Wilson Jacinto Silva de Souza

Canine Visceral Leishmaniasis in Rio de Janeiro, Brazil: clinical, parasitological, therapeutical and epidemiological findings (1977-1983)

Forty dogs from the periphery of the city of Rio de Janeiro were studied. All dogs where diagnosed as positive for leishmaniasis either parasitologically and/or serologically. Among them, 19 came from areas where only Visceral Leishmaniasis (VL) occurs (Realengo, Bangu, Senador Camará). Clinical signs of the disease were seen in 36.8% of the cases, including emaciation - 100%, lymphadenopathy and depilation - 85.7%. The other 21 dogs came from an area (Campo Grande) where both diseases (VL, and American Cutaneous Leishmaniasis - ACL) occur. Clinical signs of the disease, mainly cutaneous or mucocutaneous ulcers were seen in 76.2% of the cases. Leishmania parasites were found in 39 cases: 22% in viscera, 42.5% in viscera and normal skin and 35% in cutaneous or mucocutaneous ulcers. All the Leishmania stocks isolated from dogs which came from Realengo, Bangu, Senador Camará (VL area), and from Campo Grande (VL + ACL area) were characterized as L. donovani (except in one case) according to their schizodeme, zymodeme and serodeme. The only stock characterized as L. b. braziliensis, was isolated from the lymph node of a dog from Campo Grande with visceral disease and without skin lesions. Antimony therapy attempted in eight Leishmania donovani positive dogs was unsuccessful.

Leishmanial antigens in the diagnosis of active lesions and ancient scars of American tegumentary leishmaniasis patients

Cutaneous biopsies (n = 94) obtained from 88 patients with American tegumentary leishmaniasis were studied by conventional and immunohistochemical techniques. Specimens were distributed as active lesions of cutaneous leishmaniasis (n = 53) (Group I), cicatricial lesions of cutaneous leishmaniasis (n = 35) (Group II) and suggestive scars of healed mucosal leishmaniasis patients (n = 6) (Group III). In addition, active cutaneous lesions of other etiology (n = 24) (Group C1) and cutaneous scars not related to leishmaniasis (n = 10) (Group C2) were also included in the protocol. Amastigotes in Group I biopsies were detected by routine histopathological exam (30.2%), imprint (28.2%), culture (43.4%), immunofluorescence (41.4%) and immunoperoxidase (58.5%) techniques; and by the five methods together (79.3%). In Group II, 5.7% of cultures were positive. Leishmanial antigen was also seen in the cytoplasm of macrophages and giant cells (cellular pattern), vessel walls (vascular pattern) and dermal nerves (neural pattern). Positive reaction was detected in 49 (92.5%), 20 (57%) and 4 (67%) biopsies of Groups I, II and III, respectively. Antigen persistency in cicatricial tissue may be related to immunoprotection or, on the contrary, to the development of late lesions. We suggest that the cellular, vascular and neural patterns could be applied in the immunodiagnosis of active and cicatricial lesions in which leishmaniasis is suspected.

Epidemiological aspects of toxoplasmosis in schoolchildren residing in localities with urban or rural characteristics within the city of Rio de Janeiro, Brazil

Immunofluorescence tests (IF) for toxoplasmosis were performed on a total of 608 schoolchildren in elementary and junior high grades. 166 being in the Bonsucesso district (an urban region of Rio de Janeiro) and 442 children from locations within the lowlands of Jacarepaguá (with rural characteristics). All the IF-IgM were nonreactive, whilst 416 schoolchildren (68.4%) were IF-IgG serum-reactive (greater than or equal to 1:16). The percentages of serum-reactives in Jacarepaguá were significantly higher than in Bonsucesso, both as regards the total number of schoolchildren (p less than 0.001), as also when subdivided according to the age-grades from six to eight years (p less than 0.001) or from twelve to fourteen (p less than 0.05). Both in Jacarepaguá and in Bonsucesso, the prevalence of reactions in the 12 to 14 year age-grade was significantly greater than in the 6 to 8 year age-grade (p less than 0.001 in both cases). Expressively larger prevalences of serum reactions were found in Jacarepaguá among schoolchildren who preferred eating raw or undercooked meat, as well as among those having cats as pets; this occurred equally in the 6 to 8 year and in the 12 to 14 year age-grades. In Bonsucesso, the only significant difference was in the 6 to 8 year age-grades that had cats as pets. Thus, it has been verified that the risk of infection is greater and more precocious in localities with rural characteristics than in urban regions.

Indirect immunofluorescence test in new world Leishmaniasis: serological and clinical relation-ship

The indirect immunofluorescence test (IF) for anti-Leishmania antibodies (IgG and IgM) was performed with sera from the following groups of individuals: 214 cutaneous leishmaniasis patients, 28 healthy subjects with positive Montenegros skin test (MST), 29 healthy subjects with negative MST and 16 visceral leishmaniasis patients. The first four groups came from a suburban area of Rio de Janeiro (Jacarepaguá) where cutaneous leishmaniasis caused by Leishmania braziliensis braziliensis is endemic. It was observed that IF-IgM titers were significantly higher amongst the cutaneous leishmaniasis patients with less than four months of disease as compared to those with longer periods and that IF-IgG titers were significantly higher in patients with multiple lesions as compared to those with single lesions. The visceral leishmaniasis patients had IF-IgG titers significantly higher than those from cutaneous leishmaniasis patients. A group of 28 individuals selected amongst the 214 cutaneous leishmaniasis patients had their IF-titers (IgG and IgM) compared to those of the two control groups of healthy subjects from the endemic area, respectively with positive and negative MST. Significantly higher titers of IF-IgG and IF-IgM were found in the group with active disease. The same group of patients showed IF-IgG titers significantly lower at the end of the antimonial therapy than those observed during this treatment.

Nitric oxide biosynthesis by Leishmania amazonensis promastigotes containing a high percentage of metacyclic forms

Due to the diversity of its physiological and pathophysiological functions and general ubiquity, the study of nitric oxide (NO) has become of great interest. In this work, it was demonstrated that Leishmania amazonensis promastigotes produces NO, a free radical synthesized from l-arginine by nitric oxide synthase (NOS). A soluble NOS was purified from L. amazonensis promastigotes by affinity chromatography (2′, 5′-ADP-agarose) and on SDS-PAGE the enzyme migrates as a single protein band of 116.2 (±6) kDa. Furthermore, the presence of a constitutive NOS was detected through indirect immunofluorescence using anti-cNOS and in NADPH consumption assays. The present work show that NO production, detected as nitrite in culture supernatant, is prominent in promastigotes preparations with high number of metacyclic forms, suggesting an association with the differentiation and the infectivity of the parasite.

Comparative analysis of the nitric oxide production by Leishmania sp.

The present report explores a comparative analysis of nitric oxide (NO·) production by three different species of Leishmania (L. amazonensis, L. braziliensis and L. chagasi). Among these species, L. braziliensis produced the highest amount of NO·, measured in the supernatants of promastigotes cultures as nitrite, a stable by-product derived from NO·. We have previously described the expression of a constitutive nitric oxide synthase (cNOS) in L. amazonensis promastigotes and axenic amastigotes. Comparing those results with the present work, using immunofluorescence assay, it was shown that both L. braziliensis and L. chagasi also express a cNOS. Immunostaining experiments showed that promastigotes from early passages of these species in culture had a strong immunoreactivity against anti-cNOS and anti-endothelial cell NOS, in comparison with the same parasite cultured for long time, suggesting a correlation between the NO· production and the presence of metacyclic forms prominent in those newly isolated parasites. These data corroborate findings of a higher NO· production by those parasites, following the growth curve. The relationship between the two NO·-generating systems in the parasite and in their host cell warrants further investigation. The presence of cNOS raises the possibility of a similar type of cross-talk or down-regulation between the NO· signaling systems in host cells and the lower eukaryotic-like Leishmania sp.

Montenegro skin tests for American cutaneous leishmaniasis carried out on school children in Rio de Janeiro, Brazil: An indicator of transmission risk

Montenegro skin tests were carried out in 1985 and 1987 on two groups of school children in the city of Rio de Janeiro. Group A consisted of 449 children residing in the Jacarepagua district, in areas where transmission of human and canine American cutaneous leishmaniasis (ACL) has been high; this group was considered to be the one at greatest risk of acquiring the infection through L. braziliensis. Group B consisted of 282 children from Bonsucesso, a suburb of Rio de Janeiro that is at a considerable distance from any area where ACL is endemic; this was a lowest risk group, and was thus used as a control. Analysis of the cutaneous test results showed that in Group A, 8.9% of the sample tested positive, whereas in Group B the result was only 2.1%. In group A there were no significant differences in the proportion of positives when analysed according to sex, age and the year when the tests were carried out. A study of the effects associated with place of residence together with other variables was carried out using log-linear regression analysis. It showed that effects arising from place of residence were maintained; that this was the only significant effect; and that it was independent of other variables. The testing of school children using the Montenegro intradermal test was shown to be a useful procedure in the characterization of localities in which there is a risk of ACL infection.

Leishmaniose visceral no Rio de Janeiro: 1 - Flebotomíneos da área de procedência de caso humano autóctone

An entomological survey was performed during the period of August to December, 1977 in Rio da Prata, region of Bangu, Rio de Janeiro. Manual insect capturing devices were utilized to study the peri-domiciliar area from 13 of 27 houses. The insects were captured mainly from 4 sites which were selected as being most productive. During 22 captures (73.3 hrs/person) 1585 sandflies were collected. They were identified as Lutzomya intermedia 828 (52.2%), Lutzomyia longipalpis 687 (43,1%), Lutzomyia migonei 57 (3.6%), Lutozmyia cortelezzii 5 (0.3%), Lutzomyia fischeri 5 (0.3%), Lutzomyia micropyga 3 (0.2%), Lutzomyi firmatoi 1 (0.1%), and Brumptomyia sp. 2 (0.2%). L. longipalpis were predominant at altitudes much higher than 100 merters either in chicken houses or piggeries. Most of them were collected form 6:00 to 9:00 pm, but occasionally were captured also from 3:00 to 5: pm. L. intermedia were predominant at altitudes much lower than 100 meters. They were captured more frequently in piggeries than in chicken houses, compared to L. longipalpis. The authors stress the necessity to implement control measures since there is a potential risk of visceral leishmaniasis transmission in areas near Rio de Janeiro city.

Clinical features of cutaneous and disseminated cutaneous leishmaniasis caused by Leishmania (Viannia) braziliensis in Paraty, Rio de Janeiro

Background  American tegumentary leishmaniasis (ATL) caused by Leishmania (Viannia) braziliensis is endemic in Rio de Janeiro State (RJ), where the disease shows epidemiologic and clinical characteristics distinct from those of ATL in other Brazilian regions. Paraty is the second most important endemic area in RJ; however, reports on leishmaniasis in this region refer to the occurrence of the disease without describing its characteristics.

Utilização da reação de imunofluorescência indireta no acompanhamento da terapêutica da leishmaniose tegumentar americana

Seventeen persons, from 2 to 78 years of age, with clinical, epidemiological,immunological and parasitological diagnosis of american tegumentary leishmaniasis, were studied. All came from the endemic area of Jacarepagua, a suburb of the city of Rio de Janeiro. The patients were treated with n-methylglucanine antimonate, using a dosage of 60 mg/kg/day, in three series of ten days duration each series, with intervals of ten days between each series, venous blood samples having been taken for the indirect immunefluorescent tests (IF-IgG) before, during and after medication. The seventeen individuals were reactive to the intradermal reaction of Montenegro (= 5 mm) and serum-reactive (= 1:45 mm) to the IF-IgG test; Leishmania b. braziliensis ssp was demonstrated or isolated in six cases (31.7%). Before treatment, the IF-IgG test showed positive in 76.4% of the cases (13 cases with titers = 1:90). The geometric averages of the reciprocal titer were as follows: before the first antimonial series (89,9); during treatment (63.6 to 29.3) and 10, 30 and 120 days after medication which revealed a clearly decreasing scale (14.9; 2.1 and 1.2), respectively. All lesions were healed upon termination of treatment, the scarring being most evident after the second series. Only 120 days after therapy were titers lower than 1:45 in all patients (16 cases - 94.1%). This suggests that, when the IF-IgG test is used as a control of cures, serological follow up is necessary during a minimum of three to four months.