Malaria
Transmission: Anopheles mosquito (nighttime bites)
Cause: Protozoan parasite (5 types) – P. falciparum, P. vivax, P. ovale, P. malariae, and P. knowlesi
Clinical Presentation: fever, headache, chills, vomiting – can progress to severe illness/death
Incubation Period: variable 12-14 days (early) to months
Diagnosis: Thick/Thin smear (gold standard), RDTs, PCR, serology/IFA (NOT FOR ACUTE DIAGNOSIS)
Treatment: Depends on uncomplicated vs. severe, suspected species, and drug-resistance

* Remember that P. vivax and P. ovale can remain dormant for months/years in your liver (hyponozoites)
* Remember to test for G6PD before administering primaquine given the risk for hemolytic anemia
* Negative Duffy blood group is protective against P. vivax – since it requires the Duffy antigen for cell entry.

Dengue Fever
Transmission: Aedes mosquito (day and night bites)
Cause: viral infection (Dengue single-stranded RNA virus 4 serotypes)
Clinical Presentation: Maculopapular rash on face, thorax, and flexor surfaces, abdominal pain, nausea/vomiting, diarrhea, saddleback fever – fever abates for a day and returns
Incubation Period: 3-14 days; >2 weeks UNLIKELY to be dengue
Diagnosis: IgM capture ELISA – serologic assay, viral RNA, NS protein-1 antigen
Treatment: Supportive care; self-limited illness

Chikungunya
Transmission: Aedes mosquito (day and night bites)
Cause: Viral infection (Chikungunya virus – arbovirus)
Clinical Presentation: Fever, joint pain (common); headache, muscle ache, joint swelling, rash
Incubation Period: 3-7 days after infection
Diagnosis: IgM anti-chikungunya ELISA
Treatment: Supportive care; self-limited illness

Typhoid Fever
Transmission: Fecal/oral from infected humans
Cause: Bacteria: Salmonella Typhi
Clinical Presentation: High fever, weakness, abdominal pain, constipation (early) followed by diarrhea (later), salmon/rose-colored rash, HSM
Incubation Period: 8-14 days usually; can range from 3 days to 1 month
Diagnosis: Culture blood/stool/bone marrow for S. Typhi; serologic testing for S. Typhi antibodies
Treatment: Flouroquinolones (resistance growing), ceftriaxone, azithromycin