The perfect storm: Cutaneous leishmaniasis in troops deployed in the Atlantic forest of Argentina.

American cutaneous leishmaniasis (ACL) is the most prevalent form of leishmaniasis, associated with an ulcerative and stigmatizing mucocutaneous pathology. This study assessed the incidence of Leishmania (Viannia) braziliensis in members of the Argentine Army who were exposed to sandfly bites in Iguazú National Park (INP), northeastern Argentina, during an outbreak of ACL in 2019, and the presence of Leishmania in rodents, opossums and phlebotomine sandflies collected in the area of exposure. Samples from military personnel, wild animals and phlebotomine sandflies were analysed. A total of 20 (40%) patients among the Army personnel and two Akodon montensis rodents (11%) were positive for the presence of Leishmania sp. genes by PCR, while Nyssomyia whitmani and Migonemyia migonei, competent vectors of Leishmania, were also found at the same site. Sequences of hsp70 DNA fragments obtained from human samples confirmed the identity of L. (V.) braziliensis. The risk to which military personnel carrying out activities in the forest are exposed is highlighted, and this risk extends to any worker and visitor who circulates without protection in the INP, coming into contact with transmission "hot spots" due to the concentration of vectors, reservoirs and/or parasites.

Caso autóctono de rickettsiosis por Rickettsia parkeri en la Selva Paranaense, Misiones, Argentina / Autochthonous Rickettsia parkeri rickettsiosis in the Paranaense Forest, Misiones, Argentina

Resumen Se informa un caso autóctono de rickettsiosis por Rickettsia parkeri, ocurrido en junio del 2018 en la zona selvática del Parque Provincial Urugua-í, Misiones, Argentina, región sin registros previos de esta enfermedad en humanos. Se describen los aspectos epidemiológicos, ecológicos, clínicos y de laboratorio necesarios para el diagnóstico oportuno y el tratamiento adecuado. Se resalta el hecho de considerar a las rickettsiosis como diagnóstico diferencial ante un paciente con síndrome febril agudo exantemático; el antecedente epidemiológico de exposición al vector característico de la región, garrapatas del género Amblyomma, es un elemento fundamental.

Abstract We report an autochthonous case of Rickettsia parkeri rickettsiosis occurred in June 2018 in a forested area of the Urugua-í Provincial Park, Misiones, Argentina. No previous records of this disease in humans have been previously reported in this region. The epidemiological, ecological, clinical, and laboratory features required for a proper diagnosis and adequate treatment are described here. The fact of considering rickettsiosis as a differential diagnosis in a patient with exanthematic acute febrile syndrome is highlighted, being the epidemiological history of exposure to the vector (ticks of the genus Amblyomma) an essential element.

[Autochthonous Rickettsia parkeri rickettsiosis in the Paranaense Forest, Misiones, Argentina]. / Caso autóctono de rickettsiosis por Rickettsia parkeri en la Selva Paranaense, Misiones, Argentina.

We report an autochthonous case of Rickettsia parkeri rickettsiosis occurred in June 2018 in a forested area of the Urugua-í Provincial Park, Misiones, Argentina. No previous records of this disease in humans have been previously reported in this region. The epidemiological, ecological, clinical, and laboratory features required for a proper diagnosis and adequate treatment are described here. The fact of considering rickettsiosis as a differential diagnosis in a patient with exanthematic acute febrile syndrome is highlighted, being the epidemiological history of exposure to the vector (ticks of the genus Amblyomma) an essential element.

[Failure to radical cure in Plasmodium vivax malaria]. / Malaria por Plasmodium vivax y falla al tratamiento radical.

Relapsing Plasmodium vivax malaria is due to activation of dormant intrahepatic parasitic forms known as hypnozoits. Primaquine is the only available drug effective against hypnozoits and, alongside a schizonticidal drug, constitutes the radical treatment of malaria. Failure of radical treatment is frequently attributed to inadequate dosing, poor adherence, or reinfection. However, several cases of radical treatment failure without these factors have been reported, inferring that metabolic properties of the host or tolerance mechanisms of the parasite may be implied. A case of malaria due to Plasmodium vivax acquired in the Amazonic region, treated outside endemic area, with multiple relapses despite adequate radical treatment is described.

Malaria por Plasmodium vivax y falla al tratamiento radical / Failure to radical cure in Plasmodium vivax malaria

Relapsing Plasmodium vivax malaria is due to activation of dormant intrahepatic parasitic forms known as hypnozoits. Primaquine is the only available drug effective against hypnozoits and, alongside a schizonticidal drug, constitutes the radical treatment of malaria. Failure of radical treatment is frequently attributed to inadequate dosing, poor adherence, or reinfection. However, several cases of radical treatment failure without these factors have been reported, inferring that metabolic properties of the host or tolerance mechanisms of the parasite may be implied. A case of malaria due to Plasmodium vivax acquired in the Amazonic region, treated outside endemic area, with multiple relapses despite adequate radical treatment is described.

La infección por Plasmodium vivax se caracteriza por la formación de hipnozoítos que permanecen quiescentes en los hepatocitos del hospedero y son responsables de las recaídas de la malaria. Primaquina es el único fármaco en uso para la erradicación de los hipnozoítos y asociado a un agente esquizonticida, constituye el tratamiento radical. Las fallas al tratamiento radical están relacionados con una dosificación subóptima, adherencia inadecuada y reinfección. Sin embargo, cuando estos factores están ausentes, se han postulado mecanismos propios del metabolismo del hospedero y de tolerancia del parásito. Se describe un caso de malaria por P. vivax adquirido en la región amazónica asistido fuera de la zona endémica, con múltiples recaídas a pesar del tratamiento radical adecuado.