Time Periods of Interest - HIV, STDs, Viral Hepatitis

Question 1

Define: Window Period

Answer 1

The time between when a person is exposed to a bacteria or virus and when a test can accurately detect organism.

Question 2

Define: Incubation Period

Answer 2

The time elapsed between exposure to a bacteria or virus and when symptoms and signs are first apparent

Question 3

HIV Window Period for Antibody Tests

Answer 3

23 to 90 Days.

This includes the Chembio SURE CHECK HIV Rapid Test

Question 4

HIV Window Period for 4th Generation Test

Answer 4

18 to 45 days.

This test detects antigens, which are a part of the virus and present during acute HIV

Question 5

HIV Window Period for Nucleic Acid Test

Answer 5

10 to 33 Days

Question 6

What should an individual do if they are concerned about being exposed to HIV in the last 72 hours?

Answer 6

They should be referred to a health care provider immediately for post-exposure prophylaxis (PEP) evaluation

Question 7

HIV Incubation Period

Answer 7

Within 2 to 4 weeks after infection.

People may experience a flu-like illness, lasting for a few weeks; these symptoms indicate an acute HIV infection.

Question 8

Chlamydia NAAT Test Window Period

Answer 8

Window period for NAAT test is unknown but may range from 5 days up to 2 weeks.

The nucleic acid amplification tests are very sensitive and are able to detect a low number of organisms. Patients should be tested at time of visit.

If exposure was within 1 to 5 days, retesting two weeks after exposure would be recommended if more reassurance is needed.

Question 9

Gonorrhea NAAT Test Window Period.

Answer 9

Window period for NAAT test is unknown but may range from 5 days up to 2 weeks.

The nucleic acid amplification tests are very sensitive and are able to detect a low number of organisms. Patients should be tested at time of visit.

If exposure was within 1 to 5 days, retesting two weeks after exposure would be recommended if more reassurance is needed.

Question 10

Chlamydia (CT) Incubation Period

Answer 10

In patients who develop symptomatic infection, the incubation period is estimated to be 7 to 21 days

Question 11

Gonorrhea (GC) Incubation Period

Answer 11

The incubation period ranges from 1 to 14 days, with most men becoming symptomatic within 2 to 5 days after exposure.

The incubation period in women is variable, but symptoms, when they do occur, usually develop within 10 days of exposure.

Question 12

Time Period for Dual Therapy for Gonorrhea.

Answer 12

To be considered appropriately treated for GC, the Azithromycin and Ceftriaxone must be given on the same day.

Appropriate treatment also occurs if ceftriaxone is administered within 5 days after the azithromycin dose.

Patients are recommended to be retreated if they are given ceftriaxone in the clinic and don’t pick up their azithromycin from the pharmacy on that same day.

Question 13

Chlamydia Retesting / Test of Cure

Answer 13

All individuals diagnosed with chlamydia should be retested 3 months after completing treatment.

Test of Cure:
Only recommended for pregnant women - 3 to 4 weeks after completing therapy

Question 14

Gonorrhea Retesting / Test of Cure

Answer 14

All individuals diagnosed with Gonorrhea should be retested 3 months after completing treatment.

Test of Cure:
Recommended for individuals with pharyngeal gonorrhea treated with an alternative regimen 3 to 4 weeks after completing therapy

Question 15

Syphilis Window Period

Answer 15

VDRL and RPR test results turn positive 1-2 weeks after chancre formation.

FTA-ABS and TP-PA are generally considered equally sensitive in the primary stage of disease.

Question 16

Syphilis Incubation Period - Primary

Answer 16

The chancre typically occurs about 3 weeks (range 10 to 90 days) after exposure. The chancre lasts 3 to 6 weeks

Question 17

Syphilis Incubation Period - Secondary

Answer 17

4 to 8 weeks after onset of primary chancre.

Question 18

Syphilis Incubation Period - Tertiary Syphilis

Answer 18

1 to 20 years after exposure.

Question 19

Syphilis Incubation Period - Early Neurosyphilis

Answer 19

Early forms of neurosyphilis usually occur a few months to a few years after initial infection

Question 20

Syphilis Incubation Period - Ocular syphilis

Answer 20

Symptoms may develop at any stage

Question 21

Hepatitis C - Window Period

Answer 21

HCV infection can be detected by anti-HCV (including HCV rapid tests) screening tests 4-10 weeks after infection.

Anti-HCV can be detected in >97% of people by 6 months after exposure.

HCV RNA can be detected as early as 2-3 weeks after infection

Question 22

Hepatitis C - Window Period for Infants

Answer 22

The optimal timing of HCV RNA testing is unknown, but 2 to 6 months after birth is reasonable.

There is no value in repeated HCV RNA testing prior to 18 months of age. Anti-HCV testing should take place at or after 18 months of age.

If infants are positive for HCV RNA at 2-6 months of age, between 25% to 50% will spontaneously resolve HCV by 3 y ears old.

Question 23

What is the overall risk of vertical transmission of Hepatitis C per pregnancy?

Answer 23

4 to 7 %

Question 24

Hepatitis C - Incubation Period

Answer 24

In those people who do develop symptoms, the average period from exposure to symptom onset is 2-12 weeks (range: 2-26 weeks)

Question 25

How long can HCV survive outside the body at room temperature?

Answer 25

Up to 3 weeks

Question 26

How long can HCV survive in the barrel of a syringe?

Answer 26

Up to 63 days

Question 27

Hepatitis B - Window Period

Answer 27

HBsAg will be detected an average of 4 weeks (range: 1-9 weeks) after exposure. All patients who do not remain chronically infected will be HBsAg negative by 15 weeks after symptom onset

Question 28

Hepatitis B - Testing in Infants

Answer 28

For Infants born to HBsAg positive mothers, post vaccination testing should be performed 1-2 months after completion of 3 or more doses of a hepatitis B vaccine series. Testing should not be performed before age 9 months in order to avoid detection of anti-HBs from hepatitis B immune globulin (HBIG) administered uring infnacy and to avoid detection of HBsAg from vaccine - HBsAg can be transiently positive for 1-18 days after vaccination

Question 29

Hepatitis B - Incubation Period

Answer 29

If symptoms occur, they begin an average of 90 days (range: 60 - 150 days) after exposure to HBV.

Question 30

How long can HBV live outside the body?

Answer 30

At least 7 days

Question 31

What percentage of infants will remain chronically infected with HBV?

Answer 31

90%

Question 32

What percentage of children aged 1 - 5 years will remain chronically infected with HBV?

Answer 32

25-50%

Question 33

What percentage of adults recover from HBV infection and do not become chronically infected?

Answer 33

95%

Question 34

Chlamydial Infection / Gonorrhea Symptomatic cases interview period

Answer 34

60 days prior to onset of symptoms through the date of treatment

Question 35

Chlamydial Infection / Gonorrhea Asymptomatic cases interview period

Answer 35

60 days prior to treatment through the date of treatment

Question 36

Pelvic Inflammatory Disease Interview period

Answer 36

60 days prior to onset of symptoms through date of treatment

Question 37

Primary Syphilis Interview period

Answer 37

Three months (90 days) prior to the onset of symptoms up to the date of adequate treatment

Question 38

Secondary Syphilis Interview period

Answer 38

6 1/2 months prior to the onset of symptoms up to the date of adequate treatment. This is derived by adding the maximum 90 day incubation period, the maximum 5 week duration of a primary lesion, and the maximum ten week latency between primary and secondary syphilis

Question 39

Early Latent Syphilis Interview Period

Answer 39

From the date of adequate treatment back 12 months

Question 40

HIV / AIDS Interview Period

Answer 40

If there is no test history: 1 year prior to the date that the positive specimen was collected through the date of the interview. If there is a test history: 6 months prior to a negative test date [through the date of interview] If there is a spouse: Ten-year interview period for current or any previous spouses. - Ryan White Reauthorization Act requires Health Departments receiving Ryan White funds show "good faith" efforts to notify marriage partners of infected patients within the last ten years (unless there is medical evidence, a non-reactive test that this would be unnecessary)

Question 41

Exception to interview period guidelines

Answer 41

The interview period may be shortened if the original patient received adequate treatment for their infection during the calculated interview period time frame. The receipt of adequate incidental treatment (within the standard interview period), which is adequate to treat uncomplicated infections, should mark the maximum interview period. In other words, the date that the adequate treatment was received marks the beginning of the interview period.