Computerized Lung Sound Screening for Pediatric Auscultation in Noisy Field Environments

GOAL

Chest auscultations offer a non-invasive and low-cost tool for monitoring lung disease. However, they present many shortcomings, including inter-listener variability, subjectivity, and vulnerability to noise and distortions. This work proposes a computer-aided approach to process lung signals acquired in the field under adverse noisy conditions, by improving the signal quality and offering automated identification of abnormal auscultations indicative of respiratory pathologies.

METHODS

The developed noise-suppression scheme eliminates ambient sounds, heart sounds, sensor artifacts, and crying contamination. The improved high-quality signal is then mapped onto a rich spectrotemporal feature space before being classified using a trained support-vector machine classifier. Individual signal frame decisions are then combined using an evaluation scheme, providing an overall patient-level decision for unseen patient records.

RESULTS

All methods are evaluated on a large dataset with 1000 children enrolled, 1-59 months old. The noise suppression scheme is shown to significantly improve signal quality, and the classification system achieves an accuracy of 86.7% in distinguishing normal from pathological sounds, far surpassing other state-of-the-art methods.

CONCLUSION

Computerized lung sound processing can benefit from the enforcement of advanced noise suppression. A fairly short processing window size (  s) combined with detailed spectrotemporal features is recommended, in order to capture transient adventitious events without highlighting sharp noise occurrences.

SIGNIFICANCE

Unlike existing methodologies in the literature, the proposed work is not limited in scope or confined to laboratory settings: This work validates a practical method for fully automated chest sound processing applicable to realistic and noisy auscultation settings.

Impact of the 13-Valent Pneumococcal Conjugate Vaccine on Clinical and Hypoxemic Childhood Pneumonia over Three Years in Central Malawi: An Observational Study

BACKGROUND

The pneumococcal conjugate vaccine's (PCV) impact on childhood pneumonia during programmatic conditions in Africa is poorly understood. Following PCV13 introduction in Malawi in November 2011, we evaluated the case burden and rates of childhood pneumonia.

METHODS AND FINDINGS

Between January 1, 2012-June 30, 2014 we conducted active pneumonia surveillance in children <5 years at seven hospitals, 18 health centres, and with 38 community health workers in two districts, central Malawi. Eligible children had clinical pneumonia per Malawi guidelines, defined as fast breathing only, chest indrawing +/- fast breathing, or, ≥1 clinical danger sign. Since pulse oximetry was not in the Malawi guidelines, oxygenation <90% defined hypoxemic pneumonia, a distinct category from clinical pneumonia. We quantified the pneumonia case burden and rates in two ways. We compared the period immediately following vaccine introduction (early) to the period with >75% three-dose PCV13 coverage (post). We also used multivariable time-series regression, adjusting for autocorrelation and exploring seasonal variation and alternative model specifications in sensitivity analyses. The early versus post analysis showed an increase in cases and rates of total, fast breathing, and indrawing pneumonia and a decrease in danger sign and hypoxemic pneumonia, and pneumonia mortality. At 76% three-dose PCV13 coverage, versus 0%, the time-series model showed a non-significant increase in total cases (+47%, 95% CI: -13%, +149%, p = 0.154); fast breathing cases increased 135% (+39%, +297%, p = 0.001), however, hypoxemia fell 47% (-5%, -70%, p = 0.031) and hospital deaths decreased 36% (-1%, -58%, p = 0.047) in children <5 years. We observed a shift towards disease without danger signs, as the proportion of cases with danger signs decreased by 65% (-46%, -77%, p<0.0001). These results were generally robust to plausible alternative model specifications.

CONCLUSIONS

Thirty months after PCV13 introduction in Malawi, the health system burden and rates of the severest forms of childhood pneumonia, including hypoxemia and death, have markedly decreased.

Non-adherence to community oral-antibiotic treatment in children with fast-breathing pneumonia in Malawi- secondary analysis of a prospective cohort study

Background

Despite significant progress, pneumonia is still the leading cause of infectious deaths in children under five years of age. Poor adherence to antibiotics has been associated with treatment failure in World Health Organisation (WHO) defined clinical pneumonia; therefore, improving adherence could improve outcomes in children with fast-breathing pneumonia. We examined clinical factors that may affect adherence to oral antibiotics in children in the community setting in Malawi.

Methods

We conducted a sub-analysis of a prospective cohort of children aged 2–59 months diagnosed by community health workers (CHW) in rural Malawi with WHO fast-breathing pneumonia. Clinical factors identified during CHW diagnosis were investigated using multivariate logistic regression for association with non-adherence, including concurrent diagnoses and treatments. Adherence was measured at both 80% and 100% completion of prescribed oral antibiotics.

Results

Eight hundred thirty-four children were included in our analysis, of which 9.5% and 20.0% were non-adherent at 80% and 100% of treatment completion, respectively. A concurrent infectious diagnosis (OR: 1.76, 95% CI: 0.84–2.96/OR: 1.81, 95% CI: 1.21–2.71) and an illness duration of >24 h prior to diagnosis (OR: 2.14, 95% CI: 1.27–3.60/OR: 1.88, 95% CI: 1.29–2.73) had higher odds of non-adherence when measured at both 80% and 100%. Older age was associated with lower odds of non-adherence when measured at 80% (OR: 0.41, 95% CI: 0.21–0.78).

Conclusion

Non-adherence to oral antibiotics was not uncommon in this rural sub-Saharan African setting. As multiple diagnoses by the CHW and longer illness were important factors, this provides an opportunity for further investigation into targeted interventions and refinement of referral guidelines at the community level. Further research into the behavioural drivers of non-adherence within this setting is needed.

Non-treatment of children with community health worker-diagnosed fast-breathing pneumonia in rural Malawi: exploratory subanalysis of a prospective cohort study

BACKGROUND

Despite recent progress, pneumonia remains the largest infectious killer of children globally. This paper describes outcomes of not treating community-diagnosed fast-breathing pneumonia on patient recovery.

METHODS

We conducted an exploratory subanalysis of an observational prospective cohort study in Malawi. We recruited children (2-59 months) diagnosed by community health workers with fast-breathing pneumonia using WHO integrated community case management (iCCM) guidelines. Children were followed at days 5 and 14 with a clinical assessment of recovery. We conducted bivariate and multivariable logistic regression for the association between treatment of fast-breathing pneumonia and recovery, adjusting for potential confounders.

RESULTS

We followed up 847 children, of whom 78 (9%) had not been given antibiotics (non-treatment). Non-treatment cases had higher baseline rates of diarrhoea, non-severe hypoxaemia and fever. Non-recovery (persistence or worsening of symptoms) was 13% and 23% at day 5 in those who did receive and those who did not receive co-trimoxazole. Non-recovery, when defined as worsening of symptoms only, at day 5 was 7% in treatment and 10% in non-treatment cases. For both definitions, combined co-trimoxazole and lumefantrine-artemether (LA) treatment trended towards protection (adjusted OR (aOR) 0.28; 95% CI 0.12 to 0.68/aOR 0.29; 95% CI 0.08 to 1.01).

CONCLUSION

We found that children who did not receive co-trimoxazole treatment had worse clinical outcomes; malaria co-diagnosis and treatment also play a significant role in non-recovery. Further research into non-treatment of fast-breathing pneumonia, using a pragmatic approach with consideration for malaria co-diagnosis and HIV status is needed to guide refinement of community treatment algorithms in this region.

Pulse oximetry for children with pneumonia treated as outpatients in rural Malawi

OBJECTIVE

To investigate implementation of outpatient pulse oximetry among children with pneumonia, in Malawi.

METHODS

In 2011, 72 health-care providers at 18 rural health centres and 38 community health workers received training in the use of pulse oximetry to measure haemoglobin oxygen saturations. Data collected, between 1 January 2012 and 30 June 2014 by the trained individuals, on children aged 2-59 months with clinically diagnosed pneumonia were analysed.

FINDINGS

Of the 14 092 children included in the analysis, 13 266 (94.1%) were successfully checked by oximetry. Among the children with chest indrawing and/or danger signs, those with a measured oxygen saturation below  90% were more than twice as likely to have been referred as those with higher saturations (84.3% [385/457] vs 41.5% [871/2099]; P < 0.001). The availability of oximetry appeared to have increased the referral rate for severely hypoxaemic children without chest indrawing or danger signs from 0% to 27.2% (P < 0.001). In the absence of oximetry, if the relevant World Health Organization (WHO) guidelines published in 2014 had been applied, 390/568 (68.7%) severely hypoxaemic children at study health centres and 52/84 (61.9%) severely hypoxaemic children seen by community health workers would have been considered ineligible for referral.

CONCLUSION

Implementation of pulse oximetry by our trainees substantially increased the referrals of Malawian children with severe hypoxaemic pneumonia. When data from oximetry were excluded, retrospective application of the guidelines published by WHO in 2014 failed to identify a considerable proportion of severely hypoxaemic children eligible only via oximetry.

Can We Predict Oral Antibiotic Treatment Failure in Children with Fast-Breathing Pneumonia Managed at the Community Level? A Prospective Cohort Study in Malawi

BACKGROUND

Pneumonia is the leading cause of infectious death amongst children globally, with the highest burden in Africa. Early identification of children at risk of treatment failure in the community and prompt referral could lower mortality. A number of clinical markers have been independently associated with oral antibiotic failure in childhood pneumonia. This study aimed to develop a prognostic model for fast-breathing pneumonia treatment failure in sub-Saharan Africa.

METHOD

We prospectively followed a cohort of children (2-59 months), diagnosed by community health workers with fast-breathing pneumonia using World Health Organisation (WHO) integrated community case management guidelines. Cases were followed at days 5 and 14 by study data collectors, who assessed a range of pre-determined clinical features for treatment outcome. We built the prognostic model using eight pre-defined parameters, using multivariable logistic regression, validated through bootstrapping.

RESULTS

We assessed 1,542 cases of which 769 were included (32% ineligible; 19% defaulted). The treatment failure rate was 15% at day 5 and relapse was 4% at day 14. Concurrent malaria diagnosis (OR: 1.62; 95% CI: 1.06, 2.47) and moderate malnutrition (OR: 1.88; 95% CI: 1.09, 3.26) were associated with treatment failure. The model demonstrated poor calibration and discrimination (c-statistic: 0.56).

CONCLUSION

This study suggests that it may be difficult to create a pragmatic community-level prognostic child pneumonia tool based solely on clinical markers and pulse oximetry in an HIV and malaria endemic setting. Further work is needed to identify more accurate and reliable referral algorithms that remain feasible for use by community health workers.

Predictors of treatment failure for non-severe childhood pneumonia in developing countries--systematic literature review and expert survey--the first step towards a community focused mHealth risk-assessment tool?

Background

Improved referral algorithms for children with non-severe pneumonia at the community level are desirable. We sought to identify predictors of oral antibiotic failure in children who fulfill the case definition of World Health Organization (WHO) non-severe pneumonia. Predictors of greatest interest were those not currently utilized in referral algorithms and feasible to obtain at the community level.

Methods

We systematically reviewed prospective studies reporting independent predictors of oral antibiotic failure for children 2–59 months of age in resource-limited settings with WHO non-severe pneumonia (either fast breathing for age and/or lower chest wall indrawing without danger signs), with an emphasis on predictors not currently utilized for referral and reasonable for community health workers. We searched PubMed, Cochrane, and Embase and qualitatively analyzed publications from 1997–2014. To supplement the limited published evidence in this subject area we also surveyed respiratory experts.

Results

Nine studies met criteria, seven of which were performed in south Asia. One eligible study occurred exclusively at the community level. Overall, oral antibiotic failure rates ranged between 7.8-22.9 %. Six studies found excess age-adjusted respiratory rate (either WHO-defined very fast breathing for age or 10–15 breaths/min faster than normal WHO age-adjusted thresholds) and four reported young age as predictive for oral antibiotic failure. Of the seven predictors identified by the expert panel, abnormal oxygen saturation and malnutrition were most highly favored per the panel’s rankings and comments.

Conclusions

This review identified several candidate predictors of oral antibiotic failure not currently utilized in childhood pneumonia referral algorithms; excess age-specific respiratory rate, young age, abnormal oxygen saturation, and moderate malnutrition. However, the data was limited and there are clear evidence gaps; research in rural, low-resource settings with community health workers is needed.

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-015-0392-x) contains supplementary material, which is available to authorized users.

Adaptive Noise Suppression of Pediatric Lung Auscultations With Real Applications to Noisy Clinical Settings in Developing Countries

GOAL

Chest auscultation constitutes a portable low-cost tool widely used for respiratory disease detection. Though it offers a powerful means of pulmonary examination, it remains riddled with a number of issues that limit its diagnostic capability. Particularly, patient agitation (especially in children), background chatter, and other environmental noises often contaminate the auscultation, hence affecting the clarity of the lung sound itself. This paper proposes an automated multiband denoising scheme for improving the quality of auscultation signals against heavy background contaminations.

METHODS

The algorithm works on a simple two-microphone setup, dynamically adapts to the background noise and suppresses contaminations while successfully preserving the lung sound content. The proposed scheme is refined to offset maximal noise suppression against maintaining the integrity of the lung signal, particularly its unknown adventitious components that provide the most informative diagnostic value during lung pathology.

RESULTS

The algorithm is applied to digital recordings obtained in the field in a busy clinic in West Africa and evaluated using objective signal fidelity measures and perceptual listening tests performed by a panel of licensed physicians. A strong preference of the enhanced sounds is revealed.

SIGNIFICANCE

The strengths and benefits of the proposed method lie in the simple automated setup and its adaptive nature, both fundamental conditions for everyday clinical applicability. It can be simply extended to a real-time implementation, and integrated with lung sound acquisition protocols.

Lay-screeners and use of WHO growth standards increase case finding of hospitalized Malawian children with severe acute malnutrition

OBJECTIVES

Strategies to effectively identify and refer children with severe acute malnutrition (SAM) to Nutritional Rehabilitation units (NRU) can reduce morbidity and mortality.

METHODS

From December 2011 to May 2012, we conducted a prospective study task-shifting inpatient malnutrition screening of Malawian children 6-60 months to lay-screeners and evaluated World Health Organization (WHO) criteria vs. the National Center for Health Statistics (NCHS) guidelines for SAM.

RESULTS

Lay-screeners evaluated 3116 children, identifying 368 (11.8%) with SAM by WHO criteria, including 210 (6.7%) who met NCHS criteria initially missed by standard clinician NRU referrals. Overall case finding increased by 56.7%. Mid-upper arm circumference (MUAC) and bipedal edema captured 86% (181/210) NCHS/NRU-eligible children and 89% of those who died (17/19) meeting WHO criteria. Mortality of NCHS/NRU-eligible children was 10 times greater than those without SAM (odds ratio 10.5, 95% confidence interval 5.4-20.6).

CONCLUSIONS

Ward-based lay-screeners and WHO guidelines identified high-risk children with SAM missed by standard NRU referral. MUAC and edema detected the majority of NRU-eligible children.

CD4 count outperforms World Health Organization clinical algorithm for point-of-care HIV diagnosis among hospitalised HIV-exposed Malawian infants

OBJECTIVE

To determine, for the WHO algorithm for point-of-care diagnosis of HIV infection, the agreement levels between paediatricians and non-physician clinicians, and to compare sensitivity and specificity profiles of the WHO algorithm and different CD4 thresholds against HIV PCR testing in hospitalised Malawian infants.

METHODS

In 2011, hospitalised HIV-exposed infants <12 months in Lilongwe, Malawi, were evaluated independently with the WHO algorithm by both a paediatrician and clinical officer. Blood was collected for CD4 and molecular HIV testing (DNA or RNA PCR). Using molecular testing as the reference, sensitivity, specificity and positive predictive value (PPV) were determined for the WHO algorithm and CD4 count thresholds of 1500 and 2000 cells/mm(3) by paediatricians and clinical officers.

RESULTS

We enrolled 166 infants (50% female, 34% <2 months, 37% HIV infected). Sensitivity was higher using CD4 thresholds (<1500, 80%; <2000, 95%) than with the algorithm (physicians, 57%; clinical officers, 71%). Specificity was comparable for CD4 thresholds (<1500, 68%, <2000, 50%) and the algorithm (paediatricians, 55%, clinical officers, 50%). The positive predictive values were slightly better using CD4 thresholds (<1500, 59%, <2000, 52%) than the algorithm (paediatricians, 43%, clinical officers 45%) at this prevalence.

CONCLUSION

Performance by the WHO algorithm and CD4 thresholds resulted in many misclassifications. Point-of-care CD4 thresholds of <1500 cells/mm(3) or <2000 cells/mm(3) could identify more HIV-infected infants with fewer false positives than the algorithm. However, a point-of-care option with better performance characteristics is needed for accurate, timely HIV diagnosis.

Determining the quality of IMCI pneumonia care in Malawian children

BACKGROUND

Although pneumonia is the leading cause of child mortality worldwide, little is known about the quality of routine pneumonia care in high burden settings like Malawi that utilize World Health Organization's Integrated Management of Childhood Illnesses (IMCI) guidelines. Due to severe human resource constraints, the majority of clinical care in Malawi is delivered by non-physician clinicians called Clinical Officers (COs).

AIM

To assess the quality of child pneumonia care delivered by Malawian COs in routine care conditions.

METHODS

At an outpatient district-level clinic in Lilongwe, Malawi, 10 COs caring for 695 children who presented with fever, cough, or difficulty breathing were compared to IMCI pneumonia diagnostic and treatment guidelines.

RESULTS

Fewer than 1% of patients received an evaluation by COs that included all 16 elements of the history and physical examination. The respiratory rate was only determined in 16.1% of patients presenting with cough or difficulty breathing. Of the 274 children with IMCI-defined pneumonia, COs correctly diagnosed 30%, and administered correct pneumonia care in less than 25%. COs failed to hospitalize 40.8% of children with severe or very severe pneumonia.

CONCLUSIONS

IMCI pneumonia care quality at this Malawian government clinic is alarmingly low. Along with reassessing current pneumonia training and supervision approaches, novel quality improvement interventions are necessary to improve care.

Multicenter study of hypoxemia prevalence and quality of oxygen treatment for hospitalized Malawian children

BACKGROUND

Although hypoxemic children have high mortality, little is known about hypoxemia prevalence and oxygen administration in African hospitals. We aimed to determine the hypoxemia prevalence and quality of oxygen treatment by local clinicians for hospitalized Malawian children.

METHODS

The study was conducted in five Malawian hospitals during January-April 2011. We prospectively measured the peripheral oxygen saturation (SpO(2)) using pulse oximetry for all children <15 years old and also determined clinical eligibility for oxygen treatment using WHO criteria for children <5 years old. We determined oxygen treatment quality by Malawian clinicians by comparing their use of WHO criteria for patients <5 years old using two standards: hypoxemia (SpO(2) <90%) and the use of WHO criteria by study staff.

RESULTS

Forty of 761 (5.3%) hospitalized children <15 years old had SpO(2) <90%. No hospital used pulse oximetry routinely, and only 9 of 40 (22.5%) patients <15 years old with SpO(2) <90% were treated with oxygen by hospital staff. Study personnel using WHO criteria for children <5 years old achieved a higher sensitivity (40.0%) and lower specificity (82.7%) than Malawian clinicians (sensitivity 25.7%, specificity 94.1%).

CONCLUSION

Although hypoxemia is common, the absence of routine pulse oximetry results in most hospitalized, hypoxemic Malawian children not receiving available oxygen treatment.

Development of a severity of illness scoring system (inpatient triage, assessment and treatment) for resource-constrained hospitals in developing countries

OBJECTIVE

To develop a new paediatric illness severity score, called inpatient triage, assessment and treatment (ITAT), for resource-limited settings to identify hospitalised patients at highest risk of death and facilitate urgent clinical re-evaluation.

METHODS

We performed a nested case-control study at a Malawian referral hospital. The ITAT score was derived from four equally weighted variables, yielding a cumulative score between 0 and 8. Variables included oxygen saturation, temperature, and age-adjusted heart and respiratory rates. We compared the ITAT score between cases (deaths) and controls (discharges) in predicting death within 2 days. Our analysis includes predictive statistics, bivariable and multivariable logistic regression, and calculation of data-driven scores.

RESULTS

A total of 54 cases and 161 controls were included in the analysis. The area under the receiver operating characteristic curve was 0.76. At an ITAT cut-off of 4, the sensitivity, specificity and likelihood ratio were 0.44, 0.86 and 1.70, respectively. A cumulative ITAT score of 4 or higher was associated with increased odds of death (OR 4.80; 95% CI 2.39-9.64). A score of 2 for all individual vital signs was a statistically significant independent predictor of death.

CONCLUSIONS

We developed an inpatient triage tool (ITAT) appropriate for resource-constrained hospitals that identifies high-risk children after hospital admission. Further research is needed to study how best to operationalise ITAT in developing countries.

Task shifting an inpatient triage, assessment and treatment programme improves the quality of care for hospitalised Malawian children

OBJECTIVE

We aimed to improve paediatric inpatient surveillance at a busy referral hospital in Malawi with two new programmes: (i) the provision of vital sign equipment and implementation of an inpatient triage programme (ITAT) that includes a simplified paediatric severity-of-illness score, and (ii) task shifting ITAT to a new cadre of healthcare workers called 'vital sign assistants' (VSAs).

METHODS

This study, conducted on the paediatric inpatient ward of a large referral hospital in Malawi, was divided into three phases, each lasting 4 weeks. In Phase A, we collected baseline data. In Phase B, we provided three new automated vital sign poles and implemented ITAT with current hospital staff. In Phase C, VSAs were introduced and performed ITAT. Our primary outcome measures were the number of vital sign assessments performed and clinician notifications to reassess patients with high ITAT scores.

RESULTS

We enrolled 3994 patients who received 5155 vital sign assessments. Assessment frequency was equal between Phases A (0.67 assessments/patient) and B (0.61 assessments/patient), but increased 3.6-fold in Phase C (2.44 assessments/patient, P < 0.001). Clinician notifications increased from Phases A (84) and B (113) to Phase C (161, P = 0.002). Inpatient mortality fell from Phase A (9.3%) to Phases B (5.7) and C (6.9%).

CONCLUSION

ITAT with VSAs improved vital sign assessments and nearly doubled clinician notifications of patients needing further assessment due to high ITAT scores, while equipment alone made no difference. Task shifting ITAT to VSAs may improve outcomes in paediatric hospitals in the developing world.

Mortality and clinical outcomes in HIV-infected children on antiretroviral therapy in Malawi, Lesotho, and Swaziland

OBJECTIVE

To determine mortality and immune status improvement in HIV-infected pediatric patients on antiretroviral treatment (ART) in Malawi, Lesotho, and Swaziland.

METHODS

We conducted a retrospective cohort study of patients aged <12 years at ART initiation at 3 sites in sub-Saharan Africa between 2004 and 2009. Twelve-month and overall mortality were estimated, and factors associated with mortality and immune status improvement were evaluated.

RESULTS

Included in the study were 2306 patients with an average follow-up time on ART of 2.3 years (interquartile range 1.5-3.1 years). One hundred four patients (4.5%) died, 9.0% were lost to follow-up, and 1.3% discontinued ART. Of the 104 deaths, 77.9% occurred in the first year of treatment with a 12-month mortality rate of 3.5%. The overall mortality rate was 2.25 deaths/100 person-years (95% confidence interval [CI] 1.84-2.71). Increased 12-month mortality was associated with younger age; <6 months (hazard ratio [HR] = 8.11, CI 4.51-14.58), 6 to <12 months (HR = 3.43, CI 1.96-6.02), and 12 to <36 months (HR = 1.92, CI 1.16-3.19), and World Health Organization stage IV (HR = 4.35, CI 2.19-8.67). Immune status improvement at 12 months was less likely in patients with advanced disease and age <12 months.

CONCLUSIONS

Despite challenges associated with pediatric ART in developing countries, low mortality and good treatment outcomes can be achieved. However, outcomes are worse in younger patients and those with advanced disease at the time of ART initiation, highlighting the importance of early diagnosis and treatment.

Pneumonia and malnutrition are highly predictive of mortality among African children hospitalized with human immunodeficiency virus infection or exposure in the era of antiretroviral therapy

OBJECTIVE

To identify clinical characteristics predicting death among inpatients who are infected with or exposed to human immunodeficiency virus (HIV) during a period of pediatric antiretroviral therapy scale-up in sub-Saharan Africa.

STUDY DESIGN

Retrospective review of medical records from every child with HIV infection (n = 834) or exposure (n = 351) identified by routine inpatient testing in Kamuzu Central Hospital, Lilongwe, Malawi, September 2007 through December 2008.

RESULTS

The inpatient mortality rate was high among children with HIV infection (16.6%) and exposure (13.4%). Clinically diagnosed Pneumocystis pneumonia or very severe pneumonia independently predicted death in inpatients with HIV infection (OR 14; 95% CI 8.2 to 23) or exposure (OR 21; CI 8.4 to 50). Severe acute malnutrition independently predicted death in children who are HIV infected (OR 2.2; CI 1.7 to 3.9) or exposed (OR 5.1; CI 2.3 to 11). Other independent predictors of death were septicemia, Kaposi sarcoma, meningitis, and esophageal candidiasis for children infected with HIV, and meningitis and severe anemia for inpatients exposed to HIV.

CONCLUSIONS

Severe respiratory tract infections and malnutrition are both highly prevalent and strongly associated with death among hospitalized children who are HIV infected or exposed. Novel programmatic and therapeutic strategies are urgently needed to reduce the high mortality rate among inpatients with HIV infection and HIV exposure in African pediatric hospitals.

Bubble continuous positive airway pressure in a human immunodeficiency virus-infected infant

World Health Organization-classified very severe pneumonia due to Pneumocystis jirovecii infection is recognized as a life-threatening condition in human immunodeficiency virus (HIV) infected infants. We recount the use of nasal bubble continuous positive airway pressure (BCPAP) in an HIV-infected African infant with very severe pneumonia and treatment failure due to suspected infection with P. jirovecii. We also examine the potential implications of BCPAP use in resource-poor settings with a high case index of acute respiratory failure due to HIV-related pneumonia, but limited access to mechanical ventilation.

Inadequate coordination of maternal and infant HIV services detrimentally affects early infant diagnosis outcomes in Lilongwe, Malawi

OBJECTIVE

To assess the continuity of care and outcome of pediatric HIV prevention, testing, and treatment services, focusing on early infant diagnosis with DNA polymerase chain reaction (PCR).

DESIGN

A retrospective observational cohort.

METHODS

Maternal HIV antibody, infant HIV DNA PCR test results, and outcome data from HIV-infected infants from the prevention of mother-to-child transmission, early infant diagnosis, and pediatric HIV treatment programs operating in Lilongwe, Malawi, between 2004 and 2008 were collected, merged, and analyzed.

RESULTS

Of the 14,669 pregnant women who tested HIV antibody positive, 7875 infants (53.7%) received HIV DNA PCR testing. One thousand eighty-four infants (13.8%) were HIV infected. Three hundred twenty (29.5%) children enrolled into pediatric HIV care, with 202 (63.1%) at the Baylor Center of Excellence. Among these, antiretroviral therapy was initiated on 110 infants (54.5%) whose median age was 9.1 months (interquartile range, 5.4-13.8) and a median of 2.5 months (interquartile range, 1.4-5.2) after HIV clinic registration. Sixty-nine HIV-infected infants (34.2%) died or were lost by December 2008. Initiation of antiretroviral therapy increased the likelihood of survival 7-fold (odds ratio, 7.1; 95% confidence interval, 3.68 to 13.70).

CONCLUSIONS

Separate programs for maternal and infant HIV prevention and care services demonstrated high attrition rates of HIV-exposed and HIV-infected infants, elevated levels of mother-to-child transmission, late infant diagnosis, delayed pediatric antiretroviral therapy initiation, and high HIV-infected infant mortality. Antiretroviral therapy increased HIV-infected infant survival, emphasizing the urgent need for improved service coordination and strategies that increase access to infant HIV diagnosis, improve patient retention, and reduce antiretroviral therapy initiation delays.

A novel mechanism for chaperone-mediated telomerase regulation during prostate cancer progression

Telomerase activity has been detected in >85% of all malignant human cancers, including 90% of prostate carcinomas. Using a well-characterized experimental prostate cancer system, we have found that telomerase activity is notably increased (>10-fold) during tumorigenic conversion. Expression profiles of the telomerase components (hTR and hTERT) revealed no substantive changes, which suggests a nontranscriptional mechanism for increased activity. Because the hsp90 chaperone complex functionally associates with telomerase, we investigated that relationship and found that along with telomerase activity, a number of hsp90-related chaperones are markedly elevated during transformation, as well as in advanced prostate carcinomas. Using the nontumorigenic cell protein extract as the source of telomerase, addition of purified chaperone components enhanced reconstitution of telomerase activity, which suggests a novel mechanism of increased telomerase assembly via a hsp90 chaperoning process during prostate cancer progression.