HIV Testing: Concerns About Variants and Accuracy

Q: HIV Testing: Concerns About Variants and Accuracy

Hello, in response to your inquiries, here are a few points： 1. The combo test kits you are using are universally applicable, so there should be no type-related issues even in Southeast Asia; the results should be consistent. 2. Based on your description, you

HIV Testing Consultation

Hello Dr.
Hong, I apologize for the interruption.
Here is my story: On August 2, 2019, after a gathering with friends, we went to a special location where the female service providers were from Southeast Asia or mainland China.
That day, I engaged in unprotected oral sex and protected vaginal intercourse.
I regretted it afterward.
On September 10, 2019 (39 days after the incident), I underwent an Alere HIV Combo test at a public hospital's anonymous testing center, and the result was negative.
The testing center indicated that the window period for their HIV screening reagent is one month.
On November 21, 2019 (111 days after the incident), I had an HIV Ag/Ab Combo blood test at a laboratory recognized by the CDC, and the result was negative.
On April 28, 2020 (270 days after the incident), I had an Anti-HIV blood test at a public hospital's health check center, and the result was negative.
Since August 2, 2019, I have not engaged in any sexual activity.

I am aware that HIV has several different subtypes, and I have read some medical articles suggesting that antibody tests may not easily detect HIV subtype O and N.
Given that the sexual partners were from Southeast Asia or mainland China, I am concerned whether the reagents or methods used in the tests I underwent are only applicable to the HIV subtypes prevalent in Taiwan.
Can the testing reagents or methods used in Taiwan detect the subtypes prevalent in Southeast Asia or mainland China? If the sexual partner is a foreign national, is there a possibility that the tests I conducted would miss detecting the infection? Related articles also mention that for subtype O or N, bDNA methods or RT-PCR may be required for detection.
Should I consider further testing with RT-PCR? Or can the results I have already obtained officially rule out HIV infection? I apologize for the complexity of my questions, and I appreciate your time in helping me with these concerns.
Thank you.

JJ, 30~39 year old female. Ask Date: 2020/05/21

Dr. Hong Yuanbin reply Internal Medicine

Hello, in response to your inquiries, here are a few points:
1.
The combo test kits you are using are universally applicable, so there should be no type-related issues even in Southeast Asia; the results should be consistent.

2.
Based on your description, you have not engaged in any unsafe sexual behavior for the past nine months, and your recent tests have also returned negative results.
This should effectively rule out the possibility of infection.
It is recommended that further testing or medical consultation is only necessary if you engage in unsafe sexual practices again or experience any unusual symptoms.
Thank you for your question.

Reply Date: 2020/05/21

More Info

Understanding HIV Testing: Concerns About Variants and Accuracy
Thank you for sharing your concerns regarding HIV testing and the potential implications of the variants of the virus. It’s understandable to feel anxious, especially after engaging in activities that may pose a risk for HIV transmission. Let’s break down your situation and address your questions regarding the accuracy of the tests and the potential for variants.

Firstly, it’s important to note that the HIV tests you underwent, including the Alere HIV Combo test and the HIV Ag/Ab Combo test, are widely recognized and utilized globally. These tests are designed to detect both HIV antibodies and antigens, providing a comprehensive assessment of HIV infection. The window period for these tests is generally around 2 to 4 weeks for antigen detection and can extend up to 12 weeks for antibody detection. Given that your last sexual encounter was on August 2, 2019, and you received negative results at 39 days, 111 days, and 270 days post-exposure, it is highly likely that you do not have an HIV infection.

Regarding your concerns about the different subtypes of HIV, it is true that there are several strains, including subtypes O and N, which are less common. However, the tests used in Taiwan, including the ones you underwent, are designed to detect a broad range of HIV variants. The Alere HIV Combo test and similar tests have been validated for use in various populations, including those from Southeast Asia and mainland China. Therefore, the likelihood of these tests missing a subtype prevalent in those regions is low.

It’s also worth mentioning that while some studies have indicated that certain tests may have reduced sensitivity for specific subtypes, the standard tests used in clinical settings are generally effective for the most common strains of HIV. If there were any concerns about a specific subtype, more specialized testing, such as RT-PCR (which detects the viral RNA), could be considered. However, given your negative results from multiple tests over an extended period, the need for RT-PCR is not warranted unless you exhibit symptoms or have further risk exposure.

In summary, based on the information you provided and the negative results from your HIV tests, it is reasonable to conclude that you are not infected with HIV. The tests you underwent are reliable and appropriate for detecting HIV, including variants that may be present in Southeast Asia or mainland China. If you continue to have concerns or experience any unusual symptoms, it would be advisable to consult with a healthcare provider for further evaluation and peace of mind.

Lastly, it’s crucial to maintain regular health check-ups and practice safe sex to minimize the risk of HIV and other sexually transmitted infections in the future. If you have any further questions or need clarification, please feel free to ask. Your health and well-being are of utmost importance.

Similar Q&A

Understanding Your HIV Test Results: What Does a 0.184 Value Mean?

Hello doctor, I went to the hospital for a blood test to check for HIV using the ELISA method due to some issues (definitely not related to casual encounters or needle exposure). My test result was 0.184. I would like to know if this indicates a possible infection or if there is ...

Dr. Liao Zhongxin reply Internal Medicine
The methods for HIV testing are as follows: (I) Preliminary Screening Tests 1. Prior to screening, health education should be provided, including: reasons for screening, assessment of infection risk, explanation of transmission routes, clarification of confidentiality regarding ...

Understanding HIV Testing: Concerns, Procedures, and Accuracy

A year ago, I had sexual intercourse with someone who was engaged in sex work, but I haven't had any sexual activity since then. However, I came across information online stating that the incubation period for HIV can be quite long, which has made me a bit concerned. 1) Ca...

Dr. Du Shixi reply Urology
Hello: 1) What is the concept of the information available online? Is it really possible for it to last this long? --> Sexual activity can be assessed through blood tests after 3 months, and the incubation period can also be detected. 2) Can every district health center conduc...

Understanding HIV Variants: Can Rapid Tests Detect All Types?

Hello, doctor. I would like to inquire about the recent HIV variant VB. Is it classified as a mutation of HIV-1? Can our current blood and oral rapid tests detect all types of HIV variants (including HIV-1, HIV-2, and VB)? The rapid tests indicate whether there is an HIV infectio...

Dr. Liao Zhongxin reply Internal Medicine
1. Yes, it belongs to the HIV-1, subtype B variant (which is prevalent in Europe, particularly in the Netherlands, with at least 109 cases reported). 2. The currently used testing tools can still detect the VB mutant. 3. The VB mutant is characterized by causing infected indivi...

Understanding HIV Testing: Can You Rule Out Infection After Risky Behavior?

Hello doctor, I had unprotected sexual intercourse with a female online friend in early April. I went to a medical testing center in mid-April for an HIV antibody test, which came back negative. On May 8, I noticed inflammation of the glans and visited a urologist, where I underw...

Dr. Liao Zhongxin reply Internal Medicine
1. Yes, after the window period, HIV infection can be ruled out. 2. Currently, the accuracy of anonymous screening or blood tests in the country is over 95%. 3. Engaging in unsafe sexual practices may also pose a risk for other sexually transmitted infections; therefore, usin...