Publications by authors named "Jacquelin M Roberts"

Background: Artemisinin-based combination therapy (ACT) has been promoted as a means to reduce malaria transmission due to their ability to kill both asexual blood stages of malaria parasites, which sustain infections over long periods and the immature derived sexual stages responsible for infecting mosquitoes and onward transmission. Early studies reported a temporal association between ACT introduction and reduced malaria transmission in a number of ecological settings. However, these reports have come from areas with low to moderate malaria transmission, been confounded by the presence of other interventions or environmental changes that may have reduced malaria transmission, and have not included a comparison group without ACT.

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Background: Toxoplasmosis-related hospitalizations often occur in persons with human immunodeficiency virus (HIV) infection and other causes of immunosuppression.

Methods: Using the National Inpatient Sample (NIS) from the Healthcare Cost and Utilization Project, we examined trends in toxoplasmosis-related hospitalizations by HIV infection status from 1993 through 2008, and rates by sex and race or ethnicity in 2008. The NIS is designed to represent a 20% sample of US community hospitals and currently includes information on up to 8 million discharges per year from ∼1000 hospitals.

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There is a need for more information regarding monochloramine disinfection efficacy for viruses in water. In this study, monochloramine disinfection efficacy was investigated for coxsackievirus B5 (CVB5), echovirus 11 (E11), murine norovirus (MNV), and human adenovirus 2 (HAdV2) in one untreated ground water and two partially treated surface waters. Duplicate disinfection experiments were completed at pH 7 and 8 in source water at concentrations of 1 and 3 mg/L monochloramine at 5 and 15 °C.

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In areas endemic for lymphatic filariasis, progression of lymphoedema is associated with recurrent bacterial acute dermatolymphangioadenitis (ADLA). The role of antibacterial soap in preventing ADLA is unknown. In a randomized double-blinded clinical trial in Leogane, Haiti, lymphoedema patients washed affected legs with antibacterial (n = 97) or plain soap (n = 100).

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Since 1971, the CDC, EPA, and Council of State and Territorial Epidemiologists (CSTE) have maintained the collaborative national Waterborne Disease and Outbreak Surveillance System (WBDOSS) to document waterborne disease outbreaks (WBDOs) reported by local, state, and territorial health departments. WBDOs were recently reclassified to better characterize water system deficiencies and risk factors; data were analyzed for trends in outbreak occurrence, etiologies, and deficiencies during 1971 to 2006. A total of 833 WBDOs, 577,991 cases of illness, and 106 deaths were reported during 1971 to 2006.

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More information is needed on the disinfection efficacy of chlorine for viruses in source water. In this study, chlorine disinfection efficacy was investigated for USEPA Contaminant Candidate List viruses coxsackievirus B5 (CVB5), echovirus 1 (E1), murine norovirus (MNV), and human adenovirus 2 (HAdV2) in one untreated groundwater source and two partially treated surface waters. Disinfection experiments using pH 7 and 8 source water were carried out in duplicate, using 0.

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We evaluated three diagnostic antigens (recombinant GP50, recombinant T24H, and synthetic Ts18var1) for cysticercosis and found that all three performed well in detecting cysticercosis in humans and pigs in several assay formats. These antigens were adapted to a new antibody detection format (QuickELISA). With one single incubation step which involves all reactants except the enzyme substrate, the QuickELISA is particularly suited for automation.

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An outbreak of Acanthamoeba keratitis, a rare, potentially blinding, corneal infection, was detected in the United States in 2007; cases had been increasing since 2004. A case-control study was conducted to investigate the outbreak. We interviewed 105 case-patients from 30 states and 184 controls matched geographically and by contact lens use.

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Malaria is a disease of global importance and accounts for up to 500 million cases per year. Nearly all malaria cases in the United States occur among persons who have traveled to areas with ongoing malaria transmission. Among the cases of malaria reported in the United States in 2000-2005, 695 were in US residents under the age of 18 years.

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Problem/condition: Malaria in humans is caused by any of four species of intraerythrocytic protozoa of the genus Plasmodium (i.e., P.

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In 2000, annual mass administration of diethlycarbamazine and albendazole began in Leogane Commune, Haiti, to interrupt transmission of lymphatic filariasis (LF). After 5 years of treatment, microfilaremia, antigenemia, and mosquito infection rates were significantly reduced, but LF transmission was not interrupted. These finding have implications for other LF elimination programs.

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Compliance and acceptance for the finger-prick method of blood collection is generally better than for venipuncture. A finger-prick method of blood collection with quantitative antibody recovery is even more important for seroepidemiological surveys. Finger-prick blood collected and dried onto filter paper has been used; but, unfortunately, this method has several disadvantages, including loss of antibody activity, possible contact contamination from blood spots on adjacent filter papers, and difficulties in extracting antibodies, justifying the search for other methods of collecting and transporting blood samples.

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Problem/condition: Malaria in humans is caused by any of four species of intraerythrocytic protozoa of the genus Plasmodium (i.e., P.

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The city of Erechim, Brazil, has a 17% prevalence of ocular toxoplasmosis, and type 1 Toxoplasma gondii predominates. To examine risk factors for acute T. gondii infection in this area, we administered a questionnaire to recently infected persons (n = 131) and seronegative controls (n = 110).

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Cryptosporidium species are ubiquitous in the environment and are frequently detected in the stools of children who live where sanitation conditions are poor. To better characterize the immune response to these parasites, we monitored immunoglobulin G (IgG) antibody levels in a cohort of children from Lima, Peru. Two new enzyme-linked immunosorbent assays based on the C.

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Background: Acute malaria has been associated with a decreased antibody response to tetanus and diphtheria toxoids, meningococcal, salmonella, and Hib vaccines. Interest in giving malaria drug therapy and prevention at the time of childhood immunizations has increased greatly following recent trials of intermittent preventive therapy during infancy (IPTi), stimulating this re-analysis of unpublished data. The effect of malaria chemoprophylaxis on vaccine response was studied following administration of measles vaccines and diphtheria-tetanus-whole cell pertussis (DTP) vaccines.

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The ability to simultaneously concentrate diverse microbes is an important consideration for sample collection methods that are used for emergency response and environmental monitoring when drinking water may be contaminated with an array of unknown microbes. This study focused on developing a concentration method using ultrafilters and different combinations of a chemical dispersant (sodium polyphosphate [NaPP]) and surfactants. Tap water samples were seeded with bacteriophage MS2, Escherichia coli, Enterococcus faecalis, Cryptosporidium parvum, 4.

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In a retrospective analysis, we assessed the usefulness of two serologic enzyme-linked immunosorbent assays as epidemiologic tools for the detection of cryptosporidiosis episodes in children from a Peruvian community. The incidence rate determined by the serologic assay was higher than the rate determined by stool microscopy (0.77 versus 0.

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A newly developed enzyme-linked immunosorbent assay (ELISA) that detects immunoglobulin G antibodies to the 27-kDa Cryptosporidium parvum sporozoite surface antigen was used to test 4,097 sera collected from pregnant women in 6 communities in British Columbia, Canada, between January 1996, and December 1997. Waterborne outbreaks of cryptosporidiosis occurred in two of the study communities during the period of follow-up, and ELISA seropositivity was high in all six communities during the study period (77% positive to 92% positive). In the community with the largest outbreak, levels of antibody to the 27-kDa antigen increased rapidly and then decayed to background levels within 3-4 months of the peak of the epidemic curve.

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Problem/condition: Malaria in humans is caused by any of four species of intraerythrocytic protozoa of the genus Plasmodium (i.e., P.

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Annual mass treatment with antifilarial drugs is the cornerstone of the global program to eliminate lymphatic filariasis (LF). Although the primary goal of the program is to interrupt transmission of LF, additional public health benefits also are expected because of the known anthelminthic properties of these drugs. Since rapid re-infection with intestinal helminths occurs following treatment, annual de-worming may not be sufficient to produce a lasting reduction in the prevalence and intensity of these infections.

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Cysticercosis, a disease caused by the larval form of Taenia solium, is diagnosed by detection of specific antibodies or by imaging techniques. Our preferred immunologic assay for cysticercosis is the enzyme-linked immunoelectrodifusion transfer blot, or immunoblot, using the lentil lectin bound antigens from larval cysts. Antibody reactivity with any one of seven glycoproteins is diagnostic for cysticercosis.

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Malaria is a leading cause of death in children aged < 5 years in Malawi. As part of the Roll Back Malaria initiative, African heads of state have pledged that by 2005, 60% of children will receive an effective antimalarial drug within 24 h of developing fever. In 1993, Malawi switched from chloroquine to sulfadoxine-pyrimethamine (SP) in its recommendations of home treatment of febrile illness in children.

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Many studies have evaluated the role of Cryptosporidium spp. in outbreaks of enteric illness, but few studies have evaluated sporadic cryptosporidiosis in the United States. To assess the risk factors for sporadic cryptosporidiosis among immunocompetent persons, a matched case-control study was conducted in seven sites of the Foodborne Diseases Active Surveillance Network (FoodNet) involving 282 persons with laboratory-identified cryptosporidiosis and 490 age-matched and geographically matched controls.

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A retrospective examination was made of archival data collected between 1940 and 1963 to determine the impact of reinfection of patients with Plasmodium vivax with homologous and heterologous strains of the parasite. Following reinfection of 14 patients with a homologous strain, the geometric mean maximum parasite count was reduced from 9,101/microL during the primary infection to 998/microL and the geometric mean daily parasite count for the first 20 days was reduced from 923/microL to 16/microL. Following reinfection of 22 patients with heterologous strains of P.

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