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1.
BMC Res Notes ; 14(1): 213, 2021 May 31.
Article in English | MEDLINE | ID: mdl-34059128

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.


Subject(s)
Leishmaniasis, Cutaneous , Mobile Applications , Telemedicine , Colombia/epidemiology , Data Management , Humans , Leishmaniasis, Cutaneous/diagnosis , Leishmaniasis, Cutaneous/epidemiology
2.
PLoS Negl Trop Dis ; 15(2): e0008989, 2021 02.
Article in English | MEDLINE | ID: mdl-33571192

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.


Subject(s)
Early Diagnosis , Leishmaniasis, Cutaneous/diagnosis , Mobile Applications , Tropical Medicine/methods , 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
3.
Article in English | MEDLINE | ID: mdl-31973162

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.


Subject(s)
Microcephaly/epidemiology , Microcephaly/virology , Pregnancy Complications, Infectious/epidemiology , Pregnancy Complications, Infectious/virology , Zika Virus Infection/epidemiology , Bayes Theorem , Brazil/epidemiology , Female , Humans , Pregnancy , Spatio-Temporal Analysis
4.
Glob Health Sci Pract ; 7(1): 128-137, 2019 03 22.
Article in English | MEDLINE | ID: mdl-30926741

ABSTRACT

In Colombia, as in many Latin American countries, decision making and development of effective strategies for vector control of urban diseases such as dengue, Zika, and chikungunya is challenging for local health authorities. The heterogeneity of transmission in urban areas requires an efficient risk-based allocation of resources to control measures. With the objective of strengthening the capacity of local surveillance systems to identify variables that favor urban arboviral transmission, a multidisciplinary research team collaborated with the local Secretary of Health officials of 3 municipalities in Colombia (Giron, Yopal, and Buga), in the design of an integrated information system called VECTOS from 2015 to 2018. Information and communication technologies were used to develop 2 mobile applications to capture entomological and social information, as well as a web-based system for the collection, geo-referencing, and integrated information analysis using free geospatial software. This system facilitates the capture and analysis of epidemiological information from the Colombian national surveillance system (SIVIGILA), periodic entomological surveys-mosquito larvae and pupae in premises and peridomestic breeding sites-and surveys of knowledge, attitudes, and practices (KAP) in a spatial and temporal context at the neighborhood level. The data collected in VECTOS are mapped and visualized in graphical reports. The system enables real-time monitoring of weekly epidemiological indicators, entomological indices, and social surveys. Additionally, the system enables risk stratification of neighborhoods, using selected epidemiological, entomological, demographic, and environmental variables. This article describes the VECTOS system and the lessons learned during its development and use. The joint analysis of epidemiological and entomological data within a geographic information system in VECTOS gives better insight to the routinely collected data and identifies the heterogeneity of risk factors between neighborhoods. We expect the system to continue to strengthen vector control programs in evidence-based decision making and in the design and enhanced follow-up of vector control strategies.


Subject(s)
Arbovirus Infections/prevention & control , Decision Making , Information Systems , Mobile Applications , Mosquito Control , Technology , Urban Population , Arbovirus Infections/transmission , Arbovirus Infections/virology , Arboviruses/growth & development , Chikungunya Fever/etiology , Chikungunya Fever/transmission , Cities , Colombia , Data Analysis , Data Collection , Dengue/etiology , Dengue/transmission , Environmental Monitoring/methods , Geographic Information Systems , Humans , Internet , Mosquito Vectors/growth & development , Mosquito Vectors/virology , Population Surveillance , Public Health , Residence Characteristics , Risk Factors , Zika Virus Infection/etiology , Zika Virus Infection/transmission
5.
BMC Health Serv Res ; 18(1): 317, 2018 05 02.
Article in English | MEDLINE | ID: mdl-29720163

ABSTRACT

BACKGROUND: Several malaria endemic countries have implemented community health worker (CHW) programmes to increase access to populations underserved by health care. There is considerable evidence on CHW adherence to case management guidelines, however, there is limited evidence on the compliance to referral advice and the outcomes of children under-5 referred by CHWs. This analysis examined whether caregivers complied with CHWs referral advice. METHODS: Data from two cluster (village) randomised trials, one in a moderate-to-high malaria transmission setting, another in a low-transmission setting conducted between January 2010-July 2011 were analysed. CHW were trained to recognise signs and symptoms that required referral to a health centre. CHW in the intervention arm also had training on; malaria rapid diagnostic tests (mRDT) and administering artemisinin based combination therapy (ACT); CHW in the control arm were trained to treat malaria with ACTs based on fever symptoms. Caregivers' referral forms were linked with CHW treatment forms to determine whether caregivers complied with the referral advice. Factors associated with compliance were examined with logistic regression. RESULTS: CHW saw 18,497 child visits in the moderate-to-high transmission setting and referred 15.2% (2815/18,497) of all visits; in the low-transmission setting, 35.0% (1135/3223) of all visits were referred. Compliance to referral was low, in both settings < 10% of caregivers complied with referral advice. In the moderate-to-high transmission setting compliance was higher if children were tested with mRDT compared to children who were not tested with mRDT. In both settings, nearly all children treated with pre-referral rectal artesunate failed to comply with referral and compliance was independently associated with factors such as health centre distance and day of referral by a CHW. In the moderate-to-high transmission setting, time of presentation, severity of referral were also associated with compliance, whilst in the low-transmission setting, compliance was low if an ACT was prescribed. CONCLUSIONS: This analysis suggests there are several barriers to comply with CHWs referral advice by caregivers. This is concerning for children who received rectal artesunate. As CHW programmes continue scale-up, barriers to referral compliance need to be addressed to ensure a continuum of care from the community to the health centre. TRIAL REGISTRATION: The study was registered with ClinicalTrials.gov. Identifier NCT01048801 , 13th January 2010.


Subject(s)
Antimalarials/therapeutic use , Caregivers , Community Health Workers , Guideline Adherence , Malaria/diagnosis , Referral and Consultation/statistics & numerical data , Treatment Adherence and Compliance , Adolescent , Artemisinins/therapeutic use , Artesunate/therapeutic use , Case Management , Child , Child, Preschool , Diagnostic Tests, Routine/methods , Female , Humans , Infant , Malaria/drug therapy , Malaria/transmission , Male , Randomized Controlled Trials as Topic , Uganda/epidemiology
6.
PLoS Negl Trop Dis ; 11(9): e0005863, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28898240

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.


Subject(s)
Antibodies, Bacterial/blood , Antigens, Bacterial/immunology , Bacterial Proteins/immunology , Chlamydia trachomatis , Trachoma/epidemiology , Trachoma/microbiology , Trichiasis/etiology , Child , Child, Preschool , Enzyme-Linked Immunosorbent Assay , Humans , Infant , Micronesia/epidemiology , Prevalence , Trachoma/complications
7.
PLoS Negl Trop Dis ; 11(1): e0005230, 2017 01.
Article in English | MEDLINE | ID: mdl-28099433

ABSTRACT

BACKGROUND: Efforts are underway to eliminate trachoma as a public health problem by 2020. Programmatic guidelines are based on clinical signs that correlate poorly with Chlamydia trachomatis (Ct) infection in post-treatment and low-endemicity settings. Age-specific seroprevalence of anti Ct Pgp3 antibodies has been proposed as an alternative indicator of the need for intervention. To standardise the use of these tools, it is necessary to develop an analytical approach that performs reproducibly both within and between studies. METHODOLOGY: Dried blood spots were collected in 2014 from children aged 1-9 years in Laos (n = 952) and Uganda (n = 2700) and from people aged 1-90 years in The Gambia (n = 1868). Anti-Pgp3 antibodies were detected by ELISA. A number of visual and statistical analytical approaches for defining serological status were compared. PRINCIPAL FINDINGS: Seroprevalence was estimated at 11.3% (Laos), 13.4% (Uganda) and 29.3% (The Gambia) by visual inspection of the inflection point. The expectation-maximisation algorithm estimated seroprevalence at 10.4% (Laos), 24.3% (Uganda) and 29.3% (The Gambia). Finite mixture model estimates were 15.6% (Laos), 17.1% (Uganda) and 26.2% (The Gambia). Receiver operating characteristic (ROC) curve analysis using a threshold calibrated against external reference specimens estimated the seroprevalence at 6.7% (Laos), 6.8% (Uganda) and 20.9% (The Gambia) when the threshold was set to optimise Youden's J index. The ROC curve analysis was found to estimate seroprevalence at lower levels than estimates based on thresholds established using internal reference data. Thresholds defined using internal reference threshold methods did not vary substantially between population samples. CONCLUSIONS: Internally calibrated approaches to threshold specification are reproducible and consistent and thus have advantages over methods that require external calibrators. We propose that future serological analyses in trachoma use a finite mixture model or expectation-maximisation algorithm as a means of setting the threshold for ELISA data. This will facilitate standardisation and harmonisation between studies and eliminate the need to establish and maintain a global calibration standard.


Subject(s)
Antibodies, Bacterial/blood , Chlamydia trachomatis/immunology , Trachoma/prevention & control , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Chlamydia trachomatis/genetics , Chlamydia trachomatis/isolation & purification , Disease Eradication , Female , Humans , Infant , Male , Middle Aged , Trachoma/blood , Trachoma/epidemiology , Trachoma/microbiology , Young Adult
8.
Am J Trop Med Hyg ; 95(6): 1398-1408, 2016 Dec 07.
Article in English | MEDLINE | ID: mdl-27799650

ABSTRACT

Malaria-endemic countries have implemented community health worker (CHW) programs to provide malaria diagnosis and treatment to populations living beyond the reach of health systems. However, there is limited evidence describing the referral practices of CHWs. We examined the impact of malaria rapid diagnostic tests (mRDTs) on CHW referral in two cluster-randomized trials, one conducted in a moderate-to-high malaria transmission setting and one in a low-transmission setting in Uganda, between January 2010 and July 2012. All CHWs were trained to prescribe artemisinin-based combination therapy (ACT) for malaria and recognize signs and symptoms for referral to health centers. CHWs in the control arm used a presumptive diagnosis for malaria based on clinical symptoms, whereas intervention arm CHWs used mRDTs. CHWs recorded ACT prescriptions, mRDT results, and referral in patient registers. An intention-to-treat analysis was undertaken using multivariable logistic regression. Referral was more frequent in the intervention arm versus the control arm (moderate-to-high transmission, P < 0.001; low transmission, P < 0.001). Despite this increase, referral advice was not always given when ACTs or prereferral rectal artesunate were prescribed: 14% prescribed rectal artesunate in the moderate-to-high setting were not referred. In addition, CHWs considered factors alongside mRDTs when referring. Child visits during the weekends or the rainy season were less likely to be referred, whereas visits to CHWs more distant from health centers were more likely to be referred (low transmission only). CHWs using mRDTs and ACTs increased referral compared with CHWs using a presumptive diagnosis. To address these concerns, referral training should be emphasized in CHW programs as they are scaled-up.


Subject(s)
Community Health Workers , Malaria/diagnosis , Malaria/epidemiology , Referral and Consultation , Adolescent , Antimalarials/therapeutic use , Child , Child, Preschool , Cluster Analysis , Female , Humans , Infant , Malaria/drug therapy , Male , Uganda/epidemiology
9.
Malar J ; 15(1): 568, 2016 Nov 24.
Article in English | MEDLINE | ID: mdl-27881136

ABSTRACT

BACKGROUND: Many malaria-endemic countries have implemented national community health worker (CHW) programmes to serve remote populations that have poor access to malaria diagnosis and treatment. Despite mounting evidence of CHWs' ability to adhere to malaria rapid diagnostic tests (RDTs) and treatment guidelines, there is limited evidence whether CHWs adhere to the referral guidelines and refer severely ill children for further management. In southwest Uganda, this study examined whether CHWs referred children according to training guidelines and described factors associated with adherence to the referral guideline. METHODS: A secondary analysis was undertaken of data collected during two cluster-randomized trials conducted between January 2010 and July 2011, one in a moderate-to-high malaria transmission setting and the other in a low malaria transmission setting. All CHWs were trained to prescribe artemisinin-based combination therapy (ACT) and recognize symptoms in children that required immediate referral to the nearest health centre. Intervention arm CHWs had additional training on how to conduct an RDT; CHWs in the control arm used a presumptive diagnosis for malaria using clinical signs and symptoms. CHW treatment registers were reviewed to identify children eligible for referral according to training guidelines (temperature of ≥38.5 °C), to assess whether CHWs adhered to the guidelines and referred them. Factors associated with adherence were examined with logistic regression models. RESULTS: CHWs failed to refer 58.8% of children eligible in the moderate-to-high transmission and 31.2% of children in the low transmission setting. CHWs using RDTs adhered to the referral guidelines more frequently than CHWs not using RDTs (moderate-to-high transmission: 50.1 vs 18.0%, p = 0.003; low transmission: 88.5 vs 44.1%, p < 0.001). In both settings, fewer than 20% of eligible children received pre-referral treatment with rectal artesunate. Children who were prescribed ACT were very unlikely to be referred in both settings (97.7 and 73.3% were not referred in the moderate-to-high and low transmission settings, respectively). In the moderate-to-high transmission setting, day and season of visit were also associated with the likelihood of adherence to the referral guidelines, but not in the low transmission setting. CONCLUSIONS: CHW adherence to referral guidelines was poor in both transmission settings. However, training CHWs to use RDT improved correct referral of children with a high fever compared to a presumptive diagnosis using sign and symptoms. As many countries scale up CHW programmes, routine monitoring of reported data should be examined carefully to assess whether CHWs adhere to referral guidelines and take remedial actions where required.


Subject(s)
Community Health Workers , Diagnostic Tests, Routine/statistics & numerical data , Guideline Adherence , Health Services Research , Malaria/diagnosis , Malaria/drug therapy , Referral and Consultation/statistics & numerical data , Adolescent , Child , Child, Preschool , Chromatography, Affinity/statistics & numerical data , Female , Humans , Infant , Male , Randomized Controlled Trials as Topic , Uganda
10.
Trials ; 16: 522, 2015 Nov 16.
Article in English | MEDLINE | ID: mdl-26573827

ABSTRACT

BACKGROUND: Visceral leishmaniasis (VL) is a parasitic disease transmitted by sandflies and is fatal if left untreated. Phase II trials of new treatment regimens for VL are primarily carried out to evaluate safety and efficacy, while pharmacokinetic data are also important to inform future combination treatment regimens. The efficacy of VL treatments is evaluated at two time points, initial cure, when treatment is completed and definitive cure, commonly 6 months post end of treatment, to allow for slow response to treatment and detection of relapses. This paper investigates a generalization of the triangular design to impose a minimum sample size for pharmacokinetic or other analyses, and methods to estimate efficacy at extended follow-up accounting for the sequential design and changes in cure status during extended follow-up. METHODS: We provided R functions that generalize the triangular design to impose a minimum sample size before allowing stopping for efficacy. For estimation of efficacy at a second, extended, follow-up time, the performance of a shrinkage estimator (SHE), a probability tree estimator (PTE) and the maximum likelihood estimator (MLE) for estimation was assessed by simulation. RESULTS: The SHE and PTE are viable approaches to estimate an extended follow-up although the SHE performed better than the PTE: the bias and root mean square error were lower and coverage probabilities higher. CONCLUSIONS: Generalization of the triangular design is simple to implement for adaptations to meet requirements for pharmacokinetic analyses. Using the simple MLE approach to estimate efficacy at extended follow-up will lead to biased results, generally over-estimating treatment success. The SHE is recommended in trials of two or more treatments. The PTE is an acceptable alternative for one-arm trials or where use of the SHE is not possible due to computational complexity. TRIAL REGISTRATION: NCT01067443 , February 2010.


Subject(s)
Leishmaniasis, Visceral/drug therapy , Models, Statistical , Research Design/statistics & numerical data , Trypanocidal Agents/pharmacokinetics , Computer Simulation , Data Interpretation, Statistical , Humans , Kenya , Leishmaniasis, Visceral/diagnosis , Leishmaniasis, Visceral/parasitology , Likelihood Functions , Probability , Recurrence , Remission Induction , Sample Size , Sudan , Treatment Outcome , Trypanocidal Agents/administration & dosage
11.
PLoS One ; 10(9): e0137448, 2015.
Article in English | MEDLINE | ID: mdl-26356099

ABSTRACT

BACKGROUND: Malaria endemic countries have scaled-up community health worker (CHW) interventions, to diagnose and treat malaria in communities with limited access to public health systems. The evaluations of these programmes have centred on CHW's compliance to guidelines, but the broader changes at public health centres including utilisation and diagnoses made, has received limited attention. METHODS: This analysis was conducted during a CHW-intervention for malaria in Rukungiri District, Western Uganda. Outpatient department (OPD) visit data were collected for children under-5 attending three health centres one year before the CHW-intervention started (pre-intervention period) and for 20 months during the intervention (intervention-period). An interrupted time series analysis with segmented regression models was used to compare the trends in malaria, non-malaria and overall OPD visits during the pre-intervention and intervention-period. RESULTS: The introduction of a CHW-intervention suggested the frequency of diagnoses of diarrhoeal diseases, pneumonia and helminths increased, whilst the frequency of malaria diagnoses declined at health centres. In May 2010 when the intervention began, overall health centre utilisation decreased by 63% compared to the pre-intervention period and the health centres saw 32 fewer overall visits per month compared to the pre-intervention period (p<0.001). Malaria visits also declined shortly after the intervention began and there were 27 fewer visits per month during the intervention-period compared with the pre-intervention period (p<0.05). The declines in overall and malaria visits were sustained for the entire intervention-period. In contrast, there were no observable changes in trends of non-malarial visits between the pre-intervention and intervention-period. CONCLUSIONS: This analysis suggests introducing a CHW-intervention can reduce the number of child malaria visits and change the profile of cases presenting at health centres. The reduction in workload of health workers may allow them to spend more time with patients or undertake additional curative or preventative roles.


Subject(s)
Case Management/statistics & numerical data , Health Facilities/statistics & numerical data , Interrupted Time Series Analysis , Malaria/epidemiology , Residence Characteristics , Child , Child, Preschool , Community Health Workers , Geography , Humans , Infant , Outpatients/statistics & numerical data , Regression Analysis , Uganda/epidemiology
12.
Ophthalmic Epidemiol ; 22(3): 214-25, 2015.
Article in English | MEDLINE | ID: mdl-26158580

ABSTRACT

PURPOSE: To complete the baseline trachoma map worldwide by conducting population-based surveys in an estimated 1238 suspected endemic districts of 34 countries. METHODS: A series of national and sub-national projects owned, managed and staffed by ministries of health, conduct house-to-house cluster random sample surveys in evaluation units, which generally correspond to "health district" size: populations of 100,000-250,000 people. In each evaluation unit, we invite all residents aged 1 year and older from h households in each of c clusters to be examined for clinical signs of trachoma, where h is the number of households that can be seen by 1 team in 1 day, and the product h × c is calculated to facilitate recruitment of 1019 children aged 1-9 years. In addition to individual-level demographic and clinical data, household-level water, sanitation and hygiene data are entered into the purpose-built LINKS application on Android smartphones, transmitted to the Cloud, and cleaned, analyzed and ministry-of-health-approved via a secure web-based portal. The main outcome measures are the evaluation unit-level prevalence of follicular trachoma in children aged 1-9 years, prevalence of trachomatous trichiasis in adults aged 15 + years, percentage of households using safe methods for disposal of human feces, and percentage of households with proximate access to water for personal hygiene purposes. RESULTS: In the first year of fieldwork, 347 field teams commenced work in 21 projects in 7 countries. CONCLUSION: With an approach that is innovative in design and scale, we aim to complete baseline mapping of trachoma throughout the world in 2015.


Subject(s)
Endemic Diseases/statistics & numerical data , Global Health , Trachoma/epidemiology , Trichiasis/epidemiology , Adolescent , Blindness/prevention & control , Child , Child, Preschool , Cluster Analysis , Community Health Planning , Female , Health Surveys , Humans , Hygiene/standards , Infant , Male , Prevalence , Sanitation/standards , Water Supply/standards
13.
BMC Med Res Methodol ; 15: 28, 2015 Apr 02.
Article in English | MEDLINE | ID: mdl-25886883

ABSTRACT

BACKGROUND: Sample size calculations should correspond to the intended method of analysis. Nevertheless, for non-normal distributions, they are often done on the basis of normal approximations, even when the data are to be analysed using generalized linear models (GLMs). METHODS: For the case of comparison of two means, we use GLM theory to derive sample size formulae, with particular cases being the negative binomial, Poisson, binomial, and gamma families. By simulation we estimate the performance of normal approximations, which, via the identity link, are special cases of our approach, and for common link functions such as the log. The negative binomial and gamma scenarios are motivated by examples in hookworm vaccine trials and insecticide-treated materials, respectively. RESULTS: Calculations on the link function (log) scale work well for the negative binomial and gamma scenarios examined and are often superior to the normal approximations. However, they have little advantage for the Poisson and binomial distributions. CONCLUSIONS: The proposed method is suitable for sample size calculations for comparisons of means of highly skewed outcome variables.


Subject(s)
Algorithms , Binomial Distribution , Linear Models , Models, Theoretical , Computer Simulation , Humans , Sample Size
14.
Trans R Soc Trop Med Hyg ; 109(3): 173-4, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25575555

ABSTRACT

Lymphatic filariasis has been targeted for elimination by 2020, and a threshold of 65% coverage of mass drug administration (MDA) has been adopted by the Global Programme to Eliminate Lymphatic Filariasis (GPELF). A recent review by Babu and Babu of 36 studies of MDA for lymphatic filariasis in India found that coverage, defined as receipt of tablets, ranged from 48.8 to 98.8%, while compliance, defined as actual ingestion of tablets, was 22% lower on average. Moreover, the denominator for these coverage figures is the eligible, rather than total, population. By contrast, the 65% threshold, in the original modelling study, refers to ingestion of tablets in the total population. This corresponds to GPELF's use of 'epidemiological drug coverage' as a trigger for the Transmission Assessment Surveys (TAS), which indicate whether to proceed to post-MDA surveillance. The existence of less strict definitions of 'coverage' should not lead to premature TAS that could impair MDA's sustainability.


Subject(s)
Diethylcarbamazine/administration & dosage , Disease Eradication , Elephantiasis, Filarial/prevention & control , Filaricides/administration & dosage , Health Plan Implementation/organization & administration , Humans
15.
PLoS Negl Trop Dis ; 6(10): e1866, 2012.
Article in English | MEDLINE | ID: mdl-23145196

ABSTRACT

BACKGROUND: Previous findings indicate that susceptibility to Leishmania (Viannia) panamensis infection of monocyte-derived macrophages from patients and asymptomatically infected individuals were associated with the adaptive immune response and clinical outcome. METHODOLOGY/PRINCIPAL FINDINGS: To understand the basis for this difference we examined differential gene expression of human monocyte-derived macrophages following exposure to L. (V.) panamensis. Gene activation profiles were determined using macrophages from healthy volunteers cultured with or without stationary phase promastigotes of L. (V.) panamensis. Significant changes in expression (>1.5-fold change; p<0.05; up- or down-regulated) were identified at 0.5, 4 and 24 hours. mRNA abundance profiles varied over time, with the highest level of activation occurring at earlier time points (0.5 and 4 hrs). In contrast to observations for other Leishmania species, most significantly changed mRNAs were up- rather than down-regulated, especially at early time points. Up-regulated transcripts over the first 24 hours belonged to pathways involving eicosanoid metabolism, oxidative stress, activation of PKC through G protein coupled receptors, or mechanism of gene regulation by peroxisome proliferators via PPARα. Additionally, a marked activation of Toll-receptor mediated pathways was observed. Comparison with published microarray data from macrophages infected with L. (Leishmania) chagasi indicate differences in the regulation of genes involved in signaling, motility and the immune response. CONCLUSIONS: Results show that the early (0.5 to 24 hours) human monocyte-derived macrophage response to L. (Viannia) panamensis is not quiescent, in contrast to published reports examining later response times (48-96 hours). Early macrophage responses are important for the developing cellular response at the site of infection. The kinetics and the mRNA abundance profiles induced by L. (Viannia) panamensis illustrate the dynamics of these interactions and the distinct biologic responses to different Leishmania species from the outset of infection within their primary host cell.


Subject(s)
Gene Expression Profiling , Host-Pathogen Interactions , Leishmania guyanensis/immunology , Macrophages/immunology , Macrophages/parasitology , Humans , Microarray Analysis , RNA, Messenger/biosynthesis , RNA, Messenger/genetics , Time Factors
16.
PLoS Negl Trop Dis ; 5(7): e1241, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21765964

ABSTRACT

BACKGROUND: Acute painful swelling of the extremities and scrotum are debilitating clinical manifestations of Wuchereria bancrofti infection. The ongoing global program to eliminate filariasis using mass drug administration is expected to decrease this and other forms of filarial morbidity in the future by preventing establishment of new infections as a consequence of eliminating transmission by the mosquito vector. We examined whether mass treatment with anti-filarial drugs has a more immediate health benefit by monitoring acute filariasis morbidity in Papua New Guinean communities that participated in a 5-year mass drug administration trial. METHODOLOGY/PRINCIPAL FINDINGS: Weekly active surveillance for acute filariasis morbidity defined by painful swelling of the extremities, scrotum and breast was performed 1 year before and each year after 4 annual mass administrations of anti-filarial drugs (16,480 person-years of observation). Acute morbidity events lasted <3 weeks in 92% of affected individuals and primarily involved the leg (74-79% of all annual events). The incidence for all communities considered together decreased from 0.39 per person-year in the pre-treatment year to 0.31, 0.15, 0.19 and 0.20 after each of 4 annual treatments (p<0.0001). Residents of communities with high pre-treatment transmission intensities (224-742 infective bites/person/year) experienced a greater reduction in acute morbidity (0.62 episodes per person-year pre-treatment vs. 0.30 in the 4(th) post-treatment year) than residents of communities with moderate pre-treatment transmission intensities (24-167 infective bites/person/year; 0.28 episodes per person-year pre-treatment vs. 0.16 in the 4(th) post-treatment year). CONCLUSIONS: Mass administration of anti-filarial drugs results in immediate health benefit by decreasing the incidence of acute attacks of leg and arm swelling in people with pre-existing infection. Reduction in acute filariasis morbidity parallels decreased transmission intensity, suggesting that continuing exposure to infective mosquitoes is involved in the pathogenesis of acute filariasis morbidity.


Subject(s)
Elephantiasis, Filarial/epidemiology , Elephantiasis, Filarial/prevention & control , Filaricides/administration & dosage , Wuchereria bancrofti/drug effects , Adolescent , Adult , Animals , Breast/pathology , Child , Child, Preschool , Elephantiasis, Filarial/diagnosis , Elephantiasis, Filarial/drug therapy , Extremities/pathology , Female , Humans , Incidence , Male , Middle Aged , Papua New Guinea/epidemiology , Scrotum/pathology , Young Adult
17.
BMJ ; 341: c6761, 2010 Dec 14.
Article in English | MEDLINE | ID: mdl-21156738

ABSTRACT

OBJECTIVE: To compare urine output between junior doctors in an intensive care unit and the patients for whom they are responsible. DESIGN: Case-control study. SETTING: General intensive care unit in a tertiary referral hospital. PARTICIPANTS: 18 junior doctors responsible for clerking patients on weekday day shifts in the unit from 23 March to 23 April 2009 volunteered as "cases." Controls were the patients in the unit clerked by those doctors. Exclusion criteria (for both groups) were pregnancy, baseline estimated glomerular filtration rate <15 ml/min/1.73 m(2), and renal replacement therapy. MAIN OUTCOME MEASURES: Oliguria (defined as mean urine output <0.5 ml/kg/hour over six or more hours of measurement) and urine output (in ml/kg/hour) as a continuous variable. RESULTS: Doctors were classed as oliguric and "at risk" of acute kidney injury on 19 (22%) of 87 shifts in which urine output was measured, and oliguric to the point of being "in injury" on one (1%) further shift. Data were available for 208 of 209 controls matched to cases in the data collection period; 13 of these were excluded because the control was receiving renal replacement therapy. Doctors were more likely to be oliguric than their patients (odds ratio 1.99, 95% confidence interval 1.08 to 3.68, P=0.03). For each additional 1 ml/kg/hour mean urine output, the odds ratio for being a case rather than a control was 0.27 (0.12 to 0.58, P=0.001). Mortality among doctors was astonishingly low, at 0% (0% to 18%). CONCLUSIONS: Managing our own fluid balance is more difficult than managing it in our patients. We should drink more water. Modifications to the criteria for acute kidney injury could be needed for the assessment of junior doctors in an intensive care unit.


Subject(s)
Intensive Care Units , Medical Staff, Hospital , Occupational Diseases/physiopathology , Oliguria/physiopathology , Urination/physiology , Water-Electrolyte Imbalance/physiopathology , Acute Kidney Injury/etiology , Acute Kidney Injury/physiopathology , Case-Control Studies , Female , Glomerular Filtration Rate/physiology , Humans , Male , Occupational Diseases/etiology , Oliguria/etiology , Urine , Water-Electrolyte Balance/physiology , Water-Electrolyte Imbalance/etiology
18.
PLoS Negl Trop Dis ; 4(10)2010 Oct 05.
Article in English | MEDLINE | ID: mdl-20957147

ABSTRACT

BACKGROUND: The elimination of blinding trachoma focuses on controlling Chlamydia trachomatis infection through mass antibiotic treatment and measures to limit transmission. As the prevalence of disease declines, uncertainty increases over the most effective strategy for treatment. There are little long-term data on the effect of treatment on infection, especially in low prevalence settings, on which to base guidelines. METHODOLOGY/PRINCIPAL FINDINGS: The population of a cluster of 14 Gambian villages with endemic trachoma was examined on seven occasions over five years (baseline, 2, 6, 12, 17, 30 and 60 months). Mass antibiotic treatment was given at baseline only. All families had accessible clean water all year round. New latrines were installed in each household after 17 months. Conjunctival swab samples were collected and tested for C. trachomatis by PCR. Before treatment the village-level prevalence of follicular trachoma in 1 to 9 year olds (TF(%1-9)) was 15.4% and C. trachomatis was 9.7%. Antibiotic treatment coverage was 83% of the population. In 12 villages all baseline infection cleared and few sporadic cases were detected during the following five years. In the other two villages treatment was followed by increased infection at two months, which was associated with extensive contact with other untreated communities. The prevalence of infection subsequently dropped to 0% in these 2 villages and 0.6% for the whole population by the end of the study in the absence of any further antibiotic treatment. However, several villages had a TF(%1-9) of >10%, the threshold for initiating or continuing mass antibiotic treatment, in the absence of any detectable C. trachomatis. CONCLUSIONS/SIGNIFICANCE: A single round of mass antibiotic treatment may be sufficient in low prevalence settings to control C. trachomatis infection when combined with environmental conditions, which suppress transmission, such as a good water supply and sanitation.


Subject(s)
Anti-Bacterial Agents/administration & dosage , Chlamydia trachomatis/isolation & purification , Trachoma/drug therapy , Trachoma/epidemiology , Adolescent , Adult , Aged , Aged, 80 and over , Bacteriological Techniques , Child , Child, Preschool , Endemic Diseases , Female , Gambia/epidemiology , Humans , Infant , Infant, Newborn , Longitudinal Studies , Male , Middle Aged , Polymerase Chain Reaction/methods , Prevalence , Trachoma/microbiology , Young Adult
19.
PLoS One ; 5(4): e9867, 2010 Apr 15.
Article in English | MEDLINE | ID: mdl-20419161

ABSTRACT

BACKGROUND: Safe, cheap and effective adjunct therapies preventing the development of, or reducing the mortality from, severe malaria could have considerable and rapid public health impact. Oral activated charcoal (oAC) is a safe and well tolerated treatment for acute poisoning, more recently shown to have significant immunomodulatory effects in man. In preparation for possible efficacy trials in human malaria, we sought to determine whether oAC would i) reduce mortality due to experimental cerebral malaria (ECM) in mice, ii) modulate immune and inflammatory responses associated with ECM, and iii) affect the pharmacokinetics of parenteral artesunate in human volunteers. METHODS/PRINCIPAL FINDINGS: We found that oAC provided significant protection against P. berghei ANKA-induced ECM, increasing overall survival time compared to untreated mice (p<0.0001; hazard ratio 16.4; 95% CI 6.73 to 40.1). Protection from ECM by oAC was associated with reduced numbers of splenic TNF(+) CD4(+) T cells and multifunctional IFNgamma(+)TNF(+) CD4(+) and CD8(+) T cells. Furthermore, we identified a whole blood gene expression signature (68 genes) associated with protection from ECM. To evaluate whether oAC might affect current best available anti-malarial treatment, we conducted a randomized controlled open label trial in 52 human volunteers (ISRCTN NR. 64793756), administering artesunate (AS) in the presence or absence of oAC. We demonstrated that co-administration of oAC was safe and well-tolerated. In the 26 subjects further analyzed, we found no interference with the pharmacokinetics of parenteral AS or its pharmacologically active metabolite dihydroartemisinin. CONCLUSIONS/SIGNIFICANCE: oAC protects against ECM in mice, and does not interfere with the pharmacokinetics of parenteral artesunate. If future studies succeed in establishing the efficacy of oAC in human malaria, then the characteristics of being inexpensive, well-tolerated at high doses and requiring no sophisticated storage would make oAC a relevant candidate for adjunct therapy to reduce mortality from severe malaria, or for immediate treatment of suspected severe malaria in a rural setting. TRIAL REGISTRATION: Controlled-Trials.com ISRCTN64793756.


Subject(s)
Artemisinins/pharmacokinetics , Charcoal/therapeutic use , Malaria, Cerebral/prevention & control , Administration, Oral , Adult , Animals , Antimalarials , Artesunate , Charcoal/pharmacology , Drug Evaluation, Preclinical , Drug Interactions , Female , Humans , Infusions, Parenteral , Malaria, Cerebral/drug therapy , Malaria, Cerebral/mortality , Male , Mice , Mice, Inbred C57BL , Middle Aged , Plasmodium berghei/drug effects , Survival Rate
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