Pulmonary infections in the HIV-infected patient in the era of highly active antiretroviral therapy: an update

The 'pulmonary diseases spectrum' in HIV infected children

Despite advances in diagnostic, therapeutic and preventive strategies for HIV, pulmonary diseases continue to be the major cause of morbidity and mortality in infants and children infected with HIV. With effective programs to prevent perinatal HIV-1 transmission to early diagnosis in infants, we have seen a substantial decline in paediatric HIV incidence. Early initiation of Highly Active Anti-Retroviral Therapy (HAART) in all HIV infected children coupled with consistent use of Pneumocystis prophylaxis in all HIV exposed/infected children under 5 years of age has considerably reduced associated infections overall and respiratory infections in particular. In developing countries already burdened with poverty, malnutrition, suboptimal immunization coverage and limited access to health care and treatment, acute and chronic HIV-associated respiratory disease remain a major cause for concern. Prevention of severe respiratory infections in advanced HIV disease among children consists mostly of rapid and optimal HAART initiation & continuation, preventing severe TB disease with BCG and TB preventive treatment, preventing Pneumocystis jirovecii pneumonia with cotrimoxazole prophylaxis and administering age-appropriate vaccinations and catch-up vaccines as per National Immunization schedule.

Bacteriology of community-acquired pneumonia, antimicrobial susceptibility pattern and associated risk factors among HIV patients, Northeast Ethiopia: cross-sectional study

Objective

Pneumonia is an opportunistic infection and it is a major cause of mortality and morbidity among human immunodeficiency virus/acquired immune deficiency syndrome-positive patients. Previous studies have shown the dominant pathogens bacterial isolates were K. pneumoniae 27.0%, S. aureus 20.8%, S. pneumoniae 18.8% and E. coli 8.3%. This study aimed to determine bacteriology of community-acquired pneumonia, antimicrobial susceptibility pattern and associated risk factors among human immunodeficiency virus patients in the Northeast Ethiopia: cross-sectional study.

Methods

A health facility-based cross-sectional study was conducted from January to April 2021 at six health facilities in Dessie Town. A total of 378 community-acquired pneumonia patients suspected to be human immunodeficiency virus-positive were recruited using a consecutive sampling technique. Sociodemographic and clinical data were collected using a structured questionnaire. A two-milliliter sputum specimen was collected aseptically from each study participant. Samples were cultivated on blood agar, chocolate agar and MacConkey agar to isolate bacterial pathogens. To identify bacteria pathogens Gram stain, colony morphology and biochemical tests were performed. The Kirby-Bauer Disc Diffusion method was used to perform the antimicrobial susceptibility test. Descriptive statistics, logistic regression analysis was carried out using Statistical package for social science version 25 software. p-value < 0.05 with a corresponding 95% confidence interval (CI) was considered for statistical significance.

Result

The overall prevalence of bacterial pneumonia was 175 (46.3%). Gram-negative bacteria accounted for 119 (68%) and the predominant isolates identified were Streptococcus pneumoniae 49 (28%) followed by Klebsiella pneumoniae 46 (26.3%), Pseudomonas aeruginosa 34 (19.4%). There were 148 (84.6%) multidrug-resistant bacteria overall. Statistically significant factors included viral load, cigarette smoking, cluster of differentiation 4 count, alcohol use, World Health Organization clinical stages III and IV and low white blood cell count.

Conclusion

The study found that both multidrug resistance and bacterial pneumonia were high. Thus, bacterial culture and antimicrobial susceptibility tests should be routinely performed in health facilities in order to prevent and control the spread of bacterial infection and concurrent drug resistance.

Atypical bacterial pneumonia in the HIV-infected population

Human immunodeficiency virus (HIV)-infected individuals are more susceptible to respiratory tract infections by other infectious agents (viruses, bacteria, parasites, and fungi) as their disease progresses to acquired immunodeficiency syndrome. Despite effective antiretroviral therapy, bacterial pneumonia (the most frequently occurring HIV-associated pulmonary illness) remains a common cause of morbidity and mortality in the HIV-infected population. Over the last few decades, studies have looked at the role of atypical bacterial pneumonia (i.e. pneumonia that causes an atypical clinical presentation or responds differently to typical therapeutics) in association with HIV infection. Due to the lack of available diagnostic strategies, the lack of consideration, and the declining immunity of the patient, HIV co-infections with atypical bacteria are currently believed to be underreported. Thus, following an extensive database search, this review aimed to highlight the current knowledge and gaps regarding atypical bacterial pneumonia in HIV. The authors discuss the prevalence of Chlamydophila pneumoniae, Mycoplasma pneumoniae, Coxiella burnetii, Legionella species and others in the HIV-infected population as well as their clinical presentation, methods of detection, and treatment. Further studies looking at the role of these microbes in association with HIV are required. Increased knowledge of these atypical bacteria will lead to a more rapid diagnosis of these infections, resulting in an improved quality of life for the HIV-infected population.

Immune Reconstitution Inflammatory Syndrome in HIV-Infected Immigrants

Immune reconstitution inflammatory syndrome (IRIS) includes a group of potentially serious inflammatory processes that may be present in HIV-infected patients after initiating highly active antiretroviral therapy (HAART). Paradoxical IRIS is a worsening of symptoms, after an overwhelming response to a previously diagnosed opportunistic infection (OI); unmasking IRIS reveals a previously occult OI. The main objective of the study was to describe the epidemiological, clinical, and outcome data of HIV-infected immigrants, stratified according to high- or low-income countries of origin, who developed IRIS and to compare them with native-born Spanish patients. This retrospective study reviewed all patients with HIV infection admitted to the Unit of Infectious Diseases and Tropical Medicine between 1998 and 2014. IRIS was identified in 25/138 (18%) immigrant patients and 24/473 (5%) native-born Spanish patients infected with HIV. Most cases, 19/25 (76%), were of unmasking IRIS. The time elapsed between initiation of HAART and development of IRIS was significantly longer in patients with unmasking versus paradoxical IRIS. OIs, in particular due to mycobacteria, were the most frequently involved processes. Twenty percent of patients died. The comparison of immigrant and native-born patients found significant differences for both IRIS type (higher incidence of paradoxical forms among immigrants) and for the absence of malignancies in native-born patients. No significant differences were found when the data of immigrants from low- and high-income countries were compared.

Serum markers as an aid in the diagnosis of pulmonary fungal infections in AIDS patients

Introduction

The etiology of pulmonary infections in HIV patients is determined by several variables including geographic region and availability of antiretroviral therapy.

Materials and methods

A cross-sectional prospective study was conducted from 2012 to 2016 to evaluate the occurrence of pulmonary fungal infection in HIV-patients hospitalized due to pulmonary infections. Patients’ serums were tested for (1–3)-β-D-Glugan, galactomannan, and lactate dehydrogenase. The association among the variables was analyzed by univariate and multivariate regression analysis.

Results

60 patients were included in the study. The patients were classified in three groups: Pneumocystis jirovecii pneumonia (19 patients), community-acquired pneumonia (18 patients), and other infections (23 patients). The overall mortality was 13.3%. The time since diagnosis of HIV infection was shorter in the pneumocystosis group (4.94 years; p = 0.001) than for the other two groups of patients. The multivariate analysis showed that higher (1-3)-β-D-Glucan level (mean: 241 pg/mL) and lactate dehydrogenase (mean: 762 U/L) were associated with the diagnosis of pneumocystosis. Pneumocystosis was the aids-defining illness in 11 out of 16 newly diagnosed HIV-infected patients.

Conclusion

In the era of antiretroviral therapy, PJP was still the most prevalent pulmonary infection and (1-3)-β-D-Glucan and lactate dehydrogenase may be suitable markers to help diagnosing pneumocystosis in our HIV population.

HIV-related pneumococcal disease prevention in adults

INTRODUCTION

HIV-infected persons are particularly susceptible to the development of severe pneumococcal disease, even in the setting of combination antiretroviral therapy (cART), due to slow, incomplete recovery of anti-pneumococcal host defenses. This risk is increased by avoidable aspects of lifestyle, particularly smoking, which intensify immunosuppression. Clearly, more effective preventive measures are needed to counter this threat. Areas covered: This is a detailed review of the published literature focusing on currently available strategies for prevention of pneumococcal infection in HIV-infected patients, including cotrimoxazole prophylaxis, cART, pneumococcal vaccination, and smoking cessation strategies. This is preceded by a consideration of the epidemiology, clinical presentation, risk factors, and outcome of pneumococcal disease. Expert commentary: Cotrimoxazole prophylaxis has been shown to reduce morbidity and mortality in HIV-infected patients, although there is inconsistent data on the preventive efficacy against pneumococcal infections. Some recent studies have documented unchanged incidences of IPD in adult patients in the cART era. With regard to pneumococcal vaccination, routine acceptance of the efficacy of the PCV13/PPV23 sequential administration prime-boost strategy awaits the outcome of clinical trials in those with HIV infection. Smoking cessation, and discontinuation of excessive alcohol consumption and intravenous drug abuse, are priority strategies to prevent severe pneumococcal infection.

Global, regional, and national estimates of pneumonia burden in HIV-infected children in 2010: a meta-analysis and modelling study

BACKGROUND

Globally, pneumonia is a leading cause of mortality and morbidity in children younger than 5 years. Underlying HIV infection is an important risk factor for pneumonia morbidity and mortality in children. There are, however, no global or country level estimates of pneumonia burden in HIV-infected children. We assessed the role of HIV in pneumonia incidence and mortality and estimated the number of pneumonia cases and deaths in HIV-infected children younger than 5 years in 133 high pneumonia-burden countries in 2010.

METHODS

We estimated the risk of hospital admission and case fatality rate caused by pneumonia in HIV-infected children compared with HIV-uninfected children from a systematic review of studies published in Medline, Embase, and Global Health between Jan 1, 1980, and Aug 31, 2013. We estimated nationwide pneumonia incidence and mortality with two different models that incorporated several risk factors for paediatric pneumonia hospital admission and mortality (including HIV infection). We then estimated the number of pneumonia episodes and deaths that occurred in HIV-infected children in 2010.

FINDINGS

The odds ratio (OR) for hospital admission for all-cause pneumonia in HIV-infected children compared with HIV-uninfected children was 6·5 (95% CI 5·9-7·2). The risk of death was higher in children with pneumonia and HIV compared with those with pneumonia only (OR 5·9, 95% CI 2·7-12·7). In 2010, 1·4 million pneumonia episodes (uncertainty range [UR] 0·6 million to 3·3 million) and 88 000 pneumonia deaths (UR 47 400-153 000) occurred in HIV-infected children in low-income countries. Of these, 1·2 million pneumonia episodes (UR 0·5 million-2·7 million) and 85 400 deaths (UR 46 000-147 300) were directly attributable to HIV. 1·3 million (90%) pneumonia episodes and 82 400 (93%) pneumonia deaths in HIV-infected children aged younger than 5 years occurred in the WHO African region.

INTERPRETATION

Globally, a small proportion of pneumonia episodes and pneumonia deaths occur in HIV-infected children. However, in the highest HIV-burden countries in sub-Saharan Africa (ie, Swaziland, Lesotho, and Zimbabwe) up to a fifth of all pneumonia cases and 60% of pneumonia deaths occur in HIV-infected children. In these countries, major reductions in child pneumonia mortality can be achieved only if the systemic challenges plaguing the health system (poor coverage of early infant testing for HIV, of antiretroviral drugs in pregnant women and young children, of co-trimoxazole prophylaxis, and of pneumococcal vaccination) can be overcome.

FUNDING

WHO.

Other HIV-associated pneumonias

The incidence, mortality, and epidemiology of human immunodeficiency virus (HIV)-associated pulmonary infections have changed as a result of effective antiretroviral and prophylaxis antimicrobial therapy. The clinical presentation, radiographic abnormalities, and treatment of pneumonia from various uncommon pathogens in patients with AIDS can be different from those in immunocompetent patients. Advances in invasive and noninvasive testing and molecular biological techniques have improved the diagnosis and prognosis of pulmonary infections in patients infected with HIV. This review focuses on pulmonary infections from nontuberculosis mycobacteria, cytomegalovirus, fungi (aspergillosis, cryptococcosis, endemic fungi), and parasites (toxoplasmosis), and uncommon bacterial pneumonia (nocardiosis, rhodococcosis) in these patients.

Mycobacterial antibody levels and immune restoration disease in HIV patients treated in South East Asia

AIM

Immune restoration disease (IRD) associated with Mycobacterium tuberculosis parallels the reconstitution of a pathogen-specific Th1 response. However, it is not clear whether humoral responses to M. tuberculosis antigens also rise, or whether antibody levels predict IRD. Here, humoral immunity to M. tuberculosis antigens was investigated in four Asian cohorts.

METHODS

Plasma samples were obtained from longitudinal prospective studies of HIV patients beginning antiretroviral therapy (ART) in New Delhi (India), Kuala Lumpur (Malaysia), Jakarta (Indonesia) and Phnom Penh (Cambodia). IgG antibodies to purified protein derivative, lipoarabinomannan and 38-kDa antigens of M. tuberculosis were quantitated using in-house ELISAs. IRD was defined as exacerbated symptoms of tuberculosis in patients on anti-tuberculosis therapy or a novel presentation of tuberculosis on ART.

RESULTS

Pre-ART IgG levels to purified protein derivative, lipoarabinomannan and 38-kDa antigen were similar in the IRD and control groups from each site. Compared with non-IRD controls, a higher proportion of IRD patients had elevated IgG levels to lipoarabinomannan (defined as a greater than twofold increase) over 12 weeks of ART. However, this trend was not significant for the other antigens and longitudinal analyses did not reveal clear rises in antibody levels at the time of IRD.

CONCLUSION

Levels of antibody to mycobacterial antigens do not predict IRD, but levels of antibody reactive with lipoarabinomannan rise during an IRD in some patients.

[Human immunodeficiency virus and AIDS-associated immune reconstitution syndrome. State of the art]

Since the arrival of highly active antiretroviral therapy (HAART), immune reconstitution syndrome (IRS) has become an increasingly more frequent complication in patients with human immunodeficiency virus (HIV) infection. This article presents a review of the available evidence on this subject, indexed in MEDLINE-PUBMED, BVS-BIREME, and BioMed Central. The review covers the definition, epidemiology, classification, and diagnostic criteria related to IRS. In addition, the clinical particularities of the most frequent etiologies are described, and a proposal for a therapeutic approach is formulated. The prognosis and future implications of this syndrome in the epidemiology of some infectious illnesses in the HIV-positive population are included. Several unresolved aspects are mentioned, such as those related to the pathophysiology of the condition, use of biomarkers for the diagnosis, and the need for evidence-based therapeutic algorithms to enable standardization of treatment for these patients.