Edna Aoba Yassui Ishikawa

The dermal leishmaniases of Brazil, with special reference to the eco-epidemiology of the disease in Amazonia

Six species of Leishmania are at present known to cause cutaneous and/or mucocutaneous leishmaniasis in Brazil, and they are all to be found in the Amazon region of this country. The eco-epidemiology of each is discussed, with the observation that the Amazonian leishmaniases are all zoonoses, with their source in silvatic mammals and phlebotomine sandfly vectors. With mans destruction of the natural forest in southern Brazil, some sandfly species have survived by adapting to a peridomestic or domiciliary habitat in rural areas. Some domestic animals, such as dogs and equines are seemingly now involved in the epidemiology of the disease. No such process has yet been reported in the Amazon region, but may well take place with the continuing devastation of its forest.

Species diversity of Leishmania (Viannia) parasites circulating in an endemic area for cutaneous leishmaniasis located in the Atlantic rainforest region of northeastern Brazil.

Objectives  To identify the aetiological agents of cutaneous leishmaniasis and to investigate the genetic polymorphism of Leishmania (Viannia) parasites circulating in an area with endemic cutaneous leishmaniasis (CL) in the Atlantic rainforest region of northeastern Brazil.

Cutaneous leishmaniasis due to Leishmania (Leishmania) amazonensis in Amazonian Brazil, and the significance of a negative Montenegro skin-test in human infections

The clinical and epidemiological features of 62 cases of cutaneous leishmaniasis due to Leishmania (Leishmania) amazonensis, from Pará State, Amazonian Brazil, are discussed. The parasite, isolated in hamster skin and/or blood-agar culture medium, was in each case identified by both biological characteristics and a monoclonal antibody specific for promastigotes of L. (L.) amazonensis. Of the 62 patients, 46 (74.2%) presented with a single cutaneous lesion, and on no occasion was evidence found indicating metastatic spread to either the naso-pharyngeal mucosae or the viscera. Recent claims that this parasite may be responsible for both mucocutaneous leishmaniasis and typical visceral leishmaniasis are discussed. Meglumine antimoniate (Glucantime) proved highly efficient in the treatment of all patients. Of the 62 patients examined by the Montenegro skin test, only 32 (51.6%) gave a positive reaction. The significance of this finding is considered and the hypothesis made that the parasite itself may induce an immunoinhibition. Field studies amply confirmed the role of Lutzomyia flaviscutellata as the major sandfly vector of L. (L.) amazonensis in Amazonia.

Psychodopygus complexus, a new vector of Leishmania braziliensis to humans in Pará State, Brazil

This paper reports the finding of 4 specimens of Psychodopygus complexus, captured in the Paragominas region of Pará State, Brazil, naturally infected with trypanosomatids that were positively identified as Leishmania (Viannia) braziliensis. Attention is drawn to the importance of this species as a vector since it is highly anthropophilic and has a very extensive geographical distribution in the lower Amazon region of Pará State south of the Amazon river, including the island of Marajó.

Leishmaniose tegumentar americana humana e canina no Município de Mariluz, Estado do Paraná, Brasil

An outbreak of American cutaneous leishmaniasis was reported in 2002 in Mariluz, northwestern Paraná State, Brazil. Of 38 humans who were investigated, four had healed lesions, ten showed lesions in the healing process, and 24 had active lesions. Of the 126 dogs, 20 (15.9%) presented suggestive lesions and 24 (19%) had positive serology. Parasites isolated from two patients and three dogs were identified as Leishmania (Viannia) braziliensis serodeme I. The captured sand flies were identified as Nyssomyia whitmani, N. neivai, and Migonemyia migonei. Considering that the region where the cases occurred is similar to other old human settlements in Paraná State, the environmental alterations and remaining forests facilitate the maintenance of the parasites enzootic cycle and transmission to humans and domestic animals, thereby maintaining the endemicity of American cutaneous leishmaniasis.

Clinical aspects of envenomation caused by Tityus obscurus (Gervais, 1843) in two distinct regions of Pará state, Brazilian Amazon basin: a prospective case series

BackgroundScorpion envenomations are a major public health problem in Brazil, whose most dangerous cases are attributable to the genus Tityus. This study was designed to compare the clinical and demographic features of envenomations by Tityus obscurus in two areas of the state of Pará located in the Amazon basin.Were compared demographic findings, local and systemic signs and symptoms of human envenomations caused by T. obscurus that occurred in western and eastern areas of the state.ResultsForty-eight patients with confirmed envenomation by T. obscurus were evaluated from January 2008 to July 2011. Most of them came from the eastern region, where male and female patients were present in similar numbers, while males predominated in the west. Median age groups were also similar in both areas. Most scorpion stings took place during the day and occurred significantly more frequently on the upper limbs. The time between the sting and admission to the health center was less than three hours in both areas. Most eastern patients had local manifestations while in the west, systemic manifestations predominated. Local symptoms were similar in both areas, but systemic signs and symptoms were more common in the west. Symptoms frequently observed at the sting site were local and radiating pain, paresthesia, edema, erythema, sweating, piloerection and burning. The systemic manifestations were significantly higher in patients from the west. Futhermore, neurological symptoms such as general paresthesia, ataxia, dysarthria, myoclonus, dysmetria, and electric shock-like sensations throughout the body were reported only by patients from the west.ConclusionThe present study shows that two regions of Para state differ in the clinical manifestations and severity of confirmed envenomation by T. obscurus which suggests a toxicity variation resulting from the diversity of T. obscurus venom in different areas of the Brazilian Amazon basin, and that T. serrulatus antivenom can be successfully used against T. obscurus.

American visceral leishmaniasis: wild animal hosts

In Colombia it has been suggested that the rodent Proechimys canicollis may be a reservoir-host of Leishmania (L.) chagasi, the cause of American visceral leishmaniasis, based on polymerase chain reaction/hybridization tests. We have detected no infection in laboratory-bred specimens of another species, P. guyannensis, after their inoculation with promastigotes or amastigotes of this parasite from Amazonian Brazil.

Geographical distribution of neotropical Leishmania of the subgenus Leishmania analysed by ribosomal oligonucleotide probes.

In the Americas, Leishmania (Leishmania) amazonensis is one of the most widely distributed species associated with both cutaneous leishmaniasis and anergic diffuse cutaneous leishmaniasis (ADCL) (SHAW & LAINSON, 1987). Another neotropical species of this subgenus, classically associated with chiclero’s ulcer and also ADCL is L. (L.) mexicana. The latter is considered to be confined to Central and North America. However, in the same area, other leishmania belonging to the subgenus Leishmania, such as L. (L.) venezuelensis and L. (L.) pifanoi, have been described from cases of cutaneous leishganiasis, as well as some isolates presumpively identified as L. CL.1 mexicana (GRIMALDI et al.. 1989). The major l&o’wn reservdirs of these Lkshmakia species are small sylvatic rodents. The proven vectors so far all belong to theflaviscutellata series but the species varies regionally. The main vector of L. (L.) amazonensis is Lutzomyiaflaviscutellata and that of L. (L.) mexicana is Lu. olmeca. Sand flies of other groups are, however, suspected vectors in places such as Texas, USA, and the Dominican Republic (YOUNG & DUNCAN, 1994). The understanding of the eco-epidemiology of this important group of Leishmania is hindered by the limited number of available markers for identification of isolates from hitherto unstudied areas. The description of DNA sequences useful in both identification and taxonomy is opening new windows in studies on leishmaniasis (GRIMALDI & TESH, 1993). In a previous paper we described a coupled PCRhybridization assay, where a set of oligo&cleotides, derived from the small subunit ribosomal RNA (SSU rRNA) sequence, provided the means for distinguiihing 4 groups of leishmania: (i) L. (L.) amazonensis, (ii) L. (L.) mexicana, (iii) L. (L.) chagasi, and (iv) all named species ofthe subgenus Viannia (ULIANA et aZ., 1994). At that time, 2 strains of L. (L.) mexicana did not follow the hybridization pattern of the reference strain, having profiles similar to L. (L.) amazonensis. In this paper, we examined a greater number of L. (L.) mexicana and L. (L.) amazonensis strains, isolated from broadly distributed geographical areas, as well as some reference strains of Leishmania species. Tissue samples from experimentally infected hamsters and mammal reservoirs captured in the Amazon region were also tested. The Leishmania strains used are listed in Tables 1 and 2. The parasites are from the Leishmaniu Bank of the Instituto Evandro Chagas in BelCm (Pa& Brazil) and were typed with a panel of 24 monoclonal antibodies

Familial Transmission of Human T-cell Lymphotrophic Virus: Silent Dissemination of an Emerging but Neglected Infection

Background HTLV-1 is a retrovirus that causes lymphoproliferative disorders and inflammatory and degenerative diseases of the central nervous system in humans. The prevalence of this infection is high in parts of Brazil and there is a general lack of public health care programs. As a consequence, official data on the transmission routes of this virus are scarce. Objective To demonstrate familial aggregation of HTLV infections in the metropolitan region of Belém, Pará, Brazil. Method A cross-sectional study involving 85 HTLV carriers treated at an outpatient clinic and other family members. The subjects were tested by ELISA and molecular methods between February 2007 and December 2010. Results The prevalence of HTLV was 43.5% (37/85) for families and 25.6% (58/227) for the family members tested (95% CI: 1.33 to 3.79, P = 0.0033). Sexual and vertical transmission was likely in 38.3% (23/60) and 20.4% (29/142) of pairs, respectively (95% CI: 1.25 to 4.69, P = 0.0130). Positivity was 51.3% (20/39) and 14.3% (3/21) in wives and husbands, respectively (95% CI: 0.04 to 0.63, P = 0.0057). By age group, seropositivity was 8.0% (7/88) in subjects <30 years of age and 36.7% (51/139) in those of over 30 years (95% CI: 0.06 to 0.34, P<0.0001). Positivity was 24.1% (7/29) in the children of patients infected with HTLV-2, as against only 5.8% (4/69) of those infected with HTLV-1 (95% CI: 0.05 to 0.72, P = 0.0143). Conclusion The results of this study indicate the existence of familial aggregations of HTLV characterized by a higher prevalence of infection among wives and subjects older than 30 years. Horizontal transmission between spouses was more frequent than vertical transmission. The higher rate of infection in children of HTLV-2 carriers suggests an increase in the prevalence of this virus type in the metropolitan region of Belém.

Fauna flebotomínica da Serra dos Carajás, Estado do Pará, Brasil, e sua possível implicação na transmissão da leishmaniose tegumentar americana

Serra dos Carajas, located in the southeast of Para State, Brazil, is a rich tropical forest where species of Leishmania sp. of medical interest are found, such as Leishmania (V.) braziliensis, L. (V.) lainsoni, L. (V.) shawi and L. (L.) amazonensis. They are transmitted by the following phlebotomi: Psychodopygus complexus or Ps. wellcomei, Lutzomyia ubiquitalis, Lu. whitmani and Lu. flaviscutellata. Considering the increase of immigrants in the region of the Carajas project, this study aimed to assess the Phlebotominae fauna and their possible participation in the transmission of American cutaneous leishmaniasis (ACL). The phlebotomi were captured from December 2005 to September 2007 at the following locations: i) Parauapebas Botanical Park; ii) an environmental protection area; and iii) Tapirape-Aquiri National Forest. During the 172 days of collection, 10 CDC (18 h to 6 h) and 2 Shannon (18 h to 20 h) light traps were used. Of the 22,095 phlebotomi captured, 6,789 (31%) were male and 15,306 (69%) were female, and they belonged to 69 species and three genera, including Psychodopygus, Lutzomyia and Brumptomyia. A total of 19 (0.16%) natural infections of the following species were detected: Ps. davisi (4), Ps. h. hirsutus (3), Lu. umbratilis (3), Lu. richardward (2), Lu. brachipyga (2), Lu. ubiquitalis (2), Lu. trinidadensis (1) and Lu. migonei (1). Although no infection was found in Ps. wellcomei/complexus, the main vector of L. (V.) braziliensis in the region, this species was the most prevalent (16%), followed by Ps. davisi (15.4%), Ps. carrerai (4.2%), Lu. shawi (3.9%), Lu. brachipyga (2.5%) and Lu. richardward (1.2%). These results show the importance of these phlebotomi as possible vectors of ACL in Serra dos Carajas.