Georgia epidemiology report, Vol. 23, no. 7 (July 2007)

July 2007

volume 23 number 07

Vibrio in Georgia

Introduction Vibrio are gram-negative bacteria generally found in sea or brackish water. People become ill with Vibrio infections by consuming contaminated food or water, or by coming in direct contact with contaminated water. Illness is not transmitted from person to person. Vibrio are classified into two categories, depending on whether or not infection results in the syndrome "cholera".
Types of Vibrio infections Vibrio cholerae: Vibrio cholerae O1 and O139 produce cholera toxin and are responsible for the clinical syndrome "cholera" (severe watery diarrhea which rapidly leads to dehydration and shock). Over 100,000 cases were reported to the World Health Organization in 2005, and over 2,000 patients died (1). V. cholerae O1 causes epidemics and pandemics, but in developed countries the risk of outbreaks is very low.
Non-choleragenic vibrios: There are over 200 other serogroups of V. cholerae, and some also produce cholera toxins and cause severe illness, but do not cause cholera epidemics. Multiple species of Vibrio found in United States (U.S.) waters cause a number of clinical syndromes. The most common, V. parahaemolyticus, generally causes gastroenteritis (without the severity of cholera). V. vulnificus is also common and has the highest case-fatality rate. It causes skin infections and sepsis. V. vulnificus infection can occur through eating contaminated seafood (such as raw oysters) or through non-intact skin exposed to sea or brackish water. In persons with immunocompromising conditions, liver disease, and conditions causing iron overload (hemochromatosis), V. vulnificus causes sepsis which can be rapidly fatal. Other types of Vibrio cause gastrointestinal disease, wound infections, and even ear or sinus infections after swimming in contaminated water.
Diagnosis and treatment of Vibrio infections Diagnosis: Incubation periods may vary depending on the clinical syndrome (i.e. toxigenic diarrhea, wound infection, etc.), but symptoms generally occur from one day to a week following exposure. Vibrio infections can be diagnosed by stool, blood, or wound culture using TCBS (Thiosulfate Citrate Bile Sucrose) agar (a selective medium).
Treatment: For cholera, the key to treatment is rehydration with fluids and electrolytes. Other syndromes such as gastroenteritis, often resolve without specific therapy. Vibrio infections can be treated with tetracyclines, quinolones, or cephalosporins. Combination therapy is recommended for V. vulnificus sepsis, due to the severity of infection and rapid progression to death in susceptible persons.

Epidemiology of Vibrio infections in the United States Until recently, only toxigenic V. cholerae O1 and O139 have been nationally notifiable diseases. Gulf coast states have voluntarily collected reports on non-cholera Vibrio cases since 1988, and, other states, including Georgia, have reported cases to the Centers for Disease Control and Prevention (CDC) since the 1990's. In 2006, The Council of State and Territorial Epidemiologists recommended that non-toxigenic Vibrios be made nationally notifiable (2). Noncholerae Vibrios cause approximately 600 cases of illness and 50 deaths per year (3). Less than 20 cases of V. cholerae O1 or O139 have been reported nationally since 2000, but non O1-non-O139 V. cholerae strains that produce cholera toxin have been reported in multiple states, including Georgia (4). Vibrio infections are likely under-reported (5). Illness may be mild, so medical care may not be sought, or medical providers may not order cultures. Secondly, the selective medium recommended for culturing is not used routinely, so cultures may not grow well. Trend data from CDC's Foodborne Disease Surveillance Network (FoodNet), demonstrates that numbers of Vibrio infections have increased 78% from a baseline period (1996-1998) to 2006 (6). These trend data come from the 10 FoodNet sites, including Georgia, but may not represent the epidemiology of Vibriosis in the entire United States.
Epidemiology of Vibrio in Georgia The Georgia Division of Public Health interviews all reported cases of Vibrio infections with a standardized CDC case report form. Exposure data are used to guide public health interventions such as food service establishment inspections and consumer education. http://www.cdc.gov/foodborneoutbreaks/documents/cholera_ vibrio_report.pdf.
Clinical and demographic features: From 2001-2006, one hundred fifty-one (151) Vibrio infections were reported to the Georgia Division of Public Health. The most common species were V. vulnificus (36, 24%) and V. parahaemolyticus (35, 23%). The median age was 48 and the majority were white (64%). Most case-patients had diarrhea, but 8.6% had shock, and 44% were ill enough to be hospitalized. Liver disease was the most common underlying illness reported, occurring among 16 (11%) case-patients, but other conditions included malignancy, hematologic disease, and renal disease. Nineteen (13%) Georgia residents with Vibrio infections died during the last six years. The majority of deaths (74%) were due to V. vulnificus infection. During fall, 2006, four V. vulnificus deaths occurred in Georgia over a short time period (see box on page 3).

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Exposures/Risk Factors: Ninety (60%) Vibrio cases ate some type of seafood in the week before becoming ill. Specifically, 40 (27%) ate raw oysters. Twentysix percent of case-patients had exposure to seawater. Often, multiple exposures are identified during case interviews. For example, 13% of cases had seafood and water exposures, so elucidating the exact source of infection can be difficult. V. cholerae patients were more likely to have direct water exposure (53%), while V. vulnificus cases had predominately seafood exposures (75%). Of the 104 case-patients with known exposure (either seafood or water), 13.5% were traced back to Georgia coastal waters.
Geography: Most Vibrio infections in Georgia occur among persons who live in either the coastal or the Atlanta metropolitan areas (101/151). The majority (91%) of seafood-related Vibrio infections in Georgia occurred due to consumption of seafood harvested from Gulf Coast waters. After the health department conducts a case interview, any seafood information available is given to partner agencies such as the Georgia Department of Agriculture so that they can ensure the products are being handled and sold appropriately.
Seasonality of Vibrio cases and environmental Vibrios in GA: The density of Vibrios in environmental waters varies with temperature. Specifically, environmental sampling of Georgia's coastal waters has found that the concentration of Vibrios associated with plankton increases with higher temperatures (Figure 1). This has relevance to human health since plankton-associated Vibrios rapidly multiply, to reach adequate infectious dose levels in the environment (7). Unfortunately, the seasonality of increased plankton-associated Vibrio concentrations in water also corresponds to increased risk of human exposures, since recreational use of water and seafood consumption is more common during warm

months. In the U.S., reported Vibrio cases increase in June, peak in July, and taper off over the next 3 months through October (8).
In Georgia, 15 cases of Vibrio infection (10%) could be attributed to contaminated Georgia water; of these 6 (40%) were due to V. vulnificus, and 3 (20%) were due to V. parahaemolyticus. V. vulnificus cases occurred from July through November; two of three cases of V. parahaemolyticus occurred in May, and the third in October. All cases occurred during months when the observed diversity of Vibrio species found in Georgia coastal waters was greatest (Figure 2). Interestingly, sampling in Georgia has found that V. parahaemolyticus can be recovered from plankton year round, while V. vulnificus and V. cholerae could only be found May through November.
Prevention messages A vaccine against the most common cholera-causing Vibrio strain can be used in travelers (but is often unnecessary) and has been used to control endemic disease in Africa. There are no vaccines available for the hundreds of other types of Vibrio. Vibrio infections can be prevented by cooking seafood, buying raw seafood from reputable sources, and cleaning kitchen surfaces to prevent cross contamination when preparing raw seafood. Wound infections can be prevented by avoiding broken skin exposure to sea or brackish water. Patients who have diabetes, who are on immunosuppressive medications, who have liver disease, or who are otherwise immunocompromised should not consume raw or undercooked seafood. Healthcare providers should educate patients at high risk of acquiring Vibrio infections.
This article was written by Melissa Tobin-D'Angelo, M.D., M.P.H., Stepy Thomas, M.S.P.H., Dana Cole, D.V.M., Ph.D., and Jeff Turner, M.S.

Vibrio CFU/mL
Temperature (Celsius)

Figure 1. Mean Vibrio Densities in GA Coastal Waters (2006-07): Comparison of free-living (water) and plankton-associated (plankton) fractions and water temperature.

1.00E+09

35.00

1.00E+07 1.00E+05 1.00E+03

25.00 15.00

1.00E+01

5.00

Jan

Mar

May June Aug Sept Oct

Nov

Dec

Jan

Feb

water

plankton

temp

Division of Public Health http://health.state.ga.us
Stuart T. Brown, M.D. Director
State Health Officer

Epidemiology Branch http://health.state.ga.us/epi
Susan Lance, D.V.M., Ph.D.
Director State Epidemiologist

Georgia Epidemiology Report Editorial Board
Carol A. Hoban, M.S., M.P.H. Editor Kathryn E. Arnold, M.D.
Cherie Drenzek, D.V.M., M.S. Susan Lance, D.V.M., Ph.D.
Stuart T. Brown, M.D. Angela Alexander - Mailing List Jimmy Clanton, Jr. - Graphic Designer
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Two Peachtree St., N.W. Atlanta, GA 30303-3186 Phone: (404) 657-2588
Fax: (404) 657-7517

Georgia Department of Human Resources
Division of Public Health

Please send comments to: gaepinfo@dhr.state.ga.us

Figure 2. Plankton-associated Vibrio species in GA Coastal Waters (2006-07) and Reported Human Cases Associated witChhCarot3ntaminated GA Coastal Waters (2001-2006)

120

3.5

Proportion of Samples Positive Number of Reported Cases

3 100
2.5 80
2 60
1.5 40
1
20 0.5

0 Jan

Mar

May

V. cholerae

June

July

Aug

V. parahaemolyticus

Sept

Oct

V. vulnificus

Nov

Dec

Jan

0 Feb

Reported Human Cases

References

Page 1

1) http://www.who.int/wer/2006/wer8131.pdf accessed 5-9-07.

2) Council of State and Territorial Epidemiologists. National

Reporting for non-cholera Vibrio Infections (Vibriosis) http://

www.cste.org/PS/2006pdfs/PSFINAL2006/06-ID-05FINAL.

pdf. Accessed 5-09-07.

3) http://www.cdc.gov/foodborneoutbreaks/vibrio_sum/

CSTEVibrio2004.pdf

4) Thomas, SM et al. Vibrio cholerae O141 Infections Emerge

in Georgia and Alabama (abstract 1110). Infectious Diseases

Society of America 2005 Annual Meeting, San Francisco, CA.

October 5-9, 2005.

5) Mead, P.S. et al. Food-Related Illness and Death in the United

States. Emerging Infectious Diseases. 1999; 5 (5): 607-625.

6) Preliminary FoodNet Data on the Incidence of Infection with

Pathogens Transmitted Commonly Through Food --- 10 States,

2006. MMWR April 13, 2007;56:336-9.

7) Urakawa H and Rivera ING. "Aquatic Environment." The Biology of Vibrios. Ed. FL Thompson et al. Washington, DC: ASM Press, 2006:175-190.
8) Vibrio Illnesses after Hurricane Katrina---Multiple States, August--September 2005. MMWR Dispatch September 14, 2005:54(Dispatch):1-4.
Resources www.health.state.ga.us www.cdc.gov www.safeoysters.org http://www.cfsan.fda.gov/~dms/vv-toc.html http://fsrio.nal.usda.gov/document_reslist.php?product_id=208 www.issc.org

Vibrio Vulnificus Deaths, Georgia, 2006

During September and October 2006, the Georgia Division of Public Health received reports of 4 patients who died due to complications of Vibrio vulnificus infections. While each patient presented with different symptoms, all went into shock before death. All 4 cases died within 4 days of being admitted to the hospital with one patient expiring in the emergency room the same day he sought care. The cases ranged in age from 43 to 76 years.
Each of the cases had multiple underlying health conditions, which increased their risk of severe outcomes related to a V. vulnificus infection. The underlying conditions included liver disease and diabetes. Two of the patients ate raw oysters before illness onset; the oysters were traced back to 2 different harvest

sites in the Gulf of Mexico. The restaurants serving the oysters to the patients displayed consumer warning signs about the risk of eating undercooked seafood. The other 2 patients ate other types of seafood before their illness onsets. One patient's family reported that the case did not know the risk associated with eating raw seafood.
Although these cases were not found to be epidemiologically associated, 4 reports of V. vulnificus deaths within 5 weeks are unusual. These 4 cases demonstrate the risk of severe illness or even death related to V. vulnificus infections in people with underlying conditions. They also emphasize the need to educate people with these underlying conditions about avoiding undercooked or raw seafood, especially oysters.

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The Georgia Epidemiology Report Epidemiology Branch Two Peachtree St., NW Atlanta, GA 30303-3186

PRESORTED STANDARD U.S. POSTAGE
PAID ATLANTA, GA PERMIT NO. 4528

July 2007

Volume23Number07

Reported Cases of Selected Notifiable Diseases in Georgia, Profile* for April 2007

Selected Notifiable Diseases
Campylobacteriosis Chlamydia trachomatis Cryptosporidiosis E. coli O157:H7 Giardiasis Gonorrhea Haemophilus influenzae (invasive) Hepatitis A (acute) Hepatitis B (acute) Legionellosis Lyme Disease Meningococcal Disease (invasive) Mumps Pertussis Rubella Salmonellosis Shigellosis Syphilis - Primary Syphilis - Secondary Syphilis - Early Latent Syphilis - Other** Syphilis - Congenital Tuberculosis

Total Reported for April 2007
2007 41 144 5 1 41 91 11 8 8 4 0 1 0 0 0 95 116 0 4 0 20 0 43

Previous 3 Months Total Ending in April

2005

2006

2007

114

140

120

8269

10024

5709

32

42

28

3

8

5

160

133

135

3586

4660

2164

36

36

33

23

12

14

55

49

29

3

1

10

1

0

0

2

8

4

1

1

0

8

5

0

0

0

0

211

189

277

109

194

253

28

33

2

128

97

25

107

87

23

253

267

118

1

4

0

115

130

114

Previous 12 Months Total Ending in April

2005

2006

2007

584

618

565

33909

35920

36097

173

175

263

19

33

41

896

695

655

15929

17323

17687

124

107

120

217

104

66

386

171

188

41

36

48

8

6

7

16

20

17

3

2

3

34

43

26

0

0

0

1953

1928

1949

592

787

1478

110

137

84

495

495

393

334

395

302

932

1001

821

5

7

3

513

509

494

* The cumulative numbers in the above table reflect the date the disease was first diagnosed rather than the date the report was received at the state office, and therefore are subject to change over time due to late reporting. The 3 month delay in the disease profile for a given month is designed to minimize any changes that may occur. This method of summarizing data is expected to provide a better overall measure of disease trends and patterns in Georgia.
** Other syphilis includes latent (unknown duration), late latent, late with symptomatic manifestations, and neurosyphilis.
AIDS Profile Update

Report Period
Latest 12 Months**:
6/06-5/07
Five Years Ago:***
6/02-5/03
Cumulative:

Disease Classification
HIV, non-AIDS

Total Cases Reported*

<13yrs

>=13yrs Total

26

3,399

3,425

AIDS

10

HIV, non-AIDS -

2,019 -

2,029 -

AIDS

1

HIV, non-AIDS 256

1,407 11,043

1,408 11,299

Percent Female MSM

29

28

28

29

-

-

26

35

33

29

Risk Group Distribution (%)

IDU

HS

Unknown

6

2

12

52

Perinatal 0.7

White 21

Race Distribution (%)

Black

Hispanic Other

73

5

1

7

2

11

51

0.4

24

70

6

<1

-

-

-

-

-

-

-

-

-

10

3

15

36

-

18

76

5

1

7

3

11

50

2

22

73

4

1

07/81-5/07 AIDS

276

36,748

37,024

20

44

15

5

14

21

0.7

31

66

3

<1

Yrs - Age at diagnosis in years

MSM - Men having sex with men

IDU - Injection drug users

HS - Heterosexual

* Case totals are accumulated by date of report to the Epidemiology Section ** Due to a change in the surveillance system, case counts may be artificially low during this time period

***HIV, non-AIDS was not collected until 12/31/2003

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