Hi thanks for asking question. Here possibilities of tuberculous peritonitis or pleuritis is there. TB can involve peritoneum and pleura ,so can lead to a effusion. You have not mentioned the site. The fluid can be transudate or exudate.Transudate involves causes due to increase hydrostatic pressure or decrease oncotic pressure, so congestive cardiac failure, cirrhosis, protein energy malnutrition,nephrotic syndrome can lead to fluid collection as an transudate. While exudate can be because of increase permeability of vessel that can be due to TB, pnemonia like infective cause. So here in your case fluid collection seems to be due to exudative cause. Better to send tapped fluid to laboratory for determining whether transudate or exudate and then accordingly causes has to be excluded. I hope my suggestion will help you.