Background: Acute lower respiratory tract infection (ALRTI) is the leading cause of childhood deaths in most developing countries, including Nigeria. Vitamin D is associated with innate immunity and may play a role in the control of infections. Case-control studies, including a small study from Nigeria, show inconsistent results for the association between vitamin D status and risk of ALRTI. Aims: To examine the relationship between vitamin D status and hospitalization for ALRTI in Nigerian children. Methods: Fifty children aged 2-60 months hospitalised with ALRTI were studied prospectively. ALRTI was diagnosed on the basis of modified WHO criteria. Each patient was matched with controls for age and gender. The controls were enrolled either from children attending well-child clinics or general clinics without evidence of respiratory infection or admitted to the hospital for elective surgery. A structured questionnaire collected data on demography, health, diet, duration of exposure to sunlight and percentage of body surface exposed to sunlight (according to type of clothing) while outdoors, and potential risk factors for ALRTI. Serum 25-hydroxyvitamin D [25(OH)D] concentration was measured using a chemiluminescenceimmuno-assay. The differences between cases and controls in serum 25(OH)D concentrations, association between vitamin D status and ALRTI and risk factors for vitamin D deficiency were assessed. Results: Mean (SD) 25(OH)D concentrations in patients and controls were similar [61·5 (25·8) vs 63·1 (22·9) nmol/L,P?=?0·95].25% of all 100 subjects studied had serum 25(OH)D<50 nmol/L. In a multiple conditional logistic regression model, only lower percentage of body surface area exposed to sunlight was associated with increased risk of ALRTI. The percentage of body surface area exposed to sunlight while outdoors (P?=?0·028) and vitamin D supplement use (P?=?0·009) were independent determinants of vitamin D deficiency in the overall study population. Conclusions: ALRTI was not associated with vitamin D status, but was associated with less exposure to sunlight. Exposure to sunlight and vitamin D supplementation contributed to vitamin D status in this population.
Pneumonia is the leading cause of childhood mortality globally. Respiratory syncytial virus (RSV) is the most important viral cause of pneumonia. Maternal serum antibody protects infants from RSV disease. The objective of our study was to characterize RSV antibody levels in mother-infant pairs.
Cysticercosis is a significant public health problem in countries where pigs are raised for consumption and remains an important cause of neurological disease worldwide. The Philippines is considered an endemic area for cysticercosis because cases in both humans and pigs have been reported; however, epidemiologic information stays limited. We conducted a pilot survey of the seroprevalence of human cysticercosis in a village in Leyte, the Philippines, by measuring antibody specific for Taenia solium cyst-fluid antigen. There were 497 subjects aged 7-30 years in our study and most subjects were infected with one or more helminths. The overall cysticercosis seroprevalence in this population was 24.6% (95% CI: 20.82% ~ 28.58%) with no significant difference based on age, sex, or other helminth coinfection status. Although the sample may not be representative of the whole community, the findings suggest that cysticercosis is a significant, but underrecognized public health concern in the Philippines.
Schistosomiasis remains a public health concern in developing countries, and rapid reinfection fostered by continued exposure to contaminated water sources necessitates a vaccine to augment current mass treatment-based control strategies. We report isotype-specific (immunoglobulin A [IgA], IgE, IgG1, IgG4, and IgG) antibody responses to soluble worm antigen preparation and the recombinant vaccine candidates rSj97, rSj67, and rSj22 from a Schistosoma japonicum-infected cohort in Leyte, the Philippines, where schistosomiasis is endemic. Sera were collected from infected individuals 1 month posttreatment with praziquantel, and antibody responses were measured using a bead-based multiplex platform. Reinfection was monitored by stool sampling every 3 months, and data up to 1 year were included in the analysis (n = 553). In repeated-measures models, individuals with detectible IgE responses to rSj97 had a 26% lower intensity of reinfection at 12 months posttreatment compared to nonresponders after adjusting for age, gender, village, exposure, pretreatment infection intensity, and clustering by household (P = 0.018). In contrast, IgG4 responses to rSj97 as well as rSj67 and rSj22 were associated with markedly increased reinfection intensity. When stratified by IgG4 and IgE responder status, individuals with IgE but not IgG4 responses to rSj97 (n = 16) had a 77% lower intensity of reinfection at 12 months compared to individuals with IgG4 responses but not IgE responses (n = 274), even after adjusting for potential confounders (P = 0.016). Together with our previously described protective cytokine responses, these data further support paramyosin as a leading vaccine candidate for human schistosomiasis japonica and underscore the importance of careful adjuvant selection to avoid the generation of blocking IgG4 antibody responses.
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