A Homeless Man TB Case Study

¶ … risk of progression when a person is exposed to the tuberculosis bacilli to the formation of active illness is a two-stage process that is directed by both endogenous and exogenous risk factors.

Exogenous factors play a key role in accentuating the progression from exposure to infection among which the bacillary load in the sputum and the proximity of an individual to an infectious TB case are key factors. Similarly, endogenous factors lead in progression from infection to active TB disease (Narasimhan, Wood, MacIntyre, & Mathai, 2013, p. 1).

Certain risk factors that have been well-established such as HIV, young age, and malnutrition could exist alongside certain emerging variables like alcohol, indoor air pollution, tobacco smoke, and use of immunosuppressive drugs making the risk for contracting the disease that much higher. Joel is a heavy smoker, homeless, and an alcoholic. It is highly likely he is malnourished and is exposed to indoor air pollution due to his heavy smoking. The alcohol also plays a main contributor and the combination of all three put him at extremely high risk of developing TB.

There are a couple of reasons why TB cases have increased in recent years. Just as seen with Joel, homelessness has increased since the back to back recessions in America. The prison population has also seen an increase and TB spreads fairly easily in prisons due to lack of healthcare options and overcrowding. People are falling prey to substance abuse as well and as was described in the article, alcoholism and tobacco use increases the chances of developing TB. While the increase is small, around 154 cases more, it is safe to assume that those three factors could be playing a major role.

Of the new cases, the majority come from high population states. They are California, New York, Texas, and Florida. These states see cases of children developing TB also showing a trend in TB development during early stages of life.

2.

Respiratory acid-fast bacilli isolation room or AFB isolation is a term used to describe a negative pressure area or room, which exhausts air directly outside or via HEPA filters if there is unavoidable recirculation. This is a way to treat and isolate anyone who has TB in order to keep exposure to a minimum for those near the infected patient. While there are established standards for isolating known or potentially infectious TB patients, levels of isolation differ depending on what are called 'sputum smear results', the age of the person, the kind of setting, the exposure status of any household members, and the immune status of the patient.

When a patient present with initial sputum1 smear-positive for AFB, home isolation is recommended if there are no children younger than five that have not been previously exposed. If there is a child that has not been exposed, patient must take appropriate four-drug TB treatment and wear a face mask. In Joel's case, he is homeless and so fits into congregate settings like a shelter. There he must take the four-drug TB treatment for three to five days or more through DOT and wear a face mask. In a 2014 quantitative study, researchers discovered TB cases increased with extreme temperatures. " ... the number of TB cases increased significantly with extreme heat and cold temperatures" (Onozuka, & Hagihara, 2014, p. 1107), so this may be something to address when caring for someone with TB to reduce exposure risk. With AFB isolation ventilation is key and therefore should be used along with PPE like an N95 respirator if available. Home isolation is often less associated with infection than in the hospital, especially due to limited exposure to others (Treas, & Wilkinson, 2014, p. 614).

3.

There are two stages of TB development. The first stage called 'latent TB', is when a person has been infected with TB bacteria. The second stage called 'active TB' or 'TB disease' is when the bacteria have sufficiently reproduced to cause the person to feel and become sick. Joel seems to be in stage two. TB can only be confirmed in the stage two phase. That is when a PPD test is performed. They may also do a chest X-ray to look for any possible effect the TB bacteria had on the suspected patient.

A person who has a negative on a PPD test, but an active TB infection usually means there is a problem with the test. A couple of the existing TB tests take a long time to process with some TB tests having low accuracy. This could happen from a TB test having low sensitivity and/or low specificity. Low sensitivity signifies a major number of what is called 'false negatives'. The same thing with low specificity which can indicate 'false positives'.

Another thing to note from false positives is people with false positives may have a weakened immune system, HIV, take steroids, have been exposed to someone with active TB, or have received an organ transplant. Intravenous drug users may have an ever bigger result. False-negative can also occur in people who have cancer and take medicines like chemotherapy and steroids causing a false-negative result. The significance in sputum cultures is seen in its predictive value. "Sputum culture conversion is often used as an early microbiological endpoint in phase 2 clinical trials of tuberculosis treatment on the basis of its assumed predictive value for end-of-treatment outcome, particularly in patients with drug-susceptible tuberculosis" (Kurbatova et al., 2015, p. 201).

4.

It takes six months of treatment for both latent TB infection as well as TB illness to be treated with antibiotics. This is because TB bacteria grow at a very slow rate and the antibiotics can only when the bacteria actively divide. Since the patient is homeless, follow up to continue taking medication may be hard. "When a homeless person has tuberculosis (TB), and must complete a minimum of six months' treatment in order to be cured, adherence to the full course can be an insurmountable problem" (Collinson, 2014, p. 1). While he may stay in a shelter, infection control for congregate settings can prove tricky. There is virtually no management of people in these kinds of settings and infection is quite a prevalent issue.