Hi Sudan, how many plants are infected? Is there any other crops surrounding? Did you notice any insects, particularly whiteflies?
It could be papaya leaf curl disease caused by papaya leaf curl virus. It is mainly transmitted by whiteflies. The main symptoms are downward and inward rolling of top leaves and thickening of veins. The leaves become leathery, brittle and distorted. In severe case the affected leaves may drop off and stop the plant growth.
Remove the infected plant and burn them. In future use yellow sticky traps to monitor and control whiteflies. Avoid growing papaya near tomato plants.