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
- Resuscitative efforts directed at affected organ
- Can deteriorate rapidly
- Initiate IV Artesunate if high level of suspicion
  - Requires call to CDC: CDC Malaria Hotline: (770) 488-7788 or (855) 856-4713 (toll-free) Monday–Friday 9am–5pm EST – (770) 488-7100 after hours, weekends, and holidays
- Benzodiazepines for seizures
- Be judicious with fluids as this can precipitate pulmonary edema and cerebral edema
  - a/w increased mortality in children at 48 hour
  - (Maitland 2011, PMID: 21615299; Hanson 2013, PMID: 23324951)

Take Home Points

This is going to be a diagnosis that is mainly made through a thorough history, and pay particular attention to those with recent travel to West-Africa
The incubation period for falciparum is 12 days, but there is a range of weeks and we should consider Malaria when consistent symptoms develop within 1 month of travel to an endemic area
Typical signs and symptoms for uncomplicated malaria are periodic fevers, jaundice, pallor
Be mindful of end organ involvement, such as cerebral edema, ATN, and pulmonary edema; these cases are considered to be severe and treated differently than uncomplicated malaria
Uncomplicated cases should get Malarone or Coartem
Severe cases require IV Artesunate
Be judicious with your fluid resuscitation as this can harm our patients

References

Centers for Disease Control and Prevention. CDC Parasites – Malaria. 2019 https://www.cdc.gov/parasites/malaria/index.html (7 July 2019, date last accessed)

Ashley EA, Pyae Phyo A, Woodrow CJ. Malaria. Lancet. 2018;391(10130):1608-21.

Hanson JP, Lam SW, Mohanty S, Alam S, Pattnaik R, Mahanta KC, et al. Fluid resuscitation of adults with severe falciparum malaria: effects on Acid-base status, renal function, and extravascular lung water. Crit Care Med. 2013;41(4):972-81.

Lampah DA, Yeo TW, Malloy M, Kenangalem E, Douglas NM, Ronaldo D, et al. Severe malarial thrombocytopenia: a risk factor for mortality in Papua, Indonesia. J Infect Dis. 2015;211(4):623-34.

Lokken KL, Stull-Lane AR, Poels K, Tsolis RM. Malaria Parasite-Mediated Alteration of Macrophage Function and Increased Iron Availability Predispose to Disseminated Nontyphoidal Salmonella Infection. Infect Immun. 2018;86(9).

Maitland K, Kiguli S, Opoka RO, Engoru C, Olupot-Olupot P, Akech SO, et al. Mortality after fluid bolus in African children with severe infection. N Engl J Med. 2011;364(26):2483-95.

Park SE, Pak GD, Aaby P, Adu-Sarkodie Y, Ali M, Aseffa A, et al. The Relationship Between Invasive Nontyphoidal Salmonella Disease, Other Bacterial Bloodstream Infections, and Malaria in Sub-Saharan Africa. Clin Infect Dis. 2016;62 Suppl 1:S23-31.

Tintanelli, Judith E., et al. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide. Eighth edition. New York: McGraw-Hill Education, 2016: p.1070-1077

World Health Organization. Guidelines for the treatment of malaria. Third edition

April 2015. WHO. 2015 https://www.who.int/malaria/publications/atoz/9789241549127/en/ (7 July 2019, date last accessed)

A special thanks to our editor:

Angelica Cifuentes Kottkamp, MD
Infectious Diseases & Immunology
NYU School of Medicine

Episode 167.0 – Malaria

Core EM - Emergency Medicine Podcast