I know that the subject sounds like the most ridiculous thing I have ever typed or even heard of. I want to clarify that it is indeed NOT possible

First and foremost I have taken multiple 4th gen tests past my last unprotected encounter and know results beyond 6 weeks are 100% accurate. So I am good there. When I arrived here in Mexico at my Air B n B, I accidentally drank some tap water because I was so thirsty. I quickly realized that this water is not safe to drink and could give me the runs and just general discomfort. It could be worse, like water in Africa. 

My questions are as follows: 

1 - It is NOT at all possible for me to have contracted HIV by drinking from tap water in mexico? The virus can't survive in water right and needs to come from a source?

2 - Getting tested would be VERY unnecessary?

3 - What are the only ways the virus can be contracted?

4 - i can certainly let this go without any worry?

1 - chlamydia and gonorrhea I test 7.5 weeks out, tested positive for chlamydia and negative for gonorrhea. Got treatment and then came back 2.5 weeks later and chlamydia was negative, while gonorrhea was negative too at 10 weeks out

2 - as for syphilis, i tested 7.5 weeks out and 20 weeks out and both were negative

3 - i have never experienced any symptom for any of these and am pretty confident that i am good to go. Does that hold true?

4 - immunized for hep B, but I also did a STD test. Would you recommend getting another shot for booster even if I got the 3 shot series as an infant? Sorry for the barrage of questions just want to make sure i fit this all in 

I'm a bit confused. In addition to the tapwater business -- which I will address (and dismiss) in a moment -- presujbably you also had one or more sexual exposures, right?

Your first set of questions;  First, it isn't necessarily true that the tapwater you drank is unsafe. I'm not an expert on this, but my understanding is that tapwater is fine in much of Mexico, especially in most urban areas. There's more concern in small towns and the countryside, I believe. In any case, there has never been a reported or even suspected case of HIV acquired by exposure to contaminated water. 

1) I don't know whether or not HIV can survive in contained water -- but even if it does, it never infects anyone that way. It takes lots of HIV for infection to take hold, and any HIV present would be too diluted to carry any risk. And swalloing is low risk anyway (e.g. swallowing infected semen is virtually risk free).

2) Definitely no need for HIV testing because of eating or drinking anything, in Mexico or anywhere else.

3) HIV is transmtted only by direct bloodstream exposure or by insertive sex (penis inside vagina, rectum, or -- extremely rarely -- mouth. Everyone knows this -- surprised you need to ask!

4) Yes, let it go without worry.

Second sets:  I remain uncertain whether you have had a sexual exposure you are concerned about. Tapwater is no mor risky for any STD than it is for HIV -- i.e. zero risk. You certainly didn't need any of the tests mentioned on account of your Mexico tourism and water drinking. 

1) Gonorrhea/chlamydia testing are conclusive any time 4-5 days or more after exposure. In any case, oral exposure (e.g. tapwater) can't infect the urinary tract -- urine or urethral swab testing were pointless.

2) Also no risk except sexually; and for such an exposure, blood tests are conclusive by 6 weeks.

3) All these STDs can be present without symptoms. But the tests are conclusive.

4) Having had 3 doses of hepatitis B vaccine, you are protected for life. And hep B is not transmitted by water or contaminated food, or by swallowing the virus. 

I hope these replies are helpful. Let me know if anything isn't clear.

HHH, MD

The timelines that I speak of come from my encounter, which happened in july

So when I said I tested for HIV 6 + weeks out multiple times that is what I am referring to. I did so with 4th gen tests so I am good (they were negative). So when I say that I did syphilis test 7.5 weeks and 20 weeks out and they came back negative I am referring to the encounter. It was tested using RPR method I think, which is plasma and both were negative. That is good enough right?

I had a thought that this was so irrational. It is good to know it is. I am done worrying about HIV tests. I am in Playa del carmen and honestly I read that the only thing I should be worried about is the runs

1 - I have read on HIV. org and avert.org (or .com) that HIV can't survive in water and that i should not worry. Even on the CDC website, it doesn't even list water as a possible transmission method. 

2 - So just to be clear, there is absolutely no need to worry and testing would be overdoing it? I can engage in sexual activity (condom for sure) and be just fine so long as I know the other person is good as well?

3 - My brother said I should never have drank that and that I could get very sick and my mind kind of turned to this (I drank the water on december 26th)

2) Correct.

3) Your brother is wrong.