Chloroquine-resistant Plasmodium falciparum cerebral malaria in a chloroquine-susceptible area

Chloroquine-resistant Plasmodium falciparum is endemic in many areas. Saudi Arabia was considered to have chloroquine-susceptible P. falciparum. During the 1997-1998 season, an outbreak of malaria occurred in the southwestern region. Over a 4-month period, 32 cases (6.2%) of 520 malaria admissions met the World Health Organization criteria for cerebral malaria. The mean patient age was 28 years. Thirteen male and 19 female patients were admitted in coma. The mean duration of coma was 4.3 days; the case fatality rate was 41%. Compared with those who recovered, patients who died had a lower mean admission diastolic blood pressure and hemoglobin level, higher mean blood urea nitrogen and blood glucose levels, and thrombocytopenia. Logistic regression analysis identified treatment with quinine rather than chloroquine to be associated with survival. These findings show the potential of P. falciparum to emerge as chloroquine resistant in previously susceptible areas, resulting in significant morbidity and mortality in spite of sophisticated medical care.