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Featured researches published by Michelle Chang.


PLOS ONE | 2013

Intermittent Preventive Therapy with Sulfadoxine-Pyrimethamine for Malaria in Pregnancy: A Cross-Sectional Study from Tororo, Uganda

Emmanuel Arinaitwe; Veronica Ades; Andrew Walakira; Boaz Ninsiima; Olive Mugagga; Teja S. Patil; Alanna Schwartz; Moses R. Kamya; Sussann Nasr; Michelle Chang; Scott G. Filler; Grant Dorsey

Background Intermittent preventive treatment during pregnancy (IPTp) with sulfadoxine-pyrimethamine (SP) is widely recommended in sub-Saharan Africa to reduce the risk of malaria and improve birth outcomes. However, there are reports that the efficacy of IPTp with SP is waning, especially in parts of Africa where antimalarial resistance to this drug has become widespread. Methodology/Principal Findings We conducted a cross-sectional study of 565 HIV-uninfected women giving birth at Tororo District Hospital in southeastern Uganda. The primary objective of the study was to measure associations between use of SP during pregnancy from antenatal records and the risk of adverse outcomes including placental malaria, low birth weight, maternal parasitemia and maternal anemia. The proportion of women who reported taking 0, 1, 2, and 3 doses of SP during pregnancy was 5.7%, 35.8%, 56.6% and 2.0% respectively. Overall, the prevalence of placental malaria was 17.5%, 28.1%, and 66.2% by placental smear, PCR, and histopathology, respectively. In multivariate analyses controlling for potential confounders, ≥2 doses of SP was associated with non-significant trends towards lower odds of placental malaria by placental smear (OR = 0.75, p = 0.25), placental malaria by PCR (OR = 0.93, p = 0.71), placental malaria by histopathology (OR = 0.75, p = 0.16), low birth weight (OR = 0.63, p = 0.11), maternal parasitemia (OR = 0.88, p = 0.60) and maternal anemia (OR = 0.88, p = 0.48). Using a composite outcome, ≥2doses of SP was associated with a significantly lower odds of placental malaria, low birth weight, maternal parasitemia, or maternal anemia (OR = 0.52, p = 0.01). Conclusions/Significance In this area of Uganda with intense malaria transmission, the prevalence of placental malaria by histopathology was high even among women who reported taking at least 2 doses of SP during pregnancy. The reported use of ≥2 doses of SP was not associated with protection against individual birth and maternal outcome measures but did protect against a composite measure of any adverse outcome.


American Journal of Tropical Medicine and Hygiene | 2012

Malaria Survey in Post-Earthquake Haiti—2010

David Townes; Alexandre Existe; Jacques Boncy; Roc Magloire; Jean Francois Vely; Ribka Amsalu; Marleen De Tavernier; James Muigai; Sarah Hoibak; Michael Albert; Meredith McMorrow; Laurence Slutsker; S. Patrick Kachur; Michelle Chang

Haitis Ministry of Public Health and Population collaborated with global partners to enhance malaria surveillance in two disaster-affected areas within 3 months of the January 2010 earthquake. Data were collected between March 4 and April 9, 2010 by mobile medical teams. Malaria rapid diagnostic tests (RDTs) were used for case confirmation. A convenience sample of 1,629 consecutive suspected malaria patients was included. Of these patients, 1,564 (96%) patients had malaria RDTs performed, and 317 (20.3%) patients were positive. Of the 317 case-patients with a positive RDT, 278 (87.7%) received chloroquine, 8 (2.5%) received quinine, and 31 (9.8%) had no antimalarial treatment recorded. Our experience shows that mobile medical teams trained in the use of malaria RDTs had a high rate of testing suspected malaria cases and that the majority of patients with positive RDTs received appropriate antimalarial treatment. Malaria RDTs were useful in the post-disaster setting where logistical and technical constraints limited the use of microscopy.


The Journal of Infectious Diseases | 2016

Artesunate/amodiaquine versus artemether/lumefantrine for the treatment of uncomplicated malaria in Uganda: a randomized trial

Adoke Yeka; Ruth Kigozi; Melissa D. Conrad; Myers Lugemwa; Peter Okui; Charles Katureebe; Kassahun Belay; Bryan K. Kapella; Michelle Chang; Moses R. Kamya; Sarah G. Staedke; Grant Dorsey; Philip J. Rosenthal

BACKGROUND In treating malaria in Uganda, artemether-lumefantrine (AL) has been associated with a lower risk of recurrent parasitemia, compared with artesunate-amodiaquine (AS/AQ), but changing treatment practices may have altered parasite susceptibility. METHODS We enrolled 602 children aged 6-59 months with uncomplicated falciparum malaria from 3 health centers in 2013-2014 and randomly assigned them to receive treatment with AS/AQ or AL. Primary outcomes were risks of recurrent parasitemia within 28 days, with or without adjustment to distinguish recrudescence from new infection. Drug safety and tolerability and Plasmodium falciparum resistance-mediating polymorphisms were assessed. RESULTS Of enrolled patients, 594 (98.7%) completed the 28-day study. Risks of recurrent parasitemia were lower with AS/AQ at all 3 sites (overall, 28.6% vs 44.6%; P < .001). Recrudescences were uncommon, and all occurred after AL treatment (0% vs 2.5%; P = .006). Recovery of the hemoglobin level was greater with AS/AQ (1.73 vs 1.39 g/dL; P = .04). Both regimens were well tolerated; serious adverse events were uncommon (1.7% in the AS/AQ group and 1.0% in the AL group). AS/AQ selected for mutant pfcrt/pfmdr1 polymorphisms and AL for wild-type pfcrt/pfmdr1 polymorphisms associated with altered drug susceptibility. CONCLUSIONS AS/AQ treatment was followed by fewer recurrences than AL treatment, contrasting with older data. Each regimen selected for polymorphisms associated with decreased treatment response. Research should consider multiple or rotating regimens to maintain treatment efficacies.


Malaria Journal | 2013

Anti-malarial prescription practices among outpatients with laboratory-confirmed malaria in the setting of a health facility-based sentinel site surveillance system in Uganda

David Sears; Ruth Kigozi; Arthur Mpimbaza; Stella Kakeeto; Asadu Sserwanga; Sarah G. Staedke; Michelle Chang; Bryan K. Kapella; Denis Rubahika; Moses R. Kamya; Grant Dorsey

BackgroundMost African countries have adopted artemisinin-based combination therapy (ACT) as the first-line treatment for uncomplicated malaria. The World Health Organization now recommends limiting anti-malarial treatment to those with a positive malaria test result. Limited data exist on how these policies have affected ACT prescription practices.MethodsData were collected from all outpatients presenting to six public health facilities in Uganda as part of a sentinel site malaria surveillance programme. Training in case management, encouragement of laboratory-based diagnosis of malaria, and regular feedback were provided. Data for this report include patients with laboratory confirmed malaria who were prescribed anti-malarial therapy over a two-year period. Patient visits were analysed in two groups: those considered ACT candidates (defined as uncomplicated malaria with no referral for admission in patients ≥ 4 months of age and ≥ 5 kg in weight) and those who may not have been ACT candidates. Associations between variables of interest and failure to prescribe ACT to patients who were ACT candidates were estimated using multivariable logistic regression.ResultsA total of 51,355 patient visits were included in the analysis and 46,265 (90.1%) were classified as ACT candidates. In the ACT candidate group, 94.5% were correctly prescribed ACT. Artemether-lumefantrine made up 97.3% of ACT prescribed. There were significant differences across the sites in the proportion of patients for whom there was a failure to prescribe ACT, ranging from 3.0-9.3%. Young children and woman of childbearing age had higher odds of failure to receive an ACT prescription. Among patients who may not have been ACT candidates, the proportion prescribed quinine versus ACT differed based on if the patient had severe malaria or was referred for admission (93.4% vs 6.5%) or was below age or weight cutoffs for ACT (41.4% vs 57.2%).ConclusionsHigh rates of compliance with recommended ACT use can be achieved in resource-limited settings. The unique health facility-based malaria surveillance system operating at these clinical sites may provide a framework for improving appropriate ACT use at other sites in sub-Saharan Africa.


PLOS ONE | 2017

Bead-based immunoassay allows sub-picogram detection of histidine-rich protein 2 from Plasmodium falciparum and estimates reliability of malaria rapid diagnostic tests

Eric Rogier; Mateusz M. Pluciński; Naomi W. Lucchi; Kimberly E. Mace; Michelle Chang; Jean Frantz Lemoine; Baltazar Candrinho; James Colborn; Rafael Dimbu; Filomeno Fortes; Venkatachalam Udhayakumar; John W. Barnwell

Detection of histidine-rich protein 2 (HRP2) from the malaria parasite Plasmodium falciparum provides evidence for active or recent infection, and is utilized for both diagnostic and surveillance purposes, but current laboratory immunoassays for HRP2 are hindered by low sensitivities and high costs. Here we present a new HRP2 immunoassay based on antigen capture through a bead-based system capable of detecting HRP2 at sub-picogram levels. The assay is highly specific and cost-effective, allowing fast processing and screening of large numbers of samples. We utilized the assay to assess results of HRP2-based rapid diagnostic tests (RDTs) in different P. falciparum transmission settings, generating estimates for true performance in the field. Through this method of external validation, HRP2 RDTs were found to perform well in the high-endemic areas of Mozambique and Angola with 86.4% and 73.9% of persons with HRP2 in their blood testing positive by RDTs, respectively, and false-positive rates of 4.3% and 0.5%. However, in the low-endemic setting of Haiti, only 14.5% of persons found to be HRP2 positive by the bead assay were RDT positive. Additionally, 62.5% of Haitians showing a positive RDT test had no detectable HRP2 by the bead assay, likely indicating that these were false positive tests. In addition to RDT validation, HRP2 biomass was assessed for the populations in these different settings, and may provide an additional metric by which to estimate P. falciparum transmission intensity and measure the impact of interventions.


The Lancet Global Health | 2017

Effectiveness of insecticide-treated bednets in malaria prevention in Haiti: a case-control study

Laura C. Steinhardt; Yvan St Jean; Daniel E. Impoinvil; Kimberly E. Mace; Ryan E. Wiegand; Curtis S. Huber; Jean Semé Fils Alexandre; Joseph Frederick; Emery Nkurunziza; Samuel E. Jean; Brian Wheeler; Ellen M. Dotson; Laurence Slutsker; S. Patrick Kachur; John W. Barnwell; Jean Frantz Lemoine; Michelle Chang

BACKGROUND Insecticide-treated bednets (ITNs) are effective in preventing malaria where vectors primarily bite indoors and late at night, but their effectiveness is uncertain where vectors bite outdoors and earlier in the evening. We studied the effectiveness of ITNs following a mass distribution in Haiti from May to September, 2012, where the Anopheles albimanus vector bites primarily outdoors and often when people are awake. METHODS In this case-control study, we enrolled febrile patients presenting to outpatient departments at 17 health facilities throughout Haiti from Sept 4, 2012, to Feb 27, 2014, who were tested with malaria rapid diagnostic tests (RDTs), and administered questionnaires on ITN use and other risk factors. Cases were defined by positive RDT and controls were febrile patients from the same clinic with a negative RDT. Our primary analysis retrospectively matched cases and controls by age, sex, location, and date, and used conditional logistic regression on the matched sample. A sensitivity analysis used propensity scores to match patients on ITN use propensity and analyse malaria among ITN users and non-users. Additional ITN bioefficacy and entomological data were collected. FINDINGS We enrolled 9317 patients, including 378 (4%) RDT-positive cases. 1202 (13%) patients reported ITN use. Post-hoc matching of cases and controls yielded 362 cases and 1201 matched controls, 19% (333) of whom reported consistent campaign net use. After using propensity scores to match on consistent campaign ITN use, 2298 patients, including 138 (7%) RDT-positive cases, were included: 1149 consistent campaign ITN users and 1149 non-consistent campaign ITN users. Both analyses revealed that ITNs did not significantly protect against clinical malaria (odds ratio [OR]=0·95, 95% CI 0·68-1·32, p=0·745 for case-control analysis; OR=0·95, 95% CI 0·45-1·97, p=0·884 for propensity score analysis). ITN and entomological data indicated good ITN physical integrity and bioefficacy, and no permethrin resistance among local mosquitoes. INTERPRETATION We found no evidence that mass ITN campaigns reduce clinical malaria in this observational study in Haiti; alternative malaria control strategies should be prioritised. FUNDING The Global Fund to Fight AIDS, Tuberculosis, and Malaria, and the US-based Centers for Disease Control and Prevention (CDC).


PLOS Neglected Tropical Diseases | 2017

Partnering for impact: Integrated transmission assessment surveys for lymphatic filariasis, soil transmitted helminths and malaria in Haiti

Alaine Knipes; Jean Frantz Lemoine; Franck Monestime; Carl Renad Fayette; Abdel N. Direny; Luccene Desir; Valery E Beau de Rochars; Thomas G. Streit; Kristen Renneker; Brian K. Chu; Michelle Chang; Kimberly E. Mace; Kimberly Y. Won; Patrick J. Lammie

Background Since 2001, Haiti’s National Program for the Elimination of Lymphatic Filariasis (NPELF) has worked to reduce the transmission of lymphatic filariasis (LF) through annual mass drug administration (MDA) with diethylcarbamazine and albendazole. The NPELF reached full national coverage with MDA for LF in 2012, and by 2014, a total of 14 evaluation units (48 communes) had met WHO eligibility criteria to conduct LF transmission assessment surveys (TAS) to determine whether prevalence had been reduced to below a threshold, such that transmission is assumed to be no longer sustainable. Haiti is also endemic for malaria and many communities suffer a high burden of soil transmitted helminths (STH). Heeding the call from WHO for integration of neglected tropical diseases (NTD) activities, Haiti’s NPELF worked with the national malaria control program (NMCP) and with partners to develop an integrated TAS (LF-STH-malaria) to include assessments for malaria and STH. Methodology/Principle findings The aim of this study was to evaluate the feasibility of using TAS surveys for LF as a platform to collect information about STH and malaria. Between November 2014 and June 2015, TAS were conducted in 14 evaluation units (EUs) including 1 TAS (LF-only), 1 TAS-STH-malaria, and 12 TAS-malaria, with a total of 16,655 children tested for LF, 14,795 tested for malaria, and 298 tested for STH. In all, 12 of the 14 EUs passed the LF TAS, allowing the program to stop MDA for LF in 44 communes. The EU where children were also tested for STH will require annual school-based treatment with albendazole to maintain reduced STH levels. Finally, only 12 of 14,795 children tested positive for malaria by RDT in 38 communes. Conclusions/Significance Haiti’s 2014–2015 Integrated TAS surveys provide evidence of the feasibility of using the LF TAS as a platform for integration of assessments for STH and or malaria.


American Journal of Tropical Medicine and Hygiene | 2015

Comparison of Routine Health Management Information System Versus Enhanced Inpatient Malaria Surveillance for Estimating the Burden of Malaria Among Children Admitted to Four Hospitals in Uganda

Arthur Mpimbaza; Melody Miles; Asadu Sserwanga; Ruth Kigozi; Humphrey Wanzira; Denis Rubahika; Sussann Nasr; Bryan K. Kapella; Steven S. Yoon; Michelle Chang; Adoke Yeka; Sarah G. Staedke; Moses R. Kamya; Grant Dorsey

The primary source of malaria surveillance data in Uganda is the Health Management Information System (HMIS), which does not require laboratory confirmation of reported malaria cases. To improve data quality, an enhanced inpatient malaria surveillance system (EIMSS) was implemented with emphasis on malaria testing of all children admitted in select hospitals. Data were compared between the HMIS and the EIMSS at four hospitals over a period of 12 months. After the implementation of the EIMSS, over 96% of admitted children under 5 years of age underwent laboratory testing for malaria. The HMIS significantly overreported the proportion of children under 5 years of age admitted with malaria (average absolute difference = 19%, range = 8-27% across the four hospitals) compared with the EIMSS. To improve the quality of the HMIS data for malaria surveillance, the National Malaria Control Program should, in addition to increasing malaria testing rates, focus on linking laboratory test results to reported malaria cases.


American Journal of Tropical Medicine and Hygiene | 2017

Haiti’s Commitment to Malaria Elimination: Progress in the Face of Challenges, 2010–2016

Michelle Chang; David L. Fitter; S. Patrick Kachur; Jacques Boncy; Scott G. Filler; Jean Frantz Lemoine

Abstract. Haiti is committed to malaria elimination by 2020. Following a 2010 earthquake and cholera epidemic, Haiti capitalized on investments in its health system to refocus on malaria elimination. Efforts, including expanding diagnostics, ensuring efficacy of standard treatments, building institutional capacity, and strengthening surveillance were undertaken to complement the broad health system strengthening activities. These efforts led to the adoption and scale-up of malaria rapid diagnostic tests as a diagnostic modality. In addition, drug-resistant monitoring has been established in the country, along with the development of molecular testing capacity for the Plasmodium falciparum parasite at the National Public Health Laboratory. The development and piloting of surveillance activities to include an enhanced community-based approach for testing and treatment of patients has increased the ability of the Ministry of Health to map foci of transmission and respond promptly to outbreaks. The reinforcement of evidence-based approaches coupled with strong collaboration among the Ministry of Health and partners has demonstrated that malaria elimination by 2020 is a realistic prospect.


PLOS ONE | 2015

Quality of Inpatient Pediatric Case Management for Four Leading Causes of Child Mortality at Six Government-Run Ugandan Hospitals

David Sears; Arthur Mpimbaza; Ruth Kigozi; Asadu Sserwanga; Michelle Chang; Bryan K. Kapella; Steven S. Yoon; Moses R. Kamya; Grant Dorsey; Theodore Ruel

Background A better understanding of case management practices is required to improve inpatient pediatric care in resource-limited settings. Here we utilize data from a unique health facility-based surveillance system at six Ugandan hospitals to evaluate the quality of pediatric case management and the factors associated with appropriate care. Methods All children up to the age of 14 years admitted to six district or regional hospitals over 15 months were included in the study. Four case management categories were defined for analysis: suspected malaria, selected illnesses requiring antibiotics, suspected anemia, and diarrhea. The quality of case management for each category was determined by comparing recorded treatments with evidence-based best practices as defined in national guidelines. Associations between variables of interest and the receipt of appropriate case management were estimated using multivariable logistic regression. Results A total of 30,351 admissions were screened for inclusion in the analysis. Ninety-two percent of children met criteria for suspected malaria and 81% received appropriate case management. Thirty-two percent of children had selected illnesses requiring antibiotics and 89% received appropriate antibiotics. Thirty percent of children met criteria for suspected anemia and 38% received appropriate case management. Twelve percent of children had diarrhea and 18% received appropriate case management. Multivariable logistic regression revealed large differences in the quality of care between health facilities. There was also a strong association between a positive malaria diagnostic test result and the odds of receiving appropriate case management for comorbid non-malarial illnesses - children with a positive malaria test were more likely to receive appropriate care for anemia and less likely for illnesses requiring antibiotics and diarrhea. Conclusions Appropriate management of suspected anemia and diarrhea occurred infrequently. Pediatric quality improvement initiatives should target deficiencies in care unique to each health facility, and interventions should focus on the simultaneous management of multiple diagnoses.

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Kimberly E. Mace

Centers for Disease Control and Prevention

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Grant Dorsey

University of California

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Bryan K. Kapella

Centers for Disease Control and Prevention

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John W. Barnwell

Centers for Disease Control and Prevention

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Venkatachalam Udhayakumar

Centers for Disease Control and Prevention

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Eric Rogier

Centers for Disease Control and Prevention

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Samuel E. Jean

Population Services International

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