Laboratory Handbook For Clinicians On HIV

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HIV TEST LABORATORY
DEPARTMENT OF MICROBIOLOGY
SAWAI MANSINGH MEDICAL COLLEGE, JAIPUR
HIV
Laboratory Handbook for Clinicians
Issue No.: 01
Issue Date: November 5th 2012
Prepared by: Dr. Babita Sharma
Approved
&
issued
by:
Dr.
Nitya
Vyas
HIV Test Laboratory, Department of Microbiology, SMS Medical College, Jaipur.
Introduction
HIV/AIDS is not like other infectious diseases. It is far more complex because HIV infection
cannot be diagnosed clinically in asymptomatic as well as symptomatic individuals. Person is
infectious and infected for life. Outcome is invariable fatal and no cure or vaccine is available so far.
Commonly HIV/AIDS is acquired through sexual contact, individuals known to be HIV infected are
stigmatized and discriminated.
HIV testing is not mandatory and it should not be imposed for providing healthcare services and
facilities. Any HIV testing must be accompanied by pre test and post test counseling services and
informed consent. Confidentiality of the results should be maintained1.
In 50-93% of cases primary HIV infection is asymptomatic. Laboratory diagnosis is the only
method for determining HIV status of such individuals. A number of tests and diagnostic kits are
available to assess the HIV status of individuals. Serological tests are most commonly performed
Objectives of HIV testing

Diagnosis of HIV infection in clinically suspected individuals.

To Diagnose asymptomatic individuals (practicing high risk behavior)

Prevention of parent to child transmission

For tissue transfusion safety (blood, sperms, organs etc)

Sentinel surveillance to monitor epidemiological trends.

Research
Services Offered
All the services offered at the HIV Test Laboratory are free of cost. Services being provided at HIV
Test Laboratory are

Counseling about HIV/AIDS

Testing of HIV antibody: Walk inpatient, Provider initiated referred patients.

CD4+ T Lymphocyte count for patients referred from ART Center.

Dried blood spot (DBS) collection for HIV exposed child.
Document Name: Laboratory Hand Book for Clinician
Document No.: SMS/MICRO/HIV/LHC/10
Page No.1 | 8
Amendment Number :
Amendment Date:
Version No.- 01
HIV Test Laboratory, Department of Microbiology, SMS Medical College, Jaipur.
Clinical Sample Required
We prefer to collect sample at our center:

For HIV antibody Testing: 3-5 ml blood/ 1ml serum in sterile plain vial.

For CD4+ T Lymphocyte count: 2 ml blood in K2/K3 EDTA vial.

Dried blood spot (DBS) is collected at HIV Test Laboratory
Sample collection
1st April to 30th September

From 8.00 am to 11 am & 11.30 am to 12.30 pm.
1st October to 31st March

From 9.00 am to12 noon & 12.30 pm to 1.30 pm
.
Report Distribution
1st April to 30th September:
Samples received from 8.00 am to 11.00 am are reported on same day between 1-2 pm.

Samples received between 11.30 am to 12.30 pm are reported on next working day between
11.30 am to 12 noon.
1st October to 31st March:

Samples received from 9.00 am to 12.00 noon are reported on same day between 2- 3 pm.
Samples received between 12.30 noon to 1.30 pm are reported on next working day between
12.30 pm -1 pm.

Reports are available with Counselors.
Laboratory diagnosis during window period
The window period is the period of time between initial infection with HIV and the time when HIV
antibodies can be detected in the blood (3-12 weeks). A blood test performed during the window
period may yield negative test result for HIV antibodies. HIV infection during window period can be
Document Name: Laboratory Hand Book for Clinician
Document No.: SMS/MICRO/HIV/LHC/10
Page No.2 | 8
Amendment Number :
Amendment Date:
Version No.- 01
HIV Test Laboratory, Department of Microbiology, SMS Medical College, Jaipur.
detected by demonstrating the presence of virus and virus components. Detection of p24 antigen and
PCR for viral products may be helpful during window period.
Counseling
Counseling is a confidential dialogue between client and a counselor to provide information on
HIV/AIDS and bringing about behavior change in the client. It is also aimed at enabling the client to
take the decision regarding HIV testing and to understand the implication of the test results.2
HIV testing is accompanied with pre and post test counseling. The pre test counseling involves
provision of basic information on HIV/ AIDS and risk assessment to direct walk in client while in post
test counseling the client is helped to understand and cope with the HIV test results.
In case of a negative test result the counselor reiterates basic information on HIV and assists the
client to adopt behaviors that reduces the risk of getting infected with HIV in future. In case the client
is in the window period as per history a repeat test is recommended.
In case of a positive test result the counselor assists the client to understand the implication of the
positive test results and help in coping with the test results. With this counselor also refer the patient to
ART, and other services for care and support.
Samples are collected after pre test counseling and informed consent of the patients.
Collected samples are accepted only when they are accompanied with completely filled requisition
forms and informed consent of patient.
HIV Testing

In HIV Test Laboratory HIV antibodies are detected by Rapid and ELISA method as per kits
available.

CD4 T+ lymphocytes count is done by BD FACS Calibur through flow cytometery.

The DBS samples are sent to All India Institute of Medical Sciences, Delhi (AIIMS) for DNA
PCR test.

In HIV test laboratory diagnosis of HIV is done according to NACO strategies.

For diagnosis of HIV, the laboratory performs 3 tests with different principle or different
antigen. The kits for these are supplied by RSACS, which are approved by NACO.
Document Name: Laboratory Hand Book for Clinician
Document No.: SMS/MICRO/HIV/LHC/10
Page No.3 | 8
Amendment Number :
Amendment Date:
Version No.- 01
HIV Test Laboratory, Department of Microbiology, SMS Medical College, Jaipur.
Strategy IIB
For patients with AIDS defining diseases
I Test (HIV antibody Test)
↓
Non Reactive
Reactive
Report Negative for HIV antibody
II Test different in principle or antigen from first test
____________________________________________________
Non Reactive
Reactive
Report Positive for HIV antibody
III Test different in principle or antigen from I & II test
____________________________________________
Non Reactive
Reactive
Report Negative for HIV antibody
Indeterminate

Sample is send for conformation
to NRL, NCDC Delhi

Patient is advised to repeat test after
4 weeks and
Document Name: Laboratory Hand Book for Clinician
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Amendment Number :
Amendment Date:
Version No.- 01
HIV Test Laboratory, Department of Microbiology, SMS Medical College, Jaipur.
Strategy III
To detect HIV infection in asymptomatic individuals
3 Different Test kits required
I Test
Non Reactive
Reactive
Report Negative for HIV antibody
II test different in principle and antigen from I test
______________________________________________________
↓
Non Reactive
Reactive
III test different in principle &
antigen from I and II test
III test different in principle &
antigen from I and II test
__________________________________
Non Reactive
_________________________________
Reactive
Non Reactive
Reactive
Report Negative for
HIV antibody
Report Positive for
HIV antibody
Indeterminate

Sample is send for conformation
to NRL, NCDC Delhi

Patient is advised to repeat test after
4 weeks and
Document Name: Laboratory Hand Book for Clinician
Document No.: SMS/MICRO/HIV/LHC/10
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Amendment Number :
Amendment Date:
Version No.- 01
HIV Test Laboratory, Department of Microbiology, SMS Medical College, Jaipur.
Occupational Exposure and Post Exposure Prophylaxis
An “ exposure” that may place a Health Care Provider (HCP) at risk of blood borne infection is
defined as percutaneous injury (e.g. needle – stick or cut with a sharp instrument), contact with the
mucous membranes of the eye or mouth, contact with non-intact skin (particularly when the
exposed skin in chapped, abraded, or afflicted with dermatitis,) or contact with intact skin when the
duration of contact is prolonged (e.g. several minutes or more) with blood or other potentially
infectious body fluids. Body fluids that are potentially infectious include blood, semen, vaginal
secretions, cerebrospinal fluid, synovial, pleural, peritoneal, pericardial and amniotic fluids or other
body fluids contaminated with visible blood.3 Exposure to tears, sweat, urine, faeces, saliva of an
infected person is normally not considered as an “exposure” unless these secretions contain visible
blood.
Average risk of HIV infection after occupational exposure to HIV infected blood4
Small amount of blood on intact skin
No risk
Needle Stick injury
0.3%
Exposure to eye, nose or mouth
0.09%
Management of Exposure:
Steps to be taken on accidental exposure to blood (or body fluid containing blood) are:

Wash wound immediately with running water and soap.

Inform the hospital management and document occupational accident.

Consult with nearest ART centre/resource for Post-Exposure prophylaxis, evaluation, and
follow-up (as per the national guidelines on PEP)

Whenever possible confidential counseling and testing of source for hepatitis, HIV etc must be
done. A history should be taken as well to ascertain likely risk of the source.
Document Name: Laboratory Hand Book for Clinician
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Amendment Number :
Amendment Date:
Version No.- 01
HIV Test Laboratory, Department of Microbiology, SMS Medical College, Jaipur.

Counseling and collection of blood for testing from the exposed HCP with written informed
consent must be done. PEP should be provided to the exposed HCP until report of source is
available and confirmed negative. PEP should be started with in 1-2 hours of exposure.

Risk of infection and transmission must be evaluated.

PEP should be provided until result of the source’s test is available and confirmed negative. If
source

is positive or unknown PEP should be given for 4 weeks.
A repeat HIV test of the exposed individual should be performed at 6 weeks, 12 weeks and 6
months post- exposure.

All HCW who report exposure to HIV at work, whether given PEP or not, is to be followed up
for 6 months before a negative antibody test is used to reassure the individual that infection has
not occurred. On all the occasions HCW is provided with a pre test and post test counseling.
The HCW is advised to refuse from donating blood, semen or organ/ tissue and abstain from
sexual intercourse.
What to do after exposure
Don’ts:

Do not panic!

Do not put pricked finger into mouth.

Do not squeeze blood from wound, this causes trauma and inflammation, increasing risk of
transmission.

Do not use bleach, alcohol, betadine, or iodine, which may cause trauma.
Do’s:

Remove gloves, if appropriate.

Wash site thoroughly with running water. Irrigate thoroughly with water or saline if splashes
have gone into the eye or mouth.
Quality Assurance
Quality assurance (QA) refers to planned, step by step activity that lets one know that the testing is
being carried out correctly, results are accurate and mistakes are found and corrected to avoid
adverse outcome. QA is an ongoing set of activities that help to ensure that the test results provided
Document Name: Laboratory Hand Book for Clinician
Document No.: SMS/MICRO/HIV/LHC/10
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Amendment Number :
Amendment Date:
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HIV Test Laboratory, Department of Microbiology, SMS Medical College, Jaipur.
are accurate and reliable as far as possible for all persons being tested. These activities are in place
during the entire testing process from when a person agrees to be tested until after the test results
are provided.
High quality HIV testing services are maintained at HIV Test Laboratory by:

Adherence to standard operating procedure.

Use of valid test kits.

Correct interpretation of results.

Internal quality control of laboratory.

Regular calibration, monitoring and maintenance of equipments

Proper documentation
References:
1. Manual for HIV testing laboratory: NACO March 2007.
2. Operational guideline for integrated testing and counseling centers NACO-2007
3. Bell DM. Occupation risk of human immune deficiency virus infection in healthcare workers.
An overview. AmJ. Med. 1997; 102. 9-15
4. Gerberdeny J L. Occupational exposure to HIV in healthcare setting.. N Engl J Med 2003; 348826-33.
5. CDC updates public health services guidelines for the management of occupational exposure
HBV, HCV, HIV and recommendation for post exposure
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Amendment Number :
Amendment Date:
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