Tuberculosis is chronic infection caused by the bacterium mycobacterium tubercolosis (M.tuberculosis). There are seven other bacterias closely related to M. tuberculosis such mycobecterial species are ( M. bovis, M. africanum, M. microti, M. carprae ,M. pinnipedii, M. canetti and M. mungi) together comprises what is known as the M. tuberculosis complex. Most, but not all, of the species have been found to cause diseases in humans. M. tuberculosis organisms are also called tubercle bacilli.
How is Tuberculosis transmitted in children ?
M. tuberculosis is transmitted through airborne infectious droplets nuclei which are generated when person who have pulmonary or laryngeal TB disease cough,sneeze, shout,or sing. These tiny particle ( 1-5 microns in diameter) can remain suspended in the air, not by surface contact. Transmission occurs when a person inhales droplets nuclei containing M .tuberculosis, and the droplet nuclei traverse the mouth or nasal passages, upper respiratory tract, and bronchi to reach the alveoli of the lungs. NB. for one to be infected with the tubercle bacillus must be exposed to infectious case of TB.
level of TB infection in person: a person with TB who expel more bacilli is more infectious than one who expel few bacilli. The level of infection is increased if the patient has a cough or pulmonary disease, poor cough etiquette, inappropriate treatment
susceptibility of the exposed child with the contact: This depend on the immune status of the exposed child. if exposed child has a weaked immune system , transmission is more likely to occur. Also very young have higher risk of developing disease upon exposure.
Evironmental factors: These are factors that may increase bacilli concentration in immediate environment of the child these include living in enclosed space without proper ventilation, improper specimen handling procedures that generate infectious droplets nuclei.
proximity, frequency and duration of exposure with the infectious person: the longer the duration of contact, the more frequency the contact, the closer the contact, the higher the risk of transmission.
When to suspect Tuberculosis (TB) in child with cough or difficulties in breathing ?
TB is suspected based on two or more typical symptoms:
Persistent cough of more than 2 weeks
Persistent fever or night sweats for more than 2 weeks
Poor weight gain or weight loss ( failure to thrive)
Unexplained lethargy/reduced playfulness/ less active for more 2 weeks
pneumonia that is not responding to antibiotic treatment.