Dr Philippe Guerin
|Research Area:||Global Health|
|Technology Exchange:||Bioinformatics and Medical statistics|
|Scientific Themes:||Tropical Medicine & Global Health|
|Keywords:||Malaria, Resistance, Clinical, Pharmacological, Molecular and Policy|
The Worldwide Antimalarial Resistance Network (WWARN) is a global collaboration working to ensure that anyone affected by malaria receives effective and safe drug treatment.
Of the approximately one million people who die from the effects of malaria every year, most are children under five years of age. In the absence of an effective vaccine, the best lines of defence are avoidance of mosquito bites or effective drug therapy. However, malarial parasites are able to become rapidly resistant to commonly-used or even new drugs.
WWARN will provide urgently needed, comprehensive, timely and quality-assured information to track the emergence of malarial drug resistance. High levels of clinical treatment failure are amongst the last indicators of drug resistance. Uniquely WWARN will, in parallel with the clinical response to drug treatment, track pharmacological, molecular and laboratory measures of parasite drug resistance. Small changes in one or more of these factors may provide early warning of emerging resistance. Collated information will allow policy makers at national, regional or international levels to develop strategies that make best use of available drugs and resources.
Global cooperation is central to WWARN’s future success. Working in close collaboration with the World Health Organization, WWARN has created the hub of a worldwide network that will supply tools, training and resources to maximize scientists’ contributions.
WWARN is an independent project within Oxford University in the United Kingdom and funded by a programme grant from the Bill and Melinda Gates Foundation. For further information, visit www.wwarn.org.
There are no collaborations listed for this principal investigator.
Malaria in pregnancy is associated with maternal and fetal morbidity and mortality. In 2006, WHO recommended use of artemisinin-based combination treatments during the second or third trimesters, but data on efficacy and safety in Africa were scarce. We aimed to assess whether artemether-lumefantrine was at least as efficacious as oral quinine for the treatment of uncomplicated falciparum malaria during the second and third trimesters of pregnancy in Mbarara, Uganda. Hide abstract
Current information on efficacy of antimalarials is crucial to provide early warning of resistance. A collaborative effort between the Global Malaria Program of the World Health Organization (WHO) and the WorldWide Antimalarial Resistance Network (WWARN) has recently been launched. The effort is planned as a collaboration with the scientific malaria community to create a global, comprehensive, and inclusive network that will provide quality-assured information on antimalarial drug resistance. Hide abstract
Effective surveillance for and rapid identification of evolved antimalarial resistance ensures that all patients are treated with efficacious drugs. This review summarizes the current status and the challenges to effective surveillance, and suggests approaches for improvement. Hide abstract
PLoS Med, 5 (8), pp. e169. | Read more2008. Assessing antimalarial efficacy in a time of change to artemisinin-based combination therapies: the role of Médecins Sans Frontières.
PLoS Med, 5 (4), pp. e89. | Read more2008. Research in complex humanitarian emergencies: the Médecins Sans Frontières/Epicentre experience.
Although vaccination has almost eliminated measles in parts of the world, the disease remains a major killer in some high birth rate countries of the Sahel. On the basis of measles dynamics for industrialized countries, high birth rate regions should experience regular annual epidemics. Here, however, we show that measles epidemics in Niger are highly episodic, particularly in the capital Niamey. Models demonstrate that this variability arises from powerful seasonality in transmission-generating high amplitude epidemics-within the chaotic domain of deterministic dynamics. In practice, this leads to frequent stochastic fadeouts, interspersed with irregular, large epidemics. A metapopulation model illustrates how increased vaccine coverage, but still below the local elimination threshold, could lead to increasingly variable major outbreaks in highly seasonally forced contexts. Such erratic dynamics emphasize the importance both of control strategies that address build-up of susceptible individuals and efforts to mitigate the impact of large outbreaks when they occur. Hide abstract
Neisseria meningitidis serogroup A is the main causative pathogen of meningitis epidemics in sub-Saharan Africa. In recent years, serogroup W135 has also been the cause of epidemics. Mass vaccination campaigns with polysaccharide vaccines are key elements in controlling these epidemics. Facing global vaccine shortage, we explored the use of fractional doses of a licensed A/C/Y/W135 polysaccharide meningococcal vaccine. Hide abstract
The proliferation of antimalarial drug trials in the last ten years provides the opportunity to launch a concerted global surveillance effort to monitor antimalarial drug efficacy. The diversity of clinical study designs and analytical methods undermines the current ability to achieve this. The proposed World Antimalarial Resistance Network (WARN) aims to establish a comprehensive clinical database from which standardised estimates of antimalarial efficacy can be derived and monitored over time from diverse geographical and endemic regions. The emphasis of this initiative is on five key variables which define the therapeutic response. Ensuring that these data are collected at the individual patient level in a consistent format will facilitate better data management and analytical practices, and ensure that clinical data can be readily collated and made amenable for pooled analyses. Such an approach, if widely adopted will permit accurate and timely recognition of trends in drug efficacy. This will guide not only appropriate interventions to deal with established multidrug resistant strains of malaria, but also facilitate prompt action when new strains of drug resistant plasmodia first emerge. A comprehensive global database incorporating the key determinants of the clinical response with in vitro, molecular and pharmacokinetic parameters will bring together relevant data on host, drug and parasite factors that are fundamental contributors to treatment efficacy. This resource will help guide rational drug policies that optimize antimalarial drug use, in the hope that the emergence and spread of resistance to new drugs can be, if not prevented, at least delayed. Hide abstract
To compare the cost-effectiveness of malaria treatment based on presumptive diagnosis with that of malaria treatment based on rapid diagnostic tests (RDTs). Hide abstract
Rolling back malaria is possible. Tools are available but they are not used. Several countries deploy, as their national malaria control treatment policy, drugs that are no longer effective. New and innovative methods of vector control, diagnosis, and treatment should be developed, and work towards development of new drugs and a vaccine should receive much greater support. But the pressing need, in the face of increasing global mortality and general lack of progress in malaria control, is research into the best methods of deploying and using existing approaches, particularly insecticide-treated mosquito nets, rapid methods of diagnosis, and artemisinin-based combination treatments. Evidence on these approaches should provide national governments and international donors with the cost-benefit information that would justify much-needed increases in global support for appropriate and effective malaria control. Hide abstract