Division of Disease Control and Health Protection

April 29, 1999

6. FDA Satellite Training: June 16-17, 1999

Research has shown that transmission of the HIV virus from mother to baby can be reduced by approximately two-thirds if the mother and newborn are given Zidovudine (AZT).¹ Zidovudine is more effective in preventing transmission of the HIV virus from mother to baby the earlier it is given (but after the first trimester) in the pregnancy. The U.S. Public Health Service has recommended routine HIV counseling and voluntary HIV testing for all pregnant women.

In Florida,F.S.384.31 (serologic testing of pregnant women; duty of the attendant) regarding HIV counseling and testing for pregnant women became effective on October 1, 1996. Health care providers must provide prenatal counseling on the benefits of HIV testing and inform pregnant women about the options for HIV treatment if they are infected with HIV. Health care providers must also offer HIV testing to all pregnant women according to this statute.

The Bureau of Epidemiology recently completed a report on HIV testing and counseling on HIV prevention and testing among pregnant women. Using data from the Pregnancy Risk Assessment Monitoring System (PRAMS) the Bureau of Epidemiology analyzed the trends in HIV counseling and testing in Florida for women receiving prenatal care in 1996 and 1997, and found that certain groups of women are more likely to be counseled and offered testing in Florida.

PRAMS is a population based, random sample mail/telephone survey of new mothers in Florida. Each month we randomly select mothers from the state’s birth certificate file. Statistical weights are applied to the data, so that inferences can be made about all live births in Florida. Selected items from the birth certificate are included for each respondent. The response rate was 80% in 1996 and 78% in 1997.

Some of the findings are:

• For women who recently had a live birth, both the percentage who reported a health care provider talked to them about HIV testing and the percentage who were tested for HIV showed statistically significant increases between 1996 and 1997. However, the percentage receiving counseling on HIV prevention did not change at all.
• Women who were counseled on HIV testing were more likely to be tested for HIV. 91% of women who reported they were counseled on HIV testing in 1997 were tested for HIV, compared to 53% who reported they were not counseled on HIV testing.
• Women who are young, black, less educated, unmarried and/or poor, are more likely to report being counseled about HIV prevention or HIV testing and to be tested for HIV during pregnancy or delivery, than other women.
• 94% of black women who are 19 and older, unmarried and have less than a high school education, reported they were tested for HIV, compared to 75% of women who are not black, are 19 and older, are married and have more than a high school education.
• Rates of counseling on either HIV prevention or HIV testing and testing for HIV vary by source of prenatal care and type of payment for prenatal care. All are lowest for women receiving prenatal care in a private doctor’s office, in both 1996 and 1997.

While the numbers of pregnant women reporting they were counseled on HIV prevention or testing, or who were tested for HIV, increased from 1996 to 1997, there is still room for improvement. Much improvement needs to be made in counseling on HIV prevention. The number of women counseled for HIV prevention was much lower than the numbers for both testing and counseling for testing. Although Florida law does not mandate counseling on HIV prevention, it should be included with prenatal counseling on HIV testing. Universal counseling of pregnant woman on HIV testing is the law, but it is not the reality. Once pregnant women are universally counseled on HIV testing, HIV testing during pregnancy or delivery may increase.

1. Connor EM, Sperling RS, Gelber R, et al, for the Pediatric AIDS Clinical Trials Group Protocol 076 Study Group. Reduction of Maternal-infant Transmission of Human Immunodeficiency Virus Type 1 with Zidovudine Treatment. New England Journal of Medicine 1994; 331:1173-1180.

To receive a copy of the full report contact the Bureau of Epidemiology or visit the Bureau of Epidemiology’s web page at http://www.doh.state.fl.us

Although human caliciviruses, more popularly known as Norwalk-like viruses, are a major and underappreciated cause of diarrheal disease and morbidity worldwide, much remains to be learned about this pathogen. The findings of recent research presented at an international conference on caliciviruses held March 29-31 at the Centers for Disease Control in Atlanta made it clear that: (1) Norwalk-like viruses are a much larger cause of disease than our current limited surveillance data indicate and (2) much of what we thought we knew about the virus and its effects is wrong.

For epidemiologists, the main take-home messages from the conference were:

• Calicivirus are a major cause of outbreaks. Norwalk-like viruses are a principal cause of sporadic and outbreak-associated enteric disease, and should be considered in the investigation of any outbreak of diarrheal disease.
• Transmission can be person-to-person or foodborne/waterborne Although food and water are important vehicles in the transmission of Norwalk-like viruses, person to person transmission appears to be the dominant mode
• Specimen testing essential for identification. Collection of unpreserved, unfrozen stool and vomitus samples for viral identification should be the first priority in any outbreak investigation where Norwalk-like virus is a suspected cause.

Other new information presented was as follows:

• Role in outbreaks of enteric disease. In the United States, caliciviruses cause 95% of outbreaks of non-bacterial acute gastroenteritis, according to laboratory data from the CDC's Viral Gastroenteritis Section. The true proportion of all gastrointestinal outbreaks that are caused by caliciviruses in the U.S. is unknown, because the infection is not a reportable disease and because most outbreaks are identified and investigated locally.
• Laboratory identification. The explosion of knowledge about the true role of Norwalk-like viruses in human disease is due to the vast improvement in laboratory techniques in recent years. Relatively insensitive electron microscopy has been supplemented by increasingly sensitive and specific molecular techniques that permit the cloning and amplification of the virus's genetic material.
• Identification of Norwalk-like viruses in food and water. Epidemiologic investigations have been hampered by the inability of laboratories to consistently identify caliciviruses in anything but human clinical samples and shellfish. New genetically-based laboratory techniques increasingly are permitting the identification of Norwalk-like viruses in environmental and food samples. Nevertheless, detection of calicivirus in non-human samples remains difficult because no cell culture system currently exists, the virus tends to be present only in low concentrations, multiple primer sequences are necessary, and foods may contain enzymes that inhibit the polymerase chain reaction technique used to amplify the virus.
• Animal to human transmission. Until recently, humans were the only known reservoir of Norwalk-like viruses. To date, approximately 40 distinct calicivirus genotypes have been identified in 27 animal species, including pigs, cattle, dogs, fish, cats, and rabbits. Whether animal to human transmission occurs is not yet known, but genetic studies in the United Kingdom have determined that bovine caliciviruses are closely related to human caliciviruses. Also a longitudinal study in Mexico found that contact with dogs is associated with a six-fold increased risk of calcivirus infection in preschool children.
• Immunity, seasonality, and identification of new strains. Limited studies indicate that strain-specific, short-term immunity does exist, but that infection confirms no long-term immunity. Although outbreaks occur year-round, they are more common in winter and early spring worldwide. New strains are being identified and added to the caliciviruses' increasingly intricate family tree as laboratory techniques improve. More than two dozen human strains have been identified to date, but differences in nomenclature and laboratory techniques make it difficult to determine how many of these are unique.
• Serodiagnosis. Although stool and vomitus are the most common clinical specimens used in laboratory diagnosis of infection, blood samples also can be used. The primary advantage of blood is that serodiagnosis can detect antibodies weeks after infection, while viruses are detectable in stool only for about two days after illness onset. The primary disadvantage of blood is the difficulty of obtaining acute and convalescent sera (although a single convalescent serum may be used for diagnosis).

The epidemiology of Norwalk-like virus may be different in Florida because of the state's unique climate and large foreign-born population. Therefore, information on outbreaks is critical to understanding and preventing Norwalk transmission in Florida.

While Norwalk-like virus infections are not in themselves reportable conditions in Florida, all outbreaks, regardless of the cause, are reportable. Because caliciviruses play a major role in the epidemiology of gastrointestinal outbreaks, epidemiologists should consider Norwalk-like viruses in the investigation of any enteric outbreak. Epidemiologists also should be aware that person-to-person transmission is probably more common than food or waterborne transmission. However, we still have a lot to learn. Our investigation of some outbreaks suggest that they may have started as foodborne and eventually become person-to-person or vice versa.

During the past 5 years, we estimate that approximately 7% of our total food and waterborne outbreaks and 20% of all cases reported for food and waterborne outbreaks have been attributable to Norwalk-like viruses. When only confirmed outbreaks are considered for the same time frame, approximately 12% of the outbreaks (24% of the cases) are related to Norwalk-like viruses.

Also, since animals have not been ruled out as a source of Norwalk-like virus infections, outbreak investigations should include questions about contact with animals, particularly calves and dogs.

The state of Florida's Bureau of Laboratories now has the capacity to identify Norwalk-like viruses in clinical samples. Samples should not be sent to the Centers for Disease Control and Prevention for identification, as they were in the past. Instead, stool and vomitus should be sent to the state's Tampa Branch Laboratory, 3952 West Dr. M.L. King Jr. Blvd., Tampa, 33614. Ideally, 10 stool or vomitus samples should be collected and sent together, using refrigerator ice packs to keep them cold. They should be refrigerated during storage, but should NOT be frozen or preserved. Before sending samples, please contact the laboratory at 813-871-7456; ask for Dr. Lillian, Stark, Christopher Webb or Dr. Deno Kanzanis.

While water, food (other than oysters), and environmental samples are not routinely tested for Norwalk-like viruses, laboratory techniques are improving rapidly, and such testing may be appropriate under certain circumstances. If a specific food, water, or environmental source is epidemologically linked to an outbreak, consult with the Tampa branch laboratory about the possibility of testing.

Current Procedural Terminology (CPT) codes are standardized codes developed and maintained by the CPT Board of the American Medical Association for reporting medical services. The Health Care Financing Administration requires use of these codes in the Common Procedure Coding System when services are reported to Medicare and Medicaid for reimbursement. Effective January 1, 1998, the CPT Board changed the hepatitis serology panel (CPT#80059) to exclude the tests for IgM antibody to hepatitis A virus (IgM anti-HAV) and IgM antibody to hepatitis B core antigen (IgM anti-HBc). These two tests specifically identify recent infection with HAV and HBV, respectively. Many providers may be unaware that these tests are not part of the standard hepatitis panel, and diagnoses of cases of acute viral hepatitis are likely to be delayed by the need to perform additional testing. As a result, reporting of cases to health departments may be delayed, and CDC has received reports of instances of insufficient time to provide postexposure prophylaxis to prevent transmission of HAV or HBV to susceptible contacts of the case-patient.

The CPT Board has revised the hepatitis serology panel to include both IgM tests that were deleted. However, these modifications will not be implemented until the next CPT code manual is issued on January 1, 2000. Until this change takes effect, health departments should notify health-care practitioners and/or laboratories of the need to order individual tests for IgM anti-HAV (CPT#86709) and IgM anti-HBc (CPT#86705) for accurate determination of the cause of illness in patients with signs and/or symptoms of acute viral hepatitis and for timely prophylaxis of contacts.

National: Influenza morbidity peaked during February and has been declining during March and early April. During week 15, there were no reports of widespread activity, but three states (Alaska, Arizona and Tennessee) reported regional activity. During the previous week, week 14, 5 states reported either widespread or regional activity. The WHO laboratories reported that 15 % (12,156 of 79,008) of the specimens tested since October 4 have been positive for influenza. Seventy-seven percent (9,336) of these were influenza A. Among the type A viruses, 26 % have been subtyped. Subtype A(H3N2) have predominated (99 % of 2,370)). Twenty-one isolates have been subtyped as A(H1N1).

So far this season, influenza A has been the most common subtype in the U.S. overall and in all of the nine regions; however the percentage of influenza type A viruses have varied by region, ranging from 61 % in the East North Central and East South Central regions to 91 % in the New England region. Of the total patient visits to sentinel physicians, 1 % were due to ILI (influenza-like-illness) in the U.S. overall. The percentage of patient visits was within baseline values of 0 %-3 % in all regions. Nationally, influenza activity peaked during early to mid-February when 5 % of the total patients' visits were due to influenza-like illness. The percentage of pneumonia and influenza deaths reported from the 122 cities during Week 15 was 8.0 %, above the epidemic threshold of 7.2 %. The percentage of deaths from pneumonia and influenza has declined after peaking at 8.8 % during the week ending March 13 1999; however, pneumonia and influenza deaths remained above the epidemic threshold for the twelve consecutive weeks.

Florida: During week 15 (11-17 April 1999) there were 2 laboratory-confirmed isolates of influenza reported: Influenza AH3N2) was reported from Sarasota county and influenza B was reported from Broward county. Since September 23 and to date, there have been 226 isolates reported; 67 ( 30%) of these were type B 159 type A. Of the influenza A isolates 74 were typed; 68 (30 %) were type A(H3N2) and 6 (3 %) were type A(H1N1). Isolates have been reported from: Alachua (1), Brevard (5), Broward (27), Dade (5), Desoto (1), Duval (14), Hillsborough (54), Indian River (5), Jackson (2), Leon (20), Martin (2) Okaloosa (2), Orange (22), Osceola (1), Palm Beach (17), Pinellas (12), Polk (5), Sarasota (24), Seminole (2), St. John’s (2) and Volusia (3) counties.

Of the total patient visits to sentinel physicians during Week 15, 1 % were due to ILI. This is within the baseline levels of 0-3 %. Since October 4 the percentage has ranged between 1 and 4 %. Influenza-like illness has been reported from health care providers in 20 of the 21 Florida counties represented (not Pasco) in the sentinel physician surveillance network.

This message is being sent to all county health department director/administrators, nursing directors, environmental health directors and regional food and waterborne illness epidemiological investigators. This is an advanced course, which discusses the steps involved in traceback investigations of foods implicated in outbreaks. Previous attendance at FDA Satellite Courses on Food Microbiology and Foodborne Illness Outbreak Investigations along with experience in foodborne outbreak investigations is STRONGLY recommended. No nursing CEUs will be available for this course, however nurses are welcome to attend. Approximately 9 CEUs will be awarded to environmental health professionals. The registration deadline is June 1.

People become infected with V. parahaemolyticus primarily through eating raw or undercooked seafood. The bacteria grows very quickly at room temperature so contaminated cooked seafood may also be a source. In Japan, V. parahaemolyticus is one of the leading causes of foodborne illness¹. Sporadic cases are common along the coasts of the United States but outbreaks have also been reported ². The most recent outbreak occurred during the summer of 1998 when 416 people (including 52 Florida residents and 10 visitors) became infected by consuming raw oysters from Galveston Bay, Texas³. Other outbreaks in Florida have included two clusters associated with cross-contamination of cooked blue crab with juices from the raw crab.

Vibrio parahaemolyticus is less virulent than V. vulnificus and the disease is normally limited to a relatively mild gastroenteritis with diarrhea, abdominal cramps, vomiting, headache and fever in otherwise healthy people. In people with underlying health problems, particularly liver disease, the bacteria may spread into the blood and cause septicemia. It can also cause wound infections. Some V. parahaemolyticus infections may require hospitalization, however the disease is rarely fatal^4.5.

Vibrio infections are reportable in Alabama, Florida, Mississippi, Louisiana and Texas and V. parahaemolyticus is responsible for the majority of these cases in Florida. On average 24 cases have been reported to date in the state each year from 1981 when the disease became reportable. Most cases occur between April and October. Records from 1981-1993 (n=206) showed gastro-intestinal illness (58%) and wound infections (27%) as the two most common forms of the disease in the state⁵. Males were 4 times or more likely to get infected than females and 43% of all patients required hospitalization.

In Florida, most people become infected by eating raw oysters. To prevent Vibrio infections in high-risk groups, the state requires warning notices everywhere raw oysters are sold. These urge people with chronic health problems to eat only fully cooked oysters.

References

1. Oliver James D and Kaper James B. 1997. Vibrio species. In Food Microbiology Fundamentals and Frontiers. Doyle Michael P., Beuchat Larry R. and Mintville Thomas J. ed. American Society for Microbiology, Washington DC, 228-264.
2. MMWR 1998 47(22) 457-462.
3. Roberta Hammond, Bureau of Environmental epidemiology, Florida DOH, personal communication
4. Hally, RJ, Rubin RA, Fraimow HS and Hoffman-Terry ML. 1995. Fatal Vibrio parahemolyticus septicemia in a patient with cirrhosis. A case report and review of the literature. Dig. Dis. Sci. 40: 1257-60.
5. Hlady, W.Gary.and Klontz Karl C. 1996. The epidemiology of Vibrio infections in Florida 1981-1993. J. Infect. Dis. 173: 1176-83.

On March 7, 1999, CDC was notified of an outbreak of an illness suspected to be Japanese encephalitis among pig farmers, as well as severe disease in pigs in Malaysia in the state of Negeri Sembilan, districts of Sikamat and Bukit Pelandok, and the state of Perak, district of Kinta. According to the Malaysian Health Authorities, from October 1998 though March 1999, more than 200 human cases have been reported, with at least 80 deaths. At the request of the Government of Malaysia, on March 21, CDC sent staff to Malaysia to join local and international health officials in an investigation of the outbreak. To date, all cases appear to be in persons who have had some contact with pigs; the majority of cases have been in adult male pig farmers. Travelers to Malaysia should be aware of this outbreak of febrile encephalitis, which thus far has involved only those closely associated with pig farms. No travel restrictions are indicated at this time.

Because epidemiologic patterns were not totally consistent with Japanese encephalitis, additional laboratory testing was performed in Malaysia. A subset of samples tested at CDC confirmed the presence of a Hendra-like paramyxovirus (formerly called equine morbillivirus). Hendra virus was first identified in 1994 in Australia and caused illness in racehorses and three humans. Two of these patients died one of respiratory infection and the other of meningoencephalitis. Al three previous human infections appear to have been acquired from close contact with horses. However, other species demonstrated evidence of infection with this virus. Researchers have shown that infected animals excrete the virus in their urine.

Relatively little is know about the clinical syndrome of this new Hendra-like virus in Malaysia. The illness apparently begins with fever, followed by drowsiness and coma. The late stages are said to be accompanied by fluctuating blood pressure and body temperature. Transmissibility of this Hendra-like virus is thought to be low for those not associated with pig farming.

Persons anticipating travel to Malaysia should carefully follow the CDC regional recommendations for Southeast Asia. These recommendations may be accessed on our (the CDC) Internet website at http://www.cdc.gov/travel/index/htm or by calling toll-free on a touch-tone phone for an autofax at 888-232-3299, then press '1' and enter document numbers 220200 and 380020. This information will be updated as more information becomes available.

Persons in Malaysia are advised to contact the Malaysian Health Authorities for additional information and/or advice.

In the mid 1950’s the State Board of Health, Bureau of Preventable Diseases, made plans to expand the state epidemiologist’s responsibility to address "Epidemiologic Studies in Non-communicable Disease." Among the activities mentioned in the 1956 and 1957 annual reports was a chronicle of efforts to establish a network of Poison Control Centers throughout the state. Apparently from the outset the main objective of this initiative was to collect epidemiologic information that would be used to develop prevention programs directed at reducing accidental poisonings, particularly in children.

Today, Children’s Medical Services, within the Department of Health has statutory authority to coordinate the activities of the Poison Information Center Network. The program provides prevention and management information to consumers and health practitioners throughout Florida on a 24-hours a day basis through a toll-free number (1-800-282-3171). During 1998, 156,340 calls were handled by poison information specialists who made 56,000 follow-up calls on exposure cases to determine the health outcome of the victims. Approximately 60% of poisonings occurred in children under age six.

Courtesy of Mary Beth Vickers, Mittie Moffett and Maxine Wenzinger at DOH/CMS.