My Synopsis of "Fever in Returning Travelers: A Case-Based Approach"

Fever in Returning Travelers: A Case-Based Approach
HENRY M. FEDER, JR., MD, and KENIA MANSILLA-RIVERA, MD, University of Connecticut School of Medicine, Farmington, Connecticut
Am Fam Physician. 2013 Oct 15;88(8):524-530.
http://www.aafp.org/afp/2013/1015/p524.pdf

     The rate of coming back from traveling to a developing world with a fever is about 3-19%. The most common diseases are dengue fever and malaria. They are usually seen in travelers going to the Caribbean, Central America, South America, South Central America, Southeast Asia, and Sub-Saharan Africa. Enteric fever may be seen in travelers coming out of South Central Asia. Sub-Saharan Africa also has a high rate of rickettsiae, schistosomiasis, and filariasis.
     When evaluating a fever in a patient who has recently returned from travel, it is important to ask about when and where they traveled, if they took any travel prophylaxis, if they were exposed to any insects or sick people, if they had sex with any of the locals, if they drank the water or ate the food, if they got sick during the travel, and if they were exposed to any illnesses since being back to the U.S. Depending on the infection, the fever may take anywhere from a day to a month to appear.
     Malaria has five different subtypes. P. knowlesi is the newest species. The life cycle of the Plasmodium starts with the human being infected from the mosquito bite. The "sporozoites" then go to the liver. They turn into "merozoites" and cause RBC rupture and fever spikes. P.malariae causes "quartan" fevers (every fourth day). The other species cause "tertian" fevers (every third day). P. falciparum can cause fulminant disease by binding to the vasculature and blocking blood flow. Symptoms of malaria include fever, headache, jaundice, muscle and joint pain, abdominal pain, nausea, and vomiting. If hemolysis, dark urine and hematuria occur, it is called blackwater fever. Prophylaxis includes using DEET mosquito repellent and oral mefloquine. The treatment of choice is chloroquine, unless the patient traveled to a chloroquine resistant area, in which the treatment is tetracycline plus mefloquine.
     Salmonella typhi and S. paratyphi are the causes of typhoid fever. It is transmitted through contaminated water and food. The clinical presentation is similar to malaria. The symptoms include fever, malaise, anorexia, vomiting, and abdominal pain. Children may present with diarrhea, whereas adults may present with constipation. Patients may also present with  maculopapular, pink colored, rose spots on the trunk. Lab tests include ESR, CRP, and liver function tests. Blood, urine or stool cultures can be used to diagnose S. typhi infection. Vaccination is the best prophylaxis. Treatment includes oral ciprofloxacin, cefixime or azithromycin. Resistance to fluoroquinolones, amoxicillin, and TMP/SMX are common.
     Dengue fever occurs through a mosquito bite. The symptoms include spiking fevers, leukopenia, retro-orbital headaches, nausea, maculopapular rash, vomiting, muscle pain, and joint pain. There is also a disease called dengue hemorrhagic fever, which presents with a triad of hemorrhage, thrombocytopenia, and plasma leakage. Patients may also present with hypotensive shock. Patients may also be asymptomatic. One diagnostic test is called the tourniquet test. A blood pressure cuff is inflated at a pressure between the systolic and diastolic pressure. If it creates the appearance of petechiae in numbers more than 20/inch on the skin, then the test is positive (it shows an increase in capillary fragility and thrombocytopenia). Dengue IgM antibody titers can be tested for as well. Prophylaxis includes using DEET and treatment consists of hydration and bed rest.