Hello Thank you for trusting HCM Dear threadworms are transmitted via eggs on the fingers and under the fingernails. Following contact between the hands and the mouth, eggs hatch and larvae are released into the small intestine.The female adult worm deposits eggs just outside the anus at night, which causes itching. Scratching results in the collection of eggs on the fingers and under the fingernails. The entire process of transfer will then be easily repeated. The eggs can be spread among family members through sharing bath towels. They can survive for a couple of weeks on clothing, bedding and in general household dust. A family pet is never responsible. The only host for threadworms is a human. so wash your hands every time before eating. Try to treat your family members also if they suffering from same problem. wash your clothing and etc.. Don t drink polluted water or food. Still symptoms not improved please consult your doctor he find the cause and treat you accordingly. Take care.