Contantia, F

Devine, A

Hailu, A

Lubell, Y

Ngo, VT

Nguyen, T-N

Pasaribu, AP

Pham, H-T

Price, RN

Teferi, T

Tran, H

Price, Richard

Lubell, Yoel

Oxford University Research Archive

427astmh.orgof the epidemic and the difficulties encountered during sputum sample analyses. This epidemic led to implementation of additional molecular diagnostic tools and strengthened the country’s capacities for multisectoral responses. Lessons learnt will help to improve responses for the upcoming plague seasons and highlight the need to strengthen research on plague to eliminate the disease in humans.1357A REVIEW OF CONTROLLED HUMAN MALARIA INFECTION TRIALS AT THE UNIVERSITY OF MARYLANDDeAnna J. Friedman-Klabanoff, Matthew B. Laurens, Andrea A. Berry, Mark A. Travassos, Matthew Adams, Kathy A. Strauss, Biraj Shrestha, Myron M. Levine, Robert Edelman, Kirsten E. LykeUniversity of Maryland School of Medicine, Baltimore, MD, United StatesEradication of malaria will not likely succeed without an effective vaccine. Controlled human malaria infection (CHMI) is a powerful tool to evaluate potential vaccine candidates, allowing for down-selection of vaccine candidates before conducting expensive field trials. Investigators at the University of Maryland School of Medicine (UM SOM) pioneered the technique in the 1970s and continue to advance CHMI research. These advances include alternate routes of sporozoite delivery, ultrasensitive PCR diagnostics, exclusive outpatient study conduct, and heterologous CHMI. We reviewed records of 357 malaria-naïve volunteers who underwent CHMI with either the NF54 or 7G8 strain of Plasmodium falciparum (Pf) at our institution from 1973 until 2017. These 357 malaria-naïve volunteers experienced 406 unique CHMI events, including 60 via parenteral administration. No volunteer suffered an unplanned hospitalization or required invasive intervention related to CHMI. Among non-vaccinated volunteers, the median prepatency period (8 days) did not differ between Pf strains (NF54 vs 7G8) but time-to-event curves differed (p=0.033, log rank test). Real time quantitative PCR detected Pf infection 3.0 days earlier in non-vaccinated participants than thick smears (p &lt 0.0001). With dose optimization, administration via direct venous inoculation resulted in a similar prepatent period to mosquito bite challenge of non-vaccinated volunteers (log-rank test, p=0.17). Historical studies with NF54 showed a shorter median prepatency period of 10.8 days as compared with more recent studies (median 11.0 days, p=0.043 by log-rank test) in those who did not undergo vaccination, despite similar study conditions and mean salivary gland scores (where available). The 46-year experience of CHMI at UM SOM has advanced this model as an effective tool to winnow and optimize candidate vaccines, enabling better resource allocation, and could provide supporting data for vaccine licensure.1358PRELIMINARY DATA FROM A BIOMARKER EVALUATION TRIAL AMONG NON-SEVERE FEBRILE PATIENTS IN A MALARIA ENDEMIC SETTING IN MALAWICamille Escadafal1, Steffen Geis2, Jullita Malava3, Louis Banda3, Hazzie Mvula3, Jacqueline Saul2, Aurélien Mace1, Victoria Harris1, Sabine Dittrich11FIND, Geneva, Switzerland, 2London School of Hygiene & Tropical Medicine, London, United Kingdom, 3Malawi Epidemiology & Intervention Research Unit, Chilumba, MalawiAlthough malaria incidence has been decreasing in low- and middle-income countries (LMICs) over the past two decades, acute febrile illnesses are still a major cause of mortality and morbidity. A lack of simple, cheap rapid tests for febrile illnesses other than malaria is resulting in overtreatment with antibiotics for those who test negative for malaria, contributing to the global rise in antimicrobial resistance. Host biomarkers appear as promising tools to differentiate bacterial from non-bacterial infections in febrile patients. However, very few evaluation studies have been performed in the overall non-severe febrile population in LMICs, resulting in poor knowledge on the performance of these biomarkers in a context of high prevalence of diseases such as malaria, HIV and arbovirus infections. To address this knowledge gap, FIND is conducting a multi-center study to evaluate the performance of candidate biomarkers to distinguish bacterial from non-bacterial infections in the adult and children febrile population presenting at outpatient departments. Since April 2017, the first study site, the Malawi Epidemiology & Intervention Research Unit in Northern rural Malawi, has recruited 1000 patients. A wide range of reference tests has been performed to inform the cause of fever. Further, clinical and microbiological data of all patients with an undetermined diagnosis will be reviewed by a clinical panel to classify each patient based on the cause of fever. Complete data for the first 406 patients (57% female; 35% 2-4y; 38% 5-17y; 27% 18-65y) and corresponding preliminary results on the performance of six biomarker tests (C-reactive protein (CRP), Procalcitonin, Human neutrophil lipocalin, Myxovirus resistance protein + CRP, Heparin binding protein, Chitinase 3-like 1) are available. This study will give a preliminary overview of the performance characteristics of multiple promising biomarkers in sub-Saharan Africa when used in non-severe febrile patients. This dataset will inform subsequent product development efforts and implementation efforts to help improve non-malarial fever management and reduce overuse of antibiotics.1359ECONOMIC COSTS OF PLASMODIUM VIVAX EPISODES: A MULTI-COUNTRY COMPARATIVE ANALYSIS USING PRIMARY TRIAL DATAAngela Devine1, Ayodhia P. Pasaribu2, Tedla Teferi3, Huong-Thu Pham4, Febrina Contantia5, Thuy-Nhien Nguyen4, Viet Thanh Ngo4, Hien Tran4, Asrat Hailu6, Ric N. Price7, Yoel Lubell11Mahidol-Oxford Tropical Medicine Research Unit, Bangkok, Thailand, 2Department of Pediatrics, Medical Faculty, Universitas Sumatera Utara, Medan, Indonesia, 3The Carter Center, Addis Ababa, Ethiopia, 4Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam, 5Tanjung Leidong Health Center, Labuhanbatu Utara, Tanjung Leidong, Indonesia, 6Addis Ababa University, Addis Ababa, Ethiopia, 7Menzies School of Health Research, Darwin, AustraliaA better understanding of the costs of P. vivax is needed to optimize the allocation of resources for malaria elimination. We elucidated the costs associated with vivax malaria across a range of endemic settings. Cost data were collected in the context of a multi-centered clinical trial comparing 7 and 14-day primaquine regimens in Afghanistan, Ethiopia, Indonesia and Vietnam. Patients were surveyed on days 0 and 14 to determine the costs of treatment and transportation, and the duration that they and any caregiver were unable to perform usual activities. These productivity losses were valued at one gross domestic product per capita per day. Micro-costing was used to collect the additional costs required to diagnose and treat vivax malaria. The mean (SD) total households costs ranged from US$8.4 (US$4.2) in Afghanistan to US$68.6 (US$ 66.8) in Indonesia. Across all countries, the productivity costs were the largest cost component with a median (range) of 2.5 (1-4) days for patients and 1 (0.5 - 3) day for carers. The cost of administering a G6PD RDT ranged from US$0.9 to US$13.9 and this was consistently lower than the costs of the widely-used Fluorescent Spot Test (FST), which ranged from US$13.7 to US$17.9. The cost of a HaemocueTM test to monitor for anemia ranged from US$0.2 in Ethiopia to US$1.6 in Indonesia. Screening for G6PD deficiency with an RDT was less costly than testing with FST. An episode of vivax malaria results in substantial costs to households. These costs are primarily due to productivity losses, which are often excluded from economic evaluations.

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Economic costs of Plasmodium vivax episodes: a multi-country comparative analysis using primary trial data

Economic costs of Plasmodium vivax episodes: a multi-country comparative analysis using primary trial data

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