OPT450 General and Systemic Pathology
Title of the issue / disease discussed :
Pulmonary tuberculosis (TB)
PREPARED BY :
Name: Nurul Natasha Shazuin Binti SafrudinMatric Number: 2017465428Group: HS246 2D
Pulmonary Tuberculosis or more popular known as TB is an airborne disease and a contagious bacterial infection that involves the lungs. Besides the lungs, it may also spread to the other organs. In our country Malaysia, Tuberculosis is known as the seventeenth top killer disease. The number of deaths caused in 2014 was 1,554 with the total number of cases reported standing at slightly more than 20,000. The number of tuberculosis cases in our country increase by 6% to 25,739 in 2016 compared with 24,220 cases in 2015. According to the Health Ministry, the total number of TB deaths also registered an increase, up 15% from 1,696 in 2015 to 1,945 fatalities in 2016.
Malaysia faces various challenges in its attempt to tackle the problem of TB. HIV infection is on the rise and contributes to Malaysia’s inability to reduce TB cases. The rising rate of patients with diabetes mellitus and growing number of smokers pose a threat to the number of latent TB reservoir. This could lead to latent TB activation and cross-infection within the general public. Incomplete treatment, high default rate and development of resistant strain also increase the persistent TB transmission in the community. Lack of knowledge about the TB-causing organism and mode of transmission causing the people at risk, unaware and unable to take measures to prevent transmission. There are also a problem of delay in diagnosis and start of treatment among TB patients.
Pulmonary tuberculosis is caused by the pathogen bacteria Mycobacterium tuberculosis (aka tubercle bacillus) that leads to serious infection of the lungs. It is spread by respiratory route from a person to person through the air via droplet nuclei. M. tuberculosis may be expelled when the infected person cough, sneeze, speak, sing or spit. These droplet nuclei can remain suspended in the air for several hours. Transmission will occur when a person inhales droplet nuclei containing M. tuberculosis and the droplet nuclei will then transverse to the mouth or nasal passages, upper respiratory tract and bronchi to reach the alveoli of the lungs.
Inhalation of Mycobacterium tuberculosis may leads to one of 4 possible outcomes. The first outcome is immediate clearance of the organism by elimination of the immune system. Second, the onset of active disease and progression to primary disease. Third, inhalation of pathogen may also cause latent infection. Latent TB occurs when a person has the TB bacteria within their body, but the bacteria are present in very small numbers. People with latent TB are not contagious and have no symptoms because their immune system is protecting them from getting sick. They cannot pass the bacteria on to other people. Fourth, it is possible for latent TB to develop into active TB many years later. Reactivation TB may occur if the individual’s immune system becomes weakened and is no longer able to contain the latent bacteria. The bacteria then become active and overwhelm the immune process causing the person to be sick with TB. It occurs in 5 to 10 percent of people with latent infection at a later time in their lives. The greatest risk for developing reactivation TB disease is within the first two years following the initial infection as a contact to a person with infectious TB.
The people who are at higher risk for active TB are elderly, infants, smokers, people with HIV, diabetes mellitus, malnutrition, or those who take medications that weaken the immune system, such as medications for rheumatoid arthritis, steroids, or cancer chemotherapy. It can also occur with aging and weakening of the immune system. Furthermore, it can also occur because of low socioeconomic status, crowded living conditions and migration from a country with high number of cases. Reactivation may also occur for other unknown reasons.
Pathological and clinical features
The symptoms of active pulmonary tuberculosis are cough with sputum and blood at times, chest pains, weakness, fever, chills, night sweats, loss of appetite and weight loss. Adult patients presenting with unexplained cough lasting more than two weeks with or without constitutional symptoms should be investigated for pulmonary tuberculosis. However, the typical symptoms may be absent in the immunocompromised or elderly patients.
Symptoms and signs due to extra pulmonary TB vary according to the organs involved and may be not specific. For example, patients with TB meningitis may present with intermittent or persistent headaches for a few weeks and subtle mental status changes, which may progress to coma over a period of days to weeks.
In children, the common clinical features suggestive of TB are prolonged fever, failure to thrive, unresolving pneumonia, loss of weight and persistent lymphadenopathy. TB should be suspected in a symptomatic child having history of contact with active TB.
Sometimes, the symptoms may be mild for many months. Thus, this can lead to delays in seeking care, and results in transmission of the bacteria to others.
Doctors generally order chest X-ray tests in conjunction with taking a medical history and performing a physical exam to confirm or exclude a suspected chest. Some of the common reasons to order a chest X-ray test are cough, shortness of breath, chest pain, poor oxygenation (hypoxia), back pain and fever.
Complications and Sequelae1365250276733000A variety of complications can occur in pulmonary tuberculosis. They can be categorized as:a) Parenchymal lesions which include thin walled cavity (open negative syndrome), aspergilloma, end stage lung destruction and scar carcinoma. b) Airway lesions which include tuberculous laryngitis, bronchiectasis, tracheobronchial stenosis, anthracofibrosis and broncholithias.c) Vascular lesions such as Rasmussen aneurysm. d) Pleural lesions which include dry pleurisy, pleural effusion, empyema, bronchopleural fistula and pneumothorax.e) General complications include cor-pulmonale, secondary amyloidosis and chronic respiratory failure.
-149225420775700-15494033603100Examples of complications
The importance of following the prescribed medication regimen cannot be overemphasized. With treatment, TB patient’s chance of full recovery is very good. Patient can expect to lead a normal life if they take their medicine regularly to be sure of a cure. It can also help others from being infected.
However, non-compliance with the medication regimen is the major cause of treatment failure. Without treatment, the disease will progress and lead to disability and also death.
Pulmonary TB is curable with an early diagnosis and antibiotic treatment. The vast majority of TB cases can be cured when medicines are provided and taken properly. Doctor will prescribe several medicines for TB patients. Patients will need to take these drugs for six months or longer for the best results. The most common TB medicines are isoniazid, pyrazinamide, ethambutol and rifampin. Besides the common four, the alternate second-line drugs are aminosalicylic acid, capreomycin, cycloserine, ethionamide, fluoroquinolones and macrolides. The treatment strategies for tuberculosis can be treated with a single drug. However, some strains M. tuberculosis can be resistant to a particular drug. Thus, treatment with multidrugs regimen become a favour in order to delay or prevent the emergence of resistant strains. However, patient compliance is often low when multidrug schedules last for six months or longer.
Thus, other than only involves treatment with the four common medicines, the doctor might also recommend an approach called Directly Observed Therapy (DOT) to ensure that TB patient complete their treatment. DOT is a successful strategy for achieving better treatment compliance rate. With DOT, a healthcare professional meets with patient every day or several times a week to administer their medication so that they don’t have to remember to take it on their own. So TB patient won’t need to go to the hospital unless they are unable to take the medication at home or have a bad reaction to the treatment.
The advantages of DOT are it ensures that the patient completes an adequate regimen. Besides, DOT also helps identify problems which might interrupt treatment and allow the healthcare worker to monitor the patient regularly for side effects and response to anti-tuberculosis therapy. Furthermore, DOT helps to decrease the risk of drug resistance resulting from inadequate or incomplete treatment. It also decrease the chances of treatment failure, reactivation and relapse. Following DOT programme, patients can finish TB therapy as quickly as possible, without unnecessary gaps. This also helps to prevent TB from spreading to others.
357505258889500 However, there is no doubt that there is also a disadvantage in carrying DOT program. The disadvantages of DOT are that it is time consuming and labor intensive. Besides, some patients may also find that it undermines their independence. It can be perceived by the patient as demeaning or punitive. It also can imply that the patient is incapable or irresponsible. Thus, it is very important to explain the benefits of DOT to each patient and stress the fact that DOT is not punitive rather that it is a way of helping the patient to remember to take their medication so that they can get better quicker and do not infect other people. This is also because, stopping treatment or skipping doses can make pulmonary TB resistant to medicines, which can also then leading to MDR-TB.
The prevention of TB infection consists of several main parts. The first part of TB prevention is to stop the transmission of TB from one adult to another. This is done through firstly, identifying people with active TB and then curing them through the provision of drug treatment. With proper TB treatment someone with TB will very quickly not be infectious and so can no longer spread the disease to others.
The second main part of TB prevention is to prevent people with latent TB from developing active and infectious TB disease. Anything which increases the number of people infected by each infectious person, such as ineffective treatment because of drug resistant TB, reduces the overall effect of the main TB prevention efforts. The presence of TB and HIV infection together also increases the number of people infected by each infectious person. As a result it is then more likely that globally the number of people developing active TB will increase rather than decrease.
The third part of TB prevention is TB infection control. This means preventing the transmission of TB in such settings as hospitals ; prisons. Doctors and other health care workers who provide care for patients for TB, must follow infection control procedures to ensure that TB infection is not passed from one person to another.
TB prevention – Education
TB education is also necessary for people with TB. People with TB need to know on how to take their TB drugs properly. They also need to know how to make sure that they do not pass TB on to other people. But TB education is also necessary for the general public. The public needs to know basic information about TB for a number of reasons including reducing the stigma still associated with TB.
TB prevention – the BCG vaccine
The vaccine called Bacillus Calmette-Guerin (BCG) was first developed in the 1920s. It is one of the most widely used of all current vaccines, and it reaches more than 80% of all new born children and infants in countries where it is part of the national childhood immunization programme. However, it is also one of the most variable vaccines in routine use.
The BCG vaccine has been shown to provide children with excellent protection against the disseminated forms of TB. However protection against pulmonary TB in adults is variable. Since most transmission originates from adult cases of pulmonary TB, the BCG vaccine is generally used to protect children, rather than to interrupt transmission among adults.
Preventing TB transmission in households
In order to reduce exposure in households where someone has infectious TB, the houses should be adequately ventilated. Besides, anyone who coughs should be educated on cough etiquette and respiratory hygiene. While smear positive, TB patients should spend as much time as possible outdoors. If possible, patient is advice to sleep alone in a separate, adequately ventilated room. Furthermore, TB patient should also spend as little time as possible on public transport and going to places where large numbers of people gather together.