B infection can acquire the infection at birth unless they are treated within 24 hours of birth with hepatitis B immune globulin (HBIG) and vaccine; the combined treatment is 85 to 95 percent effective in preventing perinatal HBV infection.

Laboratory diagnosis of acute and chronic hepatitis B can be confusing. Hepatitis B surface antigen (HBsAg) will be positive at the onset of symptoms in 95 percent of patients with acute hepatitis, although in a small percentage of patients, HBsAg is cleared rapidly and might have disappeared by the time the patient is tested. Antibody to hepatitis B core antigen (anti-HBc) usually appears at or about the time of symptoms; IgM anti-HBc disappears 6–24 months after infection, while total anti-HBc can persist longer. Hepatitis Be antigen (HBeAg) also is detectable for a short while following the onset of symptoms, and anti-HBe appears as HBeAg disappears. HBV-DNA is detectable with the onset of symptoms using gene amplification techinques such as the polymerase chain reaction (PCR) assay. Antibody to HBsAg (anti-HBs) is detectable several months into convalescence. With chronic hepatitis B, HBsAg and (usually) HBV-DNA and HBeAg remain detectable in the blood. (See Table)

As with hepatitis A, immediate reporting of an individual with acute hepatitis B allows the Vermont Department of Health to investigate the case and 1) determine a possible source of the infection, 2) identify other related cases, and 3) recommend disease control measures, including HBIG and/or hepatitis B vaccination for susceptible contacts. Hepatitis B vaccination is now part of the routine childhood immunization schedule, with the first dose to be given at 0–2 months of age, the second dose at 1–4 months of age, and the third dose at 6–18 months of age. The vaccine is also recommended for at-risk adults, including men who have sex with men, heterosexuals with multiple sex partners, persons diagnosed with a recently acquired sexually transmitted disease (STD), persons who exchange sex for money or drugs, injection drug users, persons on hemodialysis, and health care workers with potential exposure to blood or blood products.

Hepatitis C

Acute hepatitis C, caused by the hepatitis C virus (HCV) is usually asymptomatic. Of the 15 percent of cases that are diagnosed by a physician, typical acute hepatitis symptoms are accompanied by elevated transaminases (greater than 2.5 times the upper limit of normal) and negative tests for acute HAV or HBV infection. Antibody to HCV appears within 15 weeks of infection in 80 percent of patients and by six months in at least 97 percent of patients.

Chronic hepatitis C infection is usually identified as an incidental finding during a routine physical exam and laboratory workup that includes liver function tests. Physicians detecting elevated liver enzymes will often order a “hepatitis panel” and the anti-HCV test is reported as positive. Interpretation of hepatitis C tests requires care. Currently, the initially positive screening enzyme immuno assay (EIA) test must be confirmed with a recombinant immunoblot assay (RIBAtm) test before an individual should be considered positive for hepatitis C; in the near future, the signal-to-cutoff ratio of repeated EIA tests will be another way of confirming positivity. Because an EIA positive/RIBA positive individual might actually be negative for the virus, additional molecular tests are necessary. The most common qualitative HCV test is the reverse assay. A confirmed positive test for hepatitis C then must be correlated with history and other laboratory findings to determine if this is an acute case, a recovered case (no persistence of infection), or a chronic case (hepatitis C antigen detected through RNA testing and increased liver enzymes; both of these parameters can be intermittently positive).

There is no vaccine against hepatitis C, and the major preventive intervention is education to limit exposure. Hepatitis C is transmitted through blood and blood products. Individuals (including persons with hemophilia) who received blood products or blood transfusions before 1990 are at risk for having undiagnosed chronic disease, and injection drug users are at especially high risk of acquiring infection or having undiagnosed disease. Sexual transmission of HCV is also possible, though not common. Other risk factors include being on hemodialysis, having a history of sexually transmitted disease, and having a large number of lifetime sexual partners.

The Vermont Department of Health receives laboratory reports of positive anti-HCV and HCV antigen tests as well as physician reports of cases of hepatitis C. We follow up on all new reports, requesting information from the ordering physician that allows assignment of acute or chronic hepatitis C to be made. Acute hepatitis C is reportable to the CDC. Chronic hepatitis C is not currently reportable to CDC, however information on the prevalence of this illness in Vermont will be used to direct limited resources to appropriate populations for prevention, counseling and testing, and medical referral. We recently received a small grant from the Council of State and Territorial Epidemiologists (CSTE) for hepatitis C planning.

Fact sheets are available at: http://www.cdc.gov/ncidod/diseases/hepatitis/index.htm

To report a case of hepatitis contact: Infectious Disease Epidemiology, Vermont Department of Health, 802-863-7240 or 800-640-4374 (Vermont only).

References:

  1. Centers for Disease Control and Prevention. Epidemiology and Prevention of Vaccine-Preventable Diseases. 7th edition. January, 2002.

Resources

interpretation of hepatitis b seologic chart. for more info, contact the dept of health

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Vermont: Selected Reportable Diseases June 1, 2002

reportable diseases june 1 2002. for more info contact the dept of health

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2002 Sexually Transmitted Diseases Treatment Guidelines Available Online

The Centers for Disease Control and Prevention’s (CDC) updated 2002 guidelines for the diagnosis and treatment of sexually transmitted diseases (STDs) are now available at http://www.cdc.gov/std/treatment. New information in the 2002 guidelines includes:

  1. A recommendation for expanded screening for chlamydia, advising providers to screen all women under age 25 annually, as well as older women who report a change of partner or multiple sexual partners since their last screening. Individuals testing positive for chlamydia should be rescreened three to four months after treatment is completed.
  2. A warning about the emergence of ciprofloxacin-resistant gonorrhea.
  3. A notice about the availability of new serological tests to aid in diagnosing genital herpes.
  4. A recommendation that health care providers ask all male patients about the gender of their sexual partners. Men who have sex with men need annual screening for STDs, including HIV, chlamydia, syphilis, and gonorrhea, and vaccination against hepatitis A and B.

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Readership Survey Results

Thanks to all the Disease Control Bulletin (DCB) readers who responded to the readership survey published in the January, 2002 issue. By April 19, 2002, we received 205 responses.

The majority of respondents rated the overall quality of the DCB as excellent (68%) or good (32%), with excellent (56%) or good (42%) content and excellent (61%) or good (39%) readability. Most respondents always (63%) or usually (34%) read the DCB, reading all (32%), most (59%), or some (9%) of the articles. The DCB is read by more than the person to whom it is addressed most of the time; 57% of respondents share their issue with one to five people, 6 percent share with 6–10 people, and 8 percent share with more than 10 people, including one library and a bulletin board.

Respondents are interested in seeing articles addressing topics in infectious disease, environmental health, chronic disease, vital statistics and reports, injury prevention, bioterrorism, health policy and planning, maternal and child health, and occupational health (ordered by frequency of response, most frequent to least frequent). The DCB editorial board has noted specific topics that respondents suggested for articles.

Readers of the DCB work in a variety of mostly health care-related occupations. Forty percent of respondents identified themselves as nurses or nurse practitioners; 30 percent are physicians; others are infection control practitioners, administrators, physician assistants, public health professionals, veterinarians, and a variety of other occupations, including pharmacists, EMTs, researchers, midwives (not specifically identified as nurses), laboratorians, and others. They work (listed most frequent to least frequent) in ambulatory care settings, schools, hospitals, health departments, universities, nursing homes, or are retired or in other settings, such as camps, town or federal offices, outdoors, and other public and private offices.

Using the input from this survey, the editorial board of the Disease Control Bulletin will continue to work to provide a useful publication that reports the work of the Vermont Department of Health. Please feel free to contact us with your comments and suggestions at 802-863-7240, 800-640-4374, or via email at DCBulletin@vdh.state.vt.us.

REPORT DISEASE: VERMONT TOLL FREE: 1-800-640-4374 OR 1-802-863-7240

Vermont Department of Health
Division of Health Surveillance P.O. Box 70 Burlington, VT 05402-0070
Agency of Human Services
Jan K. Carney, MD, MPH
Commissioner

THIS BULLETIN IS PRODUCED BY THE DISEASE CONTROL BULLETIN EDITORIAL STAFF.

Ann R. Fingar, MD, MPH
State Epidemiologist Managing Editor

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