Possibility of Leishmania Transmission via Lutzomyia spp. Sand Flies Within the USA and Implications for Human and Canine Autochthonous Infection

Abstract

Purpose of Review Leishmaniasis is a leading cause of parasitic death, with incidence rising from decreased resources to administer insecticide and anti-leishmanial treatments due to the COVID-19 pandemic. Leishmaniasis is nonendemic in the United States (U.S.), but enzootic canine populations and potentially competent vectors warrant monitoring of autochthonous disease as a fluctuating climate facilitates vector expansion. Recent studies concerning sand fly distribution and vector capacity were assessed for implications of autochthonous transmission within the U.S. Recent Findings Climate change and insecticide resistance provide challenges in sand fly control. While most Leishmania -infected dogs in the U.S. were infected via vertical transmission or were imported, autochthonous vector-borne cases were reported. Autochthonous vector-borne human cases have been reported in four states. Further vaccine research could contribute to infection control. Summary Both cutaneous and visceral leishmaniasis cases in the U.S. are increasingly reported. Prevention measures including vector control and responsible animal breeding are critical to halt this zoonotic disease.

Quercetin as a Promising Antiprotozoan Phytochemical: Current Knowledge and Future Research Avenues

“…Treatment of human leishmaniasis is a challenging issue, and no vaccine has yet been approved for commercial use against any form of the disease [ 18 ]. Pentavalent antimonials such as sodium stibogluconate (SSG, Pentostam®) and meglumine antimoniate (Glucantime®) have been the mainstay of therapy for decades.…”

Canine leishmaniasis in the Americas: etiology, distribution, and clinical and zoonotic importance

“…Similarly, Migonemyia migonei is also a permissive vector of L. infantum and suspected to be involved in its transmission in some areas of Brazil [ 85 ] and Bolivia [ 84 ]. In the USA, Psathyromyia shannoni is a putative vector of L. infantum in areas where cases of canine leishmaniasis have been reported [ 86 ]. These examples suggest the need for more studies on the vectors involved in the Leishmania spp.…”

“…These examples suggest the need for more studies on the vectors involved in the Leishmania spp. transmission to dogs in the Americas, including in the USA [ 86 ].…”

Potential Biomarkers for Asymptomatic Visceral Leishmaniasis among Iraq-Deployed U.S. Military Personnel

“…A substantial prevalence of L. infantum AVL was observed in Operation Iraqi Freedom (OIF) U.S. military deployers; 19.5% had asymptomatic infection defined by a positive cellular/humoral response or nucleic acid testing result [ 24 , 25 ]. AVL presents a concern due to the potential of chronically infected individuals to transmit disease via blood transfusion and organ donation, the possible domestic transmission risk given a permissive and widespread U.S. sand fly vector, Lutzomyia shannoni , and the reactivation risk associated with the increasing use of immune modulating treatments and immunosuppression [ 26 , 27 ]. The current parasitological, molecular, and serological methods used to identify asymptomatic infection are resource-intensive and not completely suitable for expanded surveillance, making the identification of these individuals a challenge [ 19 , 28 ].…”