Coarse-resolution Ecology of Etiological Agent, Vector, and Reservoirs of Zoonotic Cutaneous Leishmaniasis in Libya

Cutaneous leishmaniasis ranks among the tropical diseases least known and most neglected in Libya. World Health Organization reports recognized associations of Phlebotomus papatasi, Psammomys obesus, and Meriones spp., with transmission of zoonotic cutaneous leishmaniasis (ZCL; caused by Leishmania major) across Libya. Here, we map risk of ZCL infection based on occurrence records of L. major, P. papatasi, and four potential animal reservoirs (Meriones libycus, Meriones shawi, Psammomys obesus, and Gerbillus gerbillus). Ecological niche models identified limited risk areas for ZCL across the northern coast of the country; most species associated with ZCL transmission were confined to this same region, but some had ranges extending to central Libya. All ENM predictions were significant based on partial ROC tests. As a further evaluation of L. major ENM predictions, we compared predictions with 98 additional independent records provided by the Libyan National Centre for Disease Control (NCDC); all of these records fell inside the belt predicted as suitable for ZCL. We tested ecological niche similarity among vector, parasite, and reservoir species and could not reject any null hypotheses of niche similarity. Finally, we tested among possible combinations of vector and reservoir that could predict all recent human ZCL cases reported by NCDC; only three combinations could anticipate the distribution of human cases across the country

Seroprevalence of Toxoplasma gondii antibodies in sheep from Libya

Toxoplasmosis is a worldwide contagious disease of humans and other warm-blooded animals including birds caused by coccidian parasite Toxoplasma gondii. This survey was carried out to show the prevalence of antibodies of T. gondiiin sheep by latex agglutination test (LAT) in different geographical areas in Libya (western area, central area, eastern area, and southern area). The results of this survey are showed that the overall seroprevalence of antibody of Toxoplasma is 71%. There was significant differences in infection to Toxoplasma gondii in the age group of sheep (P = 0.00). The prevalence of anti-Toxoplasma antibody in sheep in the <1 years old was higher than >1 years old sheep. The results showed that there was a significant relation between the seropositivity and presence of abortion in sheep (P = 0.000). Also a significant differences was observed between rate of infection and management system (Extensive and Intensive) of sheep (P =0.022). In total the results of this study together with the previously recorded show high seroprevalence in sheep in Libya and other countries support the impression that Toxoplasmosis is widespread cause for abortion and a latent infection in sheep. Furthermore sheep are suitable host for Toxoplasma gondii. Copy Right, IJAR, 2013,. All rights reserved. Introduction Toxoplasmosis is a worldwide contagious disease of humans and other warm-blooded animals including birds. Clinically it is manifested chiefly by abortion and stillbirths in ewes, and in all species by encephalitis, pneumonia and neonatal mortality Infection by the protozoan parasite T. gondii is widely prevalent in sheep throughout the world. Clinically, ovine toxoplasmosis does not cause any symptoms, but in non-immune ewes an infection acquired during pregnancy may spread to the placenta and fetus and cause abortion, stillbirth or delivery of weak, infected lambs. In nonpregnant ewes the parasites develop cysts containing dormant organisms in the central nervous system and muscle. These cysts could transmit the disease to humans by ingestion of raw or undercooked meat containing tissue cysts (Marca et al., 1996). The seroprevalence of toxoplasmosis in sheep has been reported in several parts around the world. The prevalence rates have been varied among countries and diagnostic methods from 25% to 65% The only documented study on T. gondii seroprevalence in sheep in Libya was in Tripoli (EL-Gomatiet al., 2008) who reported seroprevavlence rates of 40.71 % in adult in Tripoli-Libya, using the Latex agglutination test. The purpose of the present study was to determine the prevalence of T. gondii infection in adult sheep from different agro-ecological zones (Natural regions) of Libya. ISSN 2320-5407 International Journal of Advanced Research (2013) , Volume 1, Issue 9, 148-154 149 Material and Methods We divided Libya into four geographical areas (western area, central area, eastern area, and southern area).A total of 5806 blood samples were obtained from the jugular vein of sheep. These samples were collected randomly from four different geographical areas. The blood samples were collected by veterinarians and veterinary assistants in tubes without anticoagulant directly from the jugular. The samples were transported to the research laboratory in (Libyan National Center for Diseases Control) LNCDC as soon as possible in an ice keeper tanks. Upon arrival, the sera were separated into micro tubes after centrifugation at 4000 rpm for 10 min. Then the micro tubes were stored at -20˚C until analysis. The sera obtained were screened for anti-T. gondii antibodies using the Latex agglutination test (Toxocell Latex, Biokit, Spain). Data analysis was performed with computer software SPSS (Statistical Package for Social Science), version 15. SPSS Inc., Chicago, IL).Statistical significance was taken at P-value of ≤ 0.05. Result Seropositivity according to blood samples collection area

First Molecular Epidemiological Study of Cutaneous Leishmaniasis in Libya

Cutaneous leishmaniasis (CL) is caused by protozoan parasites of the genus Leishmania. The disease is characterized by the formation of chronic skin lesions followed by permanent scars and deformation of the infected area. It is distributed in many tropical and subtropical countries with more than 2 million cases every year. During the past few years CL has emerged as a major public health problem in Libya. So far, diagnosis was based on clinical symptoms and microscopic observation of parasites. Disease outbreaks were not investigated and the causative leishmanial species of CL were not identified so far. Our study indicates the presence of two coexisting species: Leishmania major and Leishmania tropica. These results are crucial in order to provide accurate treatment, precise prognosis and appropriate public health control measures. The recent armed conflict in Libya that ended with the Gadhafi regime collapse on October 2011 has affected all aspects of the life in the country. In this study we discussed multiple risk factors that could be associated with this conflict and present major challenges that should be considered by local and national health authorities for evaluating the CL burden and highlighting priority actions for disease control

A human case of urogenital myiasis caused by Psychoda sp. larvae in Tripoli, Libya

Urogenital myiasis caused by Psychoda spp. involving human are very rare and present with unusual symptoms. Larvae belonging to Psychoda sp. (Diptera: Psychodidae) were found in the urogenital tract of a 9-year-old girl, who lives in Tajoura, Libya, and had suffered from genital pruritus and moving larvae in urine. This is the first record of such case in Libya

Prevalence of IgG antibodies for the West Nile virus in human population in Tripoli, Libya

Background & objectives: West Nile fever (WNF) is a mosquito-borne viral infection, circulated in natural cycles between birds and mosquitoes, particularly Culex species. It is transmitted to humans through mosquito bites, and causes a variety of clinical outcomes, ranging from asymptomatic or mild febrile illness to severe men in go encepha- litis with some fatalities observed in older or immunocompromised patients. West Nile virus (WNV) transmission is considerably influenced by environmental conditions; and abundance of avifauna and mosquitoes.There are very few reports on WNV exposure in individuals from Tripoli City in Libya. The main objective was to provide basic epidemiological information about the WNV seroprevalence in the human population of Tripoli. Methods: A total of 400 serum samples were collected from persons (123 females, 277 males; age range: 15-78 yr) approaching the Tripoli Reference Laboratory for the purpose of obtaining health certificate; during the period from August to October 2013. The presence of WNV IgG antibodies was evaluated by a commercial kit based on WNV immunoglobulin G (IgG) enzyme-linked immunosorbent assay (ELISA). Results: It was observed that 2.75% (11/400) samples were found reactive in the WNV ELISA assay. This result suggests that WNV has a low prevalence in the study area. Interpretation & conclusion: Seropositivity rates of WNV in Tripoli region of Libya were low. However, continu- ous monitoring of population is important to keep track of the disease prevalence, risk factors, reservoir hosts and vectors for better understaning of the disease epidemiology and designing appropriate control strategies

RESEARCH Plague Outbreak in Libya, 2009, Unrelated to Plague in Algeria

After 25 years of no cases of plague, this diseas

Thresholded potential distribution maps for <i>Leishmania major</i>, <i>Phlebotomus papatasi</i>, and four candidate mammal reservoir species potentially associated with the zoonotic transmission of cutaneous leishmaniasis.

<p>Models were calibrated across sampled areas (S), and transferred across all Libya. Blue points are occurrences, pink areas are modeled suitable conditions, and gray areas are unsuitable conditions.</p

Example background similarity tests showing overall niche overlap between ecological niche models for pairs of species: (A) <i>Leishmania major</i>—<i>Phlebotomus papatasi</i> and (B) <i>Leishmania major</i> –<i>Meriones libycus</i>.

<p>The vertical purple line shows observed niche overlap, and the histograms show the distribution of the background similarity values among 100 random replicates, for the <i>I</i> and <i>D</i> similarity metrics. On the maps, red and blue shading indicates the modeled suitable areas for the two species; purple shading shows areas of overlap between the two species. Results for other species are given in the <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0004381#sec010" target="_blank">Supporting Information</a> (<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0004381#pntd.0004381.s005" target="_blank">S5 File</a>).</p

Relationship of additional independent human case records to the areas where pairs of vector <i>Phlebotomus papatasi</i> and mammal reservoir species can occur.

<p>Green areas are areas of overlap between <i>P</i>. <i>papatasi</i> and each of the potential mammal reservoirs; white dotted circle represent localities where human cases were predicted successfully; blue dotted circles indicate case records not predicted successfully by the model combination.</p

Visualization of ecological niches of <i>Leishmania major</i>, <i>Phlebotomus papatasi</i>, and animal reservoir in three environmental dimensions (PC1, PC2, and PC3).

<p>Niches are represented as minimum volume ellipsoids to illustrate the limits under which the species has been sampled. Gray shading represents environmental background, green ellipsoid represents the potential mammal reservoir, yellow is the vector <i>Phlebotomus papatasi</i>, and purple represents <i>Leishmania major</i>.</p