PURPOSE: United States military personnel deployed to Somalia were at
risk for malaria, including chloroquine-resistant Plasmodium falciparu
m malaria. This report details laboratory, clinical, preventive, and t
herapeutic aspects of malaria in this cohort. PATIENTS AND METHODS: Th
e study took place in US military field hospitals in Somalia, with US
troops deployed to Somalia between December 1992 and May 1993. Central
ized clinical care and country-wide disease surveillance facilitated s
tandardized laboratory diagnosis, clinical records, epidemiologic stud
ies, and assessment of chemoprophylactic efficacy. RESULTS: Forty-eigh
t cases of malaria occurred among US troops while in Somalia; 41 of th
ese cases were P falciparum. Risk factors associated with malaria incl
uded: noncompliance with recommended chemoprophylaxis (odds ratio [OR]
2.4); failure to use bed nets (OR 2.6); and failure to keep sleeves r
olled down (OR 2.2). Some patients developed malaria in spite of meflo
quine (n = 8) or doxycycline (n = 5) levels compatible with chemoproph
ylactic compliance. Five mefloquine failures had both serum levels gre
ater than or equal to 650 ng/mL and metabolite:mefloquine ratios over
2, indicating chemoprophylactic failure. All cases were successfully t
reated, including 1 patient who developed cerebral malaria. CONCLUSION
S: P falciparum malaria attack rates were substantial in the first sev
eral weeks of Operation Restore Hope. While most cases occurred becaus
e of noncompliance with personal protective measures or chemoprophylax
is, both mefloquine and doxycycline chemoprophylactic failures occurre
d. Military or civilian travelers to East Africa must be scrupulous in
their attention to both chemoprophylaxis and personal protection meas
ures.