Pneumonia in HIV-infected and HIV-uninfected children in developing countries

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.

Surgical implications of HIV infection

According to the joint United Nations Programme on HIV/AIDS (UNAIDS), 37.7 million adults and children worldwide were estimated to be living with HIV or acquired immune deficiency syndrome (AIDS) at the end of 2020 [UNAIDS. (2022). http://www.unaids.org . Accessed 30 May 2022]. Most reside in low- and middle-income countries, with approximately 67% in sub-Saharan Africa (SSA). At the end of 2020, the total number of children less than 15 years of age living with HIV infection was 2.6 million, of whom 2.3 million (88%) were living in SSA. Aggressive interventions have reduced the annual number of incident (new) HIV infections among children to around 150,000 [UNAIDS. (2022). http://www.unaids.org . Accessed 30 May 2022]. However, paediatric HIV infection remains a pandemic affecting children predominantly in SSA but is also seen in Asia and sporadically elsewhere particularly in areas of civil strife such as is currently the case in Ukraine [War in Ukraine. (2022). https://www.unaids.org/en/War-Ukraine-special . Accessed Apr 2022]. New HIV infections among children declined by more than half (54%) from 2010 to 2020, due mainly to the increased provision of antiretroviral therapy to pregnant and breastfeeding women living with HIV [UNAIDS. (2022). http://www.unaids.org . Accessed 30 May 2022]. These programmes include early identification of HIV infection in pregnant or breastfeeding women through routine HIV testing, provision of antiretroviral therapy (ART) to all HIV-infected women who are pregnant or breastfeeding, provision of antiretroviral prophylaxis to their newborn infants during the first 6-12 weeks of life, delivery by elective Caesarean section when indicated, promotion of exclusive breastfeeding, early infancy screening for HIV infection, and initiation of ART in infants with HIV infection. HIV-infected children may require surgery either as an emergency to deal with a life-threatening incidental condition unrelated to HIV infection or for a complication of the disease such as tuberculosis or an aggressive soft tissue infection like necrotising fasciitis. Non-emergency surgical procedures may be required to assist in the diagnosis of an HIV-related condition or to correct a routine surgical problem electively. Surgical conditions associated with HIV infection are described under categories of soft tissue or organ-specific infections requiring drainage or debridement; gastrointestinal tract disease and complications; infections in the perineal area; malignancies and HIV-associated vasculitis. Although surgical outcomes are less favourable in HIV-infected children, pre-operative treatment of coinfections, administration of cotrimoxazole prophylaxis, nutritional support and antiretroviral therapy, together with peri-operative antibiotic prophylaxis have resulted in excellent short-term outcomes [World Health Organization. Consolidated guidelines on the use of antiretroviral drugs for treating and preventing HIV infection: Recommendations for a public health approach, June 201 http://www.apps.who.int/iris/bitstream/10665/85321/1/9789241505727_eng.pdf?ua=1 ; World Health Organization Guideline on when to start antiretroviral therapy and on pre-exposure prophylaxis for HIV, September 2015. http://www.apps.who.int/iris/bitstream/10665/186275/1/9789241509565_eng.pdf?ua=1;Eley et al. in BMC Infect Dis 2:3, 2002;Karpelowsky et al. in Pediatr Surg Int 28:1007-1014, 2012;].

The Etiology of Pneumonia in HIV-infected Zambian Children: Findings From the Pneumonia Etiology Research for Child Health (PERCH) Study

BACKGROUND

Despite recent declines in new pediatric HIV infections and childhood HIV-related deaths, pneumonia remains the leading cause of death in HIV-infected children under 5. We describe the patient population, etiology and outcomes of childhood pneumonia in Zambian HIV-infected children.

METHODS

As one of the 9 sites for the Pneumonia Etiology Research for Child Health study, we enrolled children 1-59 months of age presenting to University Teaching Hospital in Lusaka, Zambia, with World Health Organization-defined severe and very severe pneumonia. Controls frequency-matched on age group and HIV infection status were enrolled from the Lusaka Pediatric HIV Clinics as well as from the surrounding communities. Clinical assessments, chest radiographs (CXR; cases) and microbiologic samples (nasopharyngeal/oropharyngeal swabs, blood, urine, induced sputum) were obtained under highly standardized procedures. Etiology was estimated using Bayesian methods and accounted for imperfect sensitivity and specificity of measurements.

RESULTS

Of the 617 cases and 686 controls enrolled in Zambia over a 24-month period, 103 cases (16.7%) and 85 controls (12.4%) were HIV infected and included in this analysis. Among the HIV-infected cases, 75% were <1 year of age, 35% received prophylactic trimethoprim-sulfamethoxazole, 13.6% received antiretroviral therapy and 36.9% of caregivers reported knowing their children's HIV status at time of enrollment. A total of 35% of cases had very severe pneumonia and 56.3% had infiltrates on CXR. Bacterial pathogens [50.6%, credible interval (CrI): 32.8-67.2], Pneumocystis jirovecii (24.9%, CrI: 15.5-36.2) and Mycobacterium tuberculosis (4.5%, CrI: 1.7-12.1) accounted for over 75% of the etiologic fraction among CXR-positive cases. Streptococcus pneumoniae (19.8%, CrI: 8.6-36.2) was the most common bacterial pathogen, followed by Staphylococcus aureus (12.7%, CrI: 0.0-25.9). Outcomes were poor, with 41 cases (39.8%) dying in hospital.

CONCLUSIONS

HIV-infected children in Zambia with severe and very severe pneumonia have poor outcomes, with continued limited access to care, and the predominant etiologies are bacterial pathogens, P. jirovecii and M. tuberculosis.

Modified PIRO (predisposition, insult, response, organ dysfunction) severity score as a predictor for mortality of children with pneumonia in Hasan Sadikin Hospital, Bandung, Indonesia

Background

Clinical manifestations for pneumonia vary from mild to severe. The PIRO model (predisposition, insult, response, organ dysfunction) was used as scoring system to determine severity of sepsis and pneumonia in adult patients. The PIRO model was modified for sorting the severity of pneumonia in children and predicting its risk of mortality.

Methods

An ambispective cohort study of pneumonia patients aged 1 month to ≤ 18 years admitted over the period from May to September 2020. Data were collected from history, physical examination, laboratory examination, and chest radiography. Based on bivariate analysis (p<0.05 and relative risk (RR) with 95% confidence interval), variables of each PIRO component that were significant for mortality were assigned a value of 1. The cut-off score for predictor of mortality was calculated using the receiver operating characteristics (ROC) curve and the scores were stratified into three degrees of risk based on interquartile range, score ≤Q1 was categorized as low risk; Q1-Q3 was categorized as moderate risk; and score >Q3 was categorized as high risk.

Results

Out of the 80 subjects enrolled, 6 months-5 years was the largest age group (56.3%). The observed mortality was 15/80 (18.8%). The modified PIRO severity score was compiled from significant variables of predisposition (malnutrition), insult (chest radiograph), response (hypoxemia, hypotension, CRP >0.5 mg/dL, PCT >0.5 ng/dL) and organ dysfunction, with range of score 0-7. Score >3 was categorized as a cut-off point score for predictor of mortality with AUC 0.919 (95% CI 0.836–0.968), sensitivity of 80%, and specificity of 84.62%. Subjects with score >3 have RR of 10.544 compared to those with score ≤3. The stratification of score level was low (≤2), moderate (3-4), and high (5-7). The mortality levels were 0%, 46.7%, and 53.3%, respectively.

Conclusions

Modified PIRO severity score can be used as a sorting tool and predictor of mortality risk in children with pneumonia. This score can also be used to select candidates for intensive care, especially in health facilities with limited intensive care capacity.

Risk factors for acute respiratory infections in children under five years attending the Bamenda Regional Hospital in Cameroon

Background

Acute respiratory infections (ARI) are a leading cause of morbidity and mortality in under-five children worldwide. About 6.6 million children less than 5 years of age die every year in the world; 95% of them in low-income countries and one third of the total deaths is due to ARI. This study aimed at determining the proportion of acute respiratory infections and the associated risk factors in children under 5 years visiting the Bamenda Regional Hospital in Cameroon.

Methods

A cross-sectional analytic study involving 512 children under 5 years was carried out from December 2014 to February 2015. Participants were enrolled by a consecutive convenient sampling method. A structured questionnaire was used to collect clinical, socio-demographic and environmental data. Diagnosis of ARI was based on the revised WHO guidelines for diagnosing and management of childhood pneumonia. The data was analyzed using the statistical software EpiInfo™ version 7.

Results

The proportion of ARIs was 54.7% (280/512), while that of pneumonia was 22.3% (112/512). Risk factors associated with ARI were: HIV infection OR_adj 2.76[1.05–7.25], poor maternal education (None or primary only) OR_adj 2.80 [1.85–4.35], exposure to wood smoke OR_adj 1.85 [1.22–2.78], passive smoking OR_adj 3.58 [1.45–8.84] and contact with someone who has cough OR_adj 3.37 [2.21–5.14].

Age, gender, immunization status, breastfeeding, nutritional status, fathers’ education, parents’ age, school attendance and overcrowding were not significantly associated with ARI.

Conclusion

The proportion of ARI is high and is associated with HIV infection, poor maternal education, exposure to wood smoke, passive cigarette smoking, and contact with persons having a cough. Control programs should focus on diagnosis, treatment and prevention of ARIs.

Early use of corticosteroids in infants with a clinical diagnosis of Pneumocystis jiroveci pneumonia in Malawi: a double-blind, randomised clinical trial

BACKGROUND

Pneumocystis jiroveci pneumonia (PJP) is the most common opportunistic infection in infants with vertically acquired HIV infection and the most common cause of death in HIV-infected infants.

OBJECTIVES

To determine whether early administration of adjuvant corticosteroids in addition to standard treatment reduces mortality in infants with vertically acquired HIV and clinically diagnosed PJP when co-infection with cytomegalovirus and other pathogens cannot be excluded.

METHODS

A double-blind placebo-controlled trial of adjuvant prednisolone treatment in HIV-exposed infants aged 2-6 months admitted to Queen Elizabeth Central Hospital, Blantyre who were diagnosed clinically with PJP was performed. All recruited infants were HIV-exposed, and the HIV status of the infant was confirmed by DNA-PCR. HIV-exposed and infected infants as well as HIV-exposed but non-infected infants were included in the study. The protocol provided for the addition of prednisolone to the treatment at 48 h if there was clinical deterioration or an independent indication for corticosteroid therapy in any patient not receiving it. Oral trimethoprim-sulfamethoxazole (TMP/SMX) therapy and full supportive treatment were provided according to established guidelines. Primary outcomes for all patients included survival to hospital discharge and 6-month post-discharge survival.

RESULTS

It was planned to enroll 200 patients but the trial was stopped early because of recruitment difficulties and a statistically significant result on interim analysis. Seventy-eight infants were enrolled between April 2012 and August 2014; 36 infants (46%) were randomised to receive corticosteroids plus standard treatment with TMP/SMX, and 42 infants (54%) received the standard treatment plus placebo. In an intention-to treat-analysis, the risk ratio of in-hospital mortality in the steroid group compared with the standard treatment plus placebo group was 0.53 [95% CI 0.29-0.97, p = 0.038]. The risk ratio of mortality at 6 months was 0.63 (95% CI 0.41-0.95, p = 0.029). Two children who received steroids developed bloody stools while in hospital.

CONCLUSION

In infants with a clinical diagnosis of PJP, early use of steroids in addition to conventional TMP/SMX therapy significantly reduced mortality in hospital and 6 months after discharge.

Teaching Pediatric Life Support in Limited-Resource Settings: Contextualized Management Guidelines

Of the estimated 6.3 million global annual deaths in children younger than the age of 5 years, nearly all (99%) occur in low- to middle-income countries (LMIC). Existing management guidelines for children with emergency conditions as taught in a variety of current pediatric life support courses are mostly applicable to high-income countries with a different disease range and full resources compared with LMIC. A revised curriculum with evidence-based application to limited-resource settings would expand their potential for reducing pediatric mortality worldwide. This review provides a supplemental curriculum of standards for selected pediatric emergency conditions with attention to the context of disease range and level-specific resources in LMIC. During training sessions, contextualized management guidelines create the framework for realistic and fruitful case simulations.

Decline in Child Hospitalization and Mortality After the Introduction of the 7-Valent Pneumococcal Conjugative Vaccine in Rwanda

Pneumonia is a public health problem in the tropics, and the 7-valent pneumococcal conjugative vaccine (PCV-7) has been introduced in an effort to prevent the disease and therefore reduce childhood mortality. In Rwanda, PCV-7 was introduced in 2009, and we aimed to determine its impact on the rate of child hospitalization/mortality due to pneumonia. A retrospective survey was conducted on hospitalization rates and pediatric deaths between two periods, that is, before the introduction of PCV-7 (2007-2009) and after the introduction of PCV-7 (2010-2013) in Kabutare District Hospital. There was a 53% reduction in hospitalization, with a significant decline in in-hospital deaths between the two periods. There was also a significant correlation between vaccination coverage and decline in hospitalization rates between 2009 and 2013. We conclude that PCV-7 vaccine is associated with significant reduction in the rate of child hospitalization and mortality but more mechanistic studies are warranted to determine the immunological impact, especially in the context of coinfections and malnutrition.

The chest X-ray features of chronic respiratory disease in HIV-infected children--a review

Several features of human immunodeficiency virus (HIV) infection contribute to the development of chronic respiratory disease in children. These include the frequency and severity of acute chest infections, as well as the increased risk of pulmonary tuberculosis, aspiration, cardiovascular disease, lymphocytic interstitial pneumonitis or pulmonary neoplasia. The chest radiograph (CXR) remains the most accessible investigation for respiratory disease and plays an important role in the baseline assessment and follow-up. This review focuses on the CXR abnormalities of HIV-related chronic respiratory disease in children. The most commonly documented chronic CXR abnormalities are homogeneous opacification and pulmonary nodules, with pulmonary tuberculosis and lymphocytic interstitial pneumonitis the leading respective causes. Deficiencies in radiographic reporting methodology and relative paucity of radiographic data contribute to current limitations in knowledge and understanding of this field. The review highlights the need for standardised terminology and systematic reporting methodology in future studies. Prospective research on the natural history of lymphocytic interstitial pneumonitis, response to anti-tuberculous therapy, the impact of anti-retroviral therapy and HIV-associated bronchiectasis are needed.

The radiological diagnosis of pneumonia in children

Despite the importance of paediatric pneumonia as a cause of short and long-term morbidity and mortality worldwide, a reliable gold standard for its diagnosis remains elusive. The utility of clinical, microbiological and radiological diagnostic approaches varies widely within and between populations and is heavily dependent on the expertise and resources available in various settings. Here we review the role of radiology in the diagnosis of paediatric pneumonia. Chest radiographs (CXRs) are the most widely employed test, however, they are not indicated in ambulatory settings, cannot distinguish between viral and bacterial infections and have a limited role in the ongoing management of disease. A standardised definition of alveolar pneumonia on a CXR exists for epidemiological studies targeting bacterial pneumonias but it should not be extrapolated to clinical settings. Radiography, computed tomography and to a lesser extent ultrasonography and magnetic resonance imaging play an important role in complicated pneumonias but there are limitations that preclude their use as routine diagnostic tools. Large population-based studies are needed in different populations to address many of the knowledge gaps in the radiological diagnosis of pneumonia in children, however, the feasibility of such studies is an important barrier.

Viral-bacterial interactions-therapeutic implications

Viral and bacterial respiratory tract infections are a leading cause of morbidity and mortality worldwide, despite the development of vaccines and potent antibiotics. Frequently, viruses and bacteria can co‐infect the same host, resulting in heightened pathology and severity of illness compared to single infections. Bacterial superinfections have been a significant cause of death during every influenza pandemic, including the 2009 H1N1 pandemic. This review will analyze the epidemiology and global impact of viral and bacterial co‐infections of the respiratory tract, with an emphasis on bacterial infections following influenza. We will next examine the mechanisms by which viral infections enhance the acquisition and severity of bacterial infections. Finally, we will discuss current management strategies for diagnosing and treating patients with suspected or confirmed viral‐bacterial infections of the respiratory tract. Further investigation into the interactions between viral and bacterial infections is necessary for developing new therapeutic approaches aimed at mitigating the severity of co‐infections.

Risk Factors for Acute Respiratory Tract Infections in Under-five Children in Enugu Southeast Nigeria

Background:

Acute respiratory tract infections (ARIs) constitute the major causes of mortality and morbidity among under-five children of the developing world. The prevalence of ARIs is determined individually or collectively by a number of factors which may be prevalent in our environment.

Aim:

The present study is aimed to determine the risk factors that affect the prevalence of ARIs in under-five children in Enugu.

Subjects and Methods:

A cross-sectional study of 436 under-five children diagnosed with ARI was carried out in three hospitals in Enugu. Participants were consecutively enrolled after being diagnosed as a case of ARI. Structured pro foma was used to collect sociodemographic characteristics, anthropometric data and risk profile. Data were analyzed using Epi info version 6.0 and significant probability value was 5%.

Results:

A total of 436 patients were enrolled for the study 224 males and 212 females M: F 1.06:1. The mean age of the population was 18.75(13.38) months and there were 31.6%(138/436) cases of pneumonia 6.9%(30/436) cases of bronchiolitis and 61.5%(268/436) cases of acute upper respiratory tract infections. Children less than 20 months accounted for 60.9% (84/138 cases) of pneumonia, 86.7% (26/30 cases) of bronchiolitis, and 64.5% (173/268 cases) of acute upper respiratory tract infections. Pneumonia was noted in about 75.7% (56/74) of inadequately nourished children compared to 22.6% (82/362) in adequately nourished children. Other risk factors identified in the study include inadequate breast feeding, poor immunization statues, attendance to daycare centers, large family size, poor parental educational statues, parental smoking, living in the urban area and use of biofuels.

Conclusion:

ARIs are affected by socio-demographic and socio-cultural risk factors, which can be modified with simple strategies. It is recommended that control program for ARIs should be multifaceted with a strong political will.

Lung infiltrates in antiretroviral-naive HIV-infected children with chronic lung disease: value of non-bronchoscopic bronchoalveolar lavage in the detection of Candida albicans

OBJECTIVE

To describe the etiology of lung infiltrates in HIV-infected antiretroviral-naive children with chronic persistent/recurrent lung disease in whom routine cultures were negative and were non-responders to World Health Organization standard antimicrobial therapy.

METHOD

Non-bronchoscopic bronchoalveolar lavage (NBBAL) was performed on these non-responders.

RESULTS

Fifty children were enrolled. Single isolates on NBBAL were seen in 28 cases, dual pathogens in 5 cases and no growth in 14 cases. Haemophilus influenzae (n = 12), Candida albicans (n = 5) and Mycobacterium spp. other than tuberculosis (n = 4) were the commonest pathogens seen. Eight cases with no growth had segmental or lobar collapse: in five cases, NBBAL was therapeutic and in two cases, a diagnosis of lymphoma was made on open lung biopsy. Thirty-two of the 38 cases (84%) had favorable outcomes on follow-up.

CONCLUSION

Haemophilus influenzae, C. albicans and Mycobacterium spp. other than tuberculosis are important pathogens in children with HIV and HIV-associated chronic lung disease.

Global paediatric advanced life support: improving child survival in limited-resource settings

Nearly all global mortality in children younger than 5 years (99%) occurs in developing countries. The leading causes of mortality in children younger than 5 years worldwide, pneumonia and diarrhoeal illness, account for 1·396 and 0·801 million annual deaths, respectively. Although important advances in prevention are being made, advanced life support management in children in developing countries is often incomplete because of limited resources. Existing advanced life support management guidelines for children in limited-resource settings are mainly empirical, rather than evidence-based, written for the hospital setting, not standardised with a systematic approach to patient assessment and categorisation of illness, and taught in current paediatric advanced life support training courses from the perspective of full-resource settings. In this Review, we focus on extension of higher quality emergency and critical care services to children in developing countries. When integrated into existing primary care programmes, simple inexpensive advanced life support management can improve child survival worldwide.

Surgical implications of human immunodeficiency virus infections

Pediatric HIV (human immunodeficiency virus) is a pandemic predominantly in sub-Saharan Africa. Approximately 2.2 million children aged less than 15 years are infected with HIV, representing almost 95% of the total number of children globally infected with HIV. Therefore, increasing numbers of HIVi or -exposed but uninfected children can be expected to require a surgical procedure to assist in the diagnosis of an HIV/acquired immune deficiency syndrome-related complication, to address a life-threatening complication of the disease, or for routine surgery encountered in HIV-unexposed children. HIVi children may present with both conditions unique to HIV infection and surgical conditions routine in pediatric surgical practice. HIV exposure confers an increased risk of complications and mortality for all children after surgery, whether they are HIV infected or not. This risk of complications is higher in the HIVi group of patients. These findings seem to be independent of whether patients undergo an elective or emergency procedure, but the risk of an adverse outcome is higher for a major procedure. Surgical implications of HIV infection are comprehensively reviewed in this article.

Systematic review on the etiology and antibiotic treatment of pneumonia in human immunodeficiency virus-infected children

BACKGROUND

Community-acquired pneumonia (CAP) is a leading cause of morbidity and mortality in human immunodeficiency virus (HIV)-infected children.

OBJECTIVES AND METHODS

A systematic review of studies that were published between January 1990 and February 2009 on the etiology and antimicrobial or adjunctive systemic management of CAP in HIV-infected children.

RESULTS

Pneumocystis jirovecii had the strongest association with HIV infection, with a summary odds ratio of 10.1 (95% confidence interval [CI], 17.7-62.1) and 9.1 (95% CI, 2.5-33.1) in antemortem and postmortem studies, respectively. Cytomegalovirus was strongly associated with HIV positivity among fatal cases of pneumonia (summary odds ratio = 14.4 [95% CI, 6.7-30.8]). There was a trend toward a greater prevalence of Staphylococcus aureus (odds ratio, 2.5; 95% CI, 0.95-6.4) in HIV-infected children. Major limitations identified included substantial methodological heterogeneity across studies, limited sensitivity of assays for diagnosing bacterial pneumonia, and studies primarily being undertaken in the absence of antiretroviral treatment or cotrimoxazole prophylaxis. No a priori-planned randomized controlled trials on antimicrobial management of CAP in HIV-infected children were identified.

CONCLUSIONS

A World Health Organization panel used this review as well as analysis of risks and benefits to revise recommendations for antimicrobial treatment of CAP. Ampicillin plus gentamicin or ceftriaxone is now recommended as first-line empiric regimens for treating severe and very severe CAP in HIV-infected children. In addition, treatment with cloxacillin or vancomycin is recommended in settings with a high incidence of methicillin-resistant S. aureus, and particularly if clinical or microbiological evidence of S. aureus pneumonia exist. Further studies in HIV-infected children on CAP etiology and antibiotic treatment are required in the era of antiretroviral treatment.

Bronconeumopatías agudas del niño

Las infecciones infantiles afectan con frecuencia al aparato respiratorio inferior. Las clasificaciones convencionales, basadas en el tipo de afección anatómica, radiológica y etiopatogénica, permiten definir entidades clínicas (bronquitis, bronquiolitis, neumopatía); sin embargo, la evaluación de la gravedad del proceso es lo más útil para decidir el tipo y la rapidez del tratamiento. Aunque la etiología viral es la más frecuente, la estrategia fundamental para reducir la morbilidad e incluso la mortalidad de las infecciones respiratorias bajas se basa en el tratamiento adecuado de las neumonías bacterianas. Ante la ausencia de especificidad, es indispensable, cuando esté indicado, recurrir a una antibioticoterapia inicial probabilística que incluya el neumococo. En el niño, las muestras no suelen proceder del parénquima pulmonar y, además, la recogida de las secreciones bronquiales durante los primeros años de vida no es de buena calidad. Al contrario de lo que ocurre con los virus, el examen bacteriológico de las secreciones de las vías respiratorias altas es poco útil, porque los niños suelen ser portadores de gérmenes que pueden causar neumopatías. Los datos clínicos y radiológicos sólo pueden sugerir el diagnóstico. El desarrollo de técnicas que detectan antígenos microbianos o la búsqueda de material genético por biología molecular han permitido mejorar de manera significativa la identificación del patógeno responsable y la elección del tratamiento adecuado. Algunos grupos particulares de pacientes pueden padecer una afección respiratoria por agentes infecciosos inusuales o, incluso, oportunistas. Una proporción importante de la afectación respiratoria del adulto puede atribuirse a las agresiones pulmonares sufridas durante su infancia. La aplicación de vacunas, en especial, la antigripal y la antineumocócica, es fundamental para la prevención de estas afecciones respiratorias.

Randomized, controlled clinical trial of zinc supplementation to prevent immunological failure in HIV-infected adults

BACKGROUND

Adequate zinc is critical for immune function; however, zinc deficiency occurs in >50% of human immunodeficiency virus (HIV)-infected adults. We examined the safety and efficacy of long-term zinc supplementation in relation to HIV disease progression.

METHODS

A prospective, randomized, controlled clinical trial was conducted involving 231 HIV-infected adults with low plasma zinc levels (<0.75 mg/L), who were randomly assigned to receive zinc (12 mg of elemental zinc for women and 15 mg for men) or placebo for 18 months. The primary end point was immunological failure. HIV viral load and CD4(+) cell count were determined every 6 months. Questionnaires, pill counts, and plasma zinc and C-reactive protein levels were used to monitor adherence to study supplements and antiretroviral therapy. Intent-to-treat analysis used multiple-event analysis, treating CD4(+) cell count <200 cells/mm(3) as a recurrent immunological failure event. Cox proportional hazard models and the general-linear model were used to analyze morbidity and mortality data.

RESULTS

Zinc supplementation for 18 months reduced 4-fold the likelihood of immunological failure, controlling for age, sex, food insecurity, baseline CD4(+) cell count, viral load, and antiretroviral therapy (relative rate, 0.24; 95% confidence interval, 0.10-0.56; P<.002). Viral load indicated poor control with antiretroviral therapy but was not affected by zinc supplementation. Zinc supplementation also reduced the rate of diarrhea by more than half (odds ratio, 0.4; 95% confidence interval, 0.183-0.981; P=.019), compared with placebo. There was no significant difference in mortality between the 2 groups.

CONCLUSIONS

This study demonstrated that long-term (18-month) zinc supplementation at nutritional levels delayed immunological failure and decreased diarrhea over time. This evidence supports the use of zinc supplementation as an adjunct therapy for HIV-infected adult cohorts with poor viral control. Trial registration. ClinicalTrials.gov identifier: NCT00149552.

Chronic respiratory symptoms and diseases among indigenous children

Children from Indigenous populations experience more frequent, severe, and recurrent lower respiratory infections as infants and toddlers. The consequences of these infections are chronic lung disorders manifested by recurrent wheezing and chronic productive cough. These symptoms are aggravated more frequently by active and passive tobacco smoke exposure among Indigenous groups. Therapies for these symptoms, although not specific to children of Indigenous origins, are described as is the evidence for their use.

The significant but understudied impact of pathogen transmission from humans to animals

Zooanthroponotic pathogens, which are transmitted from humans to nonhuman animals, are an understudied aspect of global health, despite their potential to cause significant disease burden in wild and domestic animal populations and affect global economies. Some key human-borne pathogens that have been shown to infect animals and cause morbidity and mortality include measles virus (paramyxoviruses), influenza A virus (orthomyxoviruses), herpes simplex 1 virus (herpesviruses), protozoal and helminthic parasites, and bacteria such as methicillin-resistant Staphylococcus aureus and Mycobacterium tuberculosis. However, zooanthroponotic pathogens are most commonly reported in captive animals or domestic livestock with close human contact; there, the potential for economic loss and human reinfection is most apparent. There is also the potential for infection in wild animal populations, which may threaten endangered species and decrease biodiversity. The emergence and reemergence of human-borne pathogens in wildlife may also have negative consequences for human health if these pathogens cycle back into humans. Many of the anthropogenic drivers of zoonotic disease emergence also facilitate zooanthroponotic transmission. Increasing research to better understand the occurrence of and the potential for bidirectional pathogen transmission between humans and animals is essential for improving global health. Mt Sinai J Med 76:448-455, 2009. (c) 2009 Mount Sinai School of Medicine.

Comparison of previous and present World Health Organization clinical staging criteria in HIV-infected Malawian children

In many settings, HIV infected children are looked after with limited access to CD4 cell count or viral load. The decision to initiate antiretroviral therapy (ART) is made clinically, based on the WHO paediatric staging criteria, which were revised in 2006. Results of using new and old criteria were compared. Of 694 children, 626 (90.2%) fulfilled criteria to start ART when applying the new WHO staging guidelines, whereas 330 (47.6%) children were eligible for ART when using the old WHO criteria. This signifies a marked rise in the number of paediatric patients qualifying for ART on clinical grounds.

Chest radiographic pulmonary changes reflecting extrapulmonary involvement in paediatric HIV disease

Respiratory infections are the commonest cause of pulmonary change on chest radiographs of HIV-infected children. However, HIV-related neurological, oropharyngeal, oesophageal, cardiac and haematological abnormalities may also manifest with pulmonary changes and must be considered in the interpretation of the chest radiograph in HIV-infected children.

Pulmonary infections in HIV-positive children

Infection of the lungs and airways by viral, bacterial, fungal and protozoal agents, often producing atypical radiographic features, is common in children with human immunodeficiency virus (HIV) infection. Conventional chest radiography and chest CT remain the most useful imaging modalities for evaluation of the immunocompromised patient presenting with a suspected pulmonary infection. In this review the radiological features of acute lung infections in this population are discussed.

Vertically acquired paediatric HIV infection: the challenges of providing comprehensive packages of care in resource-limited settings

The successes achieved in paediatric disease management in well-resourced countries in recent years highlight the vast divide between the care options, and ultimately survival, between developed and developing areas of the world. Using an extensive literature review, we quantify recent achievements in terms of improved survival and quality of life, and examine current evidence of the effects of treatment on the survival and morbidity of HIV-infected children in developing countries. When provided with the same care as their counterparts in developed countries, children in developing countries show similar improvements in survival and general health, with 1-year survival rates exceeding 90% in many African settings. Despite the challenges of providing comprehensive packages of care in resource-limited settings, there is an urgent need to scale up prevention and treatment of HIV infections in children, focussing on strengthening Prevention of Mother-to-Child Transmission programmes in order to reduce the numbers of infants who are infected in addition to reducing morbidity and mortality among their mothers.

Managing HIV in the PICU--the experience at the Red Cross War Memorial Children's Hospital in Cape Town

The HIV pandemic has affected children throughout the developing world. This article describes the experience of the Paediatric Intensive Care Unit at the Red Cross War Memorial Children's Hospital in Cape Town, South Africa. Over the last 20 years we have improved our management of HIV infected children requiring intensive care admission. In the absence of anti-retroviral therapy, long term outcomes from PICU admission of HIV infected children have not improved significantly, and it is debatable whether PICU admission is justified. Once anti-retroviral therapy is available to children, there may be significant improvements in outcome and possible affected children should be admitted to the PICU if resources are available.

Chronic lung disease in human immunodeficiency virus (HIV) infected children

The development of chronic lung disease is common in HIV-infected children. The spectrum of chronic HIV-associated lung disease includes lymphocytic interstitial pneumonia (LIP), chronic infections, immune reconstitution inflammatory syndrome (IRIS), bronchiectasis, malignancies, and interstitial pneumonitis. Chronic lung disease may result from recurrent or persistent pneumonia due to bacterial, mycobacterial, viral, fungal or mixed infections. In high tuberculosis (TB) prevalence areas, M. tuberculosis is an important cause of chronic respiratory illness. With increasing availability of highly active antiretroviral therapy (HAART) for children in developing countries, a rise in the incidence of IRIS due to mycobacterial or other infections is being reported. Diagnosis of chronic lung disease is based on chronic symptoms and persistent chest X-ray changes but definitive diagnosis can be difficult as clinical and radiological findings may be non-specific. Distinguishing LIP from miliary TB remains a difficult challenge in HIV-infected children living in high TB prevalence areas. Treatment includes therapy for specific infections, pulmonary clearance techniques, corticosteroids for children with LIP who are hypoxic or who have airway compression from tuberculous nodes and HAART. Children who are taking TB therapy and HAART need adjustments in their drug regimes to minimize drug interactions and ensure efficacy. Preventative strategies include immunization, chemoprophylaxis, and micronutrient supplementation. Early use of HAART may prevent the development of chronic lung disease.

Community-acquired pneumonia: a review and recent advances

In the beginning of this 21st century, community-acquired pneumonias (CAP) are still responsible for a significant number of deaths among young children in many developing countries. Public health initiatives such as those proposed by the World Health Organization (WHO) for the management of CAP by means of identifying highly predictable signs and symptoms have had great positive impact in some communities. Still, this approach induces an overdiagnosis and overtreatment of CAP in children below the age of 5 years due to the misclassification of pneumonia in children with fast breathing associated with viral bronchiolitis. Even among children of developed countries, CAP is an important public health problem and many aspects of current diagnostic and management measures are discussed here. In this article, we review the epidemiology and basic concepts of CAP and update current information on clinical evaluation and management of the disease.

Streptococcus pneumoniae virulence factors and their clinical impact: An update

The morbidity and mortality rates associated with Streptococcus pneumoniae remain very high worldwide. The virulence of this bacterium is largely dependent on its polysaccharide capsule, which is quite heterogeneous and represents a serious obstacle for designing effective vaccines. However, it has been demonstrated that numerous protein virulence factors are involved in the pathogenesis of pneumococcal disease. An important related finding from experimental animal models is that non-capsulated strains of pneumococci are protective against capsulated ones. Hence, new vaccine designs are focused on the surface proteins (e. g., PspA and PspC) and on the cytolysin, pneumolysin. Moreover, several virulence factors have potential value for pneumococcal diagnosis by urinalysis. In this paper, we review the virulence factors involved in bacteria-host interactions, and the new developments in vaccines and diagnostic methods.

Acute respiratory infections in children

Acute respiratory infections (ARI) are the leading cause of mortality in children under five years of age worldwide and most of these deaths are due to bronchiolitis and pneumonia. Recent evidence from studies using genome detection systems such as polymerase chain reaction or micro-array technology show that, in most cases, these deaths are caused or precipitated by viruses. In this paper, the definitions of upper and lower respiratory tract infections are reviewed. The principal signs of disease severity and the burden of viruses as causes of ARI are described. The prominent role of Respiratory Syncytial Virus is stressed, with data from epidemiological and clinical studies. Other important viral pathogens, such as Human Metapneumovirus, Human coronaviruses and Influenza are examined. The role of newly described viruses, such as bocavirus, is also discussed. The impact of HIV/AIDS in ARI burden and presentation assessed and the weight of Pneumocystis jiroveci and Mycobacterium tuberculosis infections is recognized. It is concluded that there is an urgent need to improve diagnostics, therapeutics and vaccines, as well as macro and micronutrient intake of children of the world, particularly in developing countries.

Global paediatric pulmonology: out of Africa

Respiratory illness is the major cause of mortality and morbidity in African children. The spectrum of disease includes acute and chronic respiratory illness. As a result of the HIV epidemic currently occurring in sub-Saharan Africa, HIV-associated acute and chronic respiratory disease has emerged as a major factor in the epidemiology of childhood respiratory illness. Pneumonia is the leading causes of childhood mortality responsible for approximately 21% of deaths in African children under five years of age each year. The HIV pandemic has increased the incidence, severity and pneumonia mortality in African children. Pulmonary tuberculosis (TB) is an important cause of morbidity and death. Globally, the highest TB incidence rates occur in sub-Saharan African countries; many of these countries are also experiencing a dual HIV epidemic, resulting in an exponential increase in TB cases. The burden of childhood respiratory illness has necessitated novel and improved ways of diagnosis, treatment and prevention, particularly in the context of limited resources. Improved diagnosis, treatment and prevention of pneumonia have been a research focus, particularly in HIV-infected children. African studies have provided information on the epidemiology, aetiology and outcome from pneumonia in HIV-infected and uninfected children. The efficacy of trimethoprim-sulphamethoxazole prophylaxis in reducing mortality and morbidity in HIV-infected African children was shown in the only randomized controlled trial. Two large studies have shown the efficacy of the pneumococcal conjugate vaccine in an African context. Regarding TB, areas of research include diagnostic studies and improved preventative strategies. Promising diagnostic studies for childhood TB include the use of sputum induction, PCR techniques and blood interferon assays. The immune reconstitution inflammatory syndrome (IRIS) has emerged as a new clinical entity in HIV-infected children with TB associated with use of antiretroviral therapy. New preventative strategies for TB include novel vaccines and primary prophylaxis. Available, effective interventions for prevention and treatment of childhood respiratory disease exist; the challenge is to achieve widespread implementation and high coverage rates in African countries. Greater access to newer vaccines and, in HIV-infected children, to anti-retroviral therapy and prophylaxis is necessary to further reduce the burden of childhood respiratory illness in Africa.

Effect of nicotine on lung S-adenosylmethionine and development of Pneumocystis pneumonia

Because S-adenosylmethionine (AdoMet) is required by Pneumocystis carinii in vitro, Pneumocystis infection depletes plasma AdoMet of rats and humans, nicotine reduces AdoMet of guinea pig lungs, and smoking correlates with reduced episodes of Pneumocystis pneumonia (PCP) in AIDS patients, we tested the effect of nicotine treatment on PCP using a rat model. Intraperitoneal infusion of 400 microg of R-(+) nicotine kg(-1) h(-1) intraperitoneal for 21 days caused a 15-fold reduction in lung AdoMet although neither plasma nor liver were changed. Infusion of 4 and 400 microg kg(-1) h(-1) into immunosuppressed rats, beginning when rats were inoculated with P. carinii, caused 85 and 99.88% reductions, respectively, in P. carinii cysts at sacrifice 21 days later; P. carinii nuclei were reduced by 91.2 and >99.99%, respectively. This effect was reversed by concomitant administration of AdoMet with nicotine. Treatment with AdoMet alone increased infection intensity. We conclude that AdoMet is a critical and limiting nutrient for Pneumocystis thus can serve as a therapeutic target for PCP. Regarding the mechanism, nicotine treatment caused no change in rat lung activity of AdoMet synthesizing methionine ATP transferase activity nor was there any evidence of increased AdoMet utilization for methylation reactions. Except of a doubling of putrescine, nicotine treatment also did not change lung polyamine content. However, key polyamine anabolic and catabolic enzymes were upregulated, and there were corresponding changes in polyamine metabolic intermediates. We conclude that chronic nicotine treatment increases lung polyamine catabolic/anabolic cycling and/or excretion leading to increased AdoMet-consuming polyamine biosynthesis and depletion of lung AdoMet.