Respected user, hi I evaluated your query in depth . * Swollen lymph node with diarrhea indicate definite underlying pathology * Allergic reactions of fire ant surely can lead to GI upset with diarrhea & throat congestion with secondary cervical lymph node enlargement . * HIV ( if contracted ) gives earliest symptoms in 2-4 weeks period in acute stage , here period is 6 days ( from exposure ) & condom was used ( assume that it was not broken nor defective ) ; so very less likely to be HIV * Needs clinical assessment , laboratory evaluations , intensive treatment & regular follow up for the progress . Hope this clears your query . Welcome for any further assistance . Thanks for using Healthcaremagic.com & giving me an opportunity to assist Wishing you fine recovery from the same . Regards .