Invasive pneumococcal disease in children<5 years of age in rural Mozambique

Pneumococcal Disease: Global Disease Prevention Strategies with a Focus on the Challenges in Iraq

Pneumococcal disease is a global public health concern that significantly contributes to clinical disease burden and economic burden. Patients frequently afflicted are young children and older adults, as well as the immunocompromised population. Immunization is the most effective public health strategy to combat pneumococcal disease and several vaccine formulations have been developed in this regard. Although vaccines have had a significant global impact in reducing pneumococcal disease, there are several barriers to its success in Iraq. The war and conflict situation, increasing economic crises and poverty, poor vaccine accessibility in the public sector, and high vaccine costs are a few of the major obstacles that impede a successful immunization program. The last reported third dose pneumococcal conjugate vaccine coverage for Iraq was 37% in 2019, which is expected to reduce even further owing to the COVID-19 pandemic. Thus, strategies and policies to improve pneumococcal vaccine availability and coverage need to be strengthened to achieve maximum benefits of immunization. In the current review, we provide an overview of the existing knowledge on pneumococcal disease-prevention strategies across the globe. The main aim of this manuscript is to discuss the current status and challenges of pneumococcal vaccination in Iraq as well as the strategies to prevent pneumococcal infections.

Child Health and Mortality Prevention Surveillance (CHAMPS): Manhiça site description, Mozambique

The Manhiça Health Research Centre (Manhiça HDSS) was established in 1996 in Manhiça, a rural district at Maputo Province in the southern part of Mozambique with approximately 49,000 inhabited households, a total population of 209.000 individuals, and an annual estimated birth cohort of about 5000 babies. Since 2016, Manhiça HDSS is implementing the Child Health and Mortality Prevention Surveillance (CHAMPS) program aiming to investigate causes of death (CoD) in stillbirths and children under the age of 5 years using, among other tools, the innovative post-mortem technique known as Minimally Invasive Tissue sampling (MITS). Both in-hospital and community pediatric deaths are investigated using MITS. For this, community-wide socio-demographic approaches (notification of community deaths by key informants, formative research involving several segments of the community, availability of free phone lines for notification of medical emergencies and deaths, etc.) are conducted alongside to foster community awareness, involvement and adherence as well as to compute mortality estimates and collect relevant information of health and mortality determinants. The main objective of this paper is to describe the Manhiça Health and Demographic Surveillance System (HDSS) site and the CHAMPS research environment in place including the local capacities among its reference hospital, laboratories, data center and other relevant areas involved in this ambitious surveillance and research project, whose ultimate aim is to improve child survival through public health actions derived from credible estimates and understanding of the major causes of childhood mortality in Mozambique.

Pediatric Invasive Pneumococcal Disease (IPD) in Yogyakarta, Indonesia: A Case Series

Given the fact that invasive pneumococcal disease (IPD) has a high clinical burden, particularly among children in developing countries, data on its occurrence and clinical profile in Indonesia is still insufficient. We presented 3 cases of IPD in children who were admitted to Dr. Sardjito General Hospital, Yogyakarta, Indonesia between 2016 and 2019. While our first 2 patients had milder course of disease, our third patient who presented with meningoencephalitis had poor outcome. Risk factors shown in our cases were young age and malignancy history. Multiple antibiotic resistance was observed in our isolates. The fact that none of our patients have received pneumococcal vaccination marks the necessity of this vaccine especially for at-risk children.

Klebsiella spp. cause severe and fatal disease in Mozambican children: antimicrobial resistance profile and molecular characterization

Background

Klebsiella spp. are important pathogens associated with bacteremia among admitted children and is among the leading cause of death in children < 5 years in postmortem studies, supporting a larger role than previously considered in childhood mortality. Herein, we compared the antimicrobial susceptibility, mechanisms of resistance, and the virulence profile of Klebsiella spp. from admitted and postmortem children.

Methods

Antimicrobial susceptibility and virulence factors of Klebsiella spp. recovered from blood samples collected upon admission to the hospital (n = 88) and postmortem blood (n = 23) from children < 5 years were assessed by disk diffusion and multiplex PCR.

Results

Klebsiella isolates from postmortem blood were likely to be ceftriaxone resistant (69.6%, 16/23 vs. 48.9%, 43/88, p = 0.045) or extended-spectrum β-lactamase (ESBL) producers (60.9%, 14/23 vs. 25%, 22/88, p = 0.001) compared to those from admitted children. bla_CTX-M-15 was the most frequent ESBL gene: 65.3%, 9/14 in postmortem isolates and 22.7% (5/22) from admitted children. We found higher frequency of genes associated with hypermucoviscosity phenotype and invasin in postmortem isolates than those from admitted children: rmpA (30.4%; 7/23 vs. 9.1%, 8/88, p = 0.011), wzi-K1 (34.7%; 8/23 vs. 8%; 7/88, p = 0.002) and traT (60.8%; 14/23 vs. 10.2%; 9/88, p < 0.0001), respectively. Additionally, serine protease auto-transporters of Enterobacteriaceae were detected from 1.8% (pic) to 12.6% (pet) among all isolates. Klebsiella case fatality rate was 30.7% (23/75).

Conclusion

Multidrug resistant Klebsiella spp. harboring genes associated with hypermucoviscosity phenotype has emerged in Mozambique causing invasive fatal disease in children; highlighting the urgent need for prompt diagnosis, appropriate treatment and effective preventive measures for infection control.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06245-x.

Declines in Pneumonia and Meningitis Hospitalizations in Children Under 5 Years of Age After Introduction of 10-Valent Pneumococcal Conjugate Vaccine in Zambia, 2010-2016

Background

Pneumococcus is a leading cause of pneumonia and meningitis. Zambia introduced a 10-valent pneumococcal conjugate vaccine (PCV10) in July 2013 using a 3-dose primary series at ages 6, 10, and 14 weeks with no booster. We evaluated the impact of PCV10 on meningitis and pneumonia hospitalizations.

Methods

Using hospitalization data from first-level care hospitals, available at the Ministry of Health, and from the largest pediatric referral hospital in Lusaka, we identified children aged <5 years who were hospitalized with pneumonia or meningitis from January 2010–December 2016. We used time-series analyses to measure the effect of PCV10 on monthly case counts by outcome and age group (<1 year, 1–4 years), accounting for seasonality. We defined the pre- and post-PCV10 periods as January 2010–June 2013 and July 2014–December 2016, respectively.

Results

At first-level care hospitals, pneumonia and meningitis hospitalizations among children aged <5 years accounted for 108 884 and 1742 admissions in the 42 months pre-PCV10, respectively, and 44 715 and 646 admissions in the 30 months post-PCV10, respectively. Pneumonia hospitalizations declined by 37.8% (95% confidence interval [CI] 21.4–50.3%) and 28.8% (95% CI 17.7–38.7%) among children aged <1 year and 1–4 years, respectively, while meningitis hospitalizations declined by 72.1% (95% CI 63.2–79.0%) and 61.6% (95% CI 50.4–70.8%), respectively, in these age groups. In contrast, at the referral hospital, pneumonia hospitalizations remained stable and a smaller but significant decline in meningitis was observed among children aged 1–4 years (39.3%, 95% CI 16.2–57.5%).

Conclusions

PCV10 introduction was associated with declines in meningitis and pneumonia hospitalizations in Zambia, especially in first-level care hospitals.

Invasive disease potential of Streptococcus pneumoniae serotypes before and after 10-valent pneumococcal conjugate vaccine introduction in a rural area, southern Mozambique

BACKGROUND

Invasive pneumococcal disease (IPD) is a significant cause of morbidity and mortality among children worldwide. In April 2013, Mozambique introduced 10-valent PCV (PCV10) into the National Expanded Program on immunization using a three-dose schedule at 2, 3, and 4 months of age. We aimed to evaluate the invasive disease potential of pneumococcal serotypes among children in our region before and after PCV10 introduction.

METHODS

We used data from ongoing population-based surveillance for IPD and cross-sectional pneumococcal carriage surveys among children aged <5 years in Manhiҫa, Mozambique. To determine the invasive disease potential for each serotype pre- and post-PCV10 introduction, odds ratios (OR) and 95% confidence intervals (95% CI) were calculated comparing serotype-specific prevalence in IPD and in carriage. For each serotype, OR and 95% CI > 1 indicated high invasive disease potential and OR and 95% CI < 1 indicated low invasive disease potential.

RESULTS

In the pre-PCV10 period, 524 pneumococcal isolates were obtained from 411 colonized children and IPD cases were detected in 40 children. In the post-PCV10 period, 540 pneumococcal isolates were obtained from 507 colonized children and IPD cases were detected in 30 children. The most prevalent serotypes causing IPD pre-PCV10 were 6A (17.5%), 6B (15.0%), 14 (12.5%), 23F (10.0%) and 19F (7.5%), and post-PCV10 were 6A (36.7%), 13 (10%), 1 (10.0%), 6B (6.7%) and 19A (6.7%). Serotypes associated with high invasive disease potential pre-PCV10 included 1 (OR:22.3 [95% CI 2.0; 251.2]), 6B (OR:3.1 [95% CI 1.2; 8.1]), 14 (OR: 3.4 [95% CI 1.2; 9.8]) and post-PCV10 included serotype 6A (OR:6.1[95% CI 2.7; 13.5]).

CONCLUSION

The number of serotypes with high invasive disease potential decreased after PCV10 introduction. Serotype 6A, which is not included in PCV10, was the most common cause of IPD throughout the study and showed a high invasive potential in the post-PCV10 period.

Pharmacokinetics and Pharmacodynamic Target Attainment of Benzylpenicillin in an Adult Severely Ill Sub-Saharan African Patient Population

Background

In intensive care (ICU) patients, systemic exposure of β-lactam antibiotics can be altered, and positive clinical outcome is associated with increasing fT > MIC ratios. In sub-Saharan African hospitals, benzylpenicillin (PEN) is frequently used for the empiric treatment of severe pneumococcal infections. Pharmacokinetic data for non-ICU hospitalized populations are lacking.

Methods

We performed a population pharmacokinetic (PPK) study in an adult Mozambican hospital population treated intravenously with PEN from October 2014 through November 2015. Four blood samples/patient were collected for total PEN (PENt) and unbound PEN (PENu) concentration measurement. We developed a PPK model through nonlinear mixed-effects analysis and performed simulations for different patient variable, dosing, and pharmacodynamic target scenarios.

Results

One hundred twelve participants yielded 387 PENt and 53 PENu concentrations. The median body mass index was 18.3 (range, 10.5-31.3) kg/m2 and the median albumin concentration and creatinine clearance (CrCl) were 29 (range, 12-44) g/L and 80 (range, 3-195) mL/minute, respectively. In a 1-compartment model, CrCl was positively correlated with PENt clearance. For infections with a microorganism with a minimum inhibitory concentration (MIC) of 1 mg/L, simulations demonstrated that with 3 million IU (1.8 g) every 6 hours, 74.1% would have a PENu concentration greater than the MIC during half of the dosing interval (fT > MIC = 50%), whereas this was 24.8% for the fT > MIC = 100% target. For pathogens with an MIC of 0.06 mg/L, these percentages were 98.2% and 72.3%, respectively.

Conclusions

Severely ill adult sub-Saharan African patients may be at high risk for underexposure to PENu during routine intermittent bolus dosing, especially when their renal function is intact and when infected with pathogens with intermediate susceptibility.

Assessing the causes of under-five mortality and proportion associated with pneumococcal diseases in Cameroon. A case-finding retrospective observational study: 2006-2012

BACKGROUND

Vital registration data outlining causes of deaths (CoD) are important for a sustainable health system, targeted interventions and other relevant policies. There is data paucity on vital registration systems in developing countries. We assessed the leading causes and proportions of under-five deaths, and particularly those related to pneumococcal infections in Yaoundé, Cameroon, using hospital registration data.

METHODS

A retrospective case-finding observational study design was used to access and identify data on 817 death cases in children under-five years of age recorded in health facilities in Yaoundé, within the period January 1, 2006 and December 31, 2012. Patients' files were randomly selected and needed information including demographic data, date of admission, clinical and laboratory diagnosis, principal and/or underlying causes of death were abstracted into structured case report forms. The International Classification of Diseases and Clinical Modifications 10th revision (ICD-10-CM) codes (ICD10Data.com 2017 edition) were used to classify the different CoD, retrospectively. Ascertainment of CoD was based on medical report and estimates were done using the Kaplan-Meier procedure and descriptive statistics.

RESULTS

Of the 817 death records assessed, malaria was the leading CoD and was responsible for 17.5% of cases. Meningitis was the second largest CoD with 11.0%; followed by sepsis (10.0%), Streptococcus pneumoniae infections (8.3%), malnutrition (8.3%), gastro-enteritis / diarrhoea (6.2%), anaemia (6.1%) and HIV (3.5%), respectively.

CONCLUSION

The main CoD in this population are either treatable or vaccine-preventable; a trend consistent with previous reports across developing countries. Besides, the health effects from non-communicable infections should not be neglected. Therefore, scaling-up measures to reduce causes of under-five deaths will demand sustainable efforts to enhance both treatment and disease prevention strategies, to avoid a decline in the progress towards reducing under-five deaths by 2/3 from the 1990 baseline.

Early Declines in Vaccine Type Pneumococcal Carriage in Children Less Than 5 Years Old After Introduction of 10-valent Pneumococcal Conjugate Vaccine in Mozambique

BACKGROUND

Pneumococcal carriage is a precursor of invasive pneumococcal disease. Mozambique introduced 10-valent pneumococcal conjugate vaccine (PCV10) in April 2013, using a 3-dose schedule without a booster. We evaluated PCV10 impact on pneumococcal carriage and colonization density by HIV status.

METHODS

We conducted 2 cross-sectional surveys (pre and post PCV10 introduction) among children 6 weeks to 59 months old. Participants included HIV-infected children presenting for routine care at outpatient clinics and a random sample of HIV-uninfected children from the community. We collected demographic data, vaccination history and nasopharyngeal swabs. Swabs were cultured and isolates serotyped by Quellung. We selected serotypes 11A, 19A and 19F for bacterial density analyses. We compared vaccine-type (VT) carriage prevalence from the pre-PCV10 with the post-PCV10 period by HIV status.

FINDINGS

Prevalence of VT carriage declined from 35.9% (110/306) pre already defined in the background. It should be pre-PCV (PCV) to 20.7% (36/174 fully vaccinated) post PCV (P < 0.001) in HIV-uninfected and from 34.8% (144/414) to 19.7% (27/137 fully vaccinated) (P = 0.002) in HIV-infected children. Colonization prevalence for the 3 serotypes (3, 6A, 19A) included in the 13-valent PCV but not in PCV10 increased from 12.4% (38/306) to 20.7% (36/174 fully vaccinated) (P = 0.009) among HIV- uninfected children, mainly driven by 19A; no significant increase was observed in HIV-infected children. VT carriage among unvaccinated children decreased by 30% (P = 0.005) in HIV-infected children, with no significant declines observed in HIV-uninfected children.

CONCLUSION

Declines in VT carriage were observed in both HIV-uninfected and HIV-infected children after PCV10 introduction with an early signal of herd effect especially in HIV-infected children. Ongoing monitoring of increases in 19A carriage and disease is necessary.

Invasive bacterial disease trends and characterization of group B streptococcal isolates among young infants in southern Mozambique, 2001-2015

Background

Maternal group B streptococcal (GBS) vaccines under development hold promise to prevent GBS disease in young infants. Sub-Saharan Africa has the highest estimated disease burden, although data on incidence and circulating strains are limited. We described invasive bacterial disease (IBD) trends among infants <90 days in rural Mozambique during 2001–2015, with a focus on GBS epidemiology and strain characteristics.

Methods

Community-level birth and mortality data were obtained from Manhiça’s demographic surveillance system. IBD cases were captured through ongoing surveillance at Manhiça district hospital. Stored GBS isolates from cases underwent serotyping by multiplex PCR, antimicrobial susceptibility testing, and whole genome sequencing.

Results

There were 437 IBD cases, including 57 GBS cases. Significant declines in overall IBD, neonatal mortality, and stillbirth rates were observed (P<0.0001), but not for GBS (P = 0.17). In 2015, GBS was the leading cause of young infant IBD (2.7 per 1,000 live births). Among 35 GBS isolates available for testing, 31 (88.6%) were highly related serotype III isolates within multilocus sequence types (STs) 17 (68.6%) or 109 (20.0%). All seven ST109 isolates (21.9%) had elevated minimum inhibitory concentration (MIC) to penicillin (≥0.12 μg/mL) associated with penicillin-binding protein (PBP) 2x substitution G398A. Epidemiologic and molecular data suggest this is a well-established clone.

Conclusion

A notable young infant GBS disease burden persisted despite improvements in overall maternal and neonatal health. We report an established strain with pbp2x point mutation, a first-step mutation associated with reduced penicillin susceptibility within a well-known virulent lineage in rural Mozambique. Our findings further underscores the need for non-antibiotic GBS prevention strategies.

Burden of invasive pneumococcal disease among children in rural Mozambique: 2001-2012

Background

Invasive pneumococcal disease (IPD) is a major cause of illness and death among children worldwide. 10-valent pneumococcal conjugate vaccine (PCV10) was introduced as part of the Mozambican routine immunization program in April 2013. We characterized the IPD burden in a rural area of Mozambique before PCV introduction and estimated the potential impact of this intervention.

Methods

We conducted population-based surveillance for IPD, defined as S. pneumoniae isolated from blood or cerebrospinal fluid, among children <5 years old admitted to Manhiça District Hospital, a referral hospital in a rural area with high prevalence of human immunodiciency virus infection. S. pneumoniae was identified using standard microbiologic methods and serotyped using sequential multiplex PCR or Quellung. IPD incidence was calculated among cases from a defined catchment area.

Results

From January 2001 through December 2012, we isolated 768 cases of IPD, 498 (65%) of which were bacteraemic pneumonia episodes. A total of 391 (51%) were from the catchment area, yielding IPD incidence rates of 479, 390 and 107 episodes per 100,000 children-years at risk among children <12, 12–23 and 24-<60 months old, respectively. The overall IPD incidence fluctuated and showed a downward trend over time. In these same age groups, in-hospital death occurred in 48 (17%), 26 (12%), and 21 (13%) of all IPD cases, respectively. Overall 90% (543/603) of IPD isolates were available for serotyping; of those, 65% were covered by PCV10 and 83% by PCV13. Among 77 hospital deaths associated with serotyped IPD, 49% and 69% were caused by isolates included in the PCV10 and PCV13, respectively.

Conclusions

We describe very high rates of IPD among children in rural Mozambique that were declining before PCV introduction. Children <1 year old have the greatest incidence and case fatality; although the rates remain high among older groups as well. Most IPD episodes and many deaths among children <5 years old will likely be prevented through PCV10 introduction in Mozambique.

The Influence of Vaccine on Febrile Seizure

BACKGROUND

The protective value of vaccines to the public has made vaccines among the major public health prophylactic measures through the entire history. However, there has been some controversy about their safety; particularly concerns have been rising about febrile seizures (FS). Vaccination was found to be the second most common cause of FS.

METHODS

We research and collect relative online content for reviewing the effects of vaccine in FS.

RESULTS

there is no causal relationship between FS and vaccination. This relationship is complex by other factors, such as age, genetic inheritance, type of vaccine, combination of different types of vaccines and the timing of vaccination.

CONCLUSION

In order to reduce FS after vaccination, it is important to understand the mechanism of epilepsy and relationship between specific vaccines and FS. Parents should be informed that some vaccines could be associated with an increased risk of FS, particularly, in children with personal and family history of FS. Children with genetic epilepsy syndrome are prone to seizures and certain vaccinations should be avoided in these children. It is highly recommended to choose vaccines with lower risk of developing FS and to administer these vaccines during the low risk window of immunizations schedule.

Childhood pneumococcal disease in Africa - A systematic review and meta-analysis of incidence, serotype distribution, and antimicrobial susceptibility

BACKGROUND

Determining the incidence, disease-associated serotypes and antimicrobial susceptibility of invasive pneumococcal disease (IPD) among children in Africa is essential in order to monitor the impact of these infections prior to widespread introduction of the pneumococcal conjugate vaccine (PCV).

METHODS

To provide updated estimates of the incidence, serotype distribution, and antimicrobial susceptibility profile of Streptococcus pneumoniae causing disease in Africa, we performed a systematic review of articles published from 2000 to 2015 using Ovid Medline and Embase. We included prospective and surveillance studies that applied predefined diagnostic criteria. Meta-analysis for all pooled analyses was based on random-effects models.

RESULTS

We included 38 studies consisting of 386,880 participants in 21 countries over a total of 350,613 person-years. The pooled incidence of IPD was 62.6 (95% CI 16.9, 226.5) per 100,000 person-years, including meningitis which had a pooled incidence of 24.7 (95% CI 11.9, 51.6) per 100,000 person-years. The pooled prevalence of penicillin susceptibility was 78.1% (95% CI 61.9, 89.2). Cumulatively, PCV10 and PCV13 included 66.9% (95% CI 55.9, 76.7) and 80.6% (95% CI 66.3, 90.5) of IPD serotypes, respectively.

CONCLUSIONS

Our study provides an integrated and robust summary of incidence data, serotype distribution and antimicrobial susceptibility for S. pneumoniae in children ≤5years of age in Africa prior to widespread introduction of PCV on the continent. The heterogeneity of studies and wide range of incidence rates across the continent indicate that surveillance efforts should be intensified in all regions of Africa to improve the integrity of epidemiologic data, vaccine impact and cost benefit. Although the incidence of IPD in young children in Africa is substantial, currently available conjugate vaccines are estimated to cover the majority of invasive disease-causing pneumococcal serotypes. These data provide a reliable baseline from which to monitor the impact of the broad introduction of PCV.

Pneumococcal infection among hospitalized Egyptian children

AIM

We aimed to describe the detection rate spectrum of clinical manifestations, and outcome of pneumococcal disease in children younger than 5 years admitted to the largest referral pediatric hospital in Egypt.

MATERIALS AND METHODS

This was a hospital-based study to detect laboratory-confirmed Streptococcus pneumoniae cases among children younger than 5 years. Data on demographic characteristics, clinical diagnosis, comorbidities, diagnostic tests, antibiotic resistance, and clinical outcome were collected during the study years from 2008 to 2011.

RESULTS

During the 4-year study period, 22 018 cases younger than 5 years had cultures performed at Cairo University Pediatric Hospital microbiology laboratory. We estimated the annual detection rate of total Streptococcus pneumonia infection to be 54.5/100 000. The incidence of invasive pneumococcal disease (IPD) was half the incidence of non-IPD (18.2 and 36.4/100 000, respectively). Infants of 1 year or younger were statistically more vulnerable to Streptococcus pneumonia infection compared with children between 1 and 5 years of age (annual rate: 110.5/100 000 and 21.6/100 000, respectively). The overall pneumococcal annual case fatality was 33.3% and was higher in IPD (75%) than in non-IPD (12.5%) cases. There was an obviously increasing trend of the pneumococcal detection rate throughout the 4 years of the study (P<0.0001).

CONCLUSION AND RECOMMENDATIONS

Our results confirm the substantial and increasing pneumococcal infection, the emerging of multidrug resistant isolates, and the vulnerability of the younger age group and high-risk population, which calls for a national surveillance to inform policy and decision-making before national wide vaccine introduction.

High prevalence of Pneumocystis jirovecii pneumonia among Mozambican children <5 years of age admitted to hospital with clinical severe pneumonia

We aimed to describe Pneumocystis jirovecii pneumonia (PCP) prevalence and features in children from sub-Saharan Africa and to investigate PCP-associated risk factors. During 2006-2007 we used molecular methods to test children younger than 5 years old admitted with severe pneumonia to a hospital in southern Mozambique for Pneumocystis infection. We recruited 834 children. PCP prevalence was 6.8% and HIV prevalence was 25.7%. The in-hospital and delayed mortality were significantly higher among children with PCP (20.8% vs. 10.2%, p 0.021, and 11.5% vs. 3.6%, p 0.044, respectively). Clinical features were mostly overlapping between the two groups. Independent risk factors for PCP were age less than a year (odds ratio (OR) 6.34, 95% confidence interval (CI) 1.86-21.65), HIV infection (OR 2.99, 95% CI 1.16-7.70), grunting (OR 2.64, 95% CI 1.04-6.73) and digital clubbing (OR 10.75, 95% CI 1.21-95.56). PCP is a common and life-threatening cause of severe pneumonia in Mozambican children. Mother-to-child HIV transmission prevention should be strengthened. Better diagnostic tools are needed.

Management of sickle cell disease: a review for physician education in Nigeria (sub-saharan Africa)

Sickle cell disease (SCD) predominates in sub-Saharan Africa, East Mediterranean areas, Middle East, and India. Nigeria, being the most populous black nation in the world, bears its greatest burden in sub-Saharan Africa. The last few decades have witnessed remarkable scientific progress in the understanding of the complex pathophysiology of the disease. Improved clinical insights have heralded development and establishment of disease modifying interventions such as chronic blood transfusions, hydroxyurea therapy, and haemopoietic stem cell transplantation. Coupled with parallel improvements in general supportive, symptomatic, and preventive measures, current evidence reveals remarkable appreciation in quality of life among affected individuals in developed nations. Currently, in Nigeria and other West African states, treatment and control of SCD are largely suboptimal. Improved knowledge regarding SCD phenotypes and its comprehensive care among Nigerian physicians will enhance quality of care for affected persons. This paper therefore provides a review on the aetiopathogenesis, clinical manifestations, and management of SCD in Nigeria, with a focus on its local patterns and peculiarities. Established treatment guidelines as appropriate in the Nigerian setting are proffered, as well as recommendations for improving care of affected persons.

Antimicrobial drug resistance among clinically relevant bacterial isolates in sub-Saharan Africa: a systematic review

BACKGROUND

Little is known about the prevalence of antimicrobial resistance (AMR) amongst bacterial pathogens in sub-Saharan Africa (sSA), despite calls for continent-wide surveillance to inform empirical treatment guidelines.

METHODS

We searched PubMed and additional databases for susceptibility data of key pathogens for surveillance, published between 1990 and 2013. Extracted data were standardized to a prevalence of resistance in populations of isolates and reported by clinical syndrome, microorganism, relevant antimicrobial drugs and region.

RESULTS

We identified 2005 publications, of which 190 were analysed. Studies predominantly originated from east sSA (61%), were hospital based (60%), were from an urban setting (73%) and reported on isolates from patients with a febrile illness (42%). Quality procedures for susceptibility testing were described in <50% of studies. Median prevalence (MP) of resistance to chloramphenicol in Enterobacteriaceae, isolated from patients with a febrile illness, ranged between 31.0% and 94.2%, whilst MP of resistance to third-generation cephalosporins ranged between 0.0% and 46.5%. MP of resistance to nalidixic acid in Salmonella enterica Typhi ranged between 15.4% and 43.2%. The limited number of studies providing prevalence data on AMR in Gram-positive pathogens or in pathogens isolated from patients with a respiratory tract infection, meningitis, urinary tract infection or hospital-acquired infection suggested high prevalence of resistance to chloramphenicol, trimethoprim/sulfamethoxazole and tetracycline and low prevalence to third-generation cephalosporins and fluoroquinolones.

CONCLUSIONS

Our results indicate high prevalence of AMR in clinical bacterial isolates to antimicrobial drugs commonly used in sSA. Enhanced approaches for AMR surveillance are needed to support empirical therapy in sSA.

Streptococcus pneumoniae invasive infections in Burkina Faso, 2007 to 2011

OBJECTIVE

We had for aim to determine the epidemiology of meningeal and lung invasive infections due to Streptococcus pneumoniae in Burkina Faso.

MATERIAL AND METHODS

We screened for S. pneumoniae with the usual bacteriology techniques and with real time polymerase chain reaction (rt-PCR) in 7917 samples of cerebrospinal fluid (CSF) and pleural fluid (PF) collected in the Ouagadougou Yalgado Ouedraogo Teaching Hospital, from 2007 to 2011.

RESULTS

S. pneumoniae was identified in 476 (6%) samples including 455 (5.7%) in CSF and 21 (0.3%) in PF. Sixty-seven percent of invasive infections occurred in patients 15 years of age or less, without any significant sex ratio difference. The infections occurred most frequently between January and August, with the first and most important peak between January and May (dry season) and the second peak between June and August (at the beginning of rain season). The introduction of rt-PCR proved the under diagnosing of invasive infections by usual bacteriological methods (latex agglutination assay and culture).

CONCLUSION

Invasive pneumococcal infections occur mainly in patients 15 years of age or less, without any difference in sex ratio and with peaks in the dry season. Vaccinal schedules should include all age ranges in Burkina Faso.

Sickle cell disease: new opportunities and challenges in Africa

Sickle cell disease (SCD) is one of the most common genetic causes of illness and death in the world. This is a review of SCD in Africa, which bears the highest burden of disease. The first section provides an introduction to the molecular basis of SCD and the pathophysiological mechanism of selected clinical events. The second section discusses the epidemiology of the disease (prevalence, morbidity, and mortality), at global level and within Africa. The third section discusses the laboratory diagnosis and management of SCD, emphasizing strategies that been have proven to be effective in areas with limited resources. Throughout the review, specific activities that require evidence to guide healthcare in Africa, as well as strategic areas for further research, will be highlighted.

Clinical Burden of Invasive Pneumococcal Disease in Selected Developing Countries

OBJECTIVE

To measure the clinical burden of invasive pneumococcal disease (IPD) in selected developing countries.

METHODS

This is an extensive literature review of published articles on IPD in selected developing countries from East Asia, South Asia, Middle East, sub-Saharan Africa, and Latin America. We reviewed all the articles retrieved from the knowledge bases that were published between the years 2000 and 2010.

RESULTS

After applying the inclusion, exclusion, and quality criteria, the comprehensive review of the literature yielded 10 articles with data for pneumococcal meningitis, septicemia/bacteremia, and pneumonia. These selected articles were from 10 developing countries from five different regions. Out of the 10 selected articles, 8 have a detailed discussion on IPD, one of them has s detailed discussion on bacteremia and meningitis, and another one has discussed pneumococcal bacteremia. Out of these 10 articles, only 5 articles discussed the case-fatality ratio (CFR). In our article review, the incidence of IPD ranged from less than 5/100,000 to 416/100,000 population and the CFR ranged from 12.2% to 80% in the developing countries.

CONCLUSIONS

The review demonstrated that the clinical burden of IPD was high in the developing countries. The incidence of IPD and CFR varies from region to region and from country to country. The IPD burden was highest in sub-Saharan African countries followed by South Asian countries. The CFR was low in high-income countries than in low-income countries.

Epidemiology of invasive pneumococcal infection among hospitalized children aged less than 5 years in Oman

The objective of this study was to describe the epidemiology of invasive pneumococcal disease (IPD) in Omani children. We retrospectively reviewed cases admitted in children <5 years of age who were admitted in one of 4 tertiary care facilities within the Muscat Governorate. These cases represented nearly 95% of all IPD admissions recorded throughout the country from 1 January 2006 to 31 December 2006. Cases of IPD were identified using the ICD-10 discharge code. Case definition required microbiological confirmation (i.e., isolation of Streptococcus pneumoniae from blood, cerebrospinal fluid or any other normally sterile biological fluid) or clinical diagnosis in the absence of a specimen. A total of 41 cases of IPD were identified. The annual incidence of IPD was 26.1 per 100,000 in children <2 years old and 18.6 per 100,000 in children <5 years old. Among the reported IPD cases, 22 (54%) isolates were resistant to at least one antibiotic and 15 (37%) of patients had a known comorbid medical condition. These results demonstrate that the incidence of IPD in Oman during 2006 was high compared to many of the neighboring countries and provides baseline data on the incidence of IPD in an era before the introduction of the pneumococcal conjugate vaccine (PCV). In light of evidence for a significant incidence of IPD, we recommended that a nationwide surveillance system be put in place to monitor the incidence of IPD in children <5 years of age in Oman and to document the impact of PCV.

Challenges in the diagnosis of iron deficiency in children exposed to high prevalence of infections

BACKGROUND

While WHO guidelines recommend iron supplements to only iron-deficient children in high infection pressure areas, these are rarely implemented. One of the reasons for this is the commonly held view that iron supplementation increases the susceptibility to some infectious diseases including malaria. Secondly, currently used markers to diagnose iron deficiency are also modified by infections. With the objective of improving iron deficiency diagnosis and thus, its management, we evaluated the performance of iron markers in children exposed to high infection pressure.

METHODOLOGY/PRINCIPAL FINDINGS

Iron markers were compared to bone marrow findings in 180 anaemic children attending a rural hospital in southern Mozambique. Eighty percent (144/180) of the children had iron deficiency by bone marrow examination, 88% (155/176) had an inflammatory process, 66% (119/180) had moderate anaemia, 25% (45/180) severe anaemia and 9% (16/180) very severe anaemia. Mean cell haemoglobin concentration had a sensitivity of 51% and specificity of 71% for detecting iron deficiency. Soluble transferrin receptor (sTfR) and soluble transferrin receptor/log ferritin (TfR-F) index (adjusted by C reactive protein) showed the highest areas under the ROC curve (AUC(ROC)) (0.75 and 0.76, respectively), and were the most sensitive markers in detecting iron deficiency (83% and 75%, respectively), but with moderate specificities (50% and 56%, respectively).

CONCLUSIONS/SIGNIFICANCE

Iron deficiency by bone marrow examination was extremely frequent in these children exposed to high prevalence of infections. However, even the best markers of bone marrow iron deficiency did not identify around a quarter of iron-deficient children. Tough not directly extrapolated to the community, these findings urge for more reliable, affordable and easy to measure iron indicators to reduce the burden of iron deficiency anaemia in resource-poor settings where it is most prevalent.

A literature review and survey of childhood pneumonia etiology studies: 2000-2010

The Pneumonia Etiology Research for Child Health (PERCH) project is the largest multicountry etiology study of childhood pneumonia since the Board on Science and Technology in International Development studies of the 1980s. However, it is not the only recent or ongoing pneumonia etiology study, and even with seven sites, it cannot capture all epidemiologic settings in the developing world. Funding providers, researchers and policymakers rely on the best available evidence to strategically plan programs, new research directions and interventions. We aimed to describe the current landscape of recent pneumonia etiology studies in children under 5 years of age in the developed and developing world, as ascertained by a literature review of relevant studies with data since the year 2000 and a survey of researchers in the field of childhood pneumonia. We collected information on the study population, study design, case definitions, laboratory samples and methods and identified pathogens. A literature review identified 88 studies with child pneumonia etiology results. As of June 2010, our survey of researchers identified an additional 65 ongoing and recently completed child pneumonia etiology studies. This demonstrates the broad existing context into which the PERCH study must be placed. However, the landscape analysis also reveals a multiplicity of case definitions, levels of clinician involvement, facility types, specimen collection, and laboratory techniques. It reinforces the need for the standardization of methods and analyses for present and future pneumonia etiology studies in order to optimize their cumulative potential to accurately describe the microbial causes of childhood pneumonia.

Increased risk of death in human immunodeficiency virus-infected children with pneumococcal meningitis in South Africa, 2003-2005

BACKGROUND

Pneumococcal disease is a major global cause of morbidity and mortality. This study evaluated risk factors for mortality in children with pneumococcal meningitis and other invasive pneumococcal diseases (IPD).

METHODS

The study population included patients <15 years of age with laboratory-confirmed IPD and available outcome data between January 1, 2003 and December 31, 2005 as reported to a national laboratory-based surveillance program. Meningitis was defined by having pneumococcus identified from cerebrospinal fluid culture, while other IPD included patients with pneumococci identified from other normally sterile site specimens. Risk factors for mortality were evaluated using multivariable logistic regression.

RESULTS

A total of 2251 patients with IPD were reported from sentinel sites: 581 with laboratory-confirmed meningitis and 1670 with other IPD. The case-fatality ratio was 35% (205/581) among meningitis cases and 18% (300/1670) among other IPD cases (P < 0.001). Among individuals with available human immunodeficiency virus (HIV) status data, HIV coinfection was less likely among patients with meningitis compared with other IPD (74% [244/328] vs. 82% [880/1067] P < 0.001). On multivariable analysis, HIV-infected status (odds ratio [OR]: 5.34, 95% confidence interval [CI]: 2.32-12.29), Pitt bacteremia score ≥4 (OR: 3.08, 95% CI: 1.21-7.83) and age group <1 year (OR: 2.58, 95% CI: 1.21-5.51) were independent predictors of death among patients with meningitis. Among children with other IPD, malnutrition was an independent predictor of death while HIV infection was not independently associated with increased risk of death.

CONCLUSIONS

Pneumococcal meningitis is associated with a high case-fatality ratio among South African children and this is increased by HIV coinfection. Increasing access to antiretroviral therapy and a catch-up program for pneumococcal conjugate vaccine among HIV-infected and malnourished children could reduce this excess mortality.

Distinguishing malaria from severe pneumonia among hospitalized children who fulfilled integrated management of childhood illness criteria for both diseases: a hospital-based study in Mozambique

Malaria and severe pneumonia in hospitalized young children may show striking clinical similarities, making differential diagnosis challenging. We investigated ways to increase diagnostic accuracy in patients hospitalized with clinical symptoms compatible with malaria and severe pneumonia, in an area with high a prevalence of infection with human immunodeficiency virus. A total of 646 children admitted at the Manhiça District Hospital in Manhiça, Mozambique who met the World Health Organization clinical criteria for severe pneumonia and malaria were recruited for 12 months and thoroughly investigated to ascertain an accurate diagnosis. Although symptom overlap between malaria and severe pneumonia was frequent among hospitalized children, true disease overlap was uncommon. Clinical presentation and laboratory determinations were ineffective in reliably distinguishing between the two diseases. Infection with human immunodeficiency virus differentially influenced the epidemiology and clinical presentation of these two infectious diseases, further challenging their discrimination on clinical grounds, and having a greater impact on the current burden and prognosis of severe pneumonia.

Effects of community-wide vaccination with PCV-7 on pneumococcal nasopharyngeal carriage in the Gambia: a cluster-randomized trial

BACKGROUND

Introduction of pneumococcal conjugate vaccines (PCVs) of limited valency is justified in Africa by the high burden of pneumococcal disease. Long-term beneficial effects of PCVs may be countered by serotype replacement. We aimed to determine the impact of PCV-7 vaccination on pneumococcal carriage in rural Gambia.

METHODS AND FINDINGS

A cluster-randomized (by village) trial of the impact of PCV-7 on pneumococcal nasopharyngeal carriage was conducted in 21 Gambian villages between December 2003 to June 2008 (5,441 inhabitants in 2006). Analysis was complemented with data obtained before vaccination. Because efficacy of PCV-9 in young Gambian children had been shown, it was considered unethical not to give PCV-7 to young children in all of the study villages. PCV-7 was given to children below 30 mo of age and to those born during the trial in all study villages. Villages were randomized (older children and adults) to receive one dose of PCV-7 (11 vaccinated villages) or meningococcal serogroup C conjugate vaccine (10 control villages). Cross-sectional surveys (CSSs) to collect nasopharyngeal swabs were conducted before vaccination (2,094 samples in the baseline CSS), and 4-6, 12, and 22 mo after vaccination (1,168, 1,210, and 446 samples in CSS-1, -2, and -3, respectively). A time trend analysis showed a marked fall in the prevalence of vaccine-type pneumococcal carriage in all age groups following vaccination (from 23.7% and 26.8% in the baseline CSS to 7.1% and 8.5% in CSS-1, in vaccinated and control villages, respectively). The prevalence of vaccine-type pneumococcal carriage was lower in vaccinated than in control villages among older children (5 y to <15 y of age) and adults (≥15 y of age) at CSS-2 (odds ratio [OR] = 0.15 [95% CI 0.04-0.57] and OR = 0.32 [95% CI 0.10-0.98], respectively) and at CSS-3 (OR = 0.37 [95% CI 0.15-0.90] for older children, and 0% versus 7.6% for adults in vaccinated and control villages, respectively). Differences in the prevalence of non-vaccine-type pneumococcal carriage between vaccinated and control villages were small.

CONCLUSIONS

Vaccination of Gambian children reduced vaccine-type pneumococcal carriage across all age groups, indicating a "herd effect" in non-vaccinated older children and adults. No significant serotype replacement was detected. Please see later in the article for the Editors' Summary.

Erythropoietin levels are not independently associated with malaria-attributable severe disease in Mozambican children

Background

Severe malaria is difficult to differentiate from other forms of malaria or other infections with similar symptoms. Any parameter associated to malaria-attributable severe disease could help to improve severe malaria diagnosis.

Methodology

This study assessed the relation between erythropoietin (EPO) and malaria-attributable severe disease in an area of Mozambique with moderate malaria transmission. 211 children <5 years, recruited at Manhiça District Hospital or in the surrounding villages, were included in one of the following groups: severe malaria (SM, n = 44), hospital malaria without severity (HM, n = 49), uncomplicated malaria (UM, n = 47), invasive bacterial infection without malaria parasites (IBI, n = 39) and healthy community controls (C, n = 32). Malaria was diagnosed by microscopy and IBI by blood/cerebrospinal fluid culture.

Principal Findings

Mean EPO concentration in the control group was 20.95 U/l (SD = 2.96 U/l). Values in this group were lower when compared to each of the clinical groups (p = 0.026 C versus UM, p<0.001 C vs HM, p<0.001 C vs SM and p<0.001 C vs IBI). In the 3 malaria groups, values increased with severity [mean = 40.82 U/l (SD = 4.07 U/l), 125.91 U/l (SD = 4.99U/l) and 320.87 U/l (SD = 5.91U/l) for UM, HM and SM, respectively, p<0.001]. The IBI group [mean = 101.75 U/l (SD = 4.12 U/l)] presented lower values than the SM one (p = 0.002). In spite of the differences, values overlapped between study groups and EPO levels were only associated to hemoglobin. Hemoglobin means of the clinical groups were 93.98 g/dl (SD = 14.77 g/dl) for UM, 75.96 g/dl (SD = 16.48 g/dl) for HM, 64.34 g/dl (SD = 22.99 g/dl) for SM and 75.67 g/dl (SD = 16.58 g/dl) for IBI.

Conclusions

Although EPO levels increase according to malaria severity and are higher in severe malaria than in bacteremia, the utility of EPO to distinguish malaria-attributable severe disease is limited due to the overlap of values between the study groups and the main role of hemoglobin in the expression of EPO.

Susceptibility of bacterial isolates from community-acquired infections in sub-Saharan Africa and Asia to macrolide antibiotics

OBJECTIVE

To review the literature on the susceptibility of common community pathogens in sub-Saharan Africa and Asia to the macrolide antibiotics.

METHODS

Inclusion criteria required that isolates were collected since 2004 to ensure results were of contemporary relevance. The data were aggregated by region, age group and sterility of site of culture sample.

RESULTS

A total of 51 studies were identified, which reported the macrolide antimicrobial susceptibilities of common bacterial pathogens isolated since 2004. In general, there was less macrolide resistance in African than in Asian isolates. Most African studies reported high levels of macrolide susceptibility in Streptococcus pneumoniae, whereas most Chinese studies reported high levels of resistance. There was very little information available for Gram-negative organisms.

CONCLUSIONS

Susceptibility of the pneumococcus to macrolides in SSA remains high in many areas, and good activity of azithromycin has been shown against Salmonellae spp. in Asia. In urban areas where high antibiotic consumption is prevalent, there was evidence of increased resistance to macrolides. However, there is no information on susceptibility from large areas in both continents.

Epidemiology of invasive pneumococcal infection in children aged five years and under in Saudi Arabia: a five-year retrospective surveillance study

BACKGROUND

The epidemiology of invasive pneumococcal disease (IPD) in children aged <or=5 years in Saudi Arabia has not been described. We conducted a retrospective surveillance study to describe the epidemiology of IPD in the population of children aged <or=5 years served by the National Guard Health Affairs hospitals in central and western regions of Saudi Arabia.

METHODS

We reviewed the medical records of children <or=5 years old admitted to the King Abdulaziz Medical City hospitals in Riyadh and Jeddah with pneumococcal infections for the period January 1999 through December 2003. Only microbiologically confirmed IPD cases (meningitis or bacteremia) were included in the analysis.

RESULTS

A total of 82 IPD cases, 19 (23.2%) meningitis and 63 (76.8%) bacteremia, were diagnosed during the five-year period. Of these, 12.2% (10/82) died, with a case-fatality slightly but insignificantly higher in cases of meningitis (15.8%) than bacteremia (11.1%). The average annual IPD incidence was 17.4 per 100,000 (4.0 for meningitis and 13.4 for bacteremia). The incidence was roughly similar in males and females (18.3 and 16.6, respectively; p=0.663) and was almost 4-fold higher in the first year of life compared to the next four years (40.6 and 11.5, respectively; p<0.001). The average annual IPD mortality was 2.1 per 100,000 and was higher in the first year of life compared to the next four years (5.2 and 1.3 , respectively; p=0.043).

CONCLUSIONS

In the pre-vaccination era (1999-2003) in Saudi Arabia, IPD incidence was comparable to the pre-vaccination incidence rates from many industrialized countries, with children aged <or=1 year suffering the highest IPD risk among those aged <or=5 years.

Procalcitonin and C-reactive protein for invasive bacterial pneumonia diagnosis among children in Mozambique, a malaria-endemic area

Background

Pneumonia is the major cause of mortality and morbidity in children worldwide. Procalcitonin (PCT) and C-reactive protein (CRP) are used in developed countries to differentiate between viral and bacterial causes of pneumonia. Validity of these markers needs to be further explored in Africa.

Methodology and Principal Findings

We assessed the utility of PCT and CRP to differentiate viral from invasive bacterial pneumonia in children <5 years hospitalized with clinical severe pneumonia (CSP) in rural Mozambique, a malaria-endemic area with high HIV prevalence. Prognostic capacity of these markers was also evaluated. Out of 835 children with CSP, 87 fulfilled definition of viral pneumonia and 89 of invasive bacterial pneumonia. In absence of malaria parasites, levels of PCT and CRP were lower in the viral group when compared to the invasive bacterial one (PCT: median = 0.21 versus 8.31 ng/ml, p<0.001; CRP: 18.3 vs. 185.35 mg/l, p<0.001). However, in presence of malaria parasites distribution between clinical groups overlapped (PCT: median = 23.1 vs. 21.75 ng/ml, p = 0.825; CRP: median = 96.8 vs. 217.4 mg/l, p = 0.052). None of the two markers could predict mortality.

Conclusions

Presence of malaria parasites should be taken into consideration, either for clinical or epidemiological purposes, if using PCT or CRP to differentiate viral from invasive bacterial pneumonia in malaria-endemic areas.

Invasive pneumococcal disease in Fiji: clinical syndromes, epidemiology, and the potential impact of pneumococcal conjugate vaccine

Invasive pneumococcal disease (IPD) epidemiology and the potential impact of the pneumococcal conjugate vaccine in Fiji are documented. The annual incidence was 26.5 and 10.9 in those aged <5 and > or =55 years per 100,000, respectively. The case fatality rate was 9.4% and 67% in <5 and >65 year olds, respectively. One pneumococcal death and case would be prevented in <5 years olds for every 1930 and 128 infants vaccinated with 7vPCV, respectively.

Severe pneumonia in Mozambican young children: clinical and radiological characteristics and risk factors

BACKGROUND

Pneumonia is a leading cause of hospitalization and death among children in Africa. We describe the clinical presentation of severe pneumonia among hospitalized children in a malaria endemic area with a high prevalence of HIV infection.

METHODS

As part of a 2-year prospective study of radiologically confirmed pneumonia, chest radiographs, malaria parasite counts and bacterial blood cultures were systematically performed for children 0-23 months admitted with severe pneumonia. Radiographs were interpreted according to WHO guidelines. HIV tests were performed during a 12-month period.

RESULTS

Severe pneumonia accounted for 16% of 4838 hospital admissions among children 0-23 months; 43% of episodes had endpoint consolidation, 15% were associated with bacteremia and 11% were fatal. Fever, cough >3 days, crepitations, hypoxemia and absence of malaria parasitemia were associated with radiologically confirmed pneumonia. Nineteen per cent of children with severe pneumonia and 27% with radiologically confirmed pneumonia had clinical malaria. HIV-prevalence was 26% among children hospitalized with severe pneumonia and HIV-testing results. HIV infection, anaemia, malnutrition, hypoxemia and bacteremia were associated with fatal episodes of severe pneumonia.

CONCLUSION

Treatment of admitted children with severe pneumonia is complicated in settings with prevalent HIV and malaria. Children with severe pneumonia and clinical malaria require antibiotic and antimalarial treatment. In addition to vertical programs, integrated approaches may greatly contribute to reduction of pneumonia-related mortality.

Seven-valent pneumococcal conjugate vaccines for developing countries

Protein conjugate bacterial vaccines for invasive pneumococcal diseases have revolutionized the epidemiology of invasive bacterial disease in young children in most of the developed world, but only a small proportion of children at greatest risk of dying from this disease are vaccinated in less developed countries. Pneumococcal disease kills more children than any other illness - more than AIDS, malaria and measles combined. While the noble effort of international agencies to promote the use of pneumococcal vaccines is commendable, studies from several developing countries have failed to recognize invasive pneumococcal disease as a major problem. Thus, even at considerably subsidized vaccine pricing, this failure to recognize the pneumococcal disease burden will deter the introduction of vaccine programs in areas where it is most needed. This lack of awareness creates an impassé for the acceptance of a 'solution'. Whether this absence of evidence is real or simply misleading deserves further urgent evaluation. Such an evaluation could propose the use of the vaccine as a 'probe' for defining the problem. In settings where disease burden is likely to be highest, disease surveillance is nonexistent, childhood immunization programs are fractured or nonexistent, and there is no system to ensure delivery, even if the vaccine is offered free of charge. Ongoing challenges with global polio eradication programs suggest that, critical to the success of any immunization program, is investment in setting up credible disease surveillance systems for vaccine preventable diseases to generate local or regional disease burden data. This will promote local ownership of any immunization programs and reveal myths about a 'hidden agenda' by foreign vaccine manufacturers.

Severe malaria and concomitant bacteraemia in children admitted to a rural Mozambican hospital

OBJECTIVES

To describe the prevalence, aetiology and prognostic implications of coexisting invasive bacterial disease in children admitted with severe malaria in a rural Mozambican Hospital.

METHODS

Retrospective study of data systematically collected from June 2003 to May 2007 in a rural Mozambican hospital, from all children younger than 5 years admitted with severe malaria.

RESULTS

Seven thousand and forty-three children were admitted with a diagnosis of malaria. 25.2% fulfilled the criteria for severe malaria. 5.4% of the children with severe malaria and valid blood culture results had a concomitant bacteraemia. Case fatality rates of severe malaria cases rose steeply when bacteraemia was also present (from 4.0% to 22.0%, P < 0.0001), and bacteraemia was an independent risk factor for death among severe malaria patients (adjusted OR 6.2, 95% CI 2.8-13.7, P = 0.0001). Streptococcus pneumoniae, Gram-negative bacteria, Staphilococcus aureus and non-typhoid Salmonella (NTS) were the most frequently isolated microorganisms among severe malaria cases. Their frequency and associated case fatality rates (CFR) varied according to age and to syndromic presentation. Streptococcus pneumoniae had a relatively low CFR, but was consistently associated with severe malaria syndromes, or anaemia severity groups. No clear-cut relationship between malarial anaemia and NTS bacteraemia was found.

CONCLUSIONS

The coexistence of malaria and invasive bacterial infections is a frequent and life-threatening condition in many endemic African settings. In Mozambique, S. pneumoniae is the leading pathogen in this interaction, possibly as a consequence of the high HIV prevalence in the area. Measures directed at reducing the burden of both those infections are urgently needed to reduce child mortality in Africa.

Enhanced diagnosis of pneumococcal meningitis with use of the Binax NOW immunochromatographic test of Streptococcus pneumoniae antigen: a multisite study

BACKGROUND

Accurate etiological diagnosis of meningitis in developing countries is needed, to improve clinical care and to optimize disease-prevention strategies. Cerebrospinal fluid (CSF) culture and latex agglutination testing are currently the standard diagnostic methods but lack sensitivity.

METHODS

We prospectively assessed the utility of an immunochromatographic test (ICT) of pneumococcal antigen (NOW Streptococcus pneumoniae Antigen Test; Binax), compared with culture, in 5 countries that are conducting bacterial meningitis surveillance in Africa and Asia. Most CSF samples were collected from patients aged 1-59 months.

RESULTS

A total of 1173 CSF samples from suspected meningitis cases were included. The ICT results were positive for 68 (99%) of the 69 culture-confirmed pneumococcal meningitis cases and negative for 124 (99%) of 125 culture-confirmed bacterial meningitis cases caused by other pathogens. By use of culture and latex agglutination testing alone, pneumococci were detected in samples from 7.4% of patients in Asia and 15.6% in Africa. The ICT increased pneumococcal detection, resulting in similar identification rates across sites, ranging from 16.2% in Nigeria to 20% in Bangladesh. ICT detection in specimens from culture-negative cases varied according to region (8.5% in Africa vs. 18.8% in Asia; P< .001), prior antibiotic use (24.2% with prior antibiotic use vs. 12.2% without; P< .001), and WBC count (9.0% for WBC count of 10-99 cells/mL, 22.1% for 100-999 cells/mL, and 25.4% for >or=1000 cells/mL; P< .001 by test for trend).

CONCLUSIONS

The ICT provided substantial benefit over the latex agglutination test and culture at Asian sites but not at African sites. With the addition of the ICT, the proportion of meningitis cases attributable to pneumococci was determined to be similar in Asia and Africa. These results suggest that previous studies have underestimated the proportion of pediatric bacterial meningitis cases caused by pneumococci.

A 10 year study of the cause of death in children under 15 years in Manhiça, Mozambique

BACKGROUND

Approximately 46 million of the estimated 60 million deaths that occur in the world each year take place in developing countries. Further, this mortality is highest in Sub-Saharan Africa, although causes of mortality in this region are not well documented. The objective of this study is to describe the most frequent causes of mortality in children under 15 years of age in the demographic surveillance area of the Manhiça Health Research Centre, between 1997 and 2006, using the verbal autopsy tool.

METHODS

Verbal autopsy interviews for causes of death in children began in 1997. Each questionnaire was reviewed independently by three physicians with experience in tropical paediatrics, who assigned the cause of death according to the International Classification of Diseases (ICD-10). Each medical doctor attributed a minimum of one and a maximum of 2 causes. A final diagnosis is reached when at least two physicians agreed on the cause of death.

RESULTS

From January 1997 to December 2006, 568,499 person-year at risk (pyrs) and 10,037 deaths were recorded in the Manhiça DSS. 3,730 deaths with 246,658 pyrs were recorded for children under 15 years of age. Verbal autopsy interviews were conducted on 3,002 (80.4%) of these deaths. 73.6% of deaths were attributed to communicable diseases, non-communicable diseases accounted for 9.5% of the defined causes of death, and injuries for 3.9% of causes of deaths. Malaria was the single largest cause, accounting for 21.8% of cases. Pneumonia with 9.8% was the second leading cause of death, followed by HIV/AIDS (8.3%) and diarrhoeal diseases with 8%.

CONCLUSION

The results of this study stand out the big challenges that lie ahead in the fight against infectious diseases in the study area. The pattern of childhood mortality in Manhiça area is typical of developing countries where malaria, pneumonia and HIV/AIDS are important causes of death.

Community-acquired bacteremia among children admitted to a rural hospital in Mozambique

BACKGROUND

Although community-acquired bacteremia is an important cause of childhood mortality in Africa, recognition of disease burden and potential impact of bacterial vaccines is limited.

METHODS

Blood cultures for bacterial pathogens were conducted systematically among children <15 years of age admitted to Manhiça District Hospital, from 2001 to 2006.

RESULTS

Blood-stream infections were identified in 8% (1550/19,896) of pediatric hospital admissions. Nontyphoidal Salmonella (NTS) and Pneumococcus were the most prevalent pathogens isolated (26% and 25% of 1550 cases, respectively). Until 28 days of life, Staphylococcus aureus (39%) and group B Streptococcus (20%) predominated. Incidence of community-acquired bacteremia per 100,000 child-years was 1730/10 in children <1 year old, 782/10 in 1-4 year oldd, and 49/10 in children 5 years and older. Case-fatality of bacteremia was 12%. Community-acquired bacteremia associated mortality accounted for 21% (162/788) of hospital deaths. Resistance to antibiotics commonly used in Mozambique was high among invasive isolates of Haemophilus influenzae, Escherichia coli, and NTS.

CONCLUSIONS

Community-acquired bacteremia is an important cause of pediatric hospital admission and death in rural African hospitals. The high burden of disease, mortality, and pattern of antibiotic resistance associated with bacteremia underscore the need for prevention in Sub-Saharan Africa.

Typhoid fever in children in Africa

Estimates for the year 2000 suggested that there were approximately 21.5 million infections and 200,000 deaths from typhoid fever globally each year, making the disease one of the most serious infectious disease threats to public health on a global scale. However, these estimates were based on little data, especially from Africa. Global prominence and high-profile outbreaks have created the perception in Kenya that typhoid is a common cause of febrile illness. The Widal test is used widely in diagnosis. We have reviewed recent literature, taking the perspective of a healthcare provider, to collate information on the prevalence of typhoid in children particularly, and to explore the role of clinical diagnosis and diagnosis based on a crude, but common, interpretation of the Widal test. Data suggest that typhoid in children in rural Africa is uncommon, perhaps 100 times or 250 times less common than invasive disease because of Haemophilus influenzae or Streptococcus pneumoniae, respectively. Frequent use of the Widal test may result in many hundreds of over-treatment episodes for every true case treated and may perpetuate the perception that typhoid is common. Countries such as Kenya need better bacterial disease surveillance systems allied to better information for healthcare providers to promote appropriate decision-making on prevention and treatment strategies.

Acute bacterial meningitis among children, in Manhiça, a rural area in Southern Mozambique

INTRODUCTION

Acute bacterial meningitis (ABM) is one of the most severe diseases in Sub-Saharan Africa. Although data for the continent is very limited, more than one million cases are estimated per year, with mortality and life-long sequelae occurring in 50% of these cases.

METHODS

As part of the clinical management of children admitted to the Manhiça District Hospital, information on cases of ABM was recorded. We analysed data from June 1998 to November 2003.

RESULTS

During the study period, 475 cerebrospinal-fluid (CSF) samples were collected from 20,173 children <15 years of age admitted to hospital. Culture results confirmed 71 (15%) cases of ABM. The most prevalent bacterial aetiologies were Streptotoccus pneumoniae (pneumococcus, n=31), Haemophilus influenzae (n=13) and Neisseria meningitis (n=8). Other important bacteria were Streptococcus sp. (n=7), Salmonella sp. (n=4) and Staphylococcus aureus (n=3). Crude incidence rates of ABM and pneumococcal meningitis were 20/100,000 and 10/100,000 children-year-at-risk, respectively. Incidences were more than three times higher in the <1 year age group. Overall case fatality rate was 36%, and was highest for H. influenzae and pneumococcal meningitis (55% and 45%, respectively, p=0.044). Pneumococcal susceptibility was 81% for oxacillin and 93% for chloramphenicol. For H. influenzae isolates, susceptibility was 54% for ampicillin and 62% for chloramphenicol.

CONCLUSIONS

S. pneumoniae and H. influenzae are the main aetiologies responsible for the high burden of morbidity and mortality associated with ABM in rural Mozambique. These findings are important to evaluate treatment guidelines and potential impact of control measures.

Sequential multiplex PCR for identifying pneumococcal capsular serotypes from South-Saharan African clinical isolates

A serial multiplex PCR approach was reformulated for pneumococcal serotyping to test 153 clinical isolates from children in Mozambique. This approach identified serotypes in 139 (90.8%) of 153 isolates; 126 (82.4%) were identified within two reactions. This approach in developing countries would require minimal training and could provide useful serotype information without requiring transport of specimens.