Georgia epidemiology report, Vol. 15, no. 6 (June 1999)

June 1999

volume 15 number 6

Division of Public Health
http://health.state.ga.us
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The Georgia Epidemiology Report is a publication of the Epidemiology Section of the Epidemiology and Prevention Branch, Division of Public Health, Georgia Department of Human Resources
Infectious diseases potentially associated with bioterrorism or intentional transmission

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The Georgia Epidemiology Report (GER) is available
online at:
health.state.ga.us/epi/ manuals/ger.htm
Director Kathleen E. Toomey, M.D., M.P.H.
Epidemiology and Prevention Branch Acting Director
Kathleen E. Toomey, M.D.,M.P.H.
Acting State Epidemiologist Paul A. Blake, M.D.,M.P.H.
Epidemiology Section Chief
Paul A. Blake, M.D., M.P.H.
Public Health Advisor Mel Ralston
Georgia Epidemiology Report Editorial Board
Carol A. Hoban, M.S., M.P.H. - Editor Kathryn E. Arnold, M.D.
Jeffrey D. Berschling, M.P.H. Paul A. Blake, M.D., M.P.H. Jane E. Koehler, D.V.M., M.P.H. Kathleen E. Toomey, M.D., M.P.H. Angela Alexander - Mailing List Jimmy Clanton, Jr. - Graphics

Editors Note: Additions to the Notifiable Disease List (effective July 1, 1999). Seven diseasesplague, tularemia, Q fever, cyclosporiasis, yersiniosis, ehrlichiosis, and infection with Staphylococcus aureus with reduced susceptibility to vancomycinhave been added to the Notifiable Diseases List for Georgia, effective immediately. The first three are considered potential weapons of bioterrorism, and are discussed below, while the remaining four newly notifiable diseases will be described in another issue later in 1999.
Several recent events have focused public attention on the potential for infectious agents to be used in terrorist attacks. Biological agents and toxins are relatively easy to obtain, inexpensive, and difficult to detect. Advanced bioweapons programs in Iraq were revealed following the Persian Gulf War. A large biological weapons program was active in the Union of Soviet Socialist Republics (USSR) well into the 1980s, and little information about the supplies and scientists involved, or their current whereabouts, is available. The apocalyptic religious cult Aum Shinrikyo attempted to disseminate anthrax and botulinum toxin in Tokyo in the 1990s, and attempted to obtain the Ebola virus, before turning to the chemical agent sarin as a weapon. In the United States (US), several anti-government groups and individuals have planned the use of or successfully obtained biological agents and toxins such as plague and ricin. In response, several laws and appropriations dealing with bioterrorism have been enacted by the U.S. Congress. Federal authorities have recommended that local and State health departments improve and enhance surveillance and response capacity for diseases with potential for intentional transmission.
No bioterrorist event has occurred in Georgia, although hoaxes involving letters declaring to contain anthrax have occurred. Bioterrorism preparedness has become an important public health function, and is similar to planning for natural disasters, chemical or radiologic accidents, or pandemic influenza. A major component of bioterrorism preparedness is providing information for health care providers about the diseases that might be involved, and developing or enhancing reporting systems. The Centers for Disease Control and Prevention (CDC) have recommended that potential bioterrorism agents, such as plague, tularemia, Q fever, anthrax, brucellosis, smallpox and botulism, be designated as notifiable diseases. The common link among these infectious agents is their ability to be intentionally transmitted by aerosol. All except smallpox and botulism are zoonoses, meaning that disease is normally acquired from animals, which may also show signs of infection. Therefore, documented infection in persons who do not have known occupational, domestic or recreational exposures may be one clue that intentional transmission has occurred. A brief overview of the natural course of infection with plague, tularemia, and Q fever is presented in this issue.
1) Plague
Plague is a life-threatening disease caused by the gram negative bacterium Yersinia pestis. Transmission to humans occurs by the bite of animal fleas (usually rodent), by direct exposure to infected tissues, or via respiratory droplets from infected humans or animals. Persons with bubonic plague typically have an abrupt onset of fever, rigors,
Georgia Department of Human Resources Division of Public Health Epidemiology & Prevention Branch, Epidemiology Section Two Peachtree St., N.W., Atlanta, GA 30303 - 3186 Phone: (404) 657-2588 Fax: (404) 657-2586

headache and myalgia beginning 2 to 8 days after exposure, concomitant with or followed shortly by severe pain and enlargement in regional lymph nodes (buboes) that drain the site of inoculation. Only a minority will have a skin lesion or visible bite at time of presentation. Bubonic plague may quickly progress to bacteremia and severe illness, or the disease may present only as a septicemia. Pneumonic plague has a shorter incubation period (2-3 days) and presents as a patchy bronchopneumonia that quickly progresses to respiratory failure and shock. The mortality rate for untreated bubonic plague approaches 50%; the mortality rate for untreated pneumonic or septicemic plague, and for those whose diagnosis is delayed beyond 18 hours, is considerably higher. Failure to consider the diagnosis, leading to delays in appropriate treatment, is common among U.S. patients.
Diagnosis (Table 1) is usually made by culture of tissue, blood, bubo aspirate or sputum. The organism grows slowly on culture media, and the optimal growth temperature is 280 C rather than the 370 used for most bacteria. Y. pestis may be seen in stained tissue preparations or bubo aspirates. For patients with bacteremia, a Wright stain of buffy coat preparations may demonstrate a characteristic bipolar staining pattern of the organisms within blood leukocytes. A fourfold or greater change in serum antibody titer to Y. pestis F1 antigen also is confirmatory. The Georgia State Public Health Laboratory offers culture diagnosis.
Aminoglycosides, chloramphenicol, tetracycline, and sulfa drugs all have activity against Y. pestis, although streptomycin is the drug of choice. Penicillin and cephalosporin-based antibiotics are ineffective. Chemoprophylaxis with chloramphenicol or tetracycline is recommended only for contacts of persons with pneumonic plague. Strict isolation for at least 48 hours after initiation of treatment is necessary for persons with pneumonic plague, as person-to-person transmission is possible. A vaccine is available but offers protection only against bubonic plague.
Plague is rare in the U.S. with fewer than 400 cases since 1943, and no person-to-person transmission has been documented since the 1920s. It has been decades since a case was identified in Georgia. However, the disease remains endemic in some western states, especially New Mexico, Arizona, California and Colorado. Plague should be suspected when travelers to these areas or possible victims of bioterrorism present with severe, systemic illness.
2) Tularemia
Tularemia is caused by the gram negative bacterium Francisella tularensis. The organism infects a remarkable variety of animal species, including mammals, birds, amphibians and fish. Tularemia can be acquired by humans through contact with infected animal tissues, or by a bite from an infected tick or deerfly. Inhalation of contaminated dusts and ingestion of contaminated material are less common routes of transmission. Mosquitoes are also an important vector in Scandinavian countries. Hunting or handling wild mammals, especially rabbits, is a risk factor for tularemia. The organism is killed by thorough cooking, but survives freezing. Person-to-person transmission has not been documented.
The incubation period from exposure to clinical symptoms ranges from 1 to 14 days, depending upon the inoculum size and route. At least 6 distinct clinical syndromes for patients with tularemia are recognized. The most common is an ulceroglandular syndrome with painful, enlarged lymph nodes draining from the ulcerated site of inoculation (tick bite or laceration). The glandular form is similar, but a primary ulcer is not present. An oropharyngeal form, with painful pharyngitis, vomiting and abdominal pain, may follow ingestion. The typhoidal form presents as a primary septicemia, or fever of unknown

origin, and usually follows inhalation or ingestion. An oculoglandular form results from inoculation into the conjunctiva. Finally, a pleuropulmonary form may follow inhalation exposures. All forms of tularemia are frequently complicated by pneumonitis, and without early recognition and treatment of disease, mortality rates may be as high as 30%. Treatment with aminoglycosides, tetracycline, doxycycline or chloramphenicol is effective, but streptomycin is the drug of choice. An investigational vaccine has been developed but is not widely available.
Tularemia is usually diagnosed (Table 1) by demonstrating a fourfold rise in serum antibody titer to F. tularensis antigen between acute- and convalescent-phase specimens. Laboratory culture of F. tularensis poses a significant risk to laboratory workers, and should only be attempted by trained personnel in specialized facilities. The Georgia State Public Health Laboratory offers culture diagnosis. The circumstances necessary for natural transmission to humans are present in Georgia, and several cases have been diagnosed in recent years. Tularemia should be suspected when persons with wild animal or tick exposures or possible victims of bioterrorism present with fever or pneumonia.
3) Q fever
Q fever is caused by the rickettsial bacterium Coxiella burnetii. The odd name for this disease is derived from it being listed as ? fever by investigators earlier in this century, who could not isolate the cause of the disease. C. burnettii normally infects sheep, goats, and cattle, especially their placental tissues, but can cause illness in a wide variety of mammals. Parturient cats (cats that are birthing) have been implicated in several outbreaks. The organisms are highly infectious, and are easily inhaled in contaminated aerosols or dusts (which may travel great distances from their origin), or from infected animal tissue. Unpasteurized cheese may also transmit disease. Person-toperson transmission is very unusual, but has been reported after exposure to infected human tissue, or the laundry of infected persons. C. burnettii is very resistant to drying and chemical agents and may remain viable in dust for months.
Following a long incubation period of 2 to 6 weeks, Q fever most commonly presents as an atypical pneumonia syndrome. An abrupt onset of high fever, chills and severe headache is typical, and hepatomegaly or splenomegaly is common. Serum aminotransferases are usually elevated and a syndrome resembling acute viral hepatitis may occur. Unlike most rickettsial diseases, a rash is not usually observed. The disease is often self-limited, but treatment with tetracycline or doxycycline may shorten the course and is advised. Chronic Q fever develops in a few patients, presenting as culturenegative endocarditis. No vaccine is commercially available.
Q fever is usually diagnosed (Table 1) by demonstrating a fourfold rise between acute- and convalescent-phase specimens in serum antibody titer to C. burnettii antigen. Laboratory culture of C. burnettii poses a significant risk to laboratory workers, and is not advised. Serologic testing is offered by the Georgia State Public Health Laboratory. Several cases of Q fever have been diagnosed in Georgia in recent years, and Q fever should be considered when a person with animal exposures or a possible victim of bioterrorism present with pneumonia and/or hepatitis.
Suspected cases of plague, tularemia or Q fever
should be reported immediately to the Georgia
Division of Public Health, Epidemiology and Preven-
tion Branch, at 404-657-2588.
This article was contributed by Anthony Fiore, M.D., M.P.H.

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Additional Readings:
Franz Dr, Jahrling PB, Friedlander AM, et al. Clinical recognition and management of patients exposed to biological warfare agents. JAMA 1997;278:399-411.
Sharp TW, Brennan RJ, Keim M, Williams RJ, Eitzen E, Lillibridge S. Medical preparedness for a terrorist incident involving chemical or biological agents during the 1996 Atlanta Olympic Games. Ann Emerg Med 1998;32:214-23.
Henderson DA. Bioterrorism as a public health threat. Emerg Infect Dis 1998;4:488-92.
Association of Practitioners of Infection Control (APIC). Bioterrorism readiness plan: a template for healthcare facilities. Available free at http://www.apic.org/html/educ/readinow.html
Perry RD, Fetherston JD. Yersinia pestis - Etiologic agent of plague. Clin Microbiol Rev 1997;10:35-66.
Centers for Disease Control and Prevention. Human plague United States, 1993-4. MMWR 1994;43:242-6.

Centers for Disease Control and Prevention. Prevention of plague: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR 1996;45(No. RR-14).
Centers for Disease Control and Prevention. Tularemia New Jersey. MMWR 1986;35:747-8.
Fredricks DN, Remington JS. Tularemia presenting as community-acquired pneumonia: implications in the era of managed care. Arch Intern Med 1996 Oct 14;156:2137-40
Centers for Disease Control and Prevention. Q fever outbreak Germany, 1996. MMWR 1997;46:29-32
Centers for Disease Control and Prevention. Q fever among slaughterhouse workers California. MMWR 1986:35:223-6.
Fournier P-E, Marrie TJ, Raoult D. Diagnosis of Q fever. J Clin Microbiol 1998;36:1823-34.

Table 1: Diagnostic criteria for plague, tularemia, and Q fever

PLAGUE
Presumptive
Confirmatory

Elevated serum antibody titer to Y. pestis fraction 1 (F1) antigen (without documented fourfold or greater change) in a patient with no history of plague vaccination
or Detection of F1 antigen in a clinical specimen by fluorescent assay
Isolation of Y. pestis from a clinical specimen or
Fourfold or greater change in serum antibody titer to Y. pestis F1 antigen

TULAREMIA
Presumptive
Confirmatory

Elevated serum antibody titer to F. tularensis antigen (without documented fourfold or greater change) in a patient with no history of tularemia vaccination
or Detection of F. tularensis in a clinical specimen by fluorescent assay
Isolation of F. tularensis in a clinical specimen or
Fourfold or greater change in serum antibody to F. tularensis antigen

Q FEVER
Presumptive
Confirmatory

Elevated serum antibody titer to C. burnettii antigen (without documented fourfold or greater change) in a patient with no history of Q fever vaccination
or Detection of C. burnettii in a clinical specimen by fluorescent assay
Isolation of C. burnettii in a clinical specimen or
Fourfold or greater change in serum antibody to C. burnettii antigen

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

Bulk Rate U.S. Postage
Paid Atlanta, Ga Permit No. 4528

June 1999

Volume 15 Number 6

Reported Cases of Selected Notifiable Diseases in Georgia Profile* for March 1999

Selected Notifiable Diseases Campylobacteriosis Chlamydia genital infection 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 March 1999
1999 39 1271 22 0 65 911 6 54 10 0 0 5 0 4 0 70 22 7 2 38 17
1 43

Previous 3 Months Total

Ending in March

1997

1998

1999

113

130

155

3284

6081

4023

8

27

53

14

2

1

214

208

258

4342

4942

3168

18

20

21

112

199

140

30

82

39

0

0

0

1

2

0

35

45

19

5

0

0

8

3

7

0

0

0

242

207

255

253

230

70

43

32

23

97

57

43

331

237

159

381

223

84

5

0

4

189

138

112

Previous 12 Months Total

Ending in March

1997

1998

1999

745

783

798

13631

18993

23192

88

93

178

49

34

81

873

910

1268

18907

19141

18897

49

44

70

471

850

829

83

276

166

2

6

8

2

10

3

124

117

76

13

6

2

37

13

42

0

0

0

1449

1345

1907

1246

1181

990

187

150

111

454

323

219

1306

1029

705

1165

1074

656

29

16

16

761

644

605

* 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.

Report Period
Latest 12 Months: 4/98 - 3/99 Five Years Ago: 4/93 - 3/94 Cumulative: 7/81 - 3/99

Total Cases Reported *

AIDS Profile Update

Percent

Risk Group Distribution (%)

Female

MSM IDU MSM&IDU

HS Blood

Unknown

Race Distribution (%) White Black Other

1291

20.4

36.8

15.2

4.9

13.1

0.8

29.1

23

74.5

2.5

1944

15.7

44.8

22.4

5.6

13

1.1

13.1

31.6

66.5

1.9

20322 15.4

50.6

19.2

5.8

12.2

1.9

10.3

38

59.9

2.1

MSM - Men having sex with men

IDU - Injection drug users

HS - Heterosexual

* Case totals are accumulated by date of report to the Epidemiology Section

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