Most common route of TB infection in neonate born by caesarean section:

C. Inhalational of aerosol"Mode of infection; The usual mode of infection is through inhalation of droplets of infected secretions. Infection through ingestion of infected material is rare. Rarely infection may be transmitted through skim mucous membrane or transplacentally"- O.RGhai 8th/250Tuberculosis CPDT 17th/56-57Congenital tuberculosis (TB) is rare but may occur in the infant of a mother with hematogenously spread TB or by aspiration of infected amniotic fluid in cases of tuberculous endometritis. Women with pulmonary TB are not likely to infect the fetus until after delivery.Postnatal acquisition is the most common mechanism of neonatal infection.Transmission of TB Nelson 20th (SAE)/1446-47Transmission of M. tuberculosis is person to person, usually by airborne mucus droplet nuclei, particles 1-5 pm in diameter that contain M. tuberculosis.Transmission rarely occurs by direct contact with an infected discharge or a contaminated fomite.The chance of transmission increases when the patient has an acid-fast smear of sputum, an extensive upper lobe infiltrate or cavity, copious production of thin sputum, and severe and forceful cough. Environmental factors, especially poor air circulation, enhance transmission.Most adults no longer transmit the organism within several days to 2 weeks after beginning adequate chemotherapy, but some patients remain infectious for many weeks.Young children with tuberculosis rarely infect other children or adults.Tubercle bacilli are sparse in the endobronchial secretions of children with pulmonary tuberculosis, and cough is often absent or lacks the tussive force required to suspend infectious particles of the correct size. However, children and adolescents with adult-type cavitary or endobronchial pulmonary tuberculosis can transmit the organism.