This question is in relation to my previous one # 7104 with Dr. HHH.  I would normally abstain from posting another question as Dr HHH's risk assessment was thorough, and I wouldn't say I'm terribly anxious otherwise,  but the diagnosis with chlamydia following unprotected vaginal sex has completely thrown me off and skyrocketed my apprehension regarding potential HIV exposure. Even though the diagnosis of chlamydia in the age group of late 30s is uncommon, it has happened to me, which makes me worry about other potential STIs related to that encounter. I've informed my now ex partner of positive chlamydia, who advised that he will get tested and will inform me accordingly. In the meantime, I find it hard to wait and contemplating getting myself tested. I don't have access to PCR/NAT testing, but I can do a 4th generation Ag/Ab test via a lab, which if done today/tomorrow will be 17-18 days post exposure. 

I realize that such testing will be inconclusive, but I do wonder how much of a confidence interval does 17-18 post exposure Ag/Ab testing provide?  Is it only 50% at this time or more? I'm asymptomatic at this time.  At this time, are antigens detectable or they begin to diminish? Are antibodies detectable in roughly only 50% of people if one has no symptoms? 

I'm sorry if all this seems irrational, but I'm finding myself dreading given that the positive diagnosis of chlamydia was unlikely and yet it was confirmed positive.  My main inquiry pertains to the percentage of assurance/conclusive result with 4th generation testing 17-18 days post potential exposure.  

I immensely appreciate your input and assistance. 

But if you're going to be tested, an HIV AgAb test would detect 80-90% of new infections at 17-18 days. Your question shows a common misunderstanding about the AgAb test. Antigen goes away because antibody develops; i.e. it's the Ab that makes Ag undtectable. If Ag was present and is now gone, Ab is always detectable. This is the main reason that the AgAb tests, once positive, remain positive for life (and why the supposed "second window" is an urban myth).

If you proceed,  the result will be negative, so don't lose any more sleep over it in the meantime. Or just wait until your partner reports his negative result. Or wait until 6 weeks to be tested. It's your call!

HHH, MD

Thank you once more for your dedication and expertise.  The following is a quick update and several  related questions. 

I tested for HCV, HIV (ag/ab, 4th generation testing) and Syphilis on day 25, all tested negative. What's the conclusivity range for that, considering it's slightly short of 4 weeks? Is it about 90-95%? If you add to it absence of symptoms, I should take it to be rather reassuring? I was quite startled by the chlamydia diagnosis, as I had previously mentioned. In terms of my former acquintance, he's been tested three weeks ago (blood work) and still awaiting his results. I received mine within 4 days and normally the process takes about a week. Three weeks comes across as concerning, because it remains unclear whether the lab is delaying things due to Covid-19, or, perhaps, there's an issue with it and he's withholding information.  I simply have no way of knowing.  

Given my level of risk and negative results on day 25, I'm assuming you'd expect the result to remain as it is at 6 weeks? Is absence of symptoms thus far (4.5 weeks) a good sign as well, or that doesn't tell us anything?  Lastly, is there data to indicate which people seroconvert weeks 4-6 (1-2%)? Is it random, or do they tend to be people with previous health/immune conditions, immunosuppressed individuals, individuals who have taken PEP? Are they represenattivces of the gen. population health wise or not?

Thanks kindly; I may be quite anxious about this subject matter, but your expertise is reassuring and in many ways guides my actions. 

Thanks for the thanks. I'm glad my comments so far have been reassuring!

This is my second and summarizing reply on this thread, which is set to expire tomorrow. I know you're an ID specialist, but your work here helping and reassuring fairly anxious people like myself is of major contribution to people's mental health (in addition to risk assessment).  I am sure I speak on behalf of many, if not all, by saying that your work here is of immense appreciation to all of us.  To summarize:

1) Chlamydia was proved to be cured by Azithromycin via a negative urine test three weeks post med intake. Both Chlamydia and Gonorrhea tested negative on secondary testing. I don't think further testing is needed. 

2)Former partner tested HCV, HIV and Syphilis negative at 16 days post our mutual exposure

3)I tested negative by 4th gen Ag/Ab test on day 25 and day 36 (5+ weeks) post exposure for HIV, as well as negative for HCV and Syphilis

4)My GP maintains that my risk was very low but says that 3 months is conclusive (that's the official stance). I may re-test closer to 3 months, but I feel that things are rather conclusive for me as is

5)One oral mucosal lesion/lump appeared around week 4 on lower/mandibular gum tissue - GP or dentist will investigate.  Hopefully it's not HPV-related.

Thank you again! I hope I can do better in the future and stick to condoms each time, no exceptions. 

1) I'm not sure what you mean by "secondary testing". It is recommended that all persons with gonorrhea or chlamydia have a repeat test at least 3 months after completing treatment, to detect treatment failures only found with delayed testing (very rare) or reinfection (of course only possible if reexposed).

2) Those results show you almost certainly were not exposed to active infection with HCV, HIV, or syphilis. 

3) Conclusive results.

4) Different resources have different "official" conclusive dates. For CDC -- arguably the most authoritative -- it's 6 weeks, even if the test manufacturers and some health departments still say 3 months. Your GP is free to rely on whichever resource she wishes.

5) Oral warts are rare and a single mucosal "bump" rarely is due to a wart. The most common is mucocele, resulting from temporary blockage of a mucus secreting gland.

I too hope you are successful in your plans for sexual safety. But don't beat yourself up over occasional human errors. In addition to condoms, it's important to select your sex partners with care and common sense. If you do, then with or without condoms you'll be at low risk for HIV and other STIs.

Best wishes and stay safe.