dengu is a mahamari , hopefully the effect will less until dashain, but still there is risk, the mosquito is relatively small n u barely feel its bite, i wouldn't confirm my trip until the final days of dashain if i had an infant traveling with me . but it also depends where u traveling in nepal, it has its effects until nagarkot which is high as 2000 mtrs , so if u travelling uphill sudnot be a problem, man with infant i would avoid kathmandu valley , if traveling is unavoidable , covering the body part is only option, n pray .. u must be aware that infants have no (very less) immune to fever like dengue, the fever goes so high in short time failing kidneys and vital organs. wait 2 more weeks n if the problem persists, avoid travel, u can take chance for health, u cannot take chance for somebody's health