Georgia epidemiology report, Vol. 22, no. 11 (Nov. 2006)

November 2006

volume 22 number 11

Genotyping Cluster of Tuberculosis Cases in Houston County, Georgia, 1997-2006

Background
In September 2004, the Georgia Tuberculosis (TB) Program and the Georgia Public Health Laboratory (GPHL) began a universal genotyping project to identify TB strains with matching DNA fingerprints (or genotypes) circulating in Georgia. The project is part of a national effort led by the Centers for Disease Control and Prevention (CDC) to maintain a standardized database of all genetic TB strains in the United States. Detecting several TB cases with matching genotype strains, referred hereon as a genotype cluster, is useful for planning interventions to prevent the spread of TB since these clusters suggest recent or on-going disease transmission. This article describes such a cluster of cases reported from Houston County, Georgia from 1997-2006.
Introduction
From September-December 2005, the Augusta State Medical Prison (ASMP), a state-run facility under the Georgia Department of Corrections which treats all inmates with active TB in the state prison system, notified the Georgia TB Program of four TB patients who transferred to their facility from Detention Center X (DCX). The index case, who was a resident of Houston County, Georgia, developed TB-like symptoms two weeks before incarceration at DCX and was diagnosed with TB after two months at the detention center. Three inmates in DCX who were contacts of the index case were later diagnosed with TB. Three of these four patients had the same genotype as TB strains from six other Houston County residents in the state genotyping database. To determine how transmission occurred among the prisoners and residents in the community, a cluster investigation was conducted in accordance with CDCdeveloped guidelines (1).
Methods
Patient Interviews, Medical Chart Reviews and Health Provider Interviews We interviewed the three ASMP inmates who had matching genotypes using a CDC-developed TB Genotype Cluster Investigation Form and asked information on their places of residence, occupation, social history, and travel history in the past five years (1). We reviewed the medical records and contact investigation sheets of all the cases in the genotype cluster to determine any possible epidemiological links between them. We interviewed TB program coordinators and clinical staff in Houston County to collect information on possible social networks, occupations, locations, and risk behaviors that may

have facilitated TB transmission among the cases in the genotype cluster. The Geographic Information System (GIS) Team of the Office of Health Information and Policy mapped the addresses of all genotype-matched cases using ArcView software.
Laboratory Genotyping Analysis The GPHL submits all Mycobacterium tuberculosis isolates collected from TB cases in Georgia to a reference laboratory in California funded by CDC's Division of TB Elimination to perform genotyping. The isolates initially undergo two polymerase chain reaction (PCR)-based screening tests to identify possible genotype matches: spacer oligonucleotide genotyping (spoligotyping) is based on spacer sequences found in the direct repeat region in the Mycobacterium tuberculosis chromosome, while the mycobacterial interspersed repetitive units (MIRU) test analyzes DNA segments containing tandem repeated sequences in which different strains of Mycobacterium tuberculosis have different number of copies of the repeated sequence (1). When TB cases who have matching genotypes but do not have obvious epidemiological links such as common risk factors or shared time or space, or when routes of transmission among the cases are unclear, the GA TB Epidemiology Section requests a confirmatory test called restriction fragment length polymorphism (RFLP) to confirm a genetic match (2). For this investigation, the GPHL retrieved isolates of additional cases who the Houston County clinic staff suspected as being epidemiologically linked to this genotype cluster but who were reported before universal genotyping started in Georgia. These isolates were submitted for genotyping to determine if they belonged to the same cluster also.
Results
To date, 13 of 15 isolates from Houston County cases reported from 1997 to 2006 for which we requested RFLP confirmatory testing belong to the same PCR/RFLP cluster (designated in CDC's national TB genotyping database as GA_022A). Until recently, no other state in the U.S. or any other county in Georgia has reported this TB strain; however, in October 2006, an isolate that matched the GA_022A cluster was identified from a patient who lived in County B, 50 miles from Houston County. RFLP results are pending for two other isolates, and PCR testing has been requested for five more isolates from potentially linked cases reported in the mid-1990s.
Among the 13 PCR/RFLP matched cases in Houston County, 11 (85%) are black, 10 (77%) are male, and the mean age is 40

The Georgia Epidemiology Report Via E-Mail To better serve our readers, we would like to know if you would prefer to receive the GER by e-mail as a readable PDF file. If yes, please send your name and e-mail address to Gaepinfo@dhr.state.ga.us. | Please visit, http://health.state.ga.us/epi/manuals/ger.asp for all current and past pdf issues of the GER.

years (range: 22-62 years). Common epidemiological links among the cases include substance abuse, working in the construction industry, and incarceration. Nine (69%) cases have a history of illicit drug abuse, seven (54%) have a history of alcohol abuse, six (46%) worked in the construction industry (lawn work, painting, construction site clean-up, welding, sand-blasting, etc.), and five (38%) have a history of incarceration. Seven cases in this cluster live within a 0.8-mile radius of each other, 10 live within 1.7-miles,

Figure 1.

The epidemiologic relationships among cases in the GA_022A

cluster are shown in Figure 2. Patient A is the index case from DCX

and reported living, "hanging out", and "doing drugs" in the area

where most of the other cases in this cluster reside. This area in

Houston County is characterized by low socioeconomic conditions,

the presence of several government housing complexes, and social

problems such as drug trafficking, prostitution and trading sex

for drugs. Several county clinic staff encountered problems with

treatment compliance, mistrust of the health department, and

misperceptions about TB skin testing from TB patients and their

infected contacts in the area. Patient P is the newest case in the

cluster reported from County B. This patient never lived or worked in Houston County, and possible epidemiological links to persons

Georgia Houston County

in the cluster are currently being investigated.

Total 7 Cases Total 10 Cases
Total 11 Cases

Conclusion
The ongoing transmission of a specific TB genotype initially limited to a small geographic area in Houston County, Georgia has recently spread to a nearby county, highlighting the importance of conducting genotype cluster investigations to prevent further transmission of TB. Although the cluster investigation did not identify specific epidemiological links between all of the patients, interpersonal interactions through substance/alcohol abuse, construction work, incarceration, and living in relatively close proximity to each other, may all have contributed to the transmission of this strain. The Georgia Division of Public Health's TB Program is exploring opportunities for educational outreach in the community in partnership with local social service agencies, community-based organizations and churches, to increase TB awareness and build trust between community residents and the public health system in this high-incidence area for TB.
This article was written by, Nora Chen, Sc.M. and Rose-Marie F. Sales, M.D., M.P.H. References 1. National TB Controllers Association/CDC Advisory Group
on Tuberculosis Genotyping. Guide to the Application of Genotyping to Tuberculosis Prevention and Control. Atlanta, GA: US Department of Health and Human Services, CDC; June 2004. 2. Goyal M, Saunders NA, van Embden JD, Young DB, Shaw RJ. Differentiation of Mycobacterium tuberculosis isolates by spoligotyping and IS6100 restriction fragment length polymorphism. J Clin Microbiol. 1997;35:647-651.

Georgia Department of Human Resources Division of Public Health Office of Health Information & Policy

97 98 99 00 01 02 03
Created: October 2006 Source: Division of Public Health Projection: State Plane Georgia West

Figure 2. Relationships of TB cases in the GA_022A cluster

GA_022A Cluster

Detention Center X

Patient E

Knew of each other in the construction industry

Patient D

Named Contacts

Patient R

Named

Patient L

Brother/sister

Patient K

Named

Patient F

Patient H Cousins

Patient M*

Patient A
Patient C Patient B
Legend
Houston County case County B case

Patient G

Patient O

Patient P

*Matching RFLP but one digit difference in MIRU (PCR)

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
-2 -

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

2006 Georgia Data Summary:
LUNG CANCER

Quitting smoking and avoiding secondhand smoke are the best strategies for preventing lung cancer.

LUNG AND BRONCHUS CANCER
Lung cancer is the most common cancer diagnosed in Georgia.
Over 6,360 new cases of lung cancer will be diagnosed in 2006 in Georgia.
Lung cancer accounts for 16% of all reported cancers.
Age-adjusted Lung Cancer Incidence Rates, Females, by Health District, Georgia, 1999-2003

For females, the Northwest (1-1), North Georgia (1-2), and Coastal (9-1) Health Districts have significantly higher lung cancer incidence rates than the state average.
For females, the DeKalb (3-5), and West Central (7) Health Districts have significantly lower lung cancer incidence rates than the state average.
For males, the Northwest (1-1), North Central (5-2), East Central (6), West Central (7), South (8-1), Southwest (8-2) and Southeast (9-2) Health Districts have significantly higher lung cancer incidence rates than the state average.
For males, the Cobb/Douglas (3-1), Fulton (3-2), East Metro (3-4) and DeKalb (3-5) Health Districts have significantly lower lung cancer incidence rates than the state average.
Age-adjusted Lung Cancer Incidence, by Race and Sex, Georgia and the United States, 1999-2003

Rate significantly higher than the state average No significant difference Rate significantly lower than the state average

Rate per 100,000

150 116 112 109

100

89

50

0
Black Males

White Males

Georgia

United States

40 51

56 56

Black

White

Females Females

Age-adjusted Lung Cancer Incidence Rates, Males, by Health District, Georgia, 1999-2003
Rate significantly higher than the state No significant difference Rate significantly lower than the state average

RISK FACTORS
Tobacco use (accounts for about 87% of lung cancers) Exposure to secondhand smoke Exposure to certain industrial substances such as
arsenic, organic chemicals, radon, and asbestos Radiation exposure from occupational, medical, and
environmental sources Air pollution
PREVENTION
Quitting smoking and avoiding secondhand smoke are the best strategies for preventing lung cancer.
Data source: Georgia Comprehensive Cancer Registry (1999-2003) Date updated: June 2006 Publication number: DPH05.119H Visit http://www.health.state.ga.us/programs/gccr/index.asp for more information about cancer in Georgia.

Georgia Department of Human Resources, Division of Public Health 2 Peachtree Street, NW Atlanta, GA 30303 (404) 657-3103 gdphinfo@dhr.state.ga.us http://health.state.ga.us
-3 -

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

November 2006

Volume22Number11

Reported Cases of Selected Notifiable Diseases in Georgia Profile* for August 2006

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 August 2006
2006 54 3430 31 5 75 1893 6 9 18 3 1 0 0 3 0 253 107 8 25 23 47 0 41

Previous 3 Months Total

Ending in August

2004

2005

2006

197

236

164

9402

8574

9660

63

44

71

2

13

17

283

198

174

4468

4215

5216

23

19

19

77

49

25

122

47

50

16

11

10

5

4

5

1

5

1

0

0

3

5

18

10

0

0

0

828

728

683

166

138

310

20

34

21

129

140

85

83

102

79

232

240

165

1

0

0

122

140

128

Previous 12 Months Total

Ending in August

2004

2005

2006

551

621

547

35029

33066

36484

160

154

214

21

29

40

890

796

675

16368

15696

17970

121

108

112

630

169

84

479

287

175

44

30

34

12

5

7

22

20

14

1

3

5

28

49

29

1

0

0

2087

1844

1922

717

538

1011

133

119

123

496

513

419

496

361

365

868

958

884

5

3

5

532

503

497

* 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

Total Cases Reported* <13yrs >=13yrs Total

Percent Female

AIDS Profile Update
Risk Group Distribution (%) MSM IDU MSM&IDU HS Blood Unknown

Race Distribution (%) White Black Other

Latest 12 Months**:

11/05-10/06

5

1,305 1,310

26.7

31.8

6.6

2.4

9.3

0.2

49.2

18.9 75.8

5.3

Five Years Ago:

11/01-10/02

1

1,543 1,544

26.6

38.1

7.6

2.9

18.9

0.8

31.7

17.5 77.2

5.3

Cumulative:

07/81-10/06

231

30,261 30,492

19.8

44.3

15.3

4.9

14

0.9

19.8

30.9 66.1

3

MSM - Men having sex with men * Case totals are accumulated by date of report to the Epidemiology Section

IDU - Injection drug users

HS - Heterosexual

** Due to a change in the surveillance system, case counts may be artificially low during this time period

- 4 -