The Changing Epidemiology of Acute Hepatitis A in Texas

Rachel Wiseman, MPH,Lucille Palenapa, MS; Linda Gaul, PhDEmerging and Acute Infectious Disease Branch

Texas Public Health Association Annual Education Conference

April 22, 2010

Overview

Describe how hepatitis A virus has

decreased in Texas since the licensing

of a vaccine– Vaccine requirements in Texas– Hepatitis A incidence– Hepatitis A distribution

Hepatitis A Epidemiology

• Reservoir Humans • Transmission Fecal-oral route;

person-to-person or ingestion of contaminated food or water

• Communicability 1-2 weeks before onset to week after onset

• Temporal Pattern None• Incubation Period Avg 28-30 days

(range 15-50 days)

CDC Hepatitis A Vaccine Recommendations

• 1995, introduction of vaccine and recommended targeted vaccination of high-risk individuals

• 1999, recommended targeted hepatitis A vaccine programs for people two years of age and older residing in high incident states old– Children are often asymptomatic and can be unknown

sources of infection– Texas identified the counties with the largest burden of

hepatitis A and targeted those for vaccine requirements

• 2005, recommended vaccination of all children 12-23 months of age and older

32 Counties Requiring Hepatitis A Vaccination

Texas Counties Requiring Hepatitis A For Childcare and School Entry, 1999, 1999

Texas Counties Requiring Hepatitis A For Childcare and School Entry, 2003, 2003

39 Counties Requiring Hepatitis A Vaccination

Seven counties, were added to the vaccination requirement.

Texas Counties Requiring Hepatitis A For Childcare and School Entry, 2005, 2005

Counties requiring vaccine for childcare entry.

Counties requiring vaccine for school and childcare entry (n=40).

Current Hepatitis A Vaccine Requirements

• Child-Care – Statewide for all children attending a

child-care facility, including pre-K– After-school care not affected

• School – Must have 2 doses for entering

kindergarten– Statewide requirement (this is new for

the 2009-10 school year!)

Reported Cases of Hepatitis A in Texas 1995-2009*

0500

1,0001,5002,0002,5003,0003,5004,0004,5005,0001995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009*

Nu

mb

er

of

cases

Hepatitis A vaccine licensed in 1995

*2009 data is provisional as of 4/6/2010.

16.1

9.3

1.1

Incidence rates per 100,000 population

0

5

10

15

20

25

30

35

<10

10-1

9

20-2

9

30-3

9

40-4

9

50-5

960

+

Unknown

Age Group (years)

Per

cen

tag

e o

f ca

ses

1995 2000 2008

Percent of Hepatitis A Cases by Age Group

0

5

10

15

20

25

30

35

<10 10-19 20-29 30-39 40-49 50-59 60+

Rat

e p

er 1

00,0

00

1995 2000 2008

Incidence Rates of Hepatitis A by Age Group

Percent of Hepatitis A Cases by Gender

0

10

20

30

40

50

60

Male Female Unknown

Pe

rce

nta

ge

of

Ca

se

s

1995 2000 2008

Percent of Hepatitis A Cases by Race

010203040506070

A/PI

Black

Hispan

ic

White

Other

Unknow

n

Pe

rce

nta

ge

of

Ca

se

s

1995 2000 2008

Incidence Rates of Hepatitis A Cases by Race

0

5

10

15

20

25

30

35

40

Black Hispanic White

Ra

te p

er

10

0,0

00

1995 2000 2008

Percentage of Cases in Age Category by Race, 2008

<10

10-19

20-29

30-39

40-49

50-59

60+

Whites Hispanics

Summary

• Requiring school/childcare vaccination in specific locations has reduced incidence across the state in all age groups

• Racial disparities in disease incidence have been eliminated

• Expansion of vaccination requirements should help to continue these trends