Steven Richard Meshnick

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Since the first reports of chloroquine-resistant falciparum malaria in southeast Asia and South America almost half a century ago, drug-resistant malaria has posed a major problem in malaria control. By the late 1980s, resistance to sulfadoxine-pyrimethamine and to mefloquine was also prevalent on the Thai-Cambodian and Thai-Myanmar (Thai-Burmese) borders,(More)
Resistance to antimalarial drugs is a public health problem worldwide. Molecular markers for drug-resistant malaria, such as pfcrt and pfmdr1 polymorphisms, could serve as useful surveillance tools. To evaluate this possibility, sequence polymorphisms in pfcrt (position 76) and pfmdr1 (positions 86, 184, 1034, 1042, and 1246) and in vitro drug sensitivities(More)
Epidemiological and molecular data on 248 bovine, 17 human, and 16 water samples of Cryptosporidium spp. collected from the lower peninsula of Michigan between 1997 and 2000 were analysed. Cryptosporidium parvum bovine genotype and Cryptosporidium andersoni were found in 56 and four cattle samples, respectively. A total of six C. parvum subgenotypes were(More)
Plasmodium falciparum parasites that are resistant to artemisinins have been detected in Southeast Asia. Resistance is associated with several polymorphisms in the parasite's K13-propeller gene. The molecular epidemiology of these artemisinin resistance genotypes in African parasite populations is unknown. We developed an assay to quantify rare(More)
Artemisinin combination therapies (ACTs) have recently been adopted as first-line therapy for Plasmodium falciparum infections in most malaria-endemic countries. In this study, we estimated the association between artesunate-mefloquine therapy failure and genetic changes in the putative transporter, pfmdr1. Blood samples were acquired from 80 patients(More)
This study examines hematologic profiles of persons with acute Plasmodium falciparum or P. vivax infection in Maesod on Thailand's western border with Myanmar compared with febrile, non-parasitemic persons also reporting to malaria clinics. Nine hundred seventy-nine subjects were malaria-negative, 414 were infected with P. falciparum, and 646 were infected(More)
Placental histopathology was studied in a cohort of 204 women living in an area of low Plasmodium falciparum and P. vivax malaria transmission. Detection of malaria antenatally was active, by weekly peripheral blood smears, and all infections were treated. Significant histopathologic placental malaria changes (increased malaria pigment, cytotrophoblastic(More)
BACKGROUND To assess the effects of human immunodeficiency virus (HIV) infection on susceptibility to malaria, we compared the incidence rates of malaria by HIV type 1 (HIV-1) serostatus, baseline blood HIV-1 RNA concentration, and baseline CD4 cell count, over the course of a malaria season. METHODS We followed a cohort of 349 adults in Malawi. For the(More)
Maternal malaria and under-nutrition are established risk factors for small-for-gestational-age (SGA) births; however, whether malaria is associated with intrauterine growth restriction (IUGR) is unknown. We investigated IUGR risk among 177 HIV-negative pregnant women enrolled in a longitudinal ultrasound study conducted in Democratic Republic of Congo from(More)
Plasmodium falciparum infection during pregnancy causes maternal anemia and low birth weight (LBW), but the effect of frequency and timing of infection on the severity of these adverse effects is unknown. We conducted a cohort study recruiting 2462 pregnant women in Malawi. Microscopy was used to diagnose malaria at enrollment, follow-up and delivery. Birth(More)