Impact of prophylaxis for Mycobacterium avium complex on bacterial infections in patients with advanced human immunodeficiency virus disease

Temporal and Spatial Distribution of Opportunistic Infections Associated with the Human Immunodeficiency Virus (HIV) in Uganda

The human immunodeficiency virus (HIV) remains one of the greatest challenges of the twenty-first century in the absence of an effective vaccine or cure. It is estimated globally that close to 38 million people are currently living with the HIV virus and more than 36 million have succumbed to this deadly virus from the time the first case was reported in early 1980s. The virus degrades the human body immunity and makes it more vulnerable to different kinds of opportunistic infections (OIs). However, with the introduction of highly active anti-retroviral therapy (HAART) in 2003, the pattern and frequency of OIs has been progressively changing though with variations in the different parts of the World. So this chapter discusses the temporal and spatial patterns of OIs in Uganda.

Effect of Macrolide Prophylactic Therapy on AIDS-Defining Conditions and HIV-Associated Mortality

BACKGROUND

Mycobacterium avium complex prophylaxis is recommended for patients with advanced HIV infection. With the decrease in incidence of disseminated Mycobacterium avium complex infection and the availability of antiretroviral therapy (ART), the benefits of macrolide prophylaxis were investigated. This study examined the impact of macrolide prophylaxis on AIDS-defining conditions and HIV-associated mortality in a cohort of HIV-infected patients on ART.

METHODS

Patients from TREAT Asia HIV Observational Database (September 2015 data transfer) aged 18 years and older with a CD4 count <50 cells/mm at ART initiation were included. The effect of macrolide prophylaxis on HIV-associated mortality or AIDS-defining conditions (as a combined outcome) and HIV-associated mortality alone were evaluated using competing risk regression. Sensitivity analysis was conducted in patients with a CD4 <100 cells/mm at ART initiation.

RESULTS

Of 1345 eligible patients, 10.6% received macrolide prophylaxis. The rate of the combined outcome was 7.35 [95% confidence interval (CI): 6.04 to 8.95] per 100 patient-years, whereas the rate of HIV-associated mortality was 3.14 (95% CI: 2.35 to 4.19) per 100 patient-years. Macrolide use was associated with a significantly decreased risk of HIV-associated mortality (hazard ratio 0.10, 95% CI: 0.01 to 0.80, P = 0.031) but not with the combined outcome (hazard ratio 0.86, 95% CI: 0.32 to 2.229, P = 0.764). Sensitivity analyses showed consistent results among patients with a CD4 <100 cells/mm at ART initiation.

CONCLUSIONS

Macrolide prophylaxis is associated with improved survival among Asian HIV-infected patients with low CD4 cell counts and on ART. This study suggests the increased usage and coverage of macrolide prophylaxis among people living with HIV in Asia.

Treating bacterial pneumonia in people living with HIV

Introduction: Bacterial pneumonia remains an important cause of morbidity and mortality in people living with HIV (PLWH) in the antiretroviral therapy (ART) era. In addition to being immunocompromised, as reflected by low CD4 cell counts and elevated HIV viral loads, PLWH often have other behaviors associated with an increased risk of pneumonia including smoking and injected drug use. As PLWH are aging, comorbid conditions such as chronic obstructive pulmonary disease (COPD), cancers, and cardiovascular, renal and liver diseases are emerging as additional risk factors for pneumonia. Pathogens are often similar to those in HIV-uninfected individuals; however, PLWH are at risk for unusual and/or multi-drug resistant organisms causing bacterial pneumonia based, in part, on their CD4 cell counts and other exposures. Areas covered: In this review, we focus on the recognition and management of bacterial community-acquired pneumonia (CAP) in PLWH. Along with antimicrobial treatment, we discuss prevention strategies such as vaccination and smoking cessation. Expert opinion: Early initiation of ART after HIV infection can decrease the risk of pneumonia. Improved efforts at vaccination, smoking cessation, and reduction of other substance use are urgently needed in PLWH to decrease the risk for bacterial pneumonia. As PLWH are aging, comorbidities are additional risk factors for bacterial CAP.

Mycobacterium avium complex infection in patients with human immunodeficiency virus: A systematic review and meta-analysis

BACKGROUND

Mycobacterium avium-intracellulare complex (MAC) is one of the leading causes of death among people living with human immunodeficiency virus (HIV). The current study was aimed to determine the frequency of MAC infection in patients infected with HIV.

METHODS

Embase, PubMed, and Web of Science were searched for relevant studies. All statistical analyses were performed by STATA version 14.

RESULTS

From 6,627 retrieved articles, 23 were included in the final analysis. A total of 18,463 patients with HIV were included in the analysis. The frequency of MAC infection in patients with HIV was found to be 10.6% (95% confidence interval, 6.9-14.2).

CONCLUSION

The relatively large fractions of HIV-infected patients were coinfected with MAC, which may poses significant public health problems. Continued progress in the development of rapid diagnostic methods and preventive therapy for MAC should lead to further improvements in survival and quality of life in patients with HIV.

Bacterial Infections in Adult HIV-Infected Patients

PURPOSE

The purpose of this article is to critically review articles published from the pre-HAART era to the present on bacterial infections in adult HIV-infected patients.

METHOD

Literature search on bacterial infections in HIV-infected patients yields predominantly small case series from single centers, many of which are retrospectively collected.

RESULTS

Variations in case selection limit the utility of these articles for assessing the epidemiology and clinical features of a particular infection. Nonetheless, numerous articles indicate that certain bacterial infections occur most often when CD4 cell counts are < 200/mm3. In the pre-HAART era, others suggest that PcP prophylaxis with TMP/SMX and MAC prophylaxis with macrolides reduced rates of several bacterial infections. Since the advent of HAART, however, some articles suggest that the incidence of various infections has declined and that withdrawal of OI prophylaxis in patients who have had HAART restoration of CD4 cell counts has not led to an increase in certain bacterial infections.

CONCLUSION

This review suggests that bacterial infections may have declined in the HAART era, as multicenter cohort studies have shown to be the case with AIDS-associated OIs. Nonetheless, preventive measures such as pneumococcal vaccination and smoking cessation remain effective strategies.

The Independent Effect of Highly Active Antiretroviral Therapy on Severe Opportunistic Disease Incidence and Mortality in HIV-Infected Adults in Côte D'Ivoire

Background

Studies in developed countries have shown highly active antiretroviral therapy (HAART) decreases incidence of severe opportunistic diseases (ODs) in HIV-infected patients beyond that which is expected from changes in CD4+T-cell count.

Objective

To estimate the independent impact of HAART on reducing ODs and mortality in Côte d'Ivoire.

Methods

Within two longitudinal studies of HIV-infected adults (1996–2003), we identified time on ‘cotrimoxazole alone’ and ‘HAART plus cotrimoxazole’. WHO stage 3–4 defining events and severe malaria were divided into those preventable and not preventable with cotrimoxazole. Incidence of ODs by CD4 count stratum was estimated using incidence density analysis. CD4+ T-cell count at time of OD was estimated using linear interpolation. Using Poisson regression, we estimated the effect of HAART on OD incidence and mortality by CD4 count stratum.

Results

Totals of 446 and 135 adults were followed during 6,216 and 3,412 person-months in the cotrimoxazole alone and HAART plus cotrimoxazole periods, respectively. There was a CD4+ T-cell-independent risk reduction for ODs and mortality during the HAART plus cotrimoxazole period compared with cotrimoxazole alone, which varied by time on HAART, CD4 count stratum and OD type. It was mainly seen after 6 months on HAART and for ODs not preventable by cotrimoxazole. The HAART effect differed significantly by CD4 count stratum ( P=0.02), but was significant in all strata after 6 months on HAART.

Conclusions

In these sub-Saharan African adults, HAART initiation reduced ODs and mortality beyond that which was expected through the HAART-induced CD4+ T-cell increase. Further studies should examine practical implications of this independent ‘HAART effect’ on clinical outcomes in patients on HAART.

Bacterial pneumonia, HIV therapy, and disease progression among HIV-infected women in the HIV epidemiologic research (HER) study

BACKGROUND

To determine the rate and predictors of community-acquired bacterial pneumonia and its effect on human immunodeficiency virus (HIV) disease progression in HIV-infected women, we performed a multiple-site, prospective study of HIV-infected women in 4 cities in the United States.

METHODS

During the period of 1993-2000, we observed 885 HIV-infected and 425 HIV-uninfected women with a history of injection drug use or high-risk sexual behavior. Participants underwent semiannual interviews, and CD4+ lymphocyte count and viral load were assessed in HIV-infected subjects. Data regarding episodes of bacterial pneumonia were ascertained from medical record reviews.

RESULTS

The rate of bacterial pneumonia among 885 HIV-infected women was 8.5 cases per 100 person-years, compared with 0.7 cases per 100 person-years in 425 HIV-uninfected women (P < .001). In analyses limited to follow-up after 1 January 1996, highly active antiretroviral therapy (HAART) and trimethoprim-sulfamethoxazole (TMP-SMX) use were associated with a decreased risk of bacterial pneumonia. Among women who had used TMP-SMX for 12 months, each month of HAART decreased bacterial pneumonia risk by 8% (adjusted hazard ratio [HR(adj)], 0.92; 95% confidence interval [CI], 0.89-0.95). Increments of 50 CD4+ cells/mm3 decreased the risk (HR(adj), 0.88; 95% CI, 0.84-0.93), and smoking doubled the risk (HR(adj), 2.12; 95% CI, 1.26-3.55). Bacterial pneumonia increased mortality risk (HR(adj), 5.02; 95% CI, 2.12-11.87), with adjustment for CD4+ lymphocyte count and duration of HAART and TMP-SMX use.

CONCLUSIONS

High rates of bacterial pneumonia persist among HIV-infected women. Although HAART and TMP-SMX treatment decreased the risk, bacterial pneumonia was associated with an accelerated progression to death. Interventions that improve HAART utilization and promote smoking cessation among HIV-infected women are warranted.

Mycobacterium avium complex in patients with HIV infection in the era of highly active antiretroviral therapy

Disseminated Mycobacterium avium complex (MAC) infection is a common complication of late-stage HIV-1 infection. Since the advent of highly active antiretroviral therapy (HAART), the rate of MAC infection has declined substantially, but patients with low CD4 cell counts remain at risk. Among patients in the Johns Hopkins cohort with advanced HIV disease, the proportion developing MAC has fallen from 16% before 1996 to 4% after 1996, with a current rate of less than 1% per year. Factors associated with developing MAC include younger age, no use of HAART, and enrollment before 1996. Prophylaxis with azithromycin or clarithromycin is recommended for all patients with CD4 counts less than 50 cells/mL. Optimum treatment for disseminated MAC includes clarithromycin and ethambutol, and another investigation suggests that the addition of rifabutin might reduce mortality. Both prophylaxis and treatment of disseminated MAC can be discontinued in patients who have responded to HAART, and specific guidelines for withdrawing treatment have been published. Although HAART has altered the frequency and outcome of MAC infection, it remains an important complication of AIDS.

Gender and Hospitalization Patterns Among HIV-Infected Drug Users Before and After the Availability of Highly Active Antiretroviral Therapy

We examined highly active antiretroviral therapy (HAART) era and pre-HAART era hospitalization rates among 604 HIV-infected drug users in a prospective study in Bronx, New York. Medical history and risk behaviors were elicited by semiannual interviews. Standardized medical record review abstracted discharge diagnoses for all hospitalizations. Hospitalization rates from January 1997 to December 2000 were compared with rates from January 1992 to December 1996. The rate of hospitalizations per 100 patient-years in the HAART era was 49.3 compared with 44.1 in the pre-HAART era (P = 0.13). Among women, the rate was significantly higher in the HAART era than in the pre-HAART era (68.1 vs. 49.4 hospitalizations per 100 patient-years, respectively; P = 0.01). In the second era, HAART users had lower rates than those who did not use HAART (37.2 vs. 83.4 hospitalizations per 100 patient-years, respectively; P < 0.001) for both HIV-associated and non-HIV-associated illnesses. Multivariate analysis revealed that in the HAART era, female gender (relative risk ratio = 1.72, P = 0.03) and not using HAART (relative risk ratio = 1.82, P = 0.02) independently predicted increased hospitalization risk. In the pre-HAART era, women were at independently higher risk of hospitalization (relative risk ratio = 1.36, P = 0.05). Among HIV-infected drug users, those who use HAART have a decreased risk of hospitalization; those who do not use HAART remain at high risk of continuing morbidity from both HIV-related and non-HIV-related illness and have high hospitalization rates.

Multisite reproducibility of results obtained by two broth dilution methods for susceptibility testing of Mycobacterium avium complex

A multicenter study was conducted to assess the interlaboratory reproducibility of susceptibility testing of Mycobacterium avium complex (MAC) by broth microdilution using two different media (cation-adjusted Mueller-Hinton broth with 5% oleic acid-albumin-dextrose-catalase and 7H9 broth with casein) and by macrodilution using the BACTEC 460TB and 12B media at pH 6.8 and 7.3 to 7.4. Ten well-characterized strains of MAC (four macrolide susceptible, six macrolide resistant) were tested against clarithromycin and azithromycin (the latter only by BACTEC 460TB, pH 6.8). At each site, strains were tested against clarithromycin three times on each of three separate days (nine testing events per isolate) by using a common lot of microdilution trays and BACTEC 12B medium, pH 6.8; strains were tested once on three separate days against clarithromycin in 12B medium at pH 7.3 to 7.4 and against azithromycin. Agreement among MICs (i.e., mode +/- 1 twofold dilution) was 100% for all strains and both drugs when BACTEC 460TB was used, regardless of the pH of the medium, but varied when microdilution with either medium was used, particularly with susceptible strains. Agreement based on interpretive category, with NCCLS-recommended breakpoints, was 100% for all strains with the BACTEC 460TB method (both drugs and both pH values) and with microdilution using 7H9 broth. With microdilution and Mueller-Hinton broth, agreement by interpretive category was 100% for eight isolates and >90% for two; errors occurred only in laboratories where personnel had minimal experience with this technique. MAC susceptibility testing may be performed by broth macrodilution or microdilution at either pH, with NCCLS-recommended interpretive breakpoints. However, because visual interpretation of broth microdilution end points is subjective, it is more prone to reader error; therefore, this method requires greater expertise than the BACTEC 460TB. Both techniques require appropriate validation and continued documentation of proficiency.

A prospective study of discontinuing primary and secondary Pneumocystis carinii pneumonia prophylaxis after CD4 cell count increase to > 200 x 106 /l

OBJECTIVE

To assess the incidence of Pneumocystis carinii pneumonia (PCP) after discontinuation of either primary or secondary prophylaxis.

DESIGN

This was a prospective, non-randomized, non-blinded study.

SETTING

Twenty-five University-based AIDS Clinical Trials Group units.

PARTICIPANTS

Participants either had a CD4 cell count < or = 100 x 106/l at any time in the past and no history of confirmed PCP (group I; n = 144), or had a confirmed episode of PCP > or = 6 months prior to study entry (group II; n = 129). All subjects had sustained CD4 cell counts > 200 x 106/l in response to antiretroviral therapy.

INTERVENTIONS

Subjects discontinued PCP prophylaxis within 3 months or at the time of study entry. Evaluations for symptoms of PCP and CD4 cell counts were performed every 8 weeks. Prophylaxis was resumed if two consecutive CD4 cell counts were < 200 x 106/l.

MAIN OUTCOME MEASURE(S)

The main outcome was development of PCP.

RESULTS

No cases of PCP occurred in 144 subjects (median follow-up, 82 weeks) in group I or in the 129 subjects (median follow-up, 63 weeks) in group II (95% upper confidence limits on the rates of 1.3 per 100 person-years and 1.96 per 100 person-years for groups I and II, respectively). Eight subjects (five in group I and three in group II) resumed PCP prophylaxis after two consecutive CD4 cell counts < 200 x 106/l.

CONCLUSIONS

The risk of developing initial or recurrent PCP after discontinuing prophylaxis is low in HIV-infected individuals who have sustained CD4 cell count increases in response to antiretroviral therapy. Neither lifelong primary nor secondary PCP prophylaxis is necessary.