Case Presentation: A 51-year-old man with a history of insulin dependent diabetes (hemoglobin A1C 11.4%) presented with abdominal pain, nausea, vomiting, and fevers. Two weeks prior to presentation, he returned from a trip in Nigeria. Vitals signs were notable for temperature 103.6°F and heart rate 106 beats per minute. Physical examination was notable for tachycardia. Laboratory work revealed hemoglobin 9.2g/dl, platelets 48 x 10E9/L, diabetic ketoacidosis, and elevated transaminases. He was started on an insulin drip, vancomycin and piperacillin-tazobactam. Blood cultures, human immunodeficiency virus, and Parvovirus B19 testing were negative. Malaria smear revealed rings forms consistent with P.falciparum with 5% parasitemia. Antibiotics were discontinued, and Artemether-Lumefantrine was given for 3 days. He improved clinically with < 0.1% of parasitemia noted on blood smear on the day of discharge. Two weeks later, he was readmitted with fevers and severe anemia (Hb 5.7g/dl). Malaria smear revealed increased parasitemia of 2.4% suggestive of malaria recrudescence. Due to concern for artemisinin resistance, atovaquone-proguanil was initiated with complete symptom resolution.
Discussion: The global malaria burden is highest in tropical countries. Nigeria has the highest incidence; with 60 million cases reported and 194,000 deaths documented in 2021, it accounts for 27% of the global malaria deaths. The first line therapy for malaria in Africa where Plasmodium falciparum is the dominant species, is artemisinin-based therapy. Though not endemic in the United States, healthcare providers often encounter returning travelers with malaria and must be aware of global antimalarial resistance patterns. Though Nigeria has not experienced the burden of artemisinin-based combination therapy (ACT) resistance reported in East Africa, it is imperative to understand the trends and identify patients with treatment failure and recognize the potential for drug resistance. Due to widespread resistance to chloroquine, ACT is currently the first line antimalarial treatment. A global initiative is underway to identify malarial species and patterns for drug resistance through molecular marker monitoring. There have been mutant strains of artemisinin-resistant P. falciparum identified in Rwanda (k13, Pfcrt, Pfmdr1, Pfdhfr, and Pfdhps), which are now being monitored for in Nigeria. Though there have been no reported cases of ACT-resistant malaria in Nigeria, there is concern for emerging resistance due to the significant burden of disease in the country.
Conclusions: Concerns in regard to the emergence of evolving variants and resistant strains of Plasmodium Falciparum in endemic regions of Africa continue to rise. Awareness of epidemiological trends and treatment variations is paramount to providing quality care to patients exposed to those endemic regions. Following first line treatment failure, we should evaluate travel or exposure history and assess resistance patterns in those regions to adequately tailor therapy. Furthermore, as resistance rises in East Africa, it is important to monitor resistance patterns of neighboring countries as well as improve efforts to provide easy access to information on current trends, resistance patterns, and effective therapies to simplify and improve treatment of malaria for exposed and at-risk populations.