Thank you for asking your query at DoctorSpring.
I assume that you are Healthcare Personnel. So I hope would be aware that no tests are 100% sensitive and test results needs to be interpreted by taking pre test and post test probably into consideration. HIV Elisa test is more than 99% sensitive. That means it is highly unlikely that positivity will be missed. So you can say the test is very accurate. (Same with case of source patient). As per recommendations, since the source patient is tested HIV negative, you will not require treatment of further testing. (Further testing is only required if the sources is unknown or positive).
What you have here is sort of a 'double' confirmation in form of a negative source and your own negative test result. If you put it mathematically ( and in a practical way !) you have near zero risk that HIV transmission has occurred. So there is no need to worry, you can breastfeed as recommend by your Physician.
Hope this helps
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