ABSTRACT
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.
Subject(s)
Leishmania braziliensis , Leishmania , Leishmaniasis, Cutaneous , Leishmaniasis , Psychodidae , Humans , Animals , Argentina/epidemiology , Insect Vectors/parasitology , Leishmaniasis, Cutaneous/epidemiology , Leishmaniasis, Cutaneous/veterinary , Leishmaniasis, Cutaneous/parasitology , Leishmania/genetics , Leishmania braziliensis/genetics , Psychodidae/parasitology , Forests , Brazil/epidemiology , Leishmaniasis/veterinaryABSTRACT
Pregnancy induces collagen-induced arthritis (CIA) remission in rats. Placental hormones, cytokines and growth factors can regulate immune cell activity at the feto-maternal interface as well as at the systemic level. We assessed the effect of placental culture supernatants (PS) in CIA developed in rats after the inoculation of collagen type II (CII) in complete Freund's adjuvant. After the onset of CIA, animals were injected by ip route with seven doses of PS. On the 18th day of treatment with PS, serum anti-CII antibody (total IgG, IgG(1), IgG(2a), IgG(2b), IgG asymmetric molecules) and cytokine levels were determined by ELISA. An arthritic index was used by daily measure of joint swelling and visual signs of arthritis. Our results demonstrated that the PS treatment diminished CIA symptoms, reduced TNF-alpha, INF-gamma and anti-CII antibody serum levels, increased the proportion of asymmetric IgG anti-CII antibodies and affected IgG(1)/IgG(2a) and IgG(1)/IgG(2b) ratio. Two weeks after the last PS inoculation there was a recurrence of arthritis, a rise in IgG anti-CII and, simultaneously, the percentage of asymmetric IgG anti-CII fell. We concluded that PS have an effective CIA suppressor activity partly due to the modulation of humoral immune response and may be closely related to an inhibitory effect on TNF-alpha and INF-gamma production.
