Transcript Sexually Transmitted Infections and Women`s Reproductive Health

Curable versus incurable
STDs
Objectives
• To describe the natural history and
epidemiology of two curable STDs (i.e.
syphilis and chlamydia) and two noncurable STDs (i.e. Herpes and HPV)
• To discuss study design issues specific
to curable versus non-curable diseases
Natural history of a curable
disease
Symptoms
Infection
diagnosis
Testing
cure
treatment
Prevalence = ∑ (incidence – cured)
Things that contribute to nontreatment among curable STDs
• Lack of index treatment
– Failure to return for treatment
– Non-adherence to medication
– Given incorrect medicine
• Lack of partner treatment
• Treatment failure
Natural history of a non-curable
disease
Symptoms
Infection
diagnosis
Testing
Prevalence = ∑ incidence
Non-curable STDs
(e.g. HIV, Herpes, HPV)
• Long infectious period
• Few population based screening
programs
• No curative treatments
• Incidence may be very different than
prevalence
Treponema pallidum (syphilis)
Issues in syphilis
• Test doesn’t tell if it is incident and won’t
pick up tertiary
• Symptoms change depending on
staging
• Most at risk, least likely to get tested
and treated
Syphilis - curable
• Caused by Treponema pallidum
• primary lesion usually occurs 3 weeks
after exposure
• secondary manifestations occur weeks
to 12 months after initial exposure
• tertiary
• treatment is parenteral penicillin G
Progression of syphilis
Staging of Syphilis
Testing and symptoms
Male chancres
Chancre in a female
Late stage manifestations of
syphilis
Chlamydia
Sexually Transmitted Disease
Surveillance 2001
Division of STD Prevention
Chlamydia — Number of states that require
reporting of Chlamydia trachomatis infections:
United States, 1987–2001
No. of states
50
40
30
20
10
0
1987
88
89
90
91
92
93
94
95
96
97
98
99
2000
01
Chlamydia — Reported rates: United States,
1984–2001
Rate (per 100,000 population)
300
240
180
120
60
0
1984
86
88
90
92
94
96
98
2000
Chlamydia — Rates by state: United States and
outlying areas, 2001
231.3
212.7
104.9
165.4
217.9
169.2
156.3
303.6
241.2
169.9
244.5
194.7
231.0
187.3
241.8
307.8
279.6
331.7
352.0 250.9
134.5
301.0
343.8
225.0
303.7
129.7 259.1
249.3
219.7
274.6
273.5
272.3
382.1
Guam 278.4
414.6
326.6
413.4
334.5
399.2
437.7
VT
NH
MA
RI
CT
NJ
DE
MD
312.8
235.4
Rate per 100,000
population
(n= 7)
<=150
150.1-300 (n= 29)
(n= 17)
>300
332.7
Puerto Rico 72.2
104.8
111.9
163.8
277.8
226.6
193.9
356.4
295.3
Virgin Is. 120.6
Note: The total rate of chlamydia for the United States and outlying areas
(including Guam, Puerto Rico and Virgin Islands) was 275.5 per 100,000
population.
Chlamydia — Rates by region: United States,
1984–2001
Rate (per 100,000 population)
350
280
210
140
West
Midwest
Northeast
South
70
0
1984
86
88
90
92
94
96
98
2000
Chlamydia — Rates by sex: United States,
1984–2001
Rate (per 100,000 population)
450
360
270
Men
Women
180
90
0
1984
86
88
90
92
94
96
98
2000
Chlamydia — Age- and sex-specific rates:
United States, 2001
Men
3,000
Rate (per 100,000 population)
2,400
1,800
1,200
600
0
9.9
375.9
604.9
284.7
140.4
70.3
37.1
15.9
5.5
2.2
114.2
Age
10-14
15-19
20-24
25-29
30-34
35-39
40-44
45-54
55-64
65+
Total
Women
0
600
1,200
1,800
2,400
3,000
139.8
2,536.1
2,447.0
824.6
301.9
119.1
51.4
18.1
5.1
2.9
436.3
Chlamydia — Positivity among 15-24 year old
women tested in family planning clinics by state:
United States and outlying areas, 2001
6.2
5.8
3.1
3.2
4.0
4.3
4.4
7.5
3.4
4.2
5.2
4.3
5.6
3.8
7.5
5.1
6.5
7.0
5.0
5.6
4.1
6.0
6.7
5.4
5.7
2.7
4.3
8.1
3.9
6.9
4.9
6.6
7.6
13.5
7.7
8.3
8.4
10.8
3.7
VT
NH
MA
RI
CT
NJ
DE
MD
DC
5.5
5.5
Positivity (%)
<4
4.0-4.9
>=5
5.4
Puerto Rico 6.1
3.4
5.9
5.2
7.0
5.0
6.3
5.8
5.1
6.1
Virgin Is. 13.9
Note: States reported chlamydia positivity data on at least 500 women aged
15-24 years screened during 2001.
SOURCE: Regional Infertility Prevention Program; Office of Population Affairs; Local and State STD
Control Programs; Centers for Disease Control and Prevention
(n= 8)
(n= 8)
(n= 37)
Tests
Culture
antigen detection (indirect)
nucleic acid amplification (direct)
Herpes
Issues for Herpes
•
•
•
•
Variable presentation
Stigma and reporting bias
Non-treatable
Prevalence increases with age
Herpes Simplex -2
• One of most common, 1 million incident and 45
million prevalent in U.S. per year.
• Less than 10% of those infected are aware.
• Greek term meaning “to creep or crawl”
• Acquired sexually
• HSV-1 (oral herpes) can cause 30-40% of genital
herpes
• Tested using an antibody test
• Increasing age, low SES, more partners, women
and African Americans at higher risk
HSV-2
• More than 20% of Americans are infected
• From 70s to 90s prevalence increased 30%
• NHANES suggests it leveled off in 1990s except
for white teenagers.
• Treated with acyclovir, famciclovir, valaciclovir,
foscarnet, cidofovir gel, trifluridine and interferon
• an effective therapeutic vaccine for genital
herpes has not been successful to date, although
a live virus glycoprotein H-deficient (DISC)
vaccine is currently in clinical trials
Genital herpes — Initial visits to physicians’
offices: United States, 1966–2001
Visits (in thousands)
250
200
150
100
50
0
1966
69
72
75
78
81
84
87
SOURCE: National Disease and Therapeutic Index (IMS America, Ltd.)
90
93
96
99
Genital herpes simplex virus type 2 infections
— Percent seroprevalence according to age in
NHANES* II (1976-1980) and NHANES III
(1988-1994)
Percent
40
32
24
16
NHANES II
NHANES III
8
0
12-19
20-29
30-39
40-49
Age Group
Note: Bars indicate 95% confidence intervals.
*National Health and Nutrition Examination Survey
50-59
60-69
70+
Complicated Scenarios
• How to measure incidence of HIV?
• How to study the efficacy of a vaccine
for Herpes?
• How to study the efficacy of treatment
for HPV?