ABSTRACT
BACKGROUND: The relapsing nature of Plasmodium vivax infection is a major barrier to its control and elimination. Factors such as adequate dosing, adherence, drug quality, and pharmacogenetics can impact the effectiveness of radical cure of P. vivax and need to be adequately evaluated. CYP2D6 pathway mediates the activation of primaquine (primaquine) into an active metabolite(s) in hepatocytes, and impaired activity has been linked to a higher risk of relapse. CASES PRESENTATION: Three patients diagnosed with P. vivax malaria presented repeated relapses after being initially treated with chloroquine (25 mg/kg) and primaquine (3.5 mg/kg in 14 days) at a non-endemic travel clinic. Recurring episodes were subsequently treated with a higher dose of primaquine (7 mg/kg in 14 days), which prevented further relapses in two patients. However, one patient still presented two episodes after a higher primaquine dose and was prescribed 300 mg of chloroquine weekly to prevent further episodes. Impaired CYP2D6 function was observed in all of them. CONCLUSION: Lack of response to primaquine was associated with impaired CYP2D6 activity in three patients presenting multiple relapses followed in a non-endemic setting. Higher primaquine dosage was safe and effectively prevented relapses in two patients and should be further investigated as an option in Latin America. It is crucial to investigate the factors associated with unsuccessful radical cures and alternative therapeutic options.
Subject(s)
Cytochrome P-450 CYP2D6/deficiency , Malaria, Vivax/prevention & control , Plasmodium vivax/drug effects , Primaquine/therapeutic use , Secondary Prevention , Adult , Dose-Response Relationship, Drug , Female , Humans , Male , Middle AgedABSTRACT
We describe a case of Zika virus infection acquired during the first trimester in a HIV-infected pregnant woman that led to multiple fetal malformations and fetal demise in Rio de Janeiro, Brazil.
Subject(s)
Arthrogryposis/pathology , Edema/pathology , Fetus/pathology , HIV Infections/pathology , Microcephaly/pathology , Pregnancy Complications, Infectious/pathology , Zika Virus Infection/pathology , Arthrogryposis/diagnostic imaging , Arthrogryposis/virology , Brazil , Edema/diagnostic imaging , Female , Fetal Death , Fetus/diagnostic imaging , Fetus/virology , HIV/pathogenicity , HIV/physiology , HIV Infections/diagnostic imaging , HIV Infections/virology , Humans , Microcephaly/diagnostic imaging , Microcephaly/virology , Pregnancy , Pregnancy Complications, Infectious/diagnostic imaging , Pregnancy Complications, Infectious/virology , Pregnancy Trimester, First , Zika Virus/pathogenicity , Zika Virus/physiology , Zika Virus Infection/diagnostic imaging , Zika Virus Infection/virologyABSTRACT
Many HIV infected patients are at risk for HTLV-I co-infection worldwide. These patients exhibit abnormally high CD4+ T lymphocyte counts that are not a reliable parameter of the immune status. We report a HIV/HTLV co-infected patient who developed progressive multifocal leukoencephalopathy despite of a high CD4+ T lymphocyte count emphasizing that this situation can be observed in regions around the world where HTLV-I infection is prevalent.
