Hello. I have gone through your question and understand your concern. It is too early for me to come to a diagnosis with little patient history and no physical examination; but keeping your travel history in mind bilateral neck swelling can be caused due to infection. Sometimes cause can be as small as common cold or viral upper respiratory tract infection. It can also be due to other non infectious causes like cancers and inflammatory diseases. Ultrasound will give us a better view of swelling and x-ray chest will help with ruling out respiratory pathology, if any. I believe both diagnostic tests are best to conclude a diagnosis. Good luck. Hope your concern is answered. Thank you.