The histopathology of cutaneous leishmaniasis due to Leishmania (Leishmania) mexicana in the Yucatan peninsula, Mexico

Localized Cutaneous Leishmaniasis (LCL) known as "chiclero's ulcer" in southeast Mexico, was described by SEIDELIN in 1912. Since then the sylvatic region of the Yucatan peninsula has been documented as an endemic focus of LCL. This study of 73 biopsies from parasitological confirmed lesions of LCL cases of Leishmania (Leishmania) mexicana infection was undertaken: 1) to examine host response at tissue level; and 2) to relate manifestations of this response to some characteristics of clinical presentation. Based on Magalhães' classification we found that the most common pattern in our LCL cases caused by L. (L.) mexicana was predominantly characterized by the presence of unorganized granuloma without necrosis, (43.8%). Another important finding to be highlighted is the fact that in 50/73 (68.5%) parasite identification was positive. There was direct relation between the size of the lesion and time of evolution (r s = 0.3079, p = 0.03), and inverse correlation between size of the lesion and abundance of amastigotes (r s = -0.2467, p = 0.03). In view of the complexity of clinical and histopathological findings, cell-mediated immune response of the disease related to clinical and histopathological features, as so genetic background should be studied.

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Comparison of small mammal prevalence of Leishmania (Leishmania) mexicana in five foci of cutaneous leishmaniasis in the State of Campeche, Mexico

Revista do Instituto de Medicina Tropical de São Paulo ◽

10.1590/s0036-46652009000200006 ◽

2009 ◽

Vol 51 (2) ◽

pp. 87-94 ◽

Cited By ~ 19

Author(s):

N.R. Van Wynsberghe ◽

S.B. Canto-Lara ◽

E.I. Sosa-Bibiano ◽

N.A. Rivero-Cárdenas ◽

F.J. Andrade-Narváez

Keyword(s):

Cutaneous Leishmaniasis ◽

Yucatan Peninsula ◽

The State ◽

Control Measures ◽

Effective Control ◽

Leishmania Mexicana ◽

Wild Rodents ◽

Terrestrial Mammals ◽

Yucatán Peninsula ◽

Reservoir Species

In the Yucatan Peninsula of Mexico, 95% of the human cases of Cutaneous Leishmaniasis are caused by Leishmania (Leishmania) mexicana with an incidence rate of 5.08 per 100,000 inhabitants. Transmission is limited to the winter months (November to March). One study on wild rodents has incriminated Ototylomys phyllotis and Peromyscus yucatanicus as primary reservoirs of L. (L.) mexicana in the focus of La Libertad, Campeche. In the present study, the prevalence of both infection and disease caused by L. (L.) mexicana in small terrestrial mammals were documented during five transmission seasons (1994-2004) in five foci of Leishmaniasis in the state of Campeche. Foci separated by only 100 km, with similar relative abundances of small mammals, were found to differ significantly in their prevalence of both symptoms and infection. Transmission rates and reservoir species seemed to change in space as well as in time which limited the implementation of effective control measures of the disease even in a small endemic area such as the south of the Yucatan Peninsula.

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