Measuring the exposure of infants and children to indoor air pollution from biomass fuels in The Gambia

Indoor air pollution (IAP) from biomass fuels contains high concentrations of health damaging pollutants and is associated with an increased risk of childhood pneumonia. We aimed to design an exposure measurement component for a matched case–control study of IAP as a risk factor for pneumonia and severe pneumonia in infants and children in The Gambia. We conducted co-located simultaneous area measurement of carbon monoxide (CO) and particles with aerodynamic diameter <2.5 lm (PM2.5) in 13 households for 48 h each. CO was measured using a passive integrated monitor and PM2.5 using a continuous monitor. In three of the 13 households, we also measured continuous PM2.5 concentration for 2 weeks in the cooking, sleeping, and playing areas. We used gravimetric PM2.5 samples as the reference to correct the continuous PM2.5 for instrument measurement error. Forty-eight hour CO and PM2.5 concentrations in the cooking area had a correlation coefficient of 0.80. Average 48-h CO and PM2.5 concentrations in the cooking area were 3.8 ± 3.9 ppm and 361 ± 312 lg/m3 , respectively. The average 48-h CO exposure was 1.5 ± 1.6 ppm for children and 2.4 ± 1.9 ppm for mothers. PM2.5 exposure was an estimated 219 lg/m3 for children and 275 lg/m3 for their mothers. The continuous PM2.5 concentration had peaks in all households representing the morning, midday, and evening cooking periods, with the largest peak corresponding to midday. The results are used to provide specific recommendations for measuring the exposure of infants and children in an epidemiological study

Nasopharyngeal carriage of streptococcus pneumoniae in gambian children who participated in a 9-valent pneumococcal conjugate vaccine trial and in their younger siblings

10.1097/INF.0b013e3181a78185Pediatric Infectious Disease Journal2811990-995PIDJ

Spatial analysis of tuberculosis in an Urban West African setting: is there evidence of clustering?

objectives To describe the pattern of tuberculosis (TB) occurrence in Greater Banjul, The Gambia with Geographical Information Systems (GIS) and Spatial Scan Statistics (SaTScan) and to determine whether there is significant TB case clustering. methods In Greater Banjul, where 80% of all Gambian TB cases arise, all patients with TB registered at chest clinics between March 2007 and February 2008 were asked to participate. Demographic, clinical characteristics and GPS co-ordinates for the residence of each consenting TB case were recorded. A spatial scan statistic was used to identify purely spatial and space–time clusters of tuberculosis among permanent residents. results Of 1145 recruited patients with TB, 84% were permanent residents with 88% living in 37 settlements that had complete maps available down to settlement level. Significant high- and low-rate spatial and space–time clusters were identified in two districts. The most likely cluster of high rate from both the purely spatial analysis and the retrospective space–time analysis were from the same geo- graphical area. A significant secondary cluster was also identified in one of the densely populated areas of the study region. conclusions There is evidence of significant clustering of TB cases in Greater Banjul, The Gambia. Systematic use of cluster detection techniques for regular TB surveillance in The Gambia may aid effective deployment of resources. However, passive case detection dictates that community-based active case detection and risk factor surveys would help confirm the presence of true clusters and their causes

T cell memory response to pneumococcal protein antigens in an area of high pneumococcal carriage and disease

Background. Streptococcus pneumoniae is a leading cause of vaccine-preventable disease worldwide. Pneumococcal protein antigens are currently under study as components of potential vaccines that offer protection against multiple serotypes. We have therefore characterized T cell pneumococcal immunity acquired through asymptomatic carriage. Methods. Peripheral blood mononuclear cells from 40 healthy Gambian adults were stimulated with supernatants derived from S. pneumoniae strain (D39), 2 isogenic mutant strains lacking either pneumolysin or choline binding protein A, and recombinant pneumolysin. Immune responses were measured by cellular proliferation and by interleukin-10 (IL-10) and interferon-gamma (IFN-gamma) enzyme-linked immunosorbent spot and bioplex cytokine assays. Nasopharyngeal swabs were cultured to determine carriage rates. Results. S. pneumoniae nasopharyngeal carriage was detected in 60% of individuals. Both effector and resting (or central) CD4(+) T cell memory were frequently present to a range of pneumococcal antigens. However, the level of the effector memory response did not relate to current nasopharyngeal carriage. Pneumolysin was not immunodominant in these T cell responses but induced a distinct proinflammatory profile (high IFN-gamma, IL-12[p40], and L-17 levels and low IL-10 and IL-13 levels). Conclusions. In this population, T cell-mediated immunological memory potentially capable of pathogen clearance and immune surveillance is common but is not associated with the absolute interruption of pneumococcal carriage. How this naturally acquired immune memory influences pneumococcal vaccine efficacy remains to be determined

Antimicrobial susceptibility and resistance patterns among helicobacter pylori strains from the gambia, west africa

Helicobacter pylori is a globally important and genetically diverse gastric pathogen that infects most people in developing countries. Eradication efforts are complicated by antibiotic resistance, which varies in frequency geographically. There are very few data on resistance in African strains. Sixty-four Gambian H. pylori strains were tested for antibiotic susceptibility. The role of rdxA in metronidazole (Mtz) susceptibility was tested by DNA transformation and sequencing; RdxA protein variants were interpreted in terms of RdxA structure. Forty-four strains (69%) were resistant to at least 8 ¿g of Mtz/ml. All six strains from infants, but only 24% of strains from adults, were sensitive (P=0.0031). Representative Mtz-resistant (Mtzr) strains were rendered Mtz susceptible (Mtzs) by transformation with a functional rdxA gene; conversely, Mtzs strains were rendered Mtzr by rdxA inactivation. Many mutations were found by Gambian H. pylori rdxA sequencing; mutations that probably inactivated rdxA in Mtz r strains were identified and explained using RdxA protein's structure. All of the strains were sensitive to clarithromycin and erythromycin. Amoxicillin and tetracycline resistance was rare. Sequence analysis indicated that most tetracycline resistance, when found, was not due to 16S rRNA gene mutations. These data suggest caution in the use of Mtz-based therapies in The Gambia. The increasing use of macrolides against respiratory infections in The Gambia calls for continued antibiotic susceptibility monitoring. The rich variety of rdxA mutations that we found will be useful in further structure-function studies of RdxA, the enzyme responsible for Mtz susceptibility in this important pathogen. Copyright © 2013, American Society for Microbiology.Peer Reviewe

Aerobic bacteria, Chlamydia trachomatis, Pneumocystis carinii and Cytomegalovirus as agents of severe peneumonia in small infants Bactérias aeróbias, Chlamydia trachomatis, Pneumocystis carinii e Cytomegalovirus: agentes causadores de pneumonia grave em pequenos lactentes

The authors studied 58 infants hospitalized for pneumonia in a semi-intensive care unit. Age ranged from 1 complete to 6 incomplete months. The infants were sent from another hospital in 20 cases and from home in a further 38. Pulmonary involvement, which was alveolar in 46 cases and interstitial in 12, was bilateral in 31 children. The investigation was carried out prospectively on the etiological agents associated with respiratory infection to look for evidence of aerobic bacteria (blood cultures), Chlamydia trachomatis and Cytomegalovirus (serology), and Pneumocystis carinii (direct microscopy of tracheal aspirated material). The following infectious agents were diagnosed in 21 children (36.2%): Aerobic bacteria (8), Chlamydia trachomatis (5), Pneumocystis carinii (3), Cytomegalovirus (3), Cytomegalovirus and Chlamydia trachomatis (1), Aerobic bacteria and Cytomegalovirus (1). Seven cases of infection by Chlamydia trachomatis and/or Cytomegalovirus were diagnosed out of the 12 cases with pulmonary interstitial involvement.<br>Os autores estudaram prospectivamente 58 lactentes internados por pneumonia em unidade semi-intensiva. A idade foi limitada entre 1 mês completo e 6 meses incompletos. A procedência das crianças foi de outro hospital em 20 casos e domiciliar em 38. O acometimento pulmonar era alveolar em 46 casos, intersticial em 12 e bilateral em 31 crianças. Foram pesquisados agentes etiológicos associados à infecção respiratória dos lactentes jovens: Bactérias aeróbias (Hemoculturas), Chlamydia trachomatis e Cytomegalovirus (sorologia), e Pneumocystis carinii (microscopia direta do aspirado traqueal). Foram diagnosticadas infecções em 21 crianças (36,2%): Bactérias aeróbias (8), Chlamydia trachomatis (5), Cytomegalovirus (3), Pneumocystis carinii (3), Cytomegalovirus e Chlamydia trachomatis (1), Bactéria aeróbia e Cytomegalovirus (1). Foram diagnosticadas 7 infecções por Chlamydia trachomatis e/ou Cytomegalovirus entre as 12 crianças com quadro intersticia