An outbreak of cutaneous leishmaniasis among soldiers in Belém, Pará State, Brazil, caused by Leishmania (Viannia) lindenbergi n. sp. A new leishmanial parasite of man in the Amazon region

In vitro infectivity of species of Leishmania (Viannia) responsible for American cutaneous leishmaniasis

There is little available information regarding the infectivity of New World Leishmania species, particularly those from the Amazonian Brazil, where there are six species of the subgenus Viannia causing American cutaneous leishmaniasis (ACL). The aim of this study was to compare, in vitro, the potential infectivity of the following Leishmania (Viannia) spp.: L. (V.) braziliensis from localized cutaneous leishmaniasis (LCL) and mucocutaneous leishmaniasis (MCL) patients, L. (V.) guyanensis, L. (V.) shawi, L. (V.) lainsoni and L. (V.) naiffi from LCL patients only, in cultured BALB/c mice peritoneal macrophage, as well as the production of NO by the infected cells. The infectivity of parasites was expressed by the infection index and, the nitric oxide (NO) production in the macrophage culture supernatant was measured by the Griess method. It was found that L. (V.) braziliensis from MCL, the more severe form of disease, showed the highest (p<or=0.05) infection index (397), as well as the lowest NO production (2.15 microM) compared with those of other species. In contrast, L. (V.) naiffi which is less pathogenic for the human showed the lowest infection index (301) and the highest NO production (4.11 microM). These results demonstrated a negative correlation between the infectivity and the ability of these parasites to escape from the microbicidal activity of the host cell.

The leishmaniases--survival and expansion in a changing world. A mini-review

The number of cases of visceral and cutaneous leishmaniasis is increasing globally at an alarming rate irrespective of the region and the leishmaniases are amongst the top emergent diseases in spite of control measures. In the present review attention is drawn to some of the reasons for this. The leishmaniases have expanded beyond their natural ecotopes due to the ecological chaos caused by man and this in turn affects the levels of his exposure to the vectors. Examples of how different phenomana (such as war, civilian migration, immuno-suppression caused by medication and viral infections, globalization of work and leisure and transmission outside endemic areas) contribute to the spread and increase of the disease are discussed.

Leishmaniose tegumentar americana em crianças: aspectos epidemiológicos de casos atendidos em Manaus, Amazonas, Brasil

No período entre janeiro a dezembro de 2005, foram avaliadas crianças de zero a 14 anos de idade com leishmaniose tegumentar americana, atendidas na Fundação de Medicina Tropical do Amazonas; registraram-se 147 casos; 55,78% do sexo masculino; 48,3% procediam do Município de Rio Preto da Eva; 76% procediam de duas estradas. Entre 90 (67,67%) pacientes, entrevistaram-se os responsáveis sobre a moradia na área de transmissão e os hábitos da criança. Desses, 58,89% residiam no local da provável infecção; 60% das crianças penetravam na mata acompanhando os pais; em 91,11% dos casos havia animais domésticos na moradia; 77,78% das residências localizavam-se até 100m de distância da mata; 76,67% pacientes tinham pelo menos um parente com história de leishmaniose tegumentar americana. O padrão de transmissão foi relacionado especialmente a atividades de manejo florestal ocorrendo próximas ao domicílio, habitações próximas à floresta primária, com a ocorrência de leishmaniose tegumentar americana em crianças pequenas, sugerindo transmissão no intra e no peridomicílio, em alguns casos, crianças penetrando na floresta.

Abundance of Lutzomyia longipalpis (Diptera: Psychodidae: Phlebotominae) and urban transmission of visceral leishmaniasis in Campo Grande, state of Mato Grosso do Sul, Brazil

The outspread and urbanization of visceral leishmaniasis (VL) in Campo Grande, state of Mato Grosso do Sul, lead us to undertake the present study over diversity and abundance of sand flies in the urban area to compare with previous search carried out during 1999/2000, before the identification of the disease in the human population. The captures were carried out with automatic light traps, weekly, from February 2004 to February 2005 on three sites including a forested area (Zé Pereira), two peridomicilies (shelters of domestic animals and cultivation areas), and intradomicilie. In the present study 110 collections were obtained during 13 months for 1320 h of collections, resulting in 5004 specimens, 3649 males and 1355 females belonging to the 20 following species: Brumptomyia avellari, Brumptomyia sp., Bichromomyia flaviscutellata, Evandromyia lenti, E. termitophila, E. cortelezzii, E. borrouli, Lutzomyia sp., L. longipalpis, Micropygomyia quinquefer, N. antunesi, N. whitmani, Pintomyia christenseni, Pi. damascenoi, Psathyromyia aragaoi, Ps. campograndensis, Ps. hermanlenti, Ps. shannoni, Pychodopygus claustrei, and Sciopemyia sordellii. L. longipalpis was the most abundant species in the anthropic environment with 92.22% of the captures. This shows an increase of sixty times in the density of L. longipalpis compared to the last sand fly evaluation in 1999/2000. The high density of L. longipalpis in Campo Grande is the main factor of risk in transmission of the disease to human in the urban area. The capture of N. antunesi, typical specie from Amazonian region, in Mato Grosso do Sul is reported for the first time.

[Epidemiology of tegumentary leishmaniasis in São João, Manaus, Amazonas, Brazil]

In Manaus, Amazonas State, Brazil, the degree of individual exposure to leishmaniasis is related to disorganized land occupation. In order to evaluate predisposing factors for an outbreak, confirm the parasitological diagnosis, treat patients, and assess etiological agents, reservoirs, and vectors, a 12-month study was conducted in Manaus in a community located along the BR-174 federal highway. Some 451 individuals were studied, among whom 17 cases of American tegumentary leishmaniasis (ATL) were diagnosed (six women and 11 men). Age varied from one to 64 years. Eleven patients had from one to three lesions. As for reservoirs, three opossums were captured. No hemoflagellates were found in the blood tests. Lutzomyia umbratilis was the predominant vector species captured. Many ATL patients were engaged in activities that exposed them to Leishmania vectors. Some patients may have been infected in the household and peridomiciliary environments. The epidemiological profile of ATL in this community is similar that of other foci in the region. This case series characterizes ATL as an endemic local public health problem.

Species diversity causing human cutaneous leishmaniasis in Rio Branco, state of Acre, Brazil

OBJECTIVE

Information on Leishmania species diversity in western Brazilian Amazon and the clinical picture of human cutaneous leishmaniasis it causes is scarce. We describe clinical findings, diagnostic procedures and identification of Leishmania species in patients from that region.

METHODS

The sample consisted of 50 patients, prospectively evaluated for epidemiological and clinical characteristics by means of a structured questionnaire. Conventional and molecular tools were applied to confirm the parasitological diagnosis and identify the species responsible for the disease.

RESULTS

Patients were predominantly male (76.5%) and living in rural areas. Median average age was 18 years and median average disease evolution was 8 weeks. For the diagnostic procedures of leishmanin skin test, direct visualization of amastigotes in dermal scrapings and parasite culture of aspirates of the ulcer border were positive for 98%, 52% and 34%, respectively. Molecular methods applied to DNA extracted from skin biopsies of the 50 patients yielded 100%, 82% and 44% positivity by PCR minicircle kDNA, PCR-RFLP ITS1rDNA and PCR-glucose-6-phosphate (G6P), respectively. Fourteen samples from 13 patients were successfully isolated and identified. Multilocus enzyme electrophoresis, PCR-RFLP ITS1rDNA and PCR-G6P permitted identification of the Leishmania species responsible for the aetiology of American tegumentary leishmaniasis in 60% of the examined patients: 16 Leishmania (Viannia) braziliensis, 12 Leishmania (Viannia) lainsoni, 1 Leishmania (Viannia) guyanensis and 1 putative hybrid of Leishmania (Viannia) naiffi and L. (V.) lainsoni.

CONCLUSION

The clinical and epidemiological behaviour of cutaneous leishmaniasis in Acre, Brazil, is similar to other Amazon scenarios previously described; however Acre's complex parasite diversity may be contributed to the concomitant circulation of at least three distinct Leishmania species. The implementation of control interventions in the studied area must take into consideration the possibility of various expected phlebotomine vectors and reservoirs.

Leishmania (Viannia) braziliensis is the prevalent species infecting patients with tegumentary leishmaniasis from Mato Grosso State, Brazil

The frequency of Leishmania (Viannia) braziliensis infection among patients of Mato Grosso, Brazil was estimated by polymerase chain reaction-PCR, DNA hybridization and by isoenzyme electrophoresis. Analysis of DNA polymorphism was carried out using random amplified polymorphic DNA-PCR (RAPDPCR) with five different primers. The patients were attended from May 1997 to February 1998 at the Reference Ambulatory for American Tegumentary Leishmaniasis at Júlio Müller University Hospital of the Federal University of Mato Grosso, Brazil. In a first screening by PCR and DNA hybridization 94.1% of 68 patients, from whom parasites were isolated in culture medium, were found to be infected with species of the Le. braziliensis complex. Only four patients (5.9%) were infected with species of Le. mexicana complex. Thirty-three samples of Le. braziliensis complex and three of Le. mexicana complex were typed by isoenzyme analysis as Le. (V.) braziliensis sensu stricto and Le. (Leishmania) amazonensis, respectively. The predominant species was Le. (V.) braziliensis, although most of the patients of this study came from the northern area of Mato Grosso, which is part of the Amazonian region of Brazil, where other known species of both subgenus Viannia (Le. braziliensis complex) and Leishmania (Le. mexicana complex) are present. The results of RAPD showed higher genetic variability among the Le. (V.) braziliensis samples from Mato Grosso. The importance of these results concerning the taxonomic status of New World Leishmania, and their implications for both clinical and epidemiological data is discussed.

Épidémie de leishmaniose cutanée chez des militaires de retour de mission en Guyane

BACKGROUND

An outbreak of cutaneous leishmaniasis occurred among 71 soldiers who had participated in various missions during a 4-month's period in French Guiana. The aims of this study were (i) to describe outbreak and (ii) to determine risk factors of cutaneous leishmaniasis.

METHODS

All patients were hospitalised. Cutaneous lesions were biopsied and cultured for species identification. Individual information was collected by a physician or a nurse, using on a standardised, anonymous chart. Data were processed with EpiInfo 6.04 and SAS.

RESULTS

Mean age of the 71 soldiers was about 25.9 years (19-37 years). Twelve soldiers presented 56 lesions due to Leishmania (Viannia) guyanensis (attack rate = 16.9 for 100). Among 56 lesions, 13 lesions were localized on the trunk, usually an unexposed body area. Logistic regression highlighted military exercises in the forest during a high risk period of leishmaniasis transmission (OR = 11.2; p < 0.01), and the young age (OR = 1.33; p = 0.04). Vector control measures were not statistically significant.

CONCLUSION

Military authorities should restrict deep forest activities during periods of high risk transmission. Vector control measures are essential. Officers should motivate their soldiers and supervise vector control measures. As ecotourism is developing, tourists as well as workers staying in deep forest must be informed of the risk and about vector control measures.

PCR-based diagnosis for detection of Leishmania in skin and blood of rodents from an endemic area of cutaneous and visceral leishmaniasis in Brazil

The technique of polymerase chain reaction (PCR) associated to hybridization was used to screen 123 samples collected from wild and synanthropic rodents captured in a cutaneous and visceral leishmaniasis endemic area in the State of Minas Gerais, Brazil. The detection of Leishmania spp in naturally infected rodents is of fundamental importance for incriminating them as possible reservoir hosts of the diseases in Minas Gerais. A total of 62 specimens belonging to wild (Thrichomys apereoides, Oryzomys subflavus, Galea spixii, Bolomys lasiurus and Wiedomys pyrrhorhinos) and synanthropic (R. rattus) rodent species were captured in different ecotopes. Blood and skin samples were submitted for PCR analyses followed by molecular hybridization with specific probes for the three Leishmania-species complexes. Fifteen samples were found positive after PCR-hybridization and identified as follows: nine belonging to the L. mexicana complex, three to the L. braziliensis complex and three to the L. donovani complex. Positive PCR results were found in 11 out of the 61 (18%) blood samples and in four out of the 62 (6.4%) skin fragments screened. R. rattus and T. apereoides were the most abundant species in the area also presenting high prevalence of natural infection. The presence of parasite DNA belonging to L. braziliensis, L. mexicana and L. donovani complexes was confirmed in several individuals of a rodent species, R. rattus. This work is the first report of the detection of L. (L.) chagasi in a naturally infected T. apereoides. The utility of filter paper as a substrate for PCR analyses and the efficacy of the procedure associated to the hybridization is emphasized.

Feline leishmaniasis due to Leishmania (Leishmania) amazonensis in Mato Grosso do Sul State, Brazil

A case of leishmaniasis in a domestic cat (Felis domesticus) is described. The animal showed a single, nodular lesion on the nose and many nodules of different size on the ears and digital regions of all the paws. Diagnosis was made by microscopic detection of amastigotes in Giemsa-stained smears from the lesions. By monoclonal antibodies the aetiological agent was identified as Leishmania (Leishmania) amazonensis, one of the seven species implicated in human leishmaniasis in Brazil. The clinical signs in feline leishmaniasis are unspecific and similar to those observed in other diseases such as cryptococcosis and in sporotrichosis, commonly found in cats. Leishmaniasis should therefore, be added to the differential diagnosis by feline veterinary practitioners and adequate investigations should carried out for dermal leishmaniasis in the area where the feline infection is detected.

Clinical and immunopathological spectrum of American cutaneous leishmaniasis with special reference to the disease in Amazonian Brazil: a review

The wide variety of Leishmania species responsible for human American cutaneous leishmaniasis combined with the immune mechanisms of the host results in a large spectrum of clinical, histopathological, and immunopathological manifestations. At the middle of this spectrum are the most frequent cases of localized cutaneous leishmaniasis (LCL) caused by members of the subgenera Leishmania and Viannia, which respond well to conventional therapy. The two pathogenicity extremes of the spectrum generally recognized are represented at the hypersensitivity pole by mucocutaneous leishmaniasis (MCL) and at the hyposensitivity pole by anergic diffuse cutaneous leishmaniasis (ADCL). Following the present study on the clinical, histopathological and immunopathological features of cutaneous leishmaniasis in Amazonian Brazil, we propose the use of the term "borderline disseminated cutaneous leishmaniasis" for the disseminated form of the disease, due to parasites of the subgenera Leishmania and Viannia, which might be regarded as intermediate between LCL and the extreme pathogenicity poles MCL and ADCL.

Characterization of the species- and stage-specificity of two monoclonal antibodies against Leishmania amazonensis

Leishmania metacyclogenesis is associated with changes in morphology, gene expression, and structural alterations of the lipophosphoglycan (LPG), the promastigote most abundant surface glycolipid. Purification of metacyclics is accomplished using lectins or monoclonal antibodies (MAbs) that exploit stage-specific differences in the LPG. Besides, LPG displays extensive interspecies polymorphisms and is synthesized by promastigotes of all species investigated to date. In this work we studied the species- and stage-specificity of two MAbs (3A1-La and LuCa-D5) used to purify metacyclics of Leishmania amazonensis. Their ability to recognize different members of the Trypanosomatidae family was tested by direct agglutination, indirect immunofluorescence, and dot-blot analysis of LPG. We found that both MAbs were highly selective for L. amazonensis: 3A1-La recognized only promastigotes and LuCa-D5 labeled amastigote and promastigote stages of this species. These MAbs might be useful for Leishmania typing.