HIV Testing FAQs

Why is the HIV ELISA test reported as non-reactive if it is ‘negative’?

A non-reactive result means that no HIV antibodies were found. This would find any exposures which happened 6 weeks prior to test or before that. A non-reactive test does not mean that a person is immune to HIV in the future only that they do not show the virus in their body at the time of the test.

A negative HIV test means that no signs of HIV infection were detected. However, the implications of a negative HIV test depend on the sensitivity of the test performed, as well as the time elapsed between testing and possible exposure to HIV.

What is the p24 antigen and HIV 1&2 ELISA test?

  • HIV antigen tests look for the presence of HIV virus.
  • HIV antibody tests look for the presence of HIV antibodies.

After infection with HIV,

  • It takes about two weeks for the virus to replicate and produce enough antigen to be detectable
  • It takes more than three weeks for the body to produce sufficient antibodies to be detectable through testing.

So if not enough time has passed since the potential exposure, it is possible to obtain false negative results, necessitating further testing.

For HIV testing: What is better – a spot test or an ELISA test?

A Spot Test for HIV detects HIV antibodies. The rapid test detects antibodies to HIV 1&2

An ELISA test for HIV also detects HIV antibodies.

Some ELISA tests for HIV detect antigen and antibodies (HIV DUO / 4th generation tests)

No HIV test can detect HIV immediately after infection.

Is HIV Spot Test a preventive test?

NO. It does not prevent HIV infection. It tests if you have HIV infection or not.

The window period for HIV p24 antigen is 28 days but can I test for it within 10 days?

A combination or fourth-generation test looks for both HIV antibodies and antigens.

Antigens are foreign substances that cause your immune system to activate. The antigen is part of the virus itself and is present during acute HIV infection (the phase of infection right after people are infected but before they develop antibodies to HIV).

Antigen can be detected between 14-21 days after infection.

So the answer to your question is NO. You cannot use the p24 antigen ELISA test to test for HIV within 10 days.

You are not testing virus at Disha Pathology, you are testing for antibody. How many days after infection will the antibody be detected?

At Disha Pathology we offer two types of HIV tests.

  1. HIV Spot test (Rapid Test)
  2. HIV p24 antigen and HIV 1&2 antibody test (ELISA Test)

So yes, we test for virus (antigen) and antibody in the same ELISA test

The time between when a person gets HIV and when a test can accurately detect it is called the window period. The window period varies from person to person and also depends upon the type of HIV test.

Most, but not all people, will make enough antigens and antibodies for fourth-generation or combination tests to accurately detect infection 2 to 6 weeks (14 to 42 days) after infection.

Antigens are foreign substances that cause your immune system to activate. The antigen is part of the virus itself and is present during acute HIV infection (the phase of infection right after people are infected but before they develop antibodies to HIV).

Antigen can be detected between 14-21 days after infection.

Antibodies are produced by your immune system when you’re exposed to viruses like HIV or bacteria. HIV antibody tests look for these antibodies to HIV in your blood.

The soonest an antibody test will detect infection is 3 weeks. Most (approximately 97%), but not all, people will develop detectable antibodies within 3 to 12 weeks (21 to 84 days) of infection.

What is the HIV PCR test?

PCR tests (polymerase chain reaction tests) – also test for the actual virus. This type of test is often used for testing the viral load of HIV-positive people, as well as testing babies born to HIV-positive mothers.

It looks for HIV in the blood. It looks for the virus and not the antibodies to the virus. This test is very expensive and not routinely used for screening individuals unless they recently had a high-risk exposure or a possible exposure with early symptoms of HIV infection.

Most, but not all people, will have enough HIV in their blood for a PCR / nucleic acid test to detect infection 1 to 4 weeks (7 to 28 days) after infection.

How often should you test yourself for HIV?

If you get an HIV test within 3 months after a potential HIV exposure and the result is negative, get tested again in 3 more months to be sure.

If you learned you were HIV-negative the last time you were tested, you can only be sure you’re still negative if you haven’t had a potential HIV exposure since your last test. If you’re sexually active, continue to take actions to prevent HIV, like using condoms the right way every time you have sex and taking medicines to prevent HIV if you’re at high risk.

Pregnancy Tests


If you have been planning to get pregnant, chances are this question will rise in your mind the day you miss your period. But for some of us who may not have regular monthly cycles, a home pregnancy test and physical symptoms can provide the answer.


The home pregnancy test works by detecting a hormone called Human Chorionic Gonadotropin (hCG) in urine. This hormone appears in a pregnant woman’s urine, approximately 20 days after her last menstrual period. The levels then rise rapidly, reaching a peak in the next 60 to 80 days. Today, these kits are available over the counter at most chemists and are quick and easy to use.

If you have a negative result when you first test, it may be that the levels of hCG have not yet reached a level where they can be detected by a test, even by the day your period is due, so you may want to wait a few days then test again.

Some laboratories also conduct the urine test in case you are not able to procure the home pregnancy test in your vicinity.


Blood tests are used less often than urine tests. These tests can detect pregnancy earlier than a home pregnancy test, or about six to eight days after ovulation. But with these tests, it takes longer to get the results than with a home pregnancy test.

Two types of blood pregnancy tests are available:

A qualitative hCG test simply checks to see if hCG is present. It gives a “yes” or “no” answer to the question, “Are you pregnant?”

A quantitative hCG test (beta hCG) measures the exact amount of hCG in your blood. It can find even very low levels of hCG. Because these pregnancy tests can measure the concentration of hCG, they may be helpful in tracking any problems during pregnancy. They may also (in combination with other tests) be used to rule out a tubal (ectopic) pregnancy or to monitor a woman after a miscarriage when hCG levels fall rapidly.


A woman’s body starts changing from the moment the fertilized egg attaches itself to the wall of the uterus, which indicates a successful start to pregnancy. Following are some symptoms that can indicate that you could be pregnant; however note that not all symptoms may occur and are not a reliable indication of pregnancy.

Breast changes: Because of hormonal changes, breasts may become swollen, sore, or tingly a week or two later. Or they may feel heavier or fuller or feel tender to the touch. The area around the nipples, called the areola, may also darken.

Spotting and cramping: When the fertilized egg attaches itself to the wall of the uterus, it can cause spotting or implantation bleeding. It occurs anywhere from six to 12 days after the egg is fertilized. The cramps resemble menstrual cramps, so some women mistake them and the bleeding for the start of their period. The bleeding and cramps, however, are slight. Some women may also experience an increased vaginal discharge without any soreness or irritation.

Fatigue: A woman can start feeling unusually fatigued as soon as one week after conceiving. It is often related to a high level of a hormone called progesterone, although other things — such as lower levels of blood sugar, lower blood pressure, and a boost in blood production — can all contribute.

Morning sickness: Not all women experience nausea or morning sickness during their pregnancy. Contrary to its name, it can happen at any time during the day. At the same time, some women crave, or can’t stand, certain foods when they become pregnant. You may also experience a strange taste in your mouth; many women describe it as metallic. While the symptoms lessen for many women at about the 13th or 14th week of their pregnancy, it is possible that the nausea, cravings, and food aversions can last for the entire pregnancy.

Frequent urination, constipation, mood swings and headaches / back pain are also experienced by some women early on in their pregnancy.


Whether you have tested positive with the home pregnancy test or have one or more of the above symptoms, it is important to confirm your pregnancy with a blood test – called the Beta hCG test – at a reliable pathology laboratory, run by a certified pathologist.

Once your pregnancy is confirmed, you will then need to make an appointment with your gynecologist to advise you further on your pregnancy. All the best!

Are You at the Risk of Vitamin B12 Deficiency?

Imagine how it would feel if a mere action of sitting would feel like an effort? Or, if you had to push yourself to the extreme to achieve the smallest thing or the feeling of being physically drained out after a handsome sleep? That is exactly how you would feel when you are suffering from Vitamin B12 deficiency. Vitamin B12 can be hard to recognize because the body stores Vitamin B12 for many years before the early symptoms appear and develops quickly. This makes Vitamin B12 deficiency a serious health issue which requires immediate attention.

10 Reasons Why Vitamin B12 is Necessary

Boost Energy Levels – Vitamin B12 converts stored carbohydrates into glucose which produces energy thereby decreasing fatigue and lethargy in the body.

Boost Metabolism Activity – With the increase in energy levels, Vitamin B12 also promotes weight loss and burning more calories.

Stimulates Absorption of Folic Acid – Vitamin B12 also leads to better absorption of folic acid (Vitamin B9) which helps in releasing more energy.

Development of Red Blood Cells – Vitamin B12 deficiency can lead to a blood disorder known as anemia which can cause severe and permanent brain and nerve damage.

Healthy Nervous System – Vitamin B12 helps in smooth and proper functioning of brain and nerve cells in the body.

Treats Depression – Vitamin B12 can influence your emotional state and mood and keep you happy and treat depression.

Healthy Hair and Skin – Vitamin B12 is vital for RNA and DNA synthesis and cell reproduction and maintaining healthy hair and skin.

Facilitates Healthy Sleep Patterns – Vitamin B12 improves melatonin production to help you sleep better.

Regulates Homocysteine Levels – A balanced dose of Vitamin B12 and folic acid can regulate homocysteine levels in the blood plasma cells decreasing the risk of stroke, osteoporosis and heart conditions.

Regulates Brain Health – Vitamin B12 eliminates mental decline and promotes healthy functioning of the brain and neurological system.

How Do I Know If I am Suffering from Vitamin B12 Deficiency?

While it can be hard to recognize Vitamin B12 deficiency, but there are some early visible signs and symptoms, digestive problems, and immune system issues like:

  • Fatigue
  • Tingling sensation in fingers and toes
  • Poor Concentration/Memory Loss
  • Dizziness
  • Pale complexion
  • Loss of taste sensation & sore tongue
  • Feeling depressed & anxious, mood swings
  • Sensitivity to light
  • Rapid heartbeat and breathing
  • Upset Stomach/Constipation/Diarrhea
  • Weight Loss

Why is My Vitamin B12 Too Low?

There are many causes that can lead to Vitamin B12 like:

  • Heavy Consumption of Alcohol
  • Immune system disorders
  • Long-term consumption of acid-reducing drugs
  • Weight loss surgery
  • Atrophic gastritis (inflammation of the lining of the stomach)
  • Pernicious Anemia (a decrease in red blood cells when the body can’t absorb enough Vitamin B12)
  • Old Age
  • Low consumption of Vitamin B12 foods (especially vegans)

Is Vitamin B12 Deficiency Hereditary?

No. However, in some cases, Vitamin B12 deficiency is caused by an inherited genetic disorder. Hence, proper genetic testing is required to determine B12 deficiencies caused by inherited disorders.

Understanding Vitamin B12 Deficiency Anemia

Vitamin B12 deficiency indicates that there is not enough B12 vitamin in your body to develop red blood cells that carry oxygen through your body. Since your body does not have adequate red blood cells you feel tired and weak and further lead to brain and nerve damage. In most cases, Vitamin B12 deficiency occurs when your stomach and intestine do not absorb the vitamin. Vitamin B12 deficiency can also occur if you don’t eat enough foods that contain Vitamin B12, or when you are consuming more alcohol and taking excessive prescription and nonprescription medicines.

How Much Vitamin B12 You Need?

Now, that we know why we need Vitamin B12, the important question is what the normal range for Vitamin B12 levels are and how much do we need?

The amount of Vitamin B12 you need depends on your age. Below is the chart that can help you find your recommended daily amount of Vitamin B12.

Age (Years) Daily Amount of Recommended B12 (in micrograms)
1-3 0.9 mcg
4-8 1.2 mcg
9-13 1.8 mcg
14 and above 2.4 mcg
Pregnant Women 2.6 mcg
Breast-feeding Women 2.8 mcg

A Vitamin B12 test measures the amount of Vitamin B12 in the blood. This helps you to check for Vitamin B12 deficiency anemia and other types of it like megaloblastic anemia. The test can also help you find the cause of dementia and other nervous system symptoms.

To take your Vitamin B12 test you can contact:

Phone: +91 22 66949876 / 9833141024