HIV/TB | Print |

The overall goal of TB control is to reduce mortality , morbidity and transmission of tuberculosis infection . The most reliable way to achieve these goals is considered the main focus of attention for patients with newly diagnosed pulmonary tuberculosis in sputum smears in which Mycobacterium tuberculosis determined by microscopy . WHO puts objective cure at least 85 % of detected cases and the identification of at least 70% of new infectious cases. HIV infection makes it difficult to cure as well as the identification of patients with tuberculosis.
Achieve cure of tuberculosis in 85 % of TB patients with positive sputum smear is virtually impossible because of the high mortality associated with HIV infection. Achieve at least 70% case detection is also not possible because the method for accurate determination of the total number of such cases ( the denominator ) has not yet been found.
The impacts of HIV on TB indicators :
1. Number of TB patients.
Over the past 10-15 years, the number of TB patients increased by 300-400 % in Africa, which has received considerable spread of HIV infection . This is mainly due to the high risk of reactivation of latent tuberculosis infection in individuals coinfected with HIV. Along with the increase in the total number of TB patients noted a disproportionate increase in the number of patients with negative sputum smears bacterioscopic research , as well as the number of patients with extrapulmonary tuberculosis . Increasing the number of patients is a significant increase in the load on the TB service . Need more staff, particularly health professionals working within the framework of the fight against tuberculosis , and laboratory workers , there is an increased need for laboratory equipment, anti-TB drugs . Increasing demand for hospital beds for hospitalization at the initial stage of treatment. Thus creating a crowded hospital wards significantly complicates patient care and increases the danger of the spread of nosocomial infections .
2 . Increase the frequency of deaths .
TB patients are infected with HIV often die during anti-TB treatment from causes related to HIV infection. Adverse reactions to anti-TB drugs in such patients develop most often , which makes it necessary to interrupt TB chemotherapy and predisposes to fatal. Should not be surprising as the higher mortality in the course of anti-TB treatment , and after its completion in HIV-infected patients compared with HIV-negative . In countries with a high prevalence of HIV-associated tuberculosis ( Africa, Asia ), approximately 30% of HIV -infected tuberculosis patients with positive sputum smear microscopy die within their first 12 months . after the start of TB treatment . Another 25% of patients who completed the full course of treatment for TB will die within the next 12 months . High mortality of HIV-infected TB patients mean significantly less effective treatment cost , which is estimated years of life saved the patient. Noted that the outcomes of pulmonary tuberculosis in HIV-infected patients with negative sputum smear results may be even worse than in patients excreting Mycobacterium tuberculosis .
3 . Increasing the number of recurrent tuberculosis .
Frequency of reactivation of tuberculosis process in HIV-infected patients is significantly higher than in HIV-negative . Using chemotherapy regimens without including them rifampicin and breaks in reception TB drugs because of adverse reactions to them are associated with an increased risk of reactivation of tuberculosis. Among reactivations referred as true relapses of tuberculosis process and its renewal as a result of reinfection.
4 . Development of drug resistance .
Outbreaks of multidrug- resistant mycobacteria have been described in both developed and developing countries in patients infected with HIV. By itself, HIV infection is not a factor in causing multidrug-resistant Mycobacterium tuberculosis , but it contributes to its spread effect that reduces the time between infection and the development of severe forms of tuberculosis .
The spread of drug - resistant TB , especially multidrug-resistant pulmonary tuberculosis , causes increasing epidemiological risk and sources of infection in the first place , for HIV- infected persons. Unlike other opportunistic infections ( herpes infection , Kaposi's sarcoma , etc.), which also complicate the course of HIV infection , tuberculosis is a danger to others by virtue of pathogen release into the environment. Therefore , incidence of tuberculosis , especially caused by drug-resistant forms of HIV-infected people increases the risk of tuberculosis among the general population.
The most common form of tuberculosis in HIV-infected persons is pulmonary tuberculosis (PTB ) , the degree of clinical manifestations of which depends on the level of immunosuppression.
HIV infection , reduction of the number CD4- lymphocytes significantly attenuated macrophage phagocytosis and the activity of natural killer cells and , in general, the immune response that increases ( more than 10 times ) susceptibility to infection and reactivation of dormant Mycobacterium tuberculosis , as well as intensifying infectious process . In patients with early stages of HIV clinical manifestations of tuberculosis are not different from those in non-HIV patients, including sputum smear-positive detection of cavities and X-ray examination of the lungs. At this stage of tuberculosis occurs as an independent disease and not have the character of an opportunistic infection .
As HIV infection progresses, the level of CD4 cells drops about 50-80/mkl per year, which steadily reduces the ability of the immune system and inhibit the reproduction of dissemination of Mycobacterium tuberculosis (MBT ) in the body. At the same time , the more pronounced immunodeficiency becomes , the more tissue reactions vary by agent of tuberculosis : lost productive reaction , increases the frequency of reactions with alterative dissimination pathogen. In the later stages of HIV infection disseminated processes predominate , tuberculosis of intrathoracic lymph nodes , often occurs generalization tuberculous process , a marked intoxication . Moreover , the clinical picture is atypical tuberculosis can - with the defeat of the middle and lower lobes of the lungs , in the form of miliary tuberculosis , extrapulmonary tuberculosis and mikobakteriemiey . In patients with clinical manifestations listed sputum culture for Mycobacterium tuberculosis may give a positive result even in the absence of radiographically defined changes in the lungs .
In the later stages of HIV infection in TB- HIV as low immunity may develop other opportunistic infections : pneumocystis pneumonia (pathogen Pneumocystis jirovecii, formerly known as Pneumocystis carinii), Candida esophagitis , cryptococcal meningitis , etc. , any of which can cause the patient's death .
Growing epidemics of HIV and tuberculosis increase the need for surveillance to better understanding the trends in these epidemics and to develop an appropriate strategy to deal with them . Surveillance of HIV infection among TB patients is particularly important, as the HIV epidemic continues to exacerbate the problem of tuberculosis, and urgent need for new measures to monitor this developing situation.
Surveillance is a "system for collecting the information needed for the protection , development, planning and evaluation of the functioning of public health ." The general objectives of the surveillance system is to collect , analyze and disseminate accurate information on the epidemiological situation . Surveillance should contribute to a better understanding of the problem and provide reliable , timely and cost-effective information on the recommended actions. Surveillance activities for HIV tend to have a focused data collection.
In accordance with international approaches , surveillance of HIV infection among TB patients under different HIV prevalence provides : information about the targeting of resources and planning activities with regard to persons with HIV infection and tuberculosis , as well as monitoring the effectiveness of these measures; awareness politicians, professionals and the public about the situation , assess the need for interaction between programs to combat HIV and tuberculosis for the development and implementation of joint strategies to combat comorbidity TB / HIV , provision of information on the HIV epidemic and its impact for TB patients quantitative assessment of the need of ART for TB patients .