Episode 167.0 – Malaria

An in depth review of this notorious parasite. Hosts: Brian Gilberti, MD Audrey Bree Tse, MD https://media.blubrry.com/coreem/content.blubrry.com/coreem/Malaria.mp3 Download Leave a Comment Tags: Infectious Diseases Show Notes Background * In 2017, there were 219 million cases and 435,000 people deaths from malaria * Five species: Falciparum, P. vivax, P. ovale, P. malariae, and P. knowlesi. * Falciparum, Vivax and Knowlesi can be fatal * History of recent travel to Africa (69% of cases in US), particularly to west-Africa should raise suspicion for malaria Clinical Manifestations * Average incubation period for Falciparum is 12 days * 95% will develop symptoms within 1 month * Clinical findings with high likelihood ratios include periodic fevers, jaundice, splenomegaly, pallor. * Can also have vomiting, headache, chills, abdominal pain, cough, and diarrhea * Severe malaria has a mortality of 5% to 30%, even with therapy * Diagnostic criteria for severe malaria: Ashley 2018 * Most common manifestations of severe malaria affect the brain, lungs, and kidneys * Patients with cerebral malaria can present encephalopathic or comatose, some severe enough to exhibit extensor posturing, or seizures * Can have acute lung injury with a quarter of these patients progressing to ARDS * Can have AKI from ATN and resultant acidosis * Labs may be unremarkable but watch for anemia and thrombocytopenia * Hgb <5 has an OR = 4.9 for death * Severe thrombocytopenia has an OR = 2.8 * Anemia + Thrombocytopenia has an OR = 13.8 (Lampah 2015, PMID 25170106) * Watch for hypoglycemia * Be mindful of co-infection with salmonella and HIV * Obtain BCx, cover with ceftriaxone Diagnosis * Blood smear * Thick smear to increase sensitivity for detecting parasites * Thin smear for quantifying parasitemia and species * The first smear is positive in over 90% of cases, but if suspicion is high, it has to be repeated BID for 2-3 days for proper exclusion of malaria (CDC 2019) Management * For uncomplicated, non-severe cases, most patients with falciparum should be admitted, especially those with no prior exposure to malaria parasites * Malarone is one of the first line options * Check out other suggested regimens from the CDC * Important to note that when they take this, ensure they take with milk or food containing fat to enhance absorption * Severe Malaria