Download Overview of Hepatitis B Virus and Serological Markers

The Changing Epidemiology
of Acute Hepatitis A in Texas
Rachel Wiseman, MPH,
Lucille Palenapa, MS; Linda Gaul, PhD
Emerging 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
• Transmission
Humans
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
Texas Counties Requiring Hepatitis A
For Childcare and School Entry, 1999
32 Counties Requiring Hepatitis A Vaccination
Texas Counties Requiring Hepatitis A
For Childcare and School Entry, 2003
Seven counties,
were added to the
vaccination
requirement.
39 Counties Requiring Hepatitis A Vaccination
Texas Counties Requiring Hepatitis A
For Childcare and School Entry, 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*
Incidence rates per
100,000 population
9.3
2009*
2008
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
*2009 data is provisional as of 4/6/2010.
2007
1.1
16.1
1996
5,000
4,500
4,000
3,500
3,000
2,500
2,000
1,500
1,000
500
0
1995
Number of cases
Hepatitis A vaccine licensed in 1995
Percent of Hepatitis A Cases
by Age Group
35
25
20
15
10
5
nk
no
w
n
U
60
+
59
50
-
49
40
-
39
30
-
29
20
-
10
-
19
0
<1
0
Percentage of cases
30
Age Group (years)
1995
2000
2008
Incidence Rates of Hepatitis A
by Age Group
35
Rate per 100,000
30
25
20
15
10
5
0
<10
10-19
20-29
1995
30-39
2000
40-49
2008
50-59
60+
Percent of Hepatitis A Cases
by Gender
Percentage of Cases
60
50
40
30
20
10
0
Male
Female
1995
2000
Unknown
2008
n
2008
U
nk
no
w
O
th
er
W
hi
te
is
pa
ni
c
2000
H
la
ck
B
/P
I
70
60
50
40
30
20
10
0
A
Percentage of Cases
Percent of Hepatitis A Cases
by Race
1995
Incidence Rates of Hepatitis A
Cases by Race
40
Rate per 100,000
35
30
25
20
15
10
5
0
Black
Hispanic
1995
2000
White
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