Acute lower respiratory tract infection in hospitalized children in Zimbabwe

The impact of childhood malnutrition on mortality from pneumonia: a systematic review and network meta-analysis

INTRODUCTION

Childhood malnutrition is widespread in low-income and middle-income countries (LMICs) and increases the frequency and severity of infections such as pneumonia. We aimed to identify studies investigating pneumonia deaths in malnourished children and estimate mortality risk by malnutrition severity.

METHODS

We conducted a systematic review of MEDLINE, EMBASE and Global Health databases to identify relevant studies. We used a network meta-analysis to derive ORs of death from pneumonia for moderately and severely underweight children using low weight-for-age, the most reported measure of malnutrition. We compared meta-estimates of studies conducted before and after 2000 to assess changes in mortality risk over time. We estimated the prevalence of underweight hospitalised children from hospital-based cohort studies and calculated the population attributable fraction of in-hospital pneumonia deaths from being underweight using our results.

RESULTS

Our network meta-analysis included 33 544 underweight children from 23 studies. The estimated OR of death from pneumonia was 2.0 (95% CI 1.6 to 2.6) and 4.6 (95% CI 3.7 to 5.9) for children moderately and severely underweight, respectively. The OR of death from pneumonia for those severely underweight was 5.3 (95% CI 3.9 to 7.4) pre-2000 and remained high post-2000 at 4.1 (95% CI 3.0 to 6.0). Prevalence of underweight children hospitalised with pneumonia varied (median 40.2%, range 19.6-66.3) but was high across many LMIC settings. We estimated a median 18.3% (range 10.8-34.6) and 40.9% (range 14.7-69.9) of in-hospital pneumonia deaths were attributable to being moderately and severely underweight, respectively.

CONCLUSIONS

The risk of death from childhood pneumonia dramatically increases with malnutrition severity. This risk has remained high in recent years with an estimated over half of in-hospital pneumonia deaths attributable to child malnutrition. Prevention and treatment of all child malnutrition must be prioritised to maintain progress on reducing pneumonia deaths.

Predictors of Mortality in Neonates and Infants Hospitalized With Sepsis or Serious Infections in Developing Countries: A Systematic Review

Background: Neonates and infants comprise the majority of the 6 million annual deaths under 5 years of age around the world. Most of these deaths occur in low/middle income countries (LMICs) and are preventable. However, the clinical identification of neonates and infants at imminent risk of death is challenging in developing countries. Objective: To systematically review the literature on clinical risk factors for mortality in infants under 12 months of age hospitalized for sepsis or serious infections in LMICs. Methods: MEDLINE and EMBASE were systematically searched using MeSH terms through April 2017. Abstracts were independently screened by two reviewers. Subsequently, full-text articles were selected by two independent reviewers based on PICOS criteria for inclusion in the final analysis. Study data were qualitatively synthesized without quantitative pooling of data due to heterogeneity in study populations and methodology. Results: A total of 1,139 abstracts were screened, and 169 full-text articles were selected for text review. Of these, 45 articles were included in the analysis, with 21 articles featuring neonatal populations (under 28 days of age) exclusively. Most studies were from Sub-Saharan Africa and South Asia. Risk factors for mortality varied significantly according to study populations. For neonatal deaths, prematurity, low birth-weight and young age at presentation were most frequently associated with mortality. For infant deaths, malnutrition, lack of breastfeeding and low oxygen saturation were associated with mortality in the highest number of studies. Conclusions: Risk factors for mortality differ between the neonatal and young infant age groups and were also dependant on the study population. These data can serve as a starting point for the development of individualized predictive models for in-hospital and post-discharge mortality and for the development of interventions to improve outcomes among these high-risk groups.

Mortality and its risk factors in Malawian children admitted to hospital with clinical pneumonia, 2001-12: a retrospective observational study

BACKGROUND

Few studies have reported long-term data on mortality rates for children admitted to hospital with pneumonia in Africa. We examined trends in case fatality rates for all-cause clinical pneumonia and its risk factors in Malawian children between 2001 and 2012.

METHODS

Individual patient data for children (<5 years) with clinical pneumonia who were admitted to hospitals participating in Malawi's Child Lung Health Programme between 2001 and 2012 were recorded prospectively on a standardised medical form. We analysed trends in pneumonia mortality and children's clinical characteristics, and we estimated the association of risk factors with case fatality for children younger than 2 months, 2-11 months of age, and 12-59 months of age using separate multivariable mixed effects logistic regression models.

FINDINGS

Between November, 2012, and May, 2013, we retrospectively collected all available hard copies of yellow forms from 40 of 41 participating hospitals. We examined 113 154 pneumonia cases, 104 932 (92·7%) of whom had mortality data and 6903 of whom died, and calculated an overall case fatality rate of 6·6% (95% CI 6·4-6·7). The case fatality rate significantly decreased between 2001 (15·2% [13·4-17·1]) and 2012 (4·5% [4·1-4·9]; ptrend<0·0001). Univariable analyses indicated that the decrease in case fatality rate was consistent across most subgroups. In multivariable analyses, the risk factors significantly associated with increased odds of mortality were female sex, young age, very severe pneumonia, clinically suspected Pneumocystis jirovecii infection, moderate or severe underweight, severe acute malnutrition, disease duration of more than 21 days, and referral from a health centre. Increasing year between 2001 and 2012 and increasing age (in months) were associated with reduced odds of mortality. Fast breathing was associated with reduced odds of mortality in children 2-11 months of age. However, case fatality rate in 2012 remained high for children with very severe pneumonia (11·8%), severe undernutrition (15·4%), severe acute malnutrition (34·8%), and symptom duration of more than 21 days (9·0%).

INTERPRETATION

Pneumonia mortality and its risk factors have steadily improved in the past decade in Malawi; however, mortality remains high in specific subgroups. Improvements in hospital care may have reduced case fatality rates though a lack of sufficient data on quality of care indicators and the potential of socioeconomic and other improvements outside the hospital precludes adequate assessment of why case-fatality rates fell. Results from this study emphasise the importance of effective national systems for data collection. Further work combining this with data on trends in the incidence of pneumonia in the community are needed to estimate trends in the overall risk of mortality from pneumonia in children in Malawi.

FUNDING

Bill & Melinda Gates Foundation.

Clinical outcomes of children with acute asthma and pneumonia in Mulago hospital, Uganda: a prospective study

BACKGROUND

Little attention has been paid to asthma in 'under-fives' in Sub-Saharan Africa. In 'under-fives', acute asthma and pneumonia have similar clinical presentation and most children with acute respiratory symptoms are diagnosed with pneumonia according to the WHO criteria. The mortality associated with acute respiratory diseases in Uganda is high but improving, dropping from 24% in 2004 to 11.9% in 2012. We describe the immediate clinical outcomes of children with acute asthma and pneumonia and document the factors associated with prolonged hospitalization and mortality.

METHODS

We enrolled 614 children aged 2 to 59 months with acute respiratory symptoms presenting at the emergency paediatric unit of Mulago hospital. Clinical histories, physical examination, blood and radiological tests were done. Children with asthma and bronchiolitis were collectively referred to as 'Asthma syndrome'. Hospitalized children were monitored every 12 hours for a maximum of 7 days. Survival analysis was done to compare outcome of children with asthma and pneumonia. Cox regression analysis was done to determine factors associated with prolonged hospitalization and mortality.

RESULTS

Overall mortality was 3.6%. The highest case fatality was due to pneumocystis jirovecii pneumonia (2/4) and pulmonary tuberculosis (2/7). None of the children with asthma syndrome died. Children with 'asthma syndrome' had a significantly shorter hospital stay compared to those with pneumonia (p<0.001). Factors independently associated with mortality included hypoxemia (HR = 10.7, 95% CI 1.4- 81.1) and severe malnutrition (HR = 5.7, 95% CI 2.1- 15.8). Factors independently associated with prolonged hospitalization among children with asthma syndrome included age less than 12 months (RR = 1.2, 95% CI 1.0-1.4), hypoxemia (RR = 1.4, 95% CI 1.2-1.7), and severe malnutrition (RR = 1.5 95% CI 1.3-1.8). Similar factors were associated with long duration of hospital stay among children with pneumonia.

CONCLUSION

This study identified a sharp decline in acute respiratory mortality compared to the previous studies in Mulago hospital. This may be related to focus on and treatment of asthma in this study, and will be analysed in a later study. Bacterial pneumonia is still associated with high case fatality. Hypoxemia, severe malnutrition, and being an infant were associated with poor prognosis among children with acute asthma and pneumonia and need to be addressed in the management protocols.

Morbidity and outcome of severe respiratory syncytial virus infection

BACKGROUND

Respiratory syncytial virus (RSV) is the main cause of severe acute respiratory infection (SARI) in infants and young children. This study aimed to identify risk factors for intensive care unit (ICU) admission, prolonged length of stay (PLOS), and mortality in patients hospitalized with SARI caused by RSV.

METHODS

This prospective cohort study included children hospitalized with SARI (according to the World Health Organization definition) and whose laboratory results proved RSV infection during the period from February 2010 to May 2011.

RESULTS

Out of 240 enrolled patients, 24 patients (10%) were admitted to the ICU, 57 patients (24.3%) had a PLOS of >9 days and 12 patients (5%) died. The presence of cyanosis (P = 0.000; OR, 351.7) and lung consolidation (P = 0.006, OR, 9.3) were independent risk factors associated with ICU admission. The need for ICU admission (P = 0.000; OR, 6.1) and lung consolidation (P = 0.008, OR, 2.46) were independent risk factors associated with PLOS. The presence of an underlying congenital heart disease (P = 0.03, OR, 18.3), thrombocytopenia (P = 0.04, OR, 32.86) and mechanical ventilation (P = 0.000; OR, 449.4) were the only independent risk factors associated with mortality in our study.

CONCLUSIONS

Early recognition of risk factors for complicated RSV disease on admission prompts early interventions and early ICU admissions for these children.

Childhood asthma in low income countries: an invisible killer?

Bacterial pneumonia has hitherto been considered the key cause of the high respiratory morbidity and mortality in children under five years of age (under-5s) in low-income countries, while asthma has not been stated as a significant reason. This paper explores the definitions and concepts of pneumonia and asthma/wheezing/bronchiolitis and examines whether asthma in under-5s may be confused with pneumonia. Over-diagnosing of bacterial pneumonia can be suspected from the limited association between clinical pneumonia and confirmatory test results such as chest x-ray and microbiological findings and poor treatment results using antibiotics. Moreover, children diagnosed with recurrent pneumonia in infancy were often later diagnosed with asthma. Recent studies showed a 10-15% prevalence of preschool asthma in low-income countries, although under-5s with long-term cough and difficulty breathing remain undiagnosed. New studies demonstrate that approximately 50% of acutely admitted under-5s diagnosed with pneumonia according to Integrated Management of Childhood Illnesses could be re-diagnosed with asthma or wheezing when using re-defined diagnostic criteria and treatment. It is hypothesised that untreated asthma may contribute to respiratory mortality since respiratory syncytial virus (RSV) is an important cause of respiratory death in childhood, and asthma in under-5s is often exacerbated by viral infections, including RSV. Furthermore, acute respiratory treatment failures were predominantly seen in under-5s without fever, which suggests the diagnosis of asthma/wheezing rather than bacterial pneumonia. Ultimately, underlying asthma may have contributed to malnutrition and fatal bacterial pneumonia. In conclusion, preschool asthma in low-income countries may be significantly under-diagnosed and misdiagnosed as pneumonia, and may be the cause of much morbidity and mortality.

Pneumonia in severely malnourished children in developing countries - mortality risk, aetiology and validity of WHO clinical signs: a systematic review

OBJECTIVES

To quantify the degree by which moderate and severe degrees of malnutrition increase the mortality risk in pneumonia, to identify potential differences in the aetiology of pneumonia between children with and without severe malnutrition, and to evaluate the validity of WHO-recommended clinical signs (age-specific fast breathing and chest wall indrawing) for the diagnosis of pneumonia in severely malnourished children.

METHODS

Systematic search of the existing literature using a variety of databases (Medline, EMBASE, the Web of Science, Scopus and CINAHL).

RESULTS

Mortality risk: Sixteen relevant studies were identified, which universally showed that children with pneumonia and moderate or severe malnutrition are at higher risk of death. For severe malnutrition, reported relative risks ranged from 2.9 to 121.2; odds ratios ranged from 2.5 to 15.1. For moderate malnutrition, relative risks ranged from 1.2 to 36.5. Aetiology: Eleven studies evaluated the aetiology of pneumonia in severely malnourished children. Commonly isolated bacterial pathogens were Klebsiella pneumoniae, Staphylococcus aureus, Streptococcus pneumoniae, Escherichia coli, and Haemophilus influenzae. The spectrum and frequency of organisms differed from those reported in children without severe malnutrition. There are very few data on the role of respiratory viruses and tuberculosis. Clinical signs: Four studies investigating the validity of clinical signs showed that WHO-recommended clinical signs were less sensitive as predictors of radiographic pneumonia in severely malnourished children.

CONCLUSIONS

Pneumonia and malnutrition are two of the biggest killers in childhood. Guidelines for the care of children with pneumonia and malnutrition need to take into account this strong and often lethal association if they are to contribute to the UN Millennium Development Goal 4, aiming for substantial reductions in childhood mortality. Additional data regarding the optimal diagnostic approach to and management of pneumonia and malnutrition are required from regions where death from these two diseases is common.

The epidemiology of hospitalized pneumonia in rural Kenya: the potential of surveillance data in setting public health priorities

INTRODUCTION

Surveillance data from inpatient health facilities can be useful for prioritization of public health initiatives, but often are not collected or analyzed in developing countries. We evaluated data on hospitalized patients diagnosed with pneumonia in rural western Kenya to characterize pneumonia epidemiology and mortality.

METHODS

Data were obtained from admission registers of all inpatient facilities from 2001 to 2003 in Bondo District (estimated 2003 population: 255901), which is holoendemic for malaria and has high HIV rates. Inpatients with diagnoses compatible with acute pneumonia were included, and census data (1999) were used to calculate incidence rates by age, sex, season, and residence.

RESULTS

From 2001 to 2003, a total of 2466 patients diagnosed with pneumonia were hospitalized with 282 deaths (11.4%). Incidence peaked at 698 per 100,000 person-years among children <5 years of age. A second peak occurred among 20-29 year-olds at 356 per 100,000 person-years; rates were twice as high in women as men in this age group (p<0.001). The incidence in persons >65 years was 121 per 100,000 person-years. Pneumonia incidence peaked during the twice-yearly high malaria seasons, 1-2 months after peak rainfall. Rates of pneumonia decreased with increasing distance of residence from the district hospital (p<0.0001).

DISCUSSION

In Bondo District, the pneumonia burden is greatest among young children and middle-aged adults, the latter peak reflecting the area's HIV epidemic. Access to care likely influenced hospital utilization and thus pneumonia rates, particularly among the elderly. Our findings show that hospital-based data can provide useful information for public health priority setting, such as the introduction of new pneumonia vaccines for children and accelerating the introduction of antiretroviral medications.

Effect of age, polymicrobial disease, and maternal HIV status on treatment response and cause of severe pneumonia in South African children: a prospective descriptive study

BACKGROUND

HIV-related pneumonia is the main cause of paediatric hospital admissions in southern Africa. We aimed to measure predictors of treatment failure and the cause of non-responsive pneumonia in children admitted to hospital with severe pneumonia in Durban, South Africa.

METHODS

We investigated 358 children aged 1-59 months who presented with WHO-defined severe or very severe pneumonia. Children were recruited irrespective of HIV status and started on a standard antimicrobial regimen of benzylpenicillin and gentamicin. All infants also received high-dose trimethoprim-sulfamethoxazole. The primary outcome measure was treatment failure at 48 h.

FINDINGS

242 (68%) children were HIV infected, 41 (12%) HIV exposed, uninfected, and 75 (21%) HIV uninfected. Failure to respond by 48 h was predicted by age under 1 year (adjusted odds ratio 6.38, 95% CI 2.72-14.91, p<0.0001), very severe disease (2.47, 1.17-5.24, p=0.0181), HIV status (HIV infected 10.3, 3.26-32.51; HIV exposed, uninfected 6.02, 1.55-23.38; p=0.0003), and polymicrobial disease (one organism 2.06, 1.05-4.05; two organisms 10.75, 4.38-26.36; p<0.0001) on logistic regression analysis. All children with three organisms failed treatment. 72/110 treatment failures had at least two organisms isolated. Three of nine HIV-exposed, uninfected infants, 29/74 HIV-infected, but no HIV-uninfected infants who failed study therapy had Pneumocystis jirovecii pneumonia.

INTERPRETATION

For children younger than 1 year, the WHO guidelines are inadequate and need to be revised since both HIV-infected and HIV-exposed, uninfected infants had more treatment failures than did HIV-uninfected infants. Polymicrobial disease is an important reason for treatment failure, and we need to identify rapid low-cost diagnostic methods to assist clinicians.

Pneumocystis carinii in children with severe pneumonia at Mulago Hospital, Uganda

The prevalence of Pneumocystis carinii pneumonia (PCP), its clinical and radiological features and the outcome in 121 children aged 2-60 months presenting with severe pneumonia over a 2-month period at Mulago Hospital, Kampala are described. Children presenting with severe pneumonia had sputum induction using 3% hypertonic saline. The sputum was stained using PCP monoclonal antibodies and viewed with fluorescent microscopy. Twenty children with confirmed PCP were compared with 101 without PCP. The prevalence of PCP was 16.5%, and 12 (60%) were < 6 months of age. Eighteen (42%) of 43 children infected with HIV had PCP and two of 78 not infected with HIV. The outcome in children with PCP was poor with a case fatality rate of 40% compared with 20% in those without HIV. Radiological findings were non-specific. Clinical features associated with PCP included: HIV-positive infants with a small head circumference, AIDS, a clear chest on auscultation and elevated LDH levels. PCP occurs in one in six children < 5 years with severe pneumonia in Mulago Hospital. In developing countries where investigations for PCP are not routinely available, infants suspected of PCP should be treated as an emergency.

Rapid emergence of resistance to penicillin and trimethoprim-sulphamethoxazole in invasive Streptococcus pneumoniae in Zimbabwe

Pneumococcal pneumonia and meningitis are common infectious disease problems in people who are HIV seropositive in southern Africa. For many years two inexpensive antibiotics, penicillin and trimethoprim-sulphamethoxazole (TMP-SMX) had been effective in treatment, but recently resistance to these agents has been reported from many parts of the world. This study was designed to determine the antimicrobial resistance patterns in invasive pneumococci from hospital patients in Harare, Zimbabwe. A total of 160 isolates of Streptococcus pneumoniae from blood cultures and CSF cultures were examined. The isolates came from adults and children in hospital in Harare between 1994 and 2000. The majority of isolates came from HIV positive adults (74%) and children (75%). Isolates of pneumococci with an MIC of 1.0 mg/l or more were first seen in 1997 and by 2000 they made up 35% of all isolates. Significantly more isolates from HIV seropositive patients (50%) showed reduced susceptibility to penicillin compared with isolates from HIV seronegative patients (16%), and high level resistance (MIC 1.0 mg/l or higher) was found in 16% isolates from HIV positive patients compared with 6% isolates from HIV seronegative patients. Resistance to TMP-SMX was common, with more than 50% isolates from HIV positive and HIV negative patients having reduced susceptibility to this antibiotic combination.

Carriage of gram-negative bacilli in young Brazilian children with community-acquired pneumonia

BACKGROUND

Gram-negative bacilli are not infrequently encountered as etiologic organisms of pneumonia in children in warm-climate countries.

OBJECTIVES

To investigate the nasopharyngeal carriage rate and antimicrobial susceptibility patterns of gram-negative bacilli colonizing children with community-acquired pneumonia in Fortaleza, Brazil.

METHODS

A single nasopharyngeal specimen was collected from children 2 months to 5 years of age presenting at one of the three children's hospitals in Fortaleza and fulfilling the World Health Organization criteria for pneumonia. Randomly recruited healthy children from public daycare centers and immunization clinics served as controls.

RESULTS

The study included 912 children, 482 (53%) with pneumonia and 430 (47%) controls. Aerobic gram-negative bacilli were seen in 79 (16%) of the 482 children with pneumonia and 51 (12%) of the 430 healthy controls. Nonfermentative gram-negative bacilli were seen in 85 (18%) of children with pneumonia and 54 (13%) of healthy controls. Neither gender, nutritional status, season, previous hospital admission nor antibiotic use was associated with carriage with gram-negative bacilli. However, pneumonia was associated with increased carriage, whereas concomitant colonization with Streptococcus pneumoniae or Haemophilus influenzae was associated with decreased carriage with gram-negative bacilli. Only 36% of all Escherichia species and 76% of all Klebsiella isolates were susceptible to cotrimoxazole; 90% of all Acinetobacter species were susceptible to gentamicin.

CONCLUSION

Nasopharyngeal carriage with gram-negative bacilli, in particular with Acinetobacter species, is common and associated with a clinical diagnosis of community-acquired pneumonia in children in Fortaleza, Brazil.

Fatal Pneumocystis carinii pneumonia in HIV-seropositive infants in Harare, Zimbabwe

Lung biopsies taken post mortem from 24 HIV-seropositive children who died of pneumonia in Harare Hospital (Zimbabwe) during 1995 were examined for pathogens using histology, culture, microscopy and polymerase chain reaction (PCR). Pneumocystis carinii was detected in 16 (67%) children, in 5 of whom bacterial pathogens were also detected. There were 2 cases of cytomegalovirus infection. On the basis of histology and PCR, none of the children had tuberculosis. These data add to the evidence that P. carinii pneumonia may be a significant cause of death in HIV-infected children in southern Africa. Policies on treatment for severe pneumonia, and on prophylaxis for children born to HIV-seropositive mothers need to be re-examined.

Bacterial infection in children with HIV: a prospective study from Cape Town, South Africa

Invasive bacterial infection in children infected with the human immunodeficiency virus (HIV) is common. South African data on this problem are limited. Over 1 year we prospectively studied 108 HIV-infected children hospitalized for 136 presumed infective episodes. Blood culture was positive in 24.8% of episodes. Streptococcus pneumoniae predominated (14/30 positive blood cultures); one-third of isolates showed resistance to penicillin. Acute lower respiratory tract infection accounted for 44% of clinical diagnoses, a bacterial cause being established for 23.8% of these. Age and stage of HIV infection did not influence the likelihood of a positive culture. A high proportion of presumed infective episodes requiring hospitalization of young HIV-infected children have a bacterial cause. Blood culture appears to be a useful method of obtaining the microbiological information required to focus antibiotic therapy.

Increased burden of respiratory viral associated severe lower respiratory tract infections in children infected with human immunodeficiency virus type-1

OBJECTIVES

To determine the burden of viral associated severe lower respiratory tract infections (SLRTI) in human immunodeficiency virus-infected (HIV+) and HIV-uninfected (HIV-) urban black South African children.

METHODS

Children with SLRTI aged 2 to 60 months were enrolled between March 1997 and March 1998. Monoclonal antibody immunofluorescent testing was performed on nasopharyngeal aspirates to detect respiratory syncytial virus (RSV), influenza A and B, parainfluenza 1-3, and adenovirus-specific antigens.

RESULTS

Of the 990 children studied, 44.6% were HIV+. The estimated burden of disease of viral associated SLRTI in children under 2 years was increased for RSV, influenza A/B viruses, parainfluenza 1-3 viruses, and adenovirus in children who were HIV+ compared with children who were HIV- (P <.001). Viral pathogens, however, were identified less frequently (15.7% vs 34.8%, P < 10(-5)) and bacterial pathogens more frequently (12.5% vs 5.8%, P <.0001) in children who were HIV+ than in children who were HIV- and had SLRTI. The seasonal peak for RSV in late summer-early autumn observed in children who were HIV- was less evident in children who were HIV+ (P =.02). Children who were HIV+ and had virus-associated SLRTI had a higher mortality rate (7. 5%) than did children who were HIV- (0%, P < 10(-3)).

CONCLUSIONS

The contribution of viral associated SLRTI differs between HIV+ and HIV- children. In HIV+ children in South Africa, RSV isolation is not limited by season.

Increased disease burden and antibiotic resistance of bacteria causing severe community-acquired lower respiratory tract infections in human immunodeficiency virus type 1-infected children

To improve the management of lower respiratory tract infections (LRTI) in human immunodeficiency virus type 1 (HIV-1)-infected children, we assessed the burden of disease, clinical outcome and antibiotic susceptibility of bacteria causing severe community-acquired LRTI in children. A prospective, descriptive study was performed in the pediatric wards at a secondary and tertiary care hospital in South Africa. Urban black children aged 2-60 months admitted with severe acute LRTI from March 1997 through February 1998 were enrolled. HIV-1 infection was present in 45.1% of 1215 cases of severe LRTI. Bacteremia occurred in 14.9% of HIV-1-infected and in 6.5% of HIV-1-uninfected children (P<.00001). The estimated relative incidence of bacteremic severe LRTI in children aged from 2 to 24 months were greater in HIV-1-infected than in -uninfected children for Streptococcus pneumoniae (risk ratio [RR], 42.9; 95% confidence interval [CI], 20.7-90.2), Haemophilus influenzae type b (RR, 21.4; 95% CI, 9.4-48.4), Staphylococcus aureus (RR, 97.9; 95% CI, 11.4-838.2) and Escherichia coli (RR, 49.0; 95% CI, 15.4-156). Isolation of Mycobacterium tuberculosis was also more common in HIV-1-infected than in -uninfected children (RR, 22.5; 95% CI, 13.4-37.6). In HIV-1-infected children, 60% of S. aureus and 85.7% of E. coli isolates were resistant to methicillin and trimethoprim-sulfamethoxazole, respectively. The case-fatality rates among HIV-1-infected children was 13.1%, and among HIV-1-uninfected children, 2.1% (adjusted odds ratio [AOR]; 6.52, 95% CI, 3.53-12.05; P<.00001). The changing spectrum of bacteria and antibiotic susceptibility patterns in HIV-1-infected children requires a reevaluation of the empirical treatment of community-acquired severe LRTI in children from developing countries with a high prevalence of childhood HIV-1 infection.

Prospects for pneumococcal vaccination in African children

Streptococcus pneumoniae (pneumococcus) remains a major cause of morbidity and mortality in both developed and undeveloped countries. Accurate disease burden estimates for developing countries and Africa in particular, where diagnostic facilities are less adequate and a disease surveillance system virtually non-existent, is difficult. However, from conservative estimates, the pneumococcus is probably responsible for at least 1 million of the 4 million deaths that occur from acute lower respiratory infections in children aged less than 5 years. The global burden of disease has been accentuated by the rising menace of multi-drug resistant strains, which defy geographic and racial borders. Thus, now more than ever before, there is an urgent need to identify and implement preventive measures to avert this problem. The currently licensed pneumococcal polysaccharide vaccine, comprises 23 capsular polysaccharides of the pneumococcus, many of which are poorly immunogenic in the very vulnerable age group of under-fives. A possible solution to the problem of poor immunogenicity is to use a protein/polysaccharide conjugate vaccine similar to that recently introduced successfully for Haemophilus influenzae type b (Hib) and using this approach, several workers have reported promising results from safety and immunogenicity studies. However, unlike Hib, the development of conjugate vaccine against pneumococcal disease is complicated by the existence of more serotypes than can be feasibly incorporated in a single conjugate vaccine formulation. Whilst this challenge has been taken on by some vaccine manufacturers, novel approaches such as the identification or construction of protective protein antigen, common to all clinically important strains are being explored. Novel application of the pneumococcal polysaccharide vaccines in pregnancy for protection of disease in early infancy is an approach that has not been evaluated. For maximum impact, the ultimate vaccine formulation should be affordable and available to resource poor countries where the burden of disease is highest. Establishing disease surveillance systems in such countries now will greatly facilitate the introduction of the vaccines.

Clinical presentation and outcome of Pneumocystis carinii pneumonia in Malawian children

BACKGROUND

Necropsy studies from Africa have shown that Pneumocystis carinii pneumonia (PCP) is common in infants with HIV infection. We aimed to describe the rate, clinical presentation, and outcome of PCP in young Malawian children with acute severe pneumonia.

METHODS

Children aged between 2 months and 5 years who were in hospital with a diagnosis of severe pneumonia were admitted to a study ward for clinical monitoring. We carried out blood culture, immunofluorescence on nasopharyngeal aspirate samples to test for PCP, polymerase chain reaction to detect HIV, and chest radiography.

FINDINGS

16 cases of PCP were identified among 150 children with radiologically confirmed severe pneumonia. All were HIV-positive and younger than 6 months. 21 children had bacterial pneumonia (including one who was also PCP positive) and 114 were not confirmed. The most common bacterial pathogens among children without PCP were Streptococcus pneumoniae (eight) and non-typhoidal salmonellae (seven). On admission, children with confirmed PCP had a lower mean age, body temperature, and oxygen saturation than children with bacterial pneumonia and were less likely to have a focal abnormality on auscultation. Oxygen requirements were much greater in children with PCP than those with bacterial pneumonias (96 of 105 hospital days vs 15 of 94, p<0.0001). Ten of 16 children with PCP and six of 21 with bacterial pneumonia died (relative risk 2.19 [95% CI 1.0-4.7]). The overall case-fatality rate of severe pneumonia was 22%. In addition to a strong association with PCP, a fatal outcome was significantly and independently associated with HIV infection (2.98 [1.1-7.9]) and with age under 6 months (2.76 [1.0-5.2]).

INTERPRETATION

PCP is common and contributes to the high mortality from pneumonia in Malawian infants. Clinical features are helpful in diagnosis. The study highlights the impact of HIV infection and difficult issues of management in countries with few resources.

Striking differences in the nasopharyngeal flora of healthy Angolan, Brazilian and Dutch children less than 5 years old

Community-acquired pneumonia from enteric gram-negative bacilli is more common in developing than in industrialized countries. We investigated the nasopharyngeal flora in healthy children from Angola, Brazil and The Netherlands to see whether enteric gram-negative bacilli are more often part of the commensal flora in developing countries. Nasopharyngeal specimens were collected from children aged between 4 months and 5 years in day-care centres and immunization clinics. Children who had received antibiotics or were malnourished were excluded. Brazilian and Angolan children had a higher number of household members than Dutch children (5.5 and 7 vs 3.9 mean number of household members, respectively) (p < 0.0001). Enteric and non-fermentative gram-negative bacilli were much more prevalent in Brazilian (50%) and Angolan (57%) children than in Dutch (4%) children (p < 0.0001). By univariate analysis, carriage of enteric gram-negative bacilli was associated with the number of household members (r = 0.26; p < 0.001). The high carriage rate of enteric gram-negative bacilli in children from Angola and Brazil may explain why enteric gram-negative bacilli are a common cause of pneumonia in developing countries.

The epidemiology of pneumococcal infection in children in the developing world

Pneumonia causes about three million deaths a year in young children, nearly all of which are in developing countries. Streptococcus pneumoniae (the pneumococcus) is the most important bacterial cause of pneumonia in young children and so is likely to be responsible for a high proportion of these deaths. The pneumococcus is also responsible for a substantial proportion of the 100,000-500,000 deaths that occur from meningitis in children each year. The incidence of invasive pneumococcal disease in children in the developing world is several times higher than in industrialized countries. This discrepancy may, in part, be due to socio-economic differences but genetic factors may also play a role. Children with sickle cell disease have a substantially increased risk of invasive pneumococcal infection and a search is being made for other possible genetic risk factors. Infection with human immunodeficiency virus (HIV) also predisposes to invasive pneumococcal disease and so the incidence of this disease in young children is expected to rise as increasing numbers of African and Asian children are born with a perinatally acquired HIV infection. Until recently, pneumococcal infections could be treated effectively with penicillin, a cheap and safe antibiotic. However, pneumococci that are resistant to penicillin are becoming prevalent in many countries, necessitating a change to more costly antibiotics which may be beyond the reach of the health services of poor, developing countries. The spread of antibiotic resistance has provided an added stimulus to the development of vaccines that might be able to prevent pneumococcal disease in infants. Recently developed polysaccharide-protein conjugate vaccines show promise and are now undergoing field trials. How deployment of these vaccines will influence the balance between invasive pneumococcal infections and asymptomatic nasopharyngeal carriage of pneumococci is uncertain.

Impact of a case management protocol for childhood pneumonia in a rural Zambian hospital

This study aimed to assess the impact of adopting the WHO case management protocol for childhood pneumonia in a district hospital in rural Zambia. The subjects were children under 5 years of age with a diagnosis of pneumonia, admitted in the 9-month period following introduction of the WHO protocol. Management and outcome were compared with a historical control group admitted during the same period in the previous year. There were 158 children in the intervention group and 135 controls with similar age and sex distribution. Both groups were malnourished (mean weight-for-age Z score in subjects = -1.91, in controls = -1.83). There was no significant difference in the numbers receiving parenteral antibiotics or supplementary fluids in each group. However, children in the intervention group were significantly more likely to receive oxygen (odds ratio 4.7, 95% confidence interval 2.8-8.1, p < 0.0001). Mortality was significantly greater in the control group (case fatality rate, 25%) compared with the intervention group (case fatality rate, 15%; chi 2 = 4.6; p = 0.032). The introduction of the WHO protocol for management of childhood pneumonia and training of staff in its use was accompanied by a fall in mortality from this condition in a rural hospital. The improved survival rate may be related to the more frequent use of oxygen.

Clinical predictors of hypoxaemia in children with pneumonia

A prospective study to determine which clinical factors identified children with acute lower respiratory infection who were hypoxaemic and at risk of death was done over a 9-month period on children under 5 years of age admitted to a district hospital in rural Zambia. Of 158 children studied, 55 (35%) were found to be hypoxaemic and 23 (14.6%) died. For the subgroup of children under 1 year of age, a respiratory rate of > 70 was the only significant predictor of hypoxaemia (p < 0.001, sensitivity 63%, specificity 89%). In older children, only the presence of crepitations/bronchial breathing was predictive (p = 0.018, sensitivity 75%, specificity 57%). The likelihood of death was increased in those children with low oxygen saturation (p = 0.021) and poor nutrition (p = 0.007). It is concluded that, on the basis of raised respiratory rate, the WHO guidelines are likely to identify children under 1 year of age who are hypoxaemic. However, it may be necessary to include auscultatory findings in the guidelines to recognize hypoxaemia in older children in order to ensure that they receive appropriate treatment with oxygen. This study demonstrates that hypoxaemia and malnutrition are risk factors for death.

Impact of HIV on mortality from acute lower respiratory tract infection in rural Zambia

AIMS

To establish the prevalence and clinical correlates of HIV among children with acute lower respiratory tract infection.

METHODS

Children admitted to a rural Zambian hospital were studied over an eight month period. The diagnosis of acute lower respiratory tract infection was made clinically, according to World Health Organisation (WHO) criteria. Clinicians, who were unaware of the children's HIV status, prescribed antibiotic and supportive treatment according to WHO guidelines. HIV status was established using the polymerase chain reaction (Amplicor HIV1, Roche) applied to dried blood spots.

RESULTS

Acute lower respiratory tract infection was diagnosed in 132 children (median age 8 months, range 1 month to 4 years). The WHO criteria for severe or very severe pneumonia were met by 96/132 patients (73%) and 21 patients (16%) died. HIV dried blood spot PCR was positive in 14 cases (11%), of whom four fulfilled the WHO clinical case definition for paediatric AIDS and five died. The group as a whole were malnourished, but the HIV positive children were more severely malnourished (mean z score for weight = -3.01) than the HIV negative children (mean z score = -1.73, p < 0.001). The relative risk of death was 2.6 in the HIV positive group but this was not significant (p = 0.079).

CONCLUSIONS

An important minority of children with acute lower respiratory tract infection in rural Zambia will be infected with HIV. However, most HIV positive children presenting with respiratory infection will survive given simple antibiotic and supportive treatment.

Pulmonary manifestations in HIV seropositivity and malnutrition in Zimbabwe

Over a 10 month period 184 children, aged 5 years or less, who died at home had their nutritional status and HIV serostatus established; necropsies were also carried out. The HIV antibody test was positive in 122/184 (66%). Of the HIV seropositive children Pneumocystis carinii pneumonia was present in 19 (16%), cytomegalovirus pneumonia in nine (7%), and lymphoid interstitial pneumonitis in 11 (9%). Opportunistic infection was therefore seen in 28/122 (23%) of the seropositive cases but in none of the seronegative cases. Tuberculosis was present in 8/184 (4%): 6/122 (5%) in HIV seropositive and 2/62 (3%) in seronegative children. Lung aspirate showed positive bacterial isolates in 106/ 122 (86%) of HIV seropositive and 46/62 (74%) of seronegative children with Gram negative organisms predominating in both groups. Malnutrition was common and affected 106/184 (58%); positive growth was obtained in 98 (92%) of the malnourished children irrespective of their HIV serostatus. Malnutrition was significantly associated with bacterial lung infection after adjustment for the confounding effect of HIV status. No association was found between HIV serostatus and bacterial lung infection that could not be attributed to malnutrition at the time of death. The importance of adequate nutrition in reducing the risk of bacterial infection in HIV infected children is apparent.

Community-acquired bacteremia in human immunodeficiency virus-infected children in Harare, Zimbabwe

BACKGROUND

HIV infection is common in mothers and their children in Zimbabwe, and HIV-infected children are particularly susceptible to bacterial infections. There is little information on the etiology and outcome of HIV-related bacteremia in African children.

METHODS

Blood cultures from 309 hospitalized children in Zimbabwe, of whom 168 were diagnosed as having HIV, were examined for pathogens. The association among significant bacteremia, HIV infection and mortality was assessed in these children.

RESULTS

The most common isolates were coagulase-negative staphylococci (31 children, 25 clinically significant), Staphylococcus aureus (22 children) and Streptococcus pneumoniae (20 children). Nontyphoidal Salmonella (10 children), Escherichia coli (4 children) and Klebsiella sp. (4 children) were the most frequent Gram-negative bacteria. Two children had Rhodococcus equi pneumonia. HIV-infected children showed increased risk of bacteremia (odds ratio (OR) = 2.68), especially if younger than 18 months of age (OR = 2.94), and high risk of enterobacteremia (OR = 15.76). There was no significant association of bacteremia with nutritional status. Mortality was 17% overall but was higher in HIV-infected children up to 6 months of age (OR = 2.81) and in bacteremic children of any age (OR = 2.03).

CONCLUSIONS

Prompt recognition of pathogens and early administration of appropriate antimicrobials is important in reducing the morbidity and mortality associated with bacteremia in HIV-infected children in Africa.