There are about 131 clinical studies being (or have been) conducted in Cambodia. The country of the clinical trial is determined by the location of where the clinical research is being studied. Most studies are often held in multiple locations & countries.
Because the artemisinins are the most potent antimalarial drugs, the reduction in parasite numbers is rapid. Therefore, early measures of reducing parasite counts are needed. This study will look at conventional markers of parasite reduction e.g. parasite clearance time, parasite reduction ratio, and the time to achieve a fall of 50%, 90% and 99% of the pre-treatment parasitaemia. Defining artemisinin resistance requires the use of artesunate (AS) alone because it is now appreciated that the partner drug in a combination treatment has a significant impact on the rate of parasite clearance. This study will dose patients for 3 days with AS alone (or longer until parasites clear) and measure the parasite count frequently in order to be able to define an accurate regression line of a graph of the natural logarithm of the parasite count (Y axis) versus time (X axis). This will be followed by a full course of an artemisinin combination therapy (ACT). Two different dose regimens of artesunate will be compared at all sites except those in western Cambodia, as unpublished observations from the Thai-Myanmar border suggest the standard lower daily dose of 2mg/kg may enable the earlier detection of low level resistance than a 4mg/kg daily dose.
Childhood tuberculosis (TB) accounts for 11% of the total 9 million annual TB cases and the difficulty of its diagnosis is increased in case of HIV infection in children. The aim of this study is to improve TB diagnosis in HIV-infected children by developing a new diagnostic algorithm incorporating new tools available such as: - interferon gamma release assays (IGRAs), as alternative to the tuberculin skin test - alternative specimen collection methods such as string test (or Enterotest (R)), nasopharyngeal aspirates and stools samples, as alternatives to gastric aspirate - the Xpert MTB/RIF assay
SODISWATER was a health impact assessment study investigating the effect of sunlight to inactivate microbial pathogens in drinking water. This study was carried out by observing whether children younger than 5 years old who drink solar disinfected water were healthier than those who did not. Health was measured by how often the children had diarrhoea or dysentery. Caregivers for the participants were given plastic bottles to place in the sun, water samples were then collected from these plastic bottles to be analyzed. They were also requested to fill in diarrhea diaries. TESTABLE RESEARCH HYPOTHESES: Health Impact Assessment: Children who use solar disinfected water will have: (a) lower morbidity due to non-bloody diarrhoea and bloody diarrhoea (c) increased growth rates (d) lower mortality (e) increased family productivity (f) decreased care-giver burden (g) increased school attendance
An observational cohort and malaria treatment study in Cambodia.
Plasmodium falciparum parasite clearance rates (PCRs) after oral artesunate treatment of patients with uncomplicated malaria were recently found to be significantly slower in Pailin (Western Cambodia) compared to Wang Pha (Eastern Thailand). This difference in PCRs has been attributed to different histories of artesunate drug pressure in the two areas. In Pailin, artesunate monotherapy has been used inappropriately for 30 years and is hypothesized to have selected for artemisinin-resistant parasites (slow PCRs). To investigate the potential contribution of human factors to the artemisinin resistance phenotype, we have identified a study site in Eastern Cambodia where artemisinin-resistant parasites are not believed to be present. The main aims of this study are to 1) determine whether the artemisinin resistance phenotype (i.e., a half-life longer than the 2-hour half-life observed in Wang Pha) is present in Eastern Cambodia, 2) determine whether hemoglobin E affects parasite clearance rates in vivo, 3) determine whether age-associated acquired immunity affects parasite clearance rates in vivo, and 4) identify parasite-heritable traits that are associated with slow parasite clearance rates in vivo. To meet these aims, we are conducting a prospective, longitudinal study to recruit Cambodian residents of Lumphat District in Ratanakiri Province who complain of fever and/or symptoms of malaria. Patients diagnosed with uncomplicated malaria will be treated with weight-based doses of artesunate given orally each day for 3 days followed by mefloquine given orally for 2 days. During this time, finger prick blood smears will be obtained every 6 hours until parasite density is zero. From these data, we will estimate parasite clearance rates using a half-life parameter. We will also collect parasitized red blood cell samples from malaria patients prior to antimalarial drug administration. These parasites will be tested in short-term in vitro culture experiments to determine their susceptibility to artemisinins and other antimalarial drugs.
The three major Soil-Transmitted Helminths (STH), Ascaris lumbricoides, Necator americanus/Ancylostoma duodenal and Trichuris trichiura are among the most prevalent parasites worldwide. The objective of this multicentre international study is to define the efficacy of a single 400 milligram dose of albendazole (ALB) against these three STHs using a standardised protocol. The trial will be undertaken among school age children in seven countries - Brazil, Cameroon, Cambodia, Ethiopia, India, Tanzania (Zanzibar) and Vietnam - each with a different epidemiologic pattern of infection. A trial of this nature is urgently required because in spite of the wide usage of albendazole over the last 3 decades, there is still no key publication reporting the efficacy of the anthelmintic accurately, and to modern conventional standards, that can act as a central reference for the baseline efficacy. The latter is critically important because albendazole is now being used even more widely, as large scale mass treatment campaigns are being implemented in Africa and elsewhere, with the intention of reducing morbidity in children. Such large scale usage of a drug risks resistance developing, but resistance cannot be detected unless benchmark values for baseline efficacy are widely known.
Evaluation of safety and effectiveness of Glucobay® under daily-life treatment conditions in a large sample of patients.
The purpose of this study is to determine the impact of varying doses of artesunate on treatment outcome and whether higher doses of artesunate can overcome the problem of compromised artemisinin sensitivity in the region. To determine the safety and tolerability of this previously untested experimental high dose (6 mg/Kg/D X 7 day, total 42 mg/Kg) artesunate monotherapy regimen.
This study, conducted by the National Center for Parasitology, Entomology and Malaria Control of Cambodia s Ministry of Health and the National Institute of Allergy and Infectious Diseases, will explore whether the following factors confer protection against malaria and associated anemia: certain blood groups, the hemoglobin E variant, G6PD-deficiency and alpha-thalassemia. Malaria is caused by parasites (P. falciparum and P. vivax) that are transmitted to humans through mosquito bites. This protocol includes two studies, a cohort study and a P. vivax collection study. Individuals are eligible for enrollment in the studies as follows: Cohort study: Residents of all ages of Kandal, Ekapheap and Sangkumthmey villages (Thmar Da commune) who plan to remain in Thmar Da commune for the next 5 years. P. vivax collection study: 2 years of age and older Participating in NIAID protocol 05-I- N210 ( Severe Malaria and Anti-malarial Drug Resistance in Cambodia ) and diagnosed with P. vivax malaria Participants undergo the following procedures: Cohort study: Baseline evaluation, including the following: - Collection of demographic information - Malaria history, temperature measurement and review of current symptoms, if any - Blood draw of 300 microliters - Additional blood draw of 10 milliliters in selected adults 18 years of age and older Treatment with artesunate-piperaquine at a commune health post for subjects who develop malaria Contact once a year for 5 years to determine continued residency in Thmar Da commune P. vivax collection study: - Medical history and physical examination - Hemoglobin level measurement - Blood draw - Treatment with chloroquine - Blood draw 3 to 5 weeks after treatment in some patients 18 years of age or older
There are worrying signs that parasitological responses to the artemisinin drugs for uncomplicated falciparum malaria are slower than elsewhere in the world.If responses to artesunate are poor it is essential to have characterised the blood concentration profile as well as the parasitological response to differentiate resistance from abnormal pharmacokinetics. The primary objective of the study is to assess the level of resistance to artemisinin derivatives in Western Cambodia. A detailed evaluation of 2 different artesunate containing regimens in patients with uncomplicated malaria will be performed. Patients will be randomised to receive either a) Artesunate 2mg/kg/day for 7 days or b) Artesunate 4mg/kg/day for 3 days plus mefloquine 15mg/kg on day 3 and 10mg/kg on day 4 The effect on parasite clearance and cure will be assessed in relation to blood concentrations of the antimalarial drugs ('PK-PD').