10 results on '"Alexander NDE"'
Search Results
2. Flies and Helicobacter pylori infection.
- Author
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Allen SJ, Thomas JE, Alexander NDE, Bailey R, and Emerson PM
- Abstract
Houseflies have been proposed to be a reservoir and vector for Helicobacter pylori. We assessed the effect of insecticide spraying in villages in The Gambia on H. pylori infection in young children. Effective control of flies did not prevent infection with H. pylori. [ABSTRACT FROM AUTHOR]
- Published
- 2004
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3. Mass treatment with single-dose azithromycin for trachoma.
- Author
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Solomon AW, Holland MJ, Alexander NDE, Massae PA, Aguirre A, Natividad-Sancho A, Molina S, Safari S, Shao JF, Courtright P, Peeling RW, West SK, Bailey RL, Foster A, Mabey DCW, Solomon, Anthony W, Holland, Martin J, Alexander, Neal D E, Massae, Patrick A, and Aguirre, Aura
- Abstract
Background: Trachoma, caused by repeated ocular infection with Chlamydia trachomatis, is an important cause of blindness. Current recommended dosing intervals for mass azithromycin treatment for trachoma are based on a mathematical model.Methods: We collected conjunctival swabs for quantitative polymerase-chain-reaction assay of C. trachomatis before and 2, 6, 12, 18, and 24 months after mass treatment with azithromycin in a Tanzanian community in which trachoma was endemic. For ethical reasons, at 6, 12, and 18 months, we gave tetracycline eye ointment to residents who had clinically active trachoma.Results: At baseline, 956 of 978 residents (97.8 percent) received either one oral dose of azithromycin or (if azithromycin was contraindicated) a course of tetracycline eye ointment. The prevalence of infection fell from 9.5 percent before mass treatment to 2.1 percent at 2 months and 0.1 percent at 24 months. The quantitative burden of ocular C. trachomatis infection in the community was 13.9 percent of the pretreatment level at 2 months and 0.8 percent at 24 months. At each time point after baseline, over 90 percent of the total community burden of C. trachomatis infection was found among subjects who had been positive the previous time they were tested.Conclusions: The prevalence and intensity of infection fell dramatically and remained low for two years after treatment. One round of very-high-coverage mass treatment with azithromycin, perhaps aided by subsequent periodic use of tetracycline eye ointment for persons with active disease, can interrupt the transmission of ocular C. trachomatis infection. [ABSTRACT FROM AUTHOR]- Published
- 2004
4. Re-emergence of Chlamydia trachomatis infection after mass antibiotic treatment of a trachoma-endemic Gambian community: a longitudinal study.
- Author
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Burton MJ, Holland MJ, Makalo P, Aryee EAN, Alexander NDE, Sillah A, Faal H, West SK, Foster A, Johnson GJ, Mabey DCW, Bailey RL, Burton, Matthew J, Holland, Martin J, Makalo, Pateh, Aryee, Esther A N, Alexander, Neal D E, Sillah, Ansumana, Faal, Hannah, and West, Sheila K
- Abstract
Background: Community-wide mass antibiotic treatment is a central component of trachoma control. The optimum frequency and duration of treatment are unknown. We measured the effect of mass treatment on the conjunctival burden of Chlamydia trachomatis in a Gambian community with low to medium trachoma prevalence and investigated the rate, route, and determinants of re-emergent infection.Methods: 14 trachoma-endemic villages in rural Gambia were examined and conjunctival swabs obtained at baseline, 2, 6, 12, and 17 months. Mass antibiotic treatment with azithromycin was given to the community at baseline. C trachomatis was detected by qualitative PCR and individual infection load then estimated by real-time quantitative PCR.Findings: C trachomatis was detected in 95 (7%) of 1319 individuals at baseline. Treatment coverage was 83% of the population (1328 of 1595 people). The effect of mass treatment was heterogeneous. In 12 villages all baseline infections (34 [3%] of 1062 individuals) resolved, and prevalence (three [0.3%]) and infection load remained low throughout the study. Two villages (baseline infection: 61 [24%] of 257 individuals) had increased infection 2 months after treatment (74 [30%]), after extensive contact with other untreated communities. Subsequently, this value reduced to less than half of that before treatment (25 [11%]).Interpretation: Mass antibiotic treatment generally results in effective, longlasting control of C trachomatis in this environment. For low prevalence regions, one treatment episode might be sufficient. Infection can be reintroduced through contact with untreated populations. Communities need to be monitored for treatment failure and control measures implemented over wide geographical areas. [ABSTRACT FROM AUTHOR]- Published
- 2005
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- View/download PDF
5. Strategies for control of trachoma: observational study with quantitative PCR.
- Author
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Solomon AW, Holland MJ, Burton MJ, West SK, Alexander NDE, Aguirre A, Massae PA, Mkocha H, Muñoz B, Johnson GJ, Peeling RW, Bailey RL, Foster A, and Mabey DCW
- Published
- 2003
- Full Text
- View/download PDF
6. Meta-analysis of surgery in advanced ovarian carcinoma: Is maximum cytoreductive surgery an independent determinant of prognosis?
- Author
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Hunter, RW, Alexander, NDE, and Soutter, WP
- Published
- 1992
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7. Data management plan for a community-level study of the hidden burden of cutaneous leishmaniasis in Colombia.
- Author
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Oviedo Sarmiento OJ, Castro MDM, Lerma YO, Bernal LV, Navarro A, and Alexander NDE
- Subjects
- Colombia epidemiology, Data Management, Humans, Leishmaniasis, Cutaneous diagnosis, Leishmaniasis, Cutaneous epidemiology, Mobile Applications, Telemedicine
- Abstract
Objectives: Cutaneous leishmaniasis is a vector-borne parasitic disease whose lasting scars can cause stigmatization and depressive symptoms. It is endemic in remote rural areas and its incidence is under-reported, while the effectiveness, as opposed to efficacy, of its treatments is largely unknown. Here we present the data management plan (DMP) of a project which includes mHealth tools to address these knowledge gaps in Colombia. The objectives of the DMP are to specify the tools and procedures for data collection, data transfer, data entry, creation of analysis dataset, monitoring and archiving., Results: The DMP includes data from two mobile apps: one implements a clinical prediction rule, and the other is for follow-up and treatment of confirmed cases. A desktop interface integrates these data and facilitates their linkage with other sources which include routine surveillance as well as paper and electronic case report forms. Multiple user and programming interfaces are used, as well as multiple relational and non-relational database engines. This DMP describes the successful integration of heterogeneous data sources and technologies. However the complexity of the project meant that the DMP took longer to develop than expected. We describe lessons learned which could be useful for future mHealth projects.
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- 2021
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8. Adaptation and performance of a mobile application for early detection of cutaneous leishmaniasis.
- Author
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Rubiano L, Alexander NDE, Castillo RM, Martínez ÁJ, García Luna JA, Arango JD, Vargas L, Madriñán P, Hurtado LR, Orobio Y, Rojas CA, Del Corral H, Navarro A, Gore Saravia N, and Aronoff-Spencer E
- Subjects
- Adaptation, Physiological, Adolescent, Adult, Colombia epidemiology, Community Health Workers, Female, Humans, Leishmaniasis, Cutaneous epidemiology, Male, Mass Screening methods, Medically Underserved Area, Reproducibility of Results, Tropical Medicine instrumentation, Young Adult, Early Diagnosis, Leishmaniasis, Cutaneous diagnosis, Mobile Applications, Tropical Medicine methods
- Abstract
Background: Detection and management of neglected tropical diseases such as cutaneous leishmaniasis present unmet challenges stemming from their prevalence in remote, rural, resource constrained areas having limited access to health services. These challenges are frequently compounded by armed conflict or illicit extractive industries. The use of mobile health technologies has shown promise in such settings, yet data on outcomes in the field remain scarce., Methods: We adapted a validated prediction rule for the presumptive diagnosis of CL to create a mobile application for use by community health volunteers. We used human-centered design practices and agile development for app iteration. We tested the application in three rural areas where cutaneous leishmaniasis is endemic and an urban setting where patients seek medical attention in the municipality of Tumaco, Colombia. The application was assessed for usability, sensitivity and inter-rater reliability (kappa) when used by community health volunteers (CHV), health workers and a general practitioner, study physician., Results: The application was readily used and understood. Among 122 screened cases with cutaneous ulcers, sensitivity to detect parasitologically proven CL was >95%. The proportion of participants with parasitologically confirmed CL was high (88%), precluding evaluation of specificity, and driving a high level of crude agreement between the app and parasitological diagnosis. The chance-adjusted agreement (kappa) varied across the components of the risk score. Time to diagnosis was reduced significantly, from 8 to 4 weeks on average when CHV conducted active case detection using the application, compared to passive case detection by health facility-based personnel., Conclusions: Translating a validated prediction rule to a mHealth technology has shown the potential to improve the capacity of community health workers and healthcare personnel to provide opportune care, and access to health services for underserved populations. These findings support the use of mHealth tools for NTD research and healthcare., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2021
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9. Spatiotemporal Analysis of the Population Risk of Congenital Microcephaly in Pernambuco State, Brazil.
- Author
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Alexander NDE, Souza WV, Rodrigues LC, Braga C, Sá A, Bezerra LCA, and Turchi Martelli CM
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- Bayes Theorem, Brazil epidemiology, Female, Humans, Pregnancy, Spatio-Temporal Analysis, Microcephaly epidemiology, Microcephaly virology, Pregnancy Complications, Infectious epidemiology, Pregnancy Complications, Infectious virology, Zika Virus Infection epidemiology
- Abstract
Since an outbreak in Brazil, which started in 2015, Zika has been recognized as an important cause of microcephaly. The highest burden of this outbreak was in northeast Brazil, including the state of Pernambuco. The prevalence of congenital microcephaly in Pernambuco state was estimated from the RESP (Registro de Eventos em Saúde Pública) surveillance system, from August 2015 to August 2016 inclusive. The denominators were estimated at the municipality level from official demographic data. Microcephaly was defined as a neonatal head circumference below the 3rd percentile of the Intergrowth standards. Smoothed maps of the prevalence of microcephaly were obtained from a Bayesian model which was conditional autoregressive (CAR) in space, and first order autoregressive in time. A total of 742 cases were identified. Additionally, high and early occurrences were identified in the Recife Metropolitan Region, on the coast, and in a north-south band about 300 km inland. Over a substantial part of the state, the overall prevalence, aggregating over the study period, was above 0.5%. The reasons for the high occurrence in the inland area remain unclear., Competing Interests: The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.
- Published
- 2020
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10. Prevalence of signs of trachoma, ocular Chlamydia trachomatis infection and antibodies to Pgp3 in residents of Kiritimati Island, Kiribati.
- Author
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Cama A, Müller A, Taoaba R, Butcher RMR, Itibita I, Migchelsen SJ, Kiauea T, Pickering H, Willis R, Roberts CH, Bakhtiari A, Le Mesurier RT, Alexander NDE, Martin DL, Tekeraoi R, and Solomon AW
- Subjects
- Child, Child, Preschool, Enzyme-Linked Immunosorbent Assay, Humans, Infant, Micronesia epidemiology, Prevalence, Trachoma complications, Antibodies, Bacterial blood, Antigens, Bacterial immunology, Bacterial Proteins immunology, Chlamydia trachomatis, Trachoma epidemiology, Trachoma microbiology, Trichiasis etiology
- Abstract
Objective: In some Pacific Island countries, such as Solomon Islands and Fiji, active trachoma is common, but ocular Chlamydia trachomatis (Ct) infection and trachomatous trichiasis (TT) are rare. On Tarawa, the most populous Kiribati island, both the active trachoma sign "trachomatous inflammation-follicular" (TF) and TT are present at prevalences warranting intervention. We sought to estimate prevalences of TF, TT, ocular Ct infection, and anti-Ct antibodies on Kiritimati Island, Kiribati, to assess local relationships between these parameters, and to help determine the need for interventions against trachoma on Kiribati islands other than Tarawa., Methods: As part of the Global Trachoma Mapping Project (GTMP), on Kiritimati, we examined 406 children aged 1-9 years for active trachoma. We collected conjunctival swabs (for droplet digital PCR against Ct plasmid targets) from 1-9-year-olds with active trachoma, and a systematic selection of 1-9-year-olds without active trachoma. We collected dried blood spots (for anti-Pgp3 ELISA) from all 1-9-year-old children. We also examined 416 adults aged ≥15 years for TT. Prevalence of TF and TT was adjusted for age (TF) or age and gender (TT) in five-year age bands., Results: The age-adjusted prevalence of TF in 1-9-year-olds was 28% (95% confidence interval [CI]: 24-35). The age- and gender-adjusted prevalence of TT in those aged ≥15 years was 0.2% (95% CI: 0.1-0.3%). Twenty-six (13.5%) of 193 swabs from children without active trachoma, and 58 (49.2%) of 118 swabs from children with active trachoma were positive for Ct DNA. Two hundred and ten (53%) of 397 children had anti-Pgp3 antibodies. Both infection (p<0.0001) and seropositivity (p<0.0001) were strongly associated with active trachoma. In 1-9-year-olds, the prevalence of anti-Pgp3 antibodies rose steeply with age., Conclusion: Trachoma presents a public health problem on Kiritimati, where the high prevalence of ocular Ct infection and rapid increase in seropositivity with age suggest intense Ct transmission amongst young children. Interventions are required here to prevent future blindness.
- Published
- 2017
- Full Text
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