Typhoid and jaundice
are water born diseases, so be careful about drinking water and avoid eating unhygienic food. Malaria
is transmitted through mosquitoes and you got to take all precautions to prevent mosquito bites. If he is otherwise healthy and not getting any other repeated infections not likely to be immune deficiency
. If the jaundice is because of hepatitis A
or E then medications have very virtually no role, recovery is usually spontaneous.