Reservoir Host Of Cutaneous Leishmaniasis Research Articles

Genetic Identification of Meriones spp. The Reservoir Host of Cutaneous Leishmaniasis in the North Western Region of Libya

The identification and classification of reservoir hosts of zoonotic cutaneous leishmaniasis are very crucial towards the integrated management and control planning. Molecular techniques have been deployed and showed very sensitive and specific results to identify and differentiate rodents with great similarity in phenotypes including Meriones spp. Meriones species are very difficult to distinguish and separate according to their morphology and phenotype traits. This study was carried out in western region of Libya and three Meriones rodents were collected and their genetic identification was conducted by PCR technique using designed forward and reverse primers from Meriones spp. cytochrome b (cytb) gene sequence. This study has differentiated three haplotypes of M. shawi. with sequences similarities between samples of haplotypes were 99.13%, 99.42% and 99.71% between H1 and H2, between H1 and H3 and between H2 and H3 respectively. The current work is the first to use molecular techniques to study the genetic sequence of Meriones in Libya and has illustrated that PCR technique is powerful tool to discriminate Meriones species in western region of Libya.

A Feasibility Study on Using the Facilities of Health Centers for Developing a Laboratory Network on Vectors and Reservoir Hosts of Cutaneous Leishmaniasis in Iran.

Cutaneous leishmaniasis is an ancient endemic disease in Iran and continues to be a growing health threat to community development and the environment. This paper explains how to use the facilities of health centers for developing a laboratory network on vectors and reservoir hosts of cutaneous leishmaniasis in Iran. A literature search was performed of the relevant multiple databases to include studies on vectors and reservoirs of cutaneous leishmaniasis in Iran. A team of experienced experts was performed. After holding several meetings, field visits and organizing workshops, the activities of laboratories were determined at three levels. Entomological studies showed that 5 species of the genus Phlebotomus and 10 species of the genus Sergentomyia are active in the south, 4 species of the genus Phlebotomus and one species of the genus Sergentomyia in the central part and 5 species of the genus Phlebotomus and 2 species of the genus Sergentomyia in the north east. Reservoir hosts were identified in the study areas. The tasks of laboratories were regulated at different levels. The Iranian Ministry of Health and Medical Education should prioritize the employment of capable persons in the field of Medical Entomology and Vector Control. The survival of this laboratory network depends on hiring and employing interested and persistent people. The universities of Medical Sciences that have the facilities to set up this network will be a very effective partner in the control of the disease in high risk areas. The results can be used in neighboring countries.

Shelter availability and human attitudes as drivers of rock hyrax (Procavia capensis) expansion along a rural-urban gradient.

While anthropogenic land‐use changes threaten wildlife globally, some species take advantage of such changes and disperse into urban areas. The wildlife in urban areas often promotes conflicts with humans, notably when the animals are associated with the spread of zoonotic diseases. In Israel, current urban invasion of rock hyraxes (Procavia capensis) draws public attention, since the species is a reservoir host of cutaneous leishmaniasis, a serious skin disease. The rock hyrax, however, has seldom been studied in densely populated areas, and the drivers for its urban expansion, as well as its abilities to live and spread in core urban areas, are relatively unknown. Here, we explore the rock hyrax expansion to urban areas process by examining the availability, characteristics and use of shelter along an urban gradient. Our findings suggest that a series of factors determines shelter availability and quality for the rock hyrax, which facilitates its dispersion across the urban gradient. We found that rock hyraxes from the Judean Desert expand to the peri‐urban region of Jerusalem by colonizing new rocky shelters formed as by‐products of urban development. With their populations reaching extreme densities in this area and saturating the available shelters, there is some spill over to the adjacent core urban areas where they colonize littered sites, which are made available due to the local socio‐economic conditions and cultural norms of waste disposal and illegal placement of temporary structures. Our work emphasizes the significance of the urban gradient approach for studying the mechanisms promoting wildlife expansion to cities. Our findings suggest that changes in shelter availability and quality due to urban development, and cultural norms promote shifts of the hyrax population by pushing from the already established areas and pulling into new environment across the urban gradient.

A spatially explicit agent-based simulation model of a reservoir host of cutaneous leishmaniasis, Rhombomys opimus

Rhombomys opimus (R. opimus), a social rodent, is the main reservoir host for zoonotic cutaneous leishmaniasis (ZCL) in most parts of the Middle East and central Asia. The difficulties in monitoring rodent population patterns have hindered the effective application of preventive measures of ZCL. This study presents a spatially explicit agent-based simulation model of R. opimus behaviors that is integrated with Geographic Automata System (GAS) and a heuristic optimization method, cuckoo search (CS). The model is used to explore the relationships among rodent population dynamics, ZCL incidence and authority interventions using statistical data generated from simulated rodent societies rather than observational data, which are difficult to obtain through field surveys. The model simulation considers three agent types: rodents, colonies and cell agents. The model components and overall approach are calibrated, investigated with sensitivity analysis and validated with empirical field data in a ZCL-endemic area in Isfahan, central Iran. The results suggest that unsupervised and sporadic preventive measures could cause rodent emigration towards human population centers and start new waves of infections.

Isolation and Identification of Leishmania Species From Sandflies and Rodents Collected From Roffaye District, Khuzestan Province, Southwest of Iran.

Background: Leishmaniais which is one of the six most important tropical diseases in the world are in Iran in 3 forms. Cutaneous leishmaniasis (CL) is endemic in Iran, however, Zoonotic Cutaneous Leishmaniasis (ZCL) is endemic in Khuzestan province. Objectives: This study aimed to determine the species of Leishmania in vector and reservoir hosts of cutaneous leishmaniasis based on molecular methods in Roffaye District, Khuzestan, Iran. Materials and Methods: In this study sand flies were collected from indoors and outdoors using sticky traps and rodents using Sherman live traps. They were both subjected to the nested PCR method to detect Leishmania parasite. Results: Phlebotomus papatasi was the most common species of sandflies in outdoor and indoor resting places and Tatera indica (Indian gerbil) was the most common species among rodents. PCR technique showed that only 2 out of the 27 P. papatasi (7.4%) and1 of the Tatera indica out of 12 rodents (8.3%) were positive for parasite due Leishmania major. The trapped Alactaga sp. were not infected by L. major. Conclusions: This is the first molecular report on parasite infection of both vector (P. papatas) and reservoir (T. indica) to L. major from this area. Therefore, the population of both sandflies and rodents should be reduced using control methods.

Phlebotomus papatasi and Meriones libycus as the vector and reservoir host of cutaneous leishmaniasis in Qomrood District, Qom Province, central Iran

Objective To determine the sand flies species responsible for most transmission of Leishmania major (L. major) to human, as well as to determine the main reservoir hosts of the disease. Methods Sand flies were collected using sticky papers and mounted in Puri's medium for species identification. Rodents were trapped by live Sherman traps. Both sand flies and rodents were subjected to molecular methods for detection of leishmanial parasite. Results Phlebotomus papatasi (P. papatasi) was the common species in outdoor and indoor resting places. Employing PCR technique only three specimens of 150 P. papatasi (2%) were found naturally infected by parasites with a band of 350 bp which is equal to the L. major parasite. Forty six rodents were captured by Sherman traps and identified. Microscopic investigation on blood smear of the animals for amastigote parasites revealed 1 (3.22%) infected Meriones libycus (M. libycus). Infection of this animal to L. major was confirmed by PCR against rDNA loci of the parasite. Conclusions This is the first molecular report of parasite infection of both vector (P. papatasi) and reservoir (M. libycus) to L. major in the region. The results indicated that P. papatasi was the primary vector of the disease and circulating the parasite between human and reservoirs and M. libycus was the most important host reservoir for maintenance of the parasite source in the area.

The spatio‐temporal distribution of a rodent reservoir host of cutaneous leishmaniasis

Summary 1. The rodent Psammomys obesus is the main reservoir host for Leishmania major, the causative agent of cutaneous leishmaniasis in Tunisia, much of North Africa and mid‐western Asia. An understanding of the population dynamics of this rodent is essential to establish a preventive control strategy based on the early prediction of rodent outbreaks. 2. The study of P. obesus dynamics at a regional scale requires index‐based sampling. Rodent numbers were monitored twice per year at the beginning and end of the breeding season, using transects around the Sidi Bouzid region in central Tunisia. 3. Two different types of dynamics occurred in two drainage basins. Rodents living in the northern basin were at low density and those living in the southern basin were at high density. 4. At the scale of a plot, occupied burrows were generally associated with the presence of three Chenopodiaceae: Arthrocnemum glaucum, Salsola tetrandra and Suæda fruticosa, rarely in monospecific formations. However, in dry periods, occupied burrows drifted to A. glaucum formation linked with high moisture and salinity of the soil (χ2 MacNemar = 6·26). 5. The risk of a P. obesus outbreak can be assessed by a simultaneous knowledge of flooding regimes in the drainage basins, the distribution of halophytic plant formations, and the progressive movements of the rodents as drying out proceeds. The transect indices of rodents are easily repeatable, economical and would be applicable in other developing countries where cutaneous leishmaniasis occurs. 6. This work illustrates that simple ecological methods can assist the assessment of spatial and temporal components of epidemiological risk such as the proximity between rodent colonies and human habitats at the time of outbreaks.

Reproduction and abundance of the fat sand rat (Psammomys obesus) in relation to weather conditions in Tunisia

AbstractThe fat sand rat Psammomys obesus is the main reservoir host of cutaneous leishmaniasis in North Africa and western Asia. In order to understand better the transmission of this disease to humans, a longitudinal study of a population of the rodent was carried out in Tunisia. Rodents were collected in 10 trapping sessions between May 1995 and January 1997, using mole traps and cage traps. The structure of the population was established from eye lens weights and the reproductive state was determined on dissection. Reproduction took place continuously from autumn 1995 to spring 1996 with sexual activity rates from 60–65% in females and 23–100% in males. The mean litter size rose from 3.6 in September to 6.1 in March. Reproduction ceased completely in the summer of 1996, and did not start again till January 1997, following an apparent failure in the autumn. Animals born early in the breeding season bred at an early age, but those born later delayed breeding till the following season. At most times the population clearly consisted of two cohorts, one born in the most recent breeding season, and one born in the preceding one. In response to the reproductive cycle, population numbers showed an increase in winter and a decline in summer. The peak observed in March 1996 was due to the sexual activity of multiparous females and young breeding females. At this time there was a female bias in the sex ratio. In a winter dry period, favourable habitat for breeding was confined to an area in which several species of Chenopodiaceae were associated. Sexual activity in females was clearly correlated with rainfall and rain days, with a 1 month delay (r= 0.78; P= 0.007). Male sexual activity was independent of weather conditions. This result is comparable with other rodents of Sahelian or tropical conditions. The increase in fertility was unrelated to age and is discussed in the light of food availability as a proximate factor. The persistence of the parasite causing cutaneous leishmaniasis in host populations is discussed.

Reproduction and abundance of the fat sand rat (Psammomys obesus) in relation to weather conditions in Tunisia

The fat sand rat Psammomys obesus is the main reservoir host of cutaneous leishmaniasis in North Africa and western Asia. In order to understand better the transmission of this disease to humans, a longitudinal study of a population of the rodent was carried out in Tunisia. Rodents were collected in 10 trapping sessions between May 1995 and January 1997, using mole traps and cage traps. The structure of the population was established from eye lens weights and the reproductive state was determined on dissection. Reproduction took place continuously from autumn 1995 to spring 1996 with sexual activity rates from 60–65% in females and 23–100% in males. The mean litter size rose from 3.6 in September to 6.1 in March. Reproduction ceased completely in the summer of 1996, and did not start again till January 1997, following an apparent failure in the autumn. Animals born early in the breeding season bred at an early age, but those born later delayed breeding till the following season. At most times the population clearly consisted of two cohorts, one born in the most recent breeding season, and one born in the preceding one. In response to the reproductive cycle, population numbers showed an increase in winter and a decline in summer. The peak observed in March 1996 was due to the sexual activity of multiparous females and young breeding females. At this time there was a female bias in the sex ratio. In a winter dry period, favourable habitat for breeding was confined to an area in which several species of Chenopodiaceae were associated. Sexual activity in females was clearly correlated with rainfall and rain days, with a 1 month delay (r= 0.78; P= 0.007). Male sexual activity was independent of weather conditions. This result is comparable with other rodents of Sahelian or tropical conditions. The increase in fertility was unrelated to age and is discussed in the light of food availability as a proximate factor. The persistence of the parasite causing cutaneous leishmaniasis in host populations is discussed.

Rodents as reservoir hosts of cutaneous leishmaniasis in Jordan.

Rodents were collected from endemic foci of cutaneous leishmaniasis in Jordan, either by flooding their burrows with water or using Sherman traps. Of the 170 jirds (Psammomys obesus) collected, 39 (23%) had Leishmania amastigotes in one or both ears. Although cultures of ear biopsies from the infected animals were all positive, cultures made using biopsies from their noses, livers or spleens were all negative. The infected jirds were encountered in seven of the nine areas studied. Biochemical characterization of six isolates from P. obesus, using cellulose acetate electrophoresis of six enzymes (glucose-6-phosphate dehydrogenase, 6-phosphogluconic dehydrogenase, malic enzyme, phosphoglucomutase, phosphoglucoisomerase and fructokinase) showed that the jird isolates were isoenzymatically identical with two Jordanian human Leishmania isolates and reference isolates of L. major but differed from reference strains of L. tropica. None of the other rodents caught (Meriones libycus, M. crassus, M. tristrami, Allactaga euphratica and Gerbillus spp.) yielded Leishmania parasites, confirming that P. obesus is the major reservoir host of cutaneous leishmaniasis in Jordan.

The principal reservoir host of cutaneous leishmaniasis in the urban areas of Manaus, Central Amazon of Brazil.

Twenty one opossums (Didelphis marsupialis) from disturbed primary forest in the vicinity of Manaus, and seven from an isolated island of secondary vegetation within the city of Manaus, were examined for the presence of Leishmania. Of the opossums from the primary forests, 13 (61.9%) were found to be positive for Leishmania braziliensis guyanenesis. One additional opossum was found to be positive for Le. mexicana amazonensis. A simple and economical trapping technique for opossums is presented here, and a control method in special cases is suggested.

Reservoir hosts of cutaneous leishmaniasis among Panamanian forest mammals.

Reservoir hosts of cutaneous leishmaniasis among Panamanian forest mammals.