Malaria prophylaxis for travelers 7th Annual Travel Medicine National Conference Friday October 16th Orange County D. Scott Smith, MD, MSc, DTM&H Kais...
Malaria prophylaxis for travelers 7th Annual Travel Medicine National Conference Friday October 16th Orange County D. Scott Smith, MD, MSc, DTM&H Kaiser Redwood City & Stanford University
Malaria Prevention Objectives
Prescribe appropriate prophylaxis for travelers to specific destinations Evaluate contraindications and select alternative regimens for malaria prophylaxis List new strategies for malaria prevention and treatment in travelers D. Scott Smith
Objectives (2)
Describe the difference between adult and pediatric malaria prophylaxis List language resources available when encountering a traveler who speaks another language
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D. Scott Smith
http://www.cdc.gov/malaria/distribution_epi/distribution.htm D. Scott Smith
Accessed July 14, 2008, at www.who.int/ith D. Scott Smith
• 3.3 billion people at risk of infection in 2006 • 109 countries and territories endemic for malaria in 2008 • Estimated 247 million cases annually Who is atdeaths risk? • 880,000 from • Of all the people living with malaria each year malaria, 92% live in African territories. Proportionate number of malaria cases worldwide (2004) D. Scott Smith
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A Truth “Estimating the risk of infection in travelers is difficult.” difficult.” Malaria Chapter, p. 213
--- CDC Health Information for International Travel 2008
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The Impact of Malaria, a Leading Cause of Death Worldwide
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Even within tropical and subtropical areas, transmission will NOT occur:
At high altitudes During cooler seasons in some areas In deserts (excluding the oases) In some islands in the Pacific Ocean, which have no local Anopheles species capable of transmitting malaria In some countries where transmission has been interrupted through successful eradication. D. Scott Smith
Malaria: Global Epidemiology
Over 2 billion people (41% of the world population) live in malariamalaria-risk areas 500 million cases of clinical disease annually Global mortality: 870,000 /year Worldwide a child dies every 60 seconds from malaria >90% of malaria deaths are in subsubSaharan Africa where 5% of children die from malaria before reaching the age of 5 years D. Scott Smith
Freedman D. N Engl J Med 2008;359:603-612
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Dx by region
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Percent Fever in Returned Travelers N=3907 NEJM 2006;354 etiology
Carib
CAm
SAm
SSA
SA
SEA
malaria
causal
• Dose: 30 mg (base) = 2 tabs/day, 1 day before and 3 days after exposure
D. Scott Smith
Primaquine Drug Advantage
Disadvantage
Primaquine
G6PD* level required
Low cost $$ 1 day pre-exposure 3 days post Tissue schizonticide
Daily Take with food Lower efficacy
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(Malarone) D. Scott Smith
Atovaquone /proguanil (Malarone) Drug
Advantage
Disadvantage
Atovaquone Safety /proguanil Convenience: 1 day pre; (Malarone) 7 days post
Highest Cost $$$$$ headache, GI upset, insomnia; Daily
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Tolerability of antimalarials: antimalarials: RDB 4 arm study % Neuropsychological AE’ AE’s* Schlagenhauf BMJ 2003;327:1078 Mefloquine N=153
Doxycycline N=153
Atov/prog N=154
5
1
3
moderate
37
24
20
all events
77
69
67
Adverse event severe
*headache, vivid dreams, dizziness, depression, anxiety, insomnia D. Scott Smith
Atov/Pro vs. Mefloquine Discontinuations Discontinuation rate
Atov/Pro (n=493)
Mefloquine (n=483)
Overall
1.2%*
5.0%
Neuropsychiatric event as cause
0.6%*
3.9%
*P = .001 MALARONE vs. Mefloquine
Overbosch et al. Clin Infect Dis. 2001;33:1015–1021.
D. Scott Smith
Summary of Drugs for Chloroquine Resistant Malaria Drug
Advantage
Disadvantage
Mefloquine Lariam
Weekly Moderate cost $$
Neuropsychiatric ADR 1-2 wks pre;4 wks post
Doxycycline
Lowest cost $
Daily; sun burn; GI vaginal yeast infection 1day pre,4 wks post
Primaquine
Low cost $$ 1 day pre; 3 days post
G6PD level required; Daily; efficacy
Atov/proguanil Malarone
Safety 1 day pre ; 7 days post
Highest cost $$$$ Daily Must take with food D. Scott Smith
Geographic distribution of mefloquineresistant malaria
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N=276 , 74 days
Protective Efficacy: Pv: 98% (88-100%) Pf : 71% (-14-94%) (too few cases of Pf) D. Scott Smith
3 drugs of choice for Chloroquine Resistant areas
Drug
Indication
Mefloquine Lariam
Previous drug use Long-stay traveler Pregnancy, infancy
Doxycycline
Impecunious traveler Thai borders
Atovaquone/ proguanil Malarone
Short-stay traveler Drug plan positive Thai borders D. Scott Smith
Malaria Drug Contraindications List Drug
Contraindications
Mefloquine Lariam
Irregular heart beat Depression Schizophrenia Anxiety disorder Any Psychosis
