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 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.

Maternal immunization with pneumococcal polysaccharide vaccine in the Philippines

A randomized, controlled study was conducted to evaluate the immunogenicity and reactogenicity of the 23-valent pneumococcal (Pnc) polysaccharide (PS) vaccine among pregnant women and to ascertain the transfer of anti-Pnc antibody (Ab) from mother to infant. One hundred and sixty women received either one dose of Pnc PS vaccine, Haemophilus influenzae type b conjugate vaccine and tetanus toxoid (TT) (Pnc vaccine group, N=106) or TT only (control group, N=54). Sera were obtained from all mothers prior to vaccination and 4 weeks after from the vaccinated group. Cord blood was obtained in 75% of deliveries. Anti-Pnc Ab for serotypes 1, 5, 6B, 14, 18C and 19F was determined using enzyme immunoassay. The Pnc vaccine and control groups were comparable in terms of age, parity, gravidity, prior doses of TT, and pre-vaccination geometric mean concentration (GMC in microg/ml) of anti-Pnc Ab. Between 66 and 87% of the mothers had type-specific Ab prior to vaccination. There was a significant rise in anti-Pnc Ab (varying from 3.3- to 9.1-fold for the individual serotypes) between the pre and post-vaccination samples. Adverse reactions were mild and required no treatment. The level of anti-Pnc Ab in cord blood was significantly lower in the control group compared to the Pnc vaccine group. Vaccination of pregnant women with Pnc Ps vaccine induces good immune response and Ab can be transferred to their infants via cord blood thus providing enhanced protection.

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

The etiology of invasive bacterial infections was studied among 956 Filipino children less than five years old who fulfilled the World Health Organization criteria for severe or very severe pneumonia or had suspected meningitis or sepsis. The most common invasive infections were due to Streptococcus pneumoniae (12 [1.3%]) and Haemophilus influenzae (12 [1.3%]); including four cases of pneumococcal meningitis and 11 cases of H. influenzae meningitis. Type 1 was the most common (six of the 12 isolates) of the pneumococcal serotypes. Serotypes/groups 1, 6, 14, and 23 accounted for 91.7% of the invasive isolates. The majority of the H. influenzae strains from blood (10 out of 10) and cerebrospinal fluid (6 out of 7) were type b. Almost all of the invasive S. pneumoniae (9 out of 12) and H. influenzae (11 out of 12) infections were seen before one year of age, which stresses the need to investigate early immunization of children for H. influenzae type b and S. pneumoniae, as well as maternal immunization to maximize the potential of immunoprophylaxis.

Immunogenicity and effectiveness of post-exposure rabies prophylaxis with a new chromatographically purified Vero-cell rabies vaccine (CPRV): a two-stage randomised clinical trial in the Philippines

Recent improvements in chromatographic purification procedures have made it possible to develop a new chromatographically purified rabies vaccine (CPRV) by further purifying the current rabies vaccine prepared from Vero-cell culture (PVRV) (Verorab; Pasteur Merieux Connaught). The immunogenicity and effectiveness of post-exposure rabies prophylaxis with this new vaccine were evaluated in a two-stage clinical trial conducted in the Philippines. In both study stages. post-exposure treatment consisted of five injections of vaccine [(D)ays 0, 3, 7, 14, 28], together with a dose of rabies immunoglobulin (RIG) of equine or human origin on D0. In stage 1, 231 subjects with low-risk rabies exposure (WHO category I or II), and who had a negative ERIG skin test, were treated with either CPRV (n = 114) or PVRV (n = 117). By D14, all subjects in each group had achieved rabies antibody titres over ten times that recommended by the WHO as indicating seroconversion (> or = 0.5 IU/ml). The kinetics of the immune response to vaccination were very similar in the two groups, and at D28, the immunogenicity of CPRV was equivalent to that of PVRV (one-sided equivalence test). Following these positive results, 132 subjects with severe rabies exposure were included in the second stage of this trial. All were scheduled to receive four vaccine doses with CPRV. After D14, only those 57 patients with confirmed rabies exposure (animal with positive FA test) and seven patients for whom rabies exposure could not be excluded (animal lost or not tested) completed the treatment and were followed for one year to assess survival. After 1 year, 62 patients treated for confirmed or possible severe rabies exposure had been examined and were still alive. Two patients contacted by letter and telephone confirmed good health 7 and 16 months after exposure. No severe local or systemic reactions were reported in either stage of the study, and no treatment-related serious adverse event occurred. This two-stage clinical trial attests to the safety and satisfactory immunogenicity of CPRV in post-exposure rabies treatment, and confirms the effectiveness of a new rabies vaccine in patients with severe confirmed exposure.

Bacterial and viral etiology of serious infections in very young Filipino infants

OBJECTIVE

Pneumonia, meningitis and other serious infections are leading causes of death in developing countries. As part of a multicenter study we aimed to determine the etiology of pneumonia, meningitis and other serious infections in a cohort of Filipino infants ages 90 days or younger.

METHOD

During a 2-year period, 2053 infants age 90 days or younger presenting to 1 of 3 Manila community hospitals were screened; 873 had signs or symptoms suggestive of an infectious illness, and 608 were judged to have clinical features suggestive of severe infection and had laboratory workup including blood for culture and white blood cell count, nasopharyngeal aspirate for virology, cerebrospinal fluid culture when indicated and chest radiograph. Chest radiographs were read independently by 3 radiologists without knowledge of clinical findings.

RESULTS

Of the 873 enrolled infants, 81 died (91%). After exclusion of presumed contaminants, positive bacterial culture from blood and/or cerebrospinal fluid was obtained in 35 infants (5.8%; 95% confidence interval 4%, 8%), 9 of whom died. The organisms responsible for meningitis were Acinetobacter spp. (4), Streptococcus pneumoniae (2), Escherichia coli (2), Enterobacter spp. (1), Pseudomonas aeruginosa (1), Haemophilus influenzae (1) and Staphylococcus aureus (1); those responsible for the other clinical diagnoses were Salmonella spp. (6), Enterobacter spp. (3), Streptococcus pyogenes (3), other Gram-negative organisms (8), S. pneumoniae (1) and Staphylococcus aureus (2). In 685 infants examined for viral causes of their illness, 223 viruses were isolated from 219 infants (32%; 95% confidence interval 28%, 36%). Enteroviruses were the most common potential pathogens identified (22% of infants studied), followed by respiratory syncytial virus (17%), rhinovirus (10%) and adenovirus (4%). Concomitant virus identification occurred in 10 of those with positive bacterial culture (29%; 95% confidence interval, 15%, 46%), with enterovirus being found in 7 of these cases.

CONCLUSION

Many young Filipino infants with life-threatening illness were evaluated in this study. Thirty-five had infections attributable to bacteria, with Salmonella spp. being the most common, followed by Gram-negative organisms. Pneumococcus was an unusual cause.

Coinfection is common in measles-associated pneumonia

BACKGROUND

Measles continues to be a significant health problem in developing countries.

OBJECTIVES

To describe the clinical features of measles-associated pneumonia (MAP) and to identify other pathogens involved.

METHODS

Measles diagnosis was ascertained either by the typical symptom complex or by a sensitive enzyme immunoassay for antibody among children < 5 years of age admitted to the hospital with pneumonia. Other pathogens were identified by blood culture, virus isolation or antigen detection from nasopharyngeal aspirate and antibody determination from serum.

RESULTS

Of 182 MAP cases 162 (89%) had clinically typical measles. Twenty patients had a diagnostic antibody finding with an atypical clinical presentation. Thirteen percent were younger than 9 months of age. The case fatality rate was 17%, with a significantly increased odds ratio (OR) for those with cyanosis [OR 4.6, 95% confidence interval (CI) 1.7 to 13], respiratory rate > or = 60/min (OR 3, 95% CI 1.3 to 7) or fulfilling criteria for very severe pneumonia (OR 5.3, 95% CI 2.3 to 12). Mixed infection was found in 53% of patients. Blood culture was positive in 10 patients, Streptococcus pneumoniae (N = 5) being the most common finding. Adenovirus (19%) and parainfluenza (25%) viruses were the most frequent other viruses. A dense infiltrate was seen significantly more often among measles patients with bacterial coinfection (87.5%) than those with other viruses (36%, P = 0.007) or no evidence of other infection (33%, P = 0.004).

CONCLUSION

In MAP, coinfection with other microbes is common. Cyanosis and a respiratory rate of > or = 60/min predict a greater risk of dying.

Halofantrine in the treatment of acute uncomplicated falciparum malaria in the Philippines

In an open clinical trial, thirty patients 14 to 44 years old and with acute uncomplicated falciparum malaria were given halofantrine hydrochloride 500 mg (2 tablets) 6-hourly for 3 doses, a total dose of 1500 mg. All 30 patients were cured, with a mean asexual parasite clearance time of 47.6 hours and mean fever clearance time of 36.6 hours. Post-dosing side-effects occurred in 6 patients consisting of mild to moderate headache, dizziness and abdominal muscle spasm. Drug-induced hemolysis did not occur in two G6PD deficient patients. Twenty-three out of 28 isolates tested (82%) were resistant to amodiaquine, 3 (11%) were resistant to the sulfadoxine-pyrimethamine combination, and all were sensitive to chloroquine, quinine and mefloquine by in vitro microtests. The study confirms the efficacy of halofantrine hydrochloride as a blood schizonticide in falciparum malaria.