E & D Services supports Center of Disease Control's mission to research Leishmaniasis

Online, October 29, 2009 (Newswire.com) - Leishmaniasis accounts for ≈2 million disability-adjusted life years in ≈90 countries, most of which are in the developing world (1). The past 3 decades have witnessed accumulation of much knowledge about the host-parasite relationship, especially about host immune responses against Leishmania spp. The focus on immunity reflects in part the central role played by the immune system for pathogenesis of leishmaniasis (2,3) and the need for appropriate prophylaxis against this heterogeneous group of diseases that remain uncontrolled and are increasing in prevalence and incidence (4,5). Therefore, better understanding and control of this disease demand additional approaches, especially investigations that focus on the parasite, the host environment, and their relationship to clinical outcomes.

E & D Services met with scientific researchers to discuss the possible differences in the geographic distribution of certain distinct clinical forms in an effort to help better understand business plans of this type of arena.

Differences in geographic distribution of distinct clinical forms of American tegumentary leishmaniasis (ATL) have long been recognized in Andean countries in South America. To a large extent, this phenomenon seems to be determined by the prevalence of various Leishmania spp. in diverse environments. For example, in Ecuador and Peru, the highlands harbor almost exclusively localized cutaneous leishmaniasis (CL) cases caused by several Leishmania spp., whereas mucosal leishmaniasis (ML) is mostly limited to the Amazon rain forest and caused by L. braziliensis (6,7). Conversely, observations such as those in the Peruvian lowlands, where L. braziliensis causes CL throughout the country but ML is almost exclusively found in Amazonian provinces (7), lend support to the hypothesis that strain variability within a species may influence the form and distribution of ATL. To understand whether geographic segregation of ATL outcomes occurs within a more confined geographic space (foci of ATL transmission), we compared how cases of ML and disseminated leishmaniasis (DL) were distributed during 1999-2003 in Corte de Pedra in northestern Brazil, where active transmission of parasites from a complex population of L. braziliensis to humans occurs.

E & D Services has been focusing on the area of Brazil and more specifically the Corte de Pedra, where it is believed that business plan development could have the most benefit for solilcited clientele.

Corte de Pedra is composed of 20 municipalities in a rural area previously dominated by the Atlantic rain forest. Lutzomyia (Nyssomyia) whitmany and Lu. (Nyssomyia) intermedia sandflies that transmit L. braziliensis are endemic in the local fauna. This biome had not undergone any major changes during the period of the study. Residents in this area work mostly in agriculture, often in primary or secondary forests. There is little population migration in or out of this region. Study participants' mean time of residence at their addresses at the time of diagnosis and parasite sampling was 17 years; >90% of the study participants lived on farms.
Disease Definitions

CL was defined as a disease with 10 nodular, acneiform, or ulcerative lesions spread over the skin of >2 body areas. ML was defined as a disease with metastatic mucosal lesions affecting the nose, palate, pharynx, or larynx and not contiguous with primary cutaneous lesions. Patients who simultaneously satisfied the definitions for ML and DL were classified as patients with DL showing mucosal involvement (MDL). This classification distinguishes these patients from those with classic ML, which usually shows skin involvement compatible with CL. All patients had their diagnosis confirmed by detection of parasites in culture aspirates or by histopathologic analysis, and a delayed-type hypersensitivity reaction.

E & D Services reviewed the studies conducted by the researchers and analyzed their findings on geographic comparisons on the participants within the ATL.

For geographic comparisons of disease distribution, participants with ATL were classified according to disease definitions into 3 groups: 30 patients with ML, 30 with DL, and 17 with MDL. Diagnoses were made during 1999-2003 in Corte de Pedra. Geographic coordinates of residence sites of these ATL patients were obtained by using a Brunton Multi-Navigator global positioning system apparatus (Brunton Company, Riverton, WY, USA), which has a range precision of 15 m. To characterize dynamics of DL spread within Corte de Pedra, we mapped the residences of 66 patients with DL with or without mucosal involvement. These patients received a diagnosis during 1993-2002 and represented ≈50% of all DL and MDL patients who came to the health post in Corte de Pedra during that period.

We analyzed clinical records of 102 patients with DL and 6,297 patients with ATL in the health post during 1993-2003. We also used geographic coordinates for another group of 21 patients (9 with L. braziliensis clade C isolates and 12 with clade A plus D isolates) whose isolated parasites had been used to define clades (i.e., subpopulations) of L. braziliensis genotypes circulating in Corte de Pedra, as determined by random amplified polymorphic DNA analysis (8). All ATL case-patients in this study were self-referred and diagnosed in 1 health post that treats ≈70% of patients with leishmaniasis in the region.
Geographic Distribution of Patients with ATL

High-resolution distribution of ATL cases was determined by acquisition of geographic coordinates of likely places of disease transmission by a global positioning system. Because leishmaniasis is believed to be transmitted mostly within plantations, where residents of the region live and work, patient residences were used as reference points for standardization purposes. Collected data were statistically compared as described below and plotted for visual inspection onto a high-definition satellite photograph of Corte de Pedra (ENGESAT, Curitiba, Brazil) by using ArcInfo version 8.3 software (Environmental Systems Research Institute Inc., Redlands, CA, USA).

E & D Services has affirmed its steadfast commitment to help solve these problems and others like it by offering business development options for principals seeking to benefit the cause.