The efficacy of chloroquine in treatment of vivax malaria in southern Laos

ISRCTN	ISRCTN17027907
DOI	https://doi.org/10.1186/ISRCTN17027907
Protocol serial number	LMC-11
Sponsor	University of Oxford (UK)
Funder	The Wellcome Trust (UK) (grant ref: 066828)

Prospectively registered

Protocol

Statistical analysis plan

Results

Individual participant data

Record updated in last year

Plain English summary of protocol

Not provided at time of registration

Dr Paul Newton
Scientific

Microbiology Laboratory
Mahosot Hospital
Vientiane
-
Lao People's Democratic Republic

Email	paul@tropmedres.ac

Primary study design	Interventional
Study design	A pilot single arm efficacy study
Secondary study design	Non randomised controlled trial
Study type	Participant information sheet
Scientific title	An assessment of the efficacy of oral chloroquine for the treatment of uncomplicated Plasmodium vivax malaria in Savannakhet Province, Lao People's Democratic Republic (PDR)
Study acronym	LVT
Study objectives	That oral chloroquine remains efficacious in the treatment of Plasmodium vivax malaria in southern Laos.
Ethics approval(s)	Ethics approval received from: 1. Oxford Tropical Research Ethics Committee (OXTREC) (UK) on the 24th May 2005 2. National Ethic Committee for Health Research (NECHR) (Lao PDR) on the 24th May 2005
Health condition(s) or problem(s) studied	Vivax malaria
Intervention	Oral chloroquine 25 mg base/kg over 3 days (10 mg base/kg stat, followed by 10 mg base/kg at 24 hours later, followed by 5 mg base/kg at 48 hours). Total duration of follow-up is 42 days.
Intervention type	Drug
Phase	Not Applicable
Drug / device / biological / vaccine name(s)	Chloroquine
Primary outcome measure(s)	Cure rate. Outcomes measured daily until parasite clearance and then weekly until 42 days post treatment.
Key secondary outcome measure(s)	1. Parasite clearance time 2. Fever clearance time Outcomes measured daily until parasite clearance and then weekly until 42 days post treatment.
Completion date	30/12/2010

Participant type(s)	Patient
Age group	Other
Sex	All
Target sample size at registration	100
Key inclusion criteria	1. Written informed consent from patient or attending relative 2. Age greater than 1 year old, either sex 3. P. vivax infection (greater than 500 asexual stages/μL) 4. Acute uncomplicated malaria (World Health Organization [WHO] 2000) 5. Axillary temperature greater than 37.5°C 6. No full course of antimalarial treatment in the previous 3 days 7. High probability that patient will be able to complete 42 days follow up
Key exclusion criteria	1. Inability or unwillingness to give informed consent 2. Mixed species malaria infections 3. Severe malaria (WHO, 2000) 4. History of allergy to chloroquine 5. Asymptomatic malaria 6. Low probability of 42 days follow up
Date of first enrolment	01/06/2005
Date of final enrolment	30/12/2010

Microbiology Laboratory

Vientiane
-
Lao People's Democratic Republic

Individual participant data (IPD) Intention to share	No
IPD sharing plan summary	Not provided at time of registration
IPD sharing plan

Output type	Details	Date created	Date added	Peer reviewed?	Patient-facing?
Participant information sheet	Participant information sheet	11/11/2025	11/11/2025	No	Yes