Plasmodium vivax
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Epidemiology
- Plasmodium vivax is transmitted by the Anopheles mosquito
- most geographically widespread human malaria parasite[3]
- highest burdens are seen in India, Pakistan, Ethiopia, Papua New Guinea, Indonesia, & countries in South America such as Brazil & Venezuela
Pathology
- P. ovale & P. vivax infect primarily younger erythrocytes.
- P. ovale & P. vivax differ from P. falciparum & P. malariae in that relapses may occur weeks to months following subsistence of previous attacks as a result of renewed schizogony from latent hepatic sporozoites (hypnozoites)
Genetics
- individuals that do not produce the Duffy antigen (FY(A-B-)) are more resistant to vivax malaria
Clinical manifestations
- nausea, vomiting, abdominal pain, cough, dyspnea
- may be absent if patient has received treatment for symptomatic. erythrocytic stage of malaria
- hepatosplenomegaly
- no rash
Laboratory
- complete blood count
- mildly elevated serum transaminases
- total bilirubin in serum may be elevated
- Plasmodium identified in blood by light microscopy (peripheral blood smear)
- erythrocytes are enlarged in size (1.5-2 X)
- basophilic stippling seen with all forms, except early ring forms
- all stages may be seen in peripheral blood
- trophozoites appear ameboid
- 12-24 merozoites, average 16
- Plasmodium vivax antigen in blood
- Plasmodium vivax serology
- Plasmodium vivax DNA
Differential diagnosis
- dengue: rash, frontal headache, retro-orbital pain, myalgia
- Salmonella enterica serotype Typhi: GI symptoms
- chikungunya:
- myalgia, arthralgia
- anemia is not a major feature of chikungunya
- illness typically resolves spontaneously in 7-10 days
Management
- treatment for the erythrocytic, symptomatic stage of malarial infection
- artemether-lumefantrine for 3 days
- additional treatment to eradicate the liver hypnozoites that can cause relapse
- primaquine or tafenoquine eradicates dormant hypnozoites in liver
More general terms
Additional terms
References
- ↑ Clinical Diagnosis & Management by Laboratory Methods, 19th edition, J.B. Henry (ed), W.B. Saunders Co., Philadelphia, PA. 1996, pg 1260-64
- ↑ Harrison's Principles of Internal Medicine, 14th ed. Fauci et al (eds), McGraw-Hill Inc. NY, 1998, pg 1180-89
- ↑ 3.0 3.1 3.2 Angrisano F, Robinson LJ. Plasmodium vivax - How hidden reservoirs hinder global malaria elimination. Parasitol Int. 2022 Apr;87:102526. PMID: https://pubmed.ncbi.nlm.nih.gov/34896312 Free article. Review. https://www.sciencedirect.com/science/article/pii/S1383576921002440
- ↑ Medical Knowledge Self Assessment Program (MKSAP) 20 American College of Physicians, Philadelphia 2025
- ↑ Price RN, Commons RJ, Battle KE, et al. Plasmodium vivax in the era of the shrinking P. falciparum map. Trends Parasitol. 2020;36:560-570. PMID: https://pubmed.ncbi.nlm.nih.gov/32407682