Invasive bacterial infections of children in a rural province in the central Philippines

A prospective observational study of community-acquired bacterial bloodstream infections in Metro Manila, the Philippines

Community-acquired bacterial bloodstream infections are caused by diverse pathogens with changing antimicrobial-resistance patterns. In low-middle income countries in Southeast Asia, where dengue fever is endemic and a leading cause of fever, limited information is available about bacterial bloodstream infections due to challenges of implementing a blood culture service. This study describes bacterial bloodstream pathogens and antimicrobial-resistance patterns in Metro Manila, the Philippines. We aimed to identify the proportion of patients with a positive blood culture, the bacteria isolated and their antimicrobial resistance patterns, and the clinical characteristics of these patients, in this dengue endemic area. We conducted a prospective observational study in a single hospital enrolling febrile patients clinically suspected of having a community-acquired bacterial bloodstream infection between 1st July 2015 and 30th June 2019. Each patient had a blood culture and additional diagnostic tests according to their clinical presentation. We enrolled 1315 patients and a significant positive blood culture was found in 77 (5.9%) including Staphylococcus aureus (n = 20), Salmonella enterica Typhi (n = 18), Escherichia coli (n = 16), Streptococcus pneumoniae (n = 3) and Burkholderia pseudomallei (n = 2). Thirty-four patients had meningococcal disease diagnosed by culture (n = 8) or blood PCR (n = 26). Additional confirmed diagnoses included leptospirosis (n = 177), dengue virus infection (n = 159) and respiratory diphtheria (n = 50). There were 79 (6.0%, 95%CI 4.8%−7.4%) patients who died within 28 days of enrollment. Patients with a positive blood culture were significantly more likely to die than patients with negative culture (15.2% vs 4.4%, P<0.01). Among S. aureus isolates, 11/20 (55%) were methicillin-resistant (MRSA) and ST30: USA1100 was dominant sequence type (88.9%). Antimicrobial-susceptibility was well preserved in S. enterica Typhi. Among hospitalized patients with clinically suspected community-acquired bacterial bloodstream infection in Metro Manila, the Philippines, 5.9% had a blood culture confirmed infection of whom 15.6% died. S. aureus, including a significant number of MRSA (USA1100 clones), S. enterica Typhi, E.coli and Neisseria meningitidis were frequently identified pathogens.

Current status and challenges in the care of patients with bacterial meningitis in the Philippines: A scoping review

OBJECTIVE

Bacterial meningitis is associated with high morbidity and mortality if not treated early. Due to the high disease burden, there are barriers in the provision of healthcare services for these patients, especially in low- to middle-income countries, such as the Philippines. We aimed to give an overview of healthcare services delivery and identify gaps in the provision of care for patients with bacterial meningitis in the Philippines.

METHOD

We conducted a scoping review on the available literature on the epidemiology, research, health services delivery, diagnostics and management of Filipino patients with bacterial meningitis. A qualitative summary of the results was conducted to provide an overview of the findings.

RESULTS

There is a paucity of epidemiological data and research on bacterial meningitis. Healthcare expenditure remains out-of-pocket, with limited coverage from the national health insurance programme. There is an inadequate number of neurologists as well as inequities in the distribution of manpower and facilities due to the devolution of the healthcare system. Diagnosis remains a challenge due to the inaccessibility of tests for CSF analysis. Costs of antibiotics, adjunctive treatment, neurosurgical interventions and rehabilitation are also prohibitive. Outbreaks can be prevented by strengthening existing surveillance systems and improving vaccination coverage against the most common causative organisms.

CONCLUSION

Enormous challenges still exist with regards to health services delivery in patients with bacterial meningitis in the Philippines in terms of epidemiologic data and research, access to healthcare facilities and diagnostic tools, healthcare costs, surveillance systems and immunisation against causative pathogens.

A Narrative Review of Pneumococcal Disease in Children in the Philippines

This narrative review describes the epidemiology of invasive pneumococcal diseases, nasopharyngeal carriage, and antibiotic resistance of Streptococcus pneumoniae serotypes, and vaccination coverage in children in the Philippines. Epidemiological data show that, despite the availability of the free-of-cost 13-valent pneumococcal conjugate vaccine for infants as part of the National Immunization Program, the burden of pneumococcal disease in young children remains high in the Philippines. The significant variability in data reported between studies highlights an urgent need for active and comprehensive disease surveillance for more accurate estimates of pneumococcal disease in the country. Although data from 2001 to 2013 show high rates of pneumococcal carriage in children in the Philippines aged < 5 years, contemporary data are lacking, again emphasizing the need for active surveillance programs. The introduction of pneumococcal conjugate vaccines has resulted in substantial declines in disease caused by pneumococcal serotypes included in the vaccines, but the emergence of pneumococcal disease due to nonvaccine serotypes is an ongoing concern. Surveillance of actively circulating serotypes is critical to better understand vaccine coverage. Antimicrobial resistance of S. pneumoniae remains a significant threat to public health worldwide; data regarding antibiotic resistance in young children in the Philippines are limited, but reports generally show low rates of antibiotic resistance in this group. National immunization rates have increased in recent years, yet many individuals are still unprotected from pneumococcal disease. Overall, there is a critical need for contemporary and accurate disease surveillance in the Philippines. Such data would provide better estimates of pneumococcal disease incidence, serotype distribution, and antibiotic resistance to better inform vaccination strategies and to ensure that children in the Philippines are best protected against pneumococcal disease.

Etiology and epidemiology of community-acquired pneumonia in adults requiring hospital admission: A prospective study in rural Central Philippines

BACKGROUND

Community-acquired pneumonia (CAP) is a common cause of morbidity and mortality among adults worldwide. However, the distribution of the etiology of CAP varies from one country to another, with limited data from rural areas.

METHODS

A prospective hospital-based study on adult CAP was conducted in Leyte, Central Philippines from May 2010 to May 2012. Blood, sputum, and nasopharyngeal samples obtained from patients were used to identify pathogens using standard microbiological culture methods and PCR.

RESULTS

Of the 535 patients enrolled, 38% were younger than 50 years old. More than half of the patients had an underlying disease, including pulmonary tuberculosis (22%). The detection rate was higher for bacteria (40%) than viruses (13%). Haemophilus influenzae (12%) was the most commonly detected bacterium and influenza virus (5%) was the most commonly detected virus. The proportion of CAP patients with Mycobacterium tuberculosis infection was higher in the younger age group than in the older age group. Among CAP patients, 14% died during hospitalization, and drowsiness on admission and SpO₂ <90% were independent risk factors for mortality.

CONCLUSIONS

Bacterial infections contribute substantially to the number of hospitalizations among CAP patients in rural Philippines. This study also highlights the importance of treatment of tuberculosis in reducing the burden of adult CAP in the country.

Carriage of Streptococcus pneumoniae and other respiratory bacterial pathogens in low and lower-middle income countries: a systematic review and meta-analysis

BACKGROUND

Infection with Streptococcus pneumoniae is a major cause of childhood morbidity and mortality worldwide, especially in low income countries where pneumococcal conjugate vaccines (PCVs) are still underused. In countries where PCVs have been introduced, much of their efficacy has resulted from their impact on nasopharyngeal carriage in vaccinated children. Understanding the epidemiology of carriage for S. pneumoniae and other common respiratory bacteria in developing countries is crucial for implementing appropriate vaccination strategies and evaluating their impact.

METHODS AND FINDINGS

We have systematically reviewed published studies reporting nasopharyngeal or oropharyngeal carriage of S. pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Staphylococcus aureus, and Neisseria meningitidis in children and adults in low and lower-middle income countries. Studies reporting pneumococcal carriage for healthy children <5 years of age were selected for a meta-analysis. The prevalences of carriage for S. pneumoniae, H. influenzae, and M. catarrhalis were generally higher in low income than in lower-middle income countries and were higher in young children than in adults. The prevalence of S. aureus was high in neonates. Meta-analysis of data from young children before the introduction of PCVs showed a pooled prevalence estimate of 64.8% (95% confidence interval, 49.8%-76.1%) in low income countries and 47.8% (95% confidence interval, 44.7%-50.8%) in lower-middle income countries. The most frequent serotypes were 6A, 6B, 19A, 19F, and 23F.

CONCLUSIONS

In low and lower-middle income countries, pneumococcal carriage is frequent, especially in children, and the spectrum of serotypes is wide. However, because data are limited, additional studies are needed to adequately assess the impact of PCV introduction on carriage of respiratory bacteria in these countries.

Prospective surveillance study of invasive pneumococcal disease among urban children in the Philippines

BACKGROUND

Worldwide, invasive pneumococcal disease (IPD) causes considerable morbidity and mortality among children, but incidence data in Asia are lacking. This 2-year hospital-based, prospective, surveillance study was conducted at 3 study sites in urban areas of the Philippines to estimate IPD and pneumonia incidence in children and describe the serotype distribution of invasive Streptococcus pneumoniae isolates.

METHODS

Children aged 28 days to <60 months residing within the 3 surveillance areas presenting with possible IPD were enrolled. Initial diagnosis, history of pneumococcal vaccine receipt and previous antimicrobial treatment were recorded. Blood specimens were collected for S. pneumoniae identification and serotyping. Final diagnosis was determined for hospitalized subjects, subjects whose culture yielded S. pneumoniae and subjects with clinically suspected meningitis.

RESULTS

A total of 5940 subjects were enrolled, 47 IPD cases identified. IPD site rates were 33.49 per 100,000, 25.38 per 100,000 and 25.85 per 100,000. Chest radiograph-confirmed pneumonia incidence ranged from 633.74 to 1683.59 per 100,000. Highest chest radiograph-confirmed pneumonia incidence occurred in those 28 days to <6 months of age at 2 sites (2166.16 and 3891.94 per 100,000) and those 6-12 months of age at the third site (3847.52 per 100,000). Thirty-five S. pneumoniae isolates were serotyped; most commonly identified were serotypes 1, 2, 5, 6B, 14 and 18F. One serotype 14 isolate was erythromycin resistant. Previous antibiotic therapy was documented in 17-53% of subjects; 2 subjects had received pneumococcal vaccine. At 2 sites, one-third of IPD subjects died.

CONCLUSIONS

IPD is an important cause of morbidity and mortality among urban children in the Philippines. Our data support the expectation that widespread immunization would decrease IPD disease burden.

Respiratory viruses from hospitalized children with severe pneumonia in the Philippines

BACKGROUND

Pneumonia remains a leading cause of child death in developing countries. The viruses in severe pneumonia remain poorly defined.

METHODS

The study was conducted at the Eastern Visayas Regional Medical Center in Tacloban City, Philippines from May 2008 to May 2009. Patients aged 8 days to 13 years old who were admitted to the Department of Pediatrics with severe pneumonia were enrolled for the study. Upon admission, polymerase chain reaction was performed using nasopharyngeal swabs and blood cultures to detect respiratory viruses and bacteria, respectively.

RESULT

Among the 819 patients enrolled, at least one virus was detected in 501 cases (61.2%). In addition, 423 cases were positive for a single virus while bacteria were detected in the blood culture sample of 31 cases. The most commonly detected viruses were human rhinoviruses (n = 189), including types A (n = 103), B (n = 17), and C (n = 69), and respiratory syncytial virus (RSV) (n = 165). Novel viruses such as human metapneumovirus, human coronavirus NL63, human bocavirus, and human polyomaviruses WU and KI were also detected. There were 70 deaths, and one or more viruses were detected in 35 (50%) of these cases. Positivity only for influenza A virus (OR = 4.3, 95% CI = 1.3-14.6) was significantly associated with fatal outcome. From the blood culture, Burkholderia cepacia group (n = 9), Streptococcus pneumoniae (n = 4), Staphylococcus aureus (n = 4), Haemophilus influenzae (n = 1), and Salmonella C1 (n = 1) were also isolated.

CONCLUSION

Viruses were commonly detected in children with severe pneumonia in the Philippines. Hence, viral etiologies should be considered while developing better effective strategies to reduce child pneumonia-related deaths in developing countries.

Prevalence of Streptococcus pneumoniae serotypes causing invasive and non-invasive disease in South East Asia: a review

BACKGROUND

Streptococcus pneumoniae is a major cause of bacterial infections resulting in significant morbidity and mortality worldwide. Currently, up to 13 serotypes are included in pneumococcal conjugate vaccines (PCVs). However, the serotype formulation of these vaccines was initially designed to protect children against serotypes most commonly causing invasive disease in North America, and may not reflect the serotype distribution across the world. Data regarding pneumococcal epidemiology from the other parts of the world, in particular South East Asia, has not been reviewed.

METHODS

This systematic literature review analyses published serotype data regarding S. pneumoniae isolates from South East Asian countries (defined as countries belonging to the Association of South East Asian Nations, ASEAN): Brunei, Cambodia, Indonesia, Laos, Malaysia, Myanmar, Philippines, Singapore, Thailand and Vietnam up to 3rd of March 2012.

RESULTS

Analysis of data from six ASEAN countries, from which information on pneumococcal serotypes was available, showed that the most common disease causing serotypes (in rank order) were 19F, 23F, 14, 6B, 1, 19A and 3. Serotype distribution of pneumococcal isolates was similar across the ASEAN region. Serotype level data was more commonly reported for pneumococcal isolates causing invasive pneumococcal disease than for those from non-invasive disease. Studies from Malaysia, Thailand and Singapore contributed the largest proportion of pneumococcal isolates, and serotype data, when compared to other ASEAN countries.

CONCLUSION

This review demonstrates that the majority of IPD causing serotypes in SE Asia are included in currently licensed PCVs. However, PCV's are included in the routine childhood immunisation schedule of only one of the ten countries included in this analysis. Our findings demonstrate the scarcity of information available on serotype prevalence and distribution of pneumococci in SE Asia.

Meningococcal disease in Asia: an under-recognized public health burden

A literature search traced existing information on meningococcal disease in Asia. Reviewed data describing the epidemiology of meningococcal disease in Asia are incomplete, due in part to absence of surveillance in many countries, poor bacterial detection methods and social and healthcare barriers to disease reporting. This suggests that meningococcal disease in some Asian countries may be under-recognized, with a need to introduce/improve existing surveillance and case identification systems. Nevertheless, in some developing Asian countries, the disease burden may be significant. Serogroup A meningococcal epidemics are responsible for high morbidity and mortality in some countries and continue to be an ongoing threat, particularly in developing countries. There is an increasing role played by serogroups C, Y, and W-135 in invasive disease, indicating evolving meningococcal disease epidemiology in some countries. Multivalent meningococcal conjugate vaccines offer new opportunities in the region for reducing the meningococcal disease burden.

Mother-infant vaccination with pneumococcal polysaccharide vaccine: persistence of maternal antibodies and responses of infants to vaccination

Protection against pneumococcal infection early in life is needed. This could be achieved by maternal vaccination or by starting infant vaccinations as early as possible. In an open controlled study, pregnant women received both 23-valent pneumococcal polysaccharide vaccine (PPV), Haemophilus influenzae type b conjugate vaccine and tetanus toxoid or tetanus toxoid alone. Infants received PPV at 7 or 17 weeks and the second dose at 3 years of age. Antibodies to six pneumococcal serotypes were measured with the non-22F and 22F enzyme immunoassays (EIA). Elevated antibody concentrations after maternal vaccination persisted in infants until 4 months of age. Infants responded to serotypes 1 and 5, but not to serotypes 6B, 14, 18C and 19F. High maternal antibody concentrations at early age reduced the responses, but not the antibody concentrations, of infants to PPV. The percentages of infants with concentrations >0.35 μg/ml and >1 μg/ml were high at birth, but decreased by age during the first 10 months of life. Revaccination with PPV at 3 years of age induced a good immune response.

Efficacy of an 11-valent pneumococcal conjugate vaccine against radiologically confirmed pneumonia among children less than 2 years of age in the Philippines: a randomized, double-blind, placebo-controlled trial

BACKGROUND

Pneumococcus is a leading cause of childhood pneumonia worldwide. Pneumococcal conjugate vaccines (PCV) have demonstrated efficacy against childhood invasive pneumococcal disease (IPD) and pneumonia in the United States and Africa. No information is available from Asia on the impact of PCV on childhood pneumonia.

METHODS

We conducted a randomized, placebo-controlled, double-blind trial in Bohol, the Philippines (ISRCTN 62323832). Children 6 weeks to <6 months of age were randomly allocated to receive 3 doses of either an 11-valent PCV (11PCV, sanofi pasteur, Lyon, France) or a saline placebo, with a minimum interval of 4 weeks between doses to determine vaccine efficacy (VE) against the primary outcome of a child experiencing first episode of community-acquired radiologically defined pneumonia in the first 2 years of life. Secondary end points were clinical pneumonia, IPD, safety, and immunogenicity.

RESULTS

Twelve thousand one hundred ninety-one children were enrolled. By per protocol (PP) analysis, 93 of 6013 fully vaccinated 11PCV recipient children had a first episode of radiologic pneumonia compared with 120 of 6018 placebo recipients. VE against radiologically defined pneumonia for the PP cohort of children 3 to 23 months old was 22.9% (95% CI: -1.1, 41.2; P = 0.06), for the prespecified subgroups of children 3 to 11 months of age, 34.0% (95% CI: 4.8, 54.3; P = 0.02), and of those 12 to 23 months old, 2.7% (95% CI: -43.5, 34.0; P = 0.88). By intent-to-treat (ITT) analysis, 119 of 6097 11PCV recipient children had an episode of radiologic pneumonia compared with 141 of 6094 placebo recipients. VE against radiologic pneumonia for the ITT cohort of children <2 years old was 16.0% (95% CI -7.3, 34.2; P = 0.16), for a subgroup of children <12 months of age, 19.8% (95% CI: -8.8, 40.8; P = 0.15). VE against clinical pneumonia by PP was not significant (VE 0.1%; 95% CI -9.4, 8.7; P = 0.99). IPD was rare: only 3 cases of IPD due to vaccine serotypes were observed during the study. 11PCV was immunogenic and well tolerated. Among 11PCV recipients, a small excess of serious adverse respiratory events was observed in the first 28 days after the first and second dose of vaccine, and of nonrespiratory events after the first dose. An excess of pneumonia episodes in 11PCV recipients in the month following the second dose of vaccination was the principal reason for lower VE by ITT analysis than by PP analysis.

CONCLUSIONS

In PP analysis, a 22.9% reduction of community-acquired radiologically confirmed pneumonia in children younger than 2 years of age in the 11-valent tetanus-diphtheria toxoid-conjugated PCV vaccinated group was observed; a reduction similar as observed in other PCV trials. We could not demonstrate any VE against clinical pneumonia. Our finding confirms for the first time that in a low-income, low-mortality developing country in Asia, at least one-fifth of radiologically confirmed pneumonia is caused by pneumococcus, and thus preventable by PCV. Whether PCV should be included in national program in such settings, however, depends on careful country specific disease burden measurement and cost-effectiveness calculation.

Overview of the disease burden of invasive pneumococcal disease in Asia

This paper represents a collaborative effort by the Asian Strategic Alliance for Pneumococcal Disease Prevention (ASAP) Working Group to collate data on the disease burden due to invasive pneumococcal disease (IPD) in participating Asian countries and territories; namely, Hong Kong, India, Indonesia, Korea, Macau, Malaysia, Pakistan, the Philippines, Singapore, Sri Lanka, Taiwan and Thailand. A review of both published and unpublished data revealed that the incidence of IPD in some countries is well documented by way of large, long-duration studies, while in other countries, much of the available data have been extrapolated from international studies or have come from small population studies of limited geographical coverage. This paper confirms that data regarding the incidence of IPD in Asia are grossly lacking and reinforces the need for urgent and more substantial studies.

Clinical case review: a method to improve identification of true clinical and radiographic pneumonia in children meeting the World Health Organization definition for pneumonia

Background

The World Health Organization's (WHO) case definition for childhood pneumonia, composed of simple clinical signs of cough, difficult breathing and fast breathing, is widely used in resource poor settings to guide management of acute respiratory infections. The definition is also commonly used as an entry criteria or endpoint in different intervention and disease burden studies.

Methods

A group of paediatricians conducted a retrospective review of clinical and laboratory data including C-reactive protein concentration and chest radiograph findings among Filipino children hospitalised in the Bohol Regional Hospital who were enrolled in a pneumococcal vaccine efficacy study and had an episode of respiratory disease fulfilling the WHO case definition for clinical pneumonia. Our aim was to evaluate which disease entities the WHO definition actually captures and what is the probable aetiology of respiratory infections among these episodes diagnosed in this population.

Results

Among the 12,194 children enrolled to the vaccine study we recorded 1,195 disease episodes leading to hospitalisation which fulfilled the WHO criteria for pneumonia. In total, 34% of these episodes showed radiographic evidence of pneumonia and 11% were classified as definitive or probable bacterial pneumonia. Over 95% of episodes of WHO-defined severe pneumonia (with chest indrawing) had an acute lower respiratory infection as final diagnosis whereas 34% of those with non-severe clinical pneumonia had gastroenteritis or other non-respiratory infection as main cause of hospitalisation.

Conclusion

The WHO definition for severe pneumonia shows high specificity for acute lower respiratory infection and provides a tool to compare the total burden of lower respiratory infections in different settings.

Trial registration

ISRCTN62323832

Low incidence of antibiotic resistance among invasive and nasopharyngeal isolates of Streptococcus pneumoniae from children in rural Philippines between 1994 and 2000

The purpose of this study was to determine the prevalence of acquired antimicrobial resistance in Streptococcus pneumoniae isolated from nasopharyngeal swabs and blood and cerebrospinal fluid (CSF) specimens of 3,028 children hospitalized with signs or symptoms of pneumonia, sepsis, or meningitis in rural Philippines between 1994 and 2000. Pneumococci were identified using standard methods, serotyped, and their susceptibility to oxacillin, erythromycin, tetracycline, chloramphenicol, and trimethoprim-sulfamethoxazole was determined using the disk diffusion method. Penicillin minimum inhibitory concentrations (MICs) of the oxacillin-resistant isolates were further tested. The clonality of the penicillin-nonsusceptible (PNSP) isolates was analyzed using pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST). Altogether 1,048 isolates were analyzed, of which 35 were invasive and 1,013 nasopharyngeal isolates. None was resistant, but 22 (2.1%) were intermediately resistant to penicillin, 4 (0.2%) were resistant to chloramphenicol, 3 (0.2%) to erythromycin, 39 (3.7%) to tetracycline, and 4 (0.2%) to trimethoprim/sulfamethoxazole. Twelve of the 22 PNSP isolates were of serotype 14 and of sequence type 63. These included the two invasive PNSP isolates. PFGE profiling further identified three separate clusters among the sequence of type 63, serotype 14 (ST63(14)) isolates. Antimicrobial resistance in both invasive and nasopharyngeal pneumococcal pediatric isolates in rural Philippines is rare. In spite of this remote setting, the PNSP isolates of the serotype 14 clusters were of ST63 type, which has been described previously on other continents.

Predictors of death from severe pneumonia among children 2-59 months old hospitalized in Bohol, Philippines: implications for referral criteria at a first-level health facility

OBJECTIVE

To determine predictors of death among children 2-59 months old admitted to hospital with severe pneumonia.

METHODS

Prospective observational study from April 1994 to May 2000 to investigate serious infections in children less than 5 years old admitted to a tertiary care government hospital in a rural province in central Philippines. The quality of clinical and laboratory work was monitored. The WHO classification for severe pneumonia was used for patient enrolment.

RESULTS

There were 1249 children with severe pneumonia and no CNS infection. Thirty children died. Using univariate analysis, the following factors were significantly associated with death: age 2-5 months, dense infiltrates on chest radiography and presence of definite bacterial pathogens in the blood. Stepwise logistic regression analysis revealed the following independent predictors of death: age 2-5 months, weight for age z-score less than -2 SD, dense infiltrates on chest radiography and definite pathogens isolated in the blood. When the results of chest radiographs and blood cultures were not included to mimic facilities available at first-level facilities, age 2-5 months and weight for age z-score less than -2 SD remained independent predictors of death.

CONCLUSION

When resources are limited, children with lower chest wall indrawing (severe pneumonia) who are 2-5 months old or moderately to severely malnourished should be referred for immediate higher-level care.

Serious community-acquired paediatric infections in rural Asia (Bohol Island, Philippines): bacterial meningitis in children less than 5 years of age

This paper describes the clinical profile and aetiology of bacterial meningitis in infants and children less than 5 y old admitted to a rural general hospital in the Philippines. A total of 989 infants and children 0-59 months old with suspected meningitis using a standardized guideline based on clinical signs and symptoms were prospectively enrolled from April 1994 to May 2000. Blood and CSF were drawn on admission for culture, antigen testing and cell count. All had blood cultures and 623 (63%) had CSF samples. Bacterial aetiology was found in 54 (5%). The most common bacterial pathogens were H. influenzae type b (Hib) (20, 37%) and S. pneumoniae (Pnc) (10, 18%). All of the Hib infections and 8 (80%) Pnc infections were in infants less than 1 y old. 12 (22%) of the subjects with bacterial meningitis died. All strains of S. pneumoniae and H. influenzae were sensitive to chloramphenicol, cotrimoxazole and ampicillin. In conclusion, S. pneumoniae and H. influenzae type b are the most common aetiological agents of bacterial meningitis in a rural area in the Philippines, and occur especially in infants less than 1 y old. Aetiological agents were susceptible to the currently recommended antimicrobial agents.

Immunogenicity and reactogenicity of 23-valent pneumococcal polysaccharide vaccine among pregnant Filipino women and placental transfer of antibodies

This randomized, controlled study among pregnant women evaluated the prevaccination distribution of anti-pneumococcal (Pnc) antibodies (Ab), the immunogenicity and reactogenicity of Pnc polysaccharide vaccine, and transplacental transfer of Ab. The Pnc vaccine group (N=106) received Pnc PS vaccine, Hemophilus influenzae type b conjugate vaccine and tetanus toxoid; the control group (N=54) received tetanus toxoid only. Sera and cord blood were assayed for anti-pnc Ab using enzyme immunoassay. In the Pnc vaccine group, anti-Pnc Ab rose by 3- to 9-fold and was significantly higher in cord blood. In evaluating Pnc conjugate vaccines, the concentration of 0.35 microg/ml is suggested as the protective threshold against invasive disease. Around 90% of mothers had this level pre-vaccination. Considering the decay of passively acquired Ab and the growth of the infant, an Ab level in cord blood of at least 4.4 microg/ml is needed if infants are to be protected up to 4 months of age. Cord blood anti-Pnc Ab was above this level in 60% and 10% of the Pnc vaccine and control groups, respectively. Maternal immunization with Pnc polysaccharide vaccine can provide prolonged protection through passively acquired Ab.

Serious community-acquired neonatal infections in rural Southeast Asia (Bohol Island, Philippines)

OBJECTIVE

To determine the bacterial etiology, clinical presentation and risk factors for outcome of serious community-acquired infections in young infants.

STUDY DESIGN

Infants younger than 60 days, admitted for severe pneumonia or suspected sepsis/meningitis were prospectively evaluated using complete blood count, blood culture, chest radiograph, cerebrospinal fluid (CSF) culture in suspected meningitis. chi2 or Fisher's exact test and stepwise logistic regression were used for analysis.

RESULTS

Thirty-four of 767 enrolled infants had a positive blood or CSF culture. Gram-negative bacteria were more frequent than Gram positive: overall (P=0.004), in those below 7 days of age (P=0.002) and among home deliveries (P=0.012). Case fatality rates were higher among infants below 1 week old (OR 4.14, P<0.001), those with dense (OR 2.92, P<0.001) or diffuse radiographic infiltrates (OR 2.79, P=0.003).

CONCLUSIONS

Gram-negative enteric bacteria are the predominant causes of community-acquired infections in Filipino infants below 2 months old. Age below 7 days and radiographic pneumonia predicted death.

Central nervous system infection is an important cause of death in underfives hospitalised with World Health Organization (WHO) defined severe and very severe pneumonia

Over 6 years, 1667 children aged 2-59 months admitted for pneumonia [1287 severe and 380 very severe] were studied. The case fatality rate (CFR) in children with severe pneumonia was 2.1% and 14.3% with CNS infection, with very severe pneumonia the CFR was 18.9%, 10.4% in those with hypoxemia and 43.6% with CNS infection. High CFRs were associated with CNS infection and inability to drink/cyanosis. The appropriate management of children with very severe pneumonia should include cerebrospinal fluid examination, oxygen monitoring and possibly ventilated support, suggesting that these are minimal standards of care at the district hospital.

Correlation between the severity of infectious diseases in children and the ratio of serum amyloid A protein and C-reactive protein

The aim of this study was to assess whether measurements of serum amyloid A protein (SAA) could provide additional information on the severity of acute infection beyond that obtained from C-reactive protein (CRP) assays. The SAA and CRP concentrations were analysed from the sera of 334 children hospitalized for suspected pneumonia, meningitis or sepsis. SAA significantly correlated with CRP (r = 0.682, p < 0.001) and did not alone provide any further clinically useful information. By contrast, the median ratio (and interquartile range) of SAA to CRP varied significantly between clinical conditions of different severity and was significantly lower in the patients who died [1.9 (0.0-8.9)] than in those who survived [6.8 (3.2-13.6)] (p = 0.001).