How is latent tb transmitted

TB usually affects the lungs, but it can also affect other parts of the body, such as the brain, the kidneys, or the spine. When a person with infectious TB coughs or sneezes, droplet nuclei containing M. If another person inhales air containing these droplet nuclei, he or she may become infected. However, not everyone infected with TB bacteria becomes sick. Persons with latent TB infection do not feel sick and do not have any symptoms.

They are infected with M. The only sign of TB infection is a positive reaction to the tuberculin skin test or TB blood test. Persons with latent TB infection are not infectious and cannot spread TB infection to others. About half of those people who develop TB will do so within the first two years of infection. For persons whose immune systems are weak, especially those with HIV infection, the risk of developing TB disease is considerably higher than for persons with normal immune systems.

In some people, TB bacteria overcome the defenses of the immune system and begin to multiply, resulting in the progression from latent TB infection to TB disease. Some people are more likely than others to develop TB disease active TB , including people who have compromised immune systems, people with certain medical conditions, the very young less than one year of age , and the elderly. Another option for children 2 years old and older includes once weekly therapy in the TB Clinic with isoniazid and rifapentine for a total of 12 weeks.

We will discuss these options with you to determine the most appropriate therapy for your child and family. Whichever medicine your child takes, we will monitor your child with you to make sure that he or she is tolerating therapy.

It is very important for your child to take this medicine and to keep appointments as directed. It is expected that rifamycins rifampin, rifapentine, and others will make urine, stool, and other body fluids such as tears and saliva turn orange. This orange color will go away at the end of therapy. During therapy, contact lenses may become permanently stained. For all other times, call , then ask to page the ID doctor on call. Skip to Content. Urgent Care.

Since the s many studies have been carried out to assess the effectiveness of the TB drug isoniazid in treating latent TB. In some of the trials the people taking part took the drug for six months, whilst in other trials the drug was taken for twelve months. There were also trials with people taking the drug daily being compared with people taking the drug five times a week.

Any adverse effects of taking the drug were also noted and compared. There was a then long period of follow up to see who developed active TB. The initial human studies of isoniazid preventative therapy established that prolonged therapy with isoniazid was effective in reducing subsequent active TB infections.

The optimum length of treatment was however unclear but the most common recommendation was for a treatment length of nine months. The WHO also recommends two other regimens of 3 or 4 months of isoniazid plus rifampicin daily and six months of isoniazid daily.

In the results were reported of a further analysis of 2 clinical trials looking specifically at side effects.

An important problem limiting the treatment of latent TB infection is the occurrence of adverse events with isoniazid. As a result of this further analysis it was recommended that in patients without contraindications, rifampicin is likely to be the safest TB infection treatment option.

In the results were announced of the ACTG study. Also, adults and adolescents in the trial were more likely to complete the short course regimen. Globally in there were an estimated 1.