I need to ask few more questions before answering your query. Early consultations can prevent complications. Kindly contact me on whatsapp chat  (84960595 six five) Dr Faisal Zoheb MBBS , MD PAEDIATRICS , PGPN (BOSTON), FELLOWSHIP IN NEONATOLOGY ( Newborn and vaccination specialist )

TB usually spreads through the air when a person with active lung TB coughs or sneezes for prolonged periods in close contact. It does not commonly spread by sharing water, food, or utensils alone. However, since your child is in close contact with the grandfather, screening is important. Another important point is that your child’s weight has remained almost the same from 1 year to 2 years 9 months, which needs proper evaluation. Poor weight gain can occur due to many reasons such as inadequate diet, recurrent infections, anemia, worm infestation, nutritional deficiencies, or sometimes infections like TB.

Your child not gaining weight from last one year is a worrisome sign. Since there’s contact history present in your family. You need to get your child evaluated for TB from nearest Pediatrician. Need to do Montoux test & CBNAAT test for Tuberculosis. Once TB is ruled out . We can then evaluate for other reasons

Do get consultation for complete evaluation for not gaining weight and screening for TB as history of TB contact in family.But sharing water glass don't spread TB.

Weight not increasing for such a long time needs proper pediatric evaluation. TB usually spreads through close air contact, not mainly by sharing water, but since grandfather has TB and child is in close contact, TB screening is advisable. Kindly consult a pediatrician for examination and tests like chest X-ray and Mantoux test.

Give prophylaxis

Greetings Tuberculosis (TB) is primarily an airborne infection transmitted through prolonged, close contact when an individual with active pulmonary TB coughs or sneezes. It is not typically transmitted via shared food, water, or utensils. Given your child’s close proximity to their grandfather, diagnostic screening is strongly indicated as a precautionary measure.Additionally, your child's weight stagnation between the ages of 1 year and 2 years, 9 months requires a thorough clinical evaluation. Inadequate weight gain in toddlers can stem from various underlying factors, including nutritional deficiencies, an inadequate diet, anemia, parasitic infestations, recurrent infections, or chronic conditions such as tuberculosis. Please consult your pediatrician to arrange the necessary screenings and growth assessments.

Urgently do TB Evaluation with Pediatrician Needs to do diagnostic tests