ref retesting
be aware that when it comes to antibody based tests - there is no evidence, once tested positive ( or in your case - diagnosed positive for lyme disease via bulls eye rash) that retesting gives any information on the state of the infection - this is a common misconception - even among some practitioners.
unfortunately antibodies can vary over time or persist for years after all symptoms have resolved
again - ref antibiotics reducing the likelihood of positive test result - this is not a black and white effect - it just increases the chances of getting a false negative - so if a person were to test multiple times over several months its quite possible they could obtain a positive test result - or they may not - so, especially in these circumstances, all physicians should know that they should not take negative or equivocal test results as proof of lack of infection.
since you meet the criteria for a definitive diagnosis of lyme disease based on a bulls eye rash alone - can you clarify the purpose or objective you are trying to pursue via testing -
regarding using different test houses - the issue with serologic testing becoming less reliable after antibiotics is not related to the testing or the test house - but to the patients immune response.
giving antibiotics - especially early in the course of infection - alters the course of the immune response - and may prevent the expected antibodies from forming at any point. if this occurs it will not matter where the test is done - or potentially even when its done - as its the patient is not producing the antibodies or not in the quantity required - that the test looks for .
ref official guidelines for Lyme treatment in the USA
actually the USA has the most extreme schism in the medical community of any nation - and in fact seems to be the source of the split
at present its a complete mess - as different medical bodies take very different views
-the CDC/IDSA and a few others take the view that its an easily diagnosed and easily treated infection that has no chronic state - only a post infectious syndrome - this is at odds with the majority of peer reviewed science on the topic - including from the USA and around the world.
however even the guidelines proposed by this group accept a bulls eye rash as definitive evidence of lyme disease
IDSA guidelines here:
https://www.idsociety.org/practice-guideline/lyme-disease/- ILADS - this group includes fully trained medical doctors (MD's) who specialise in treating Lyme disease and associated conditions - they believe Lyme disease is difficult to diagnose, has a chronic form that is often hard to treat, and is often complicated by coinfections and comorbidities requiring long term treatment. of the two groups this group is far more focussed on the most up to date science and patients needs.
ILADS guidelines here
https://www.ilads.org/patient-care/ilads-treatment-guidelines/if you do need extended treatment - its very unlikely doctors who are not in the second group will prescribe that - as they are taught not to believe in chronic lyme
however - in most cases - early treatment - as in your case - is normally sufficient to prevent chronic disease or long term problems
i have never heard of strep infections being common co-infections with lyme disease.
i am sure it does happen - but its not a recognised co-infection of lyme.
perhaps your doctor meant that PANDAS is relatively common in people with Lyme - this does seem to be teh case - but its not clear if strep is the cause of PANDAS like syndromes in all cases - or if other infections can trigger the same syndrome
beyond what i have written so far - i am afraid i have not dug deeply into PANDAS so cannot offer more on that specifically - but others here may well have something to add - so i would suggest a sperate post on that specifically - as its likely to be missed here
overall - you were diagnosed early, received appropriate treatment early and - unless you still have symptoms - you have a very good chance of experiencing no further issues from lyme disease.
are you still experiencing lyme disease symptoms?