Main Endemic Areas Research Articles

Areas of endemism as a conservation criterion for Iberian gypsophilous flora: a multi-scale test using the NDM/VNDM program

The identification of areas of endemism is a crucial tool for both the interpretation of the spatial component of biological evolution and the plotting of priority areas as far as biodiversity conservation is concerned. Geographical isolation, aridity and special substrates are among the factors which can help to explain the restricted areas of the taxa. All these factors concur in the origin of the Iberian gypsophilous flora, rich in endemic and threatened species. Gypsum is a particularly demanding rock for plants, and gypsum outcrops are usually fragmented in space, in territories with arid conditions. Information on the presence of 71 gypsophytes was collected in 10 × 10 km Universal Transverse Mercator (UTM). The distribution of these plants was used to plot the main areas of endemism for the vascular flora on Iberian gypsum outcrops. This was carried out using the eNDeMism/Visor of eNDeMism (NDM/VNDM) program and several grid cell sizes. A total of 51 areas of endemicity were identified and represented on a map according to their program selection frequency. The South East (SE) of the Iberian Peninsula was the only area selected in all the tests. The results were also compared with other factors of interest for the conservation of gypsophilous flora like genetic diversity of four gypsophytes.

Schistosomiasis in a migrating population in the lake region of China and its potential impact on control operation

Coverage of migrating people in schistosomiasis control program is a growing concern in China. Schistosomiasis caused by Schistosoma japonicum is still one of the major infectious diseases of public health importance in China though tremendous efforts have been made to control the transmission over the past decades. Along with the rapid social-economic development, migrant population has been remarkably increasing across the country. The infected migrants may introduce a new souse of infection to endemic areas or the areas where the transmission had been controlled or interrupted but the intermediate host Oncomelania snail is still present. Preliminary studies for surveillance on schistosomiasis prevalence in migrants were reported, but there is little basic information provided. We carried out an investigation on the prevalence in immigrants, emigrants and permanent residents in three villages of Hunan province located in the main endemic area of lake region, and analyzed the potential impact of migration on control practice. In the study villages, the migrant population accounts for 53.6% of the total. Schistosoma infection was detected by modified Kato-Katz method and miracidium hatching test. Questionnaire survey was conducted comprising knowledge of disease and its transmission, water contact, personal protective measures, and whether examined and treated after water contact. The survey indicated that the migrants and permanent residents had similar life style, and the majority of them experienced water contact in agricultural work or routine life activities. However, the infection rate in immigrants was significantly higher than that in permanent residents. It was also found that the migrants had significantly less knowledge about the disease than the permanent residents, and took no personal protective measures. This is due to that the control program could not cover the migrants when they were absent at the time the program being implemented. The present study suggested that the surveillance and intervention for migrants, immigrants in particular, should be included and strengthened in schistosomiasis control program and a feasible scheme be developed.

Human babesiosis, an emerging tick-borne disease in the People’s Republic of China

Babesiosis is a typical zoonotic, emerging disease caused by a tick-borne intraerythrocytic protozoan of Babesia spp. that also can be transmitted by blood transfusion. Babesiosis imposes an increasing public-health threat. We reviewed and mapped epidemiological studies on Babesia in vectors and/or rodents in the People’s Republic of China (P.R. China) and found that B. microti was the predominant species detected in the investigated regions such as Heilongjiang, Zhejiang, Fujian provinces and Taiwan island. We reviewed a series of sporadic human babesiosis cases collected from 1940’s to 2013, in Yunnan, Inner Mongolia, Taiwan and Zhejiang and other regions including a main endemic area of malaria on the China-Myanmar border areas in P.R. China. Clinical manifestations of human babesiosis were also reviewed. Human babesiosis may have previously been overlooked in P.R. China due to a lack of medical awareness and the limitation of clinical diagnostic methods.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-014-0509-3) contains supplementary material, which is available to authorized users.

Seroepidemiology of Human T-Cell Lymphotropic Virus Type-1 (HTLV1) in Mashhad

Introduction:Human T-cell lymphotropic virus (HTLV-I) is associated with adult T cell leukemia/lymphoma (ATL) and HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The major routes of HTLV-I transmission are mother-to-child, sexual contact, and blood transfusion. Mashhad is one of the main endemic areas in the world for HTLV-I, and minimizing the risk of HTLV-I transmission through blood transfusion is one of the main duties of the Blood Transfusion Center in Mashhad. The aim of this study was to determine the prevalence of HTLV-I in the blood donor population in Mashhad during 2011-2013.Methods:All the blood donors in Mashhad from March 2011 to April 2013 who were diagnosed with HTLV-I on the ELISA screening test and the Western blot confirmatory test were included in this seroepidemiological study.Results:From 174,662 blood donors, 327 donors were confirmed to be infected with HTLV-I according to Western blot assay. The seropositive donors ranged in age from 17 to 59, and their mean age was 39.88±10.49 years. The overall prevalence rates of HTLV-I infection were calculated as 0.18% and 0.19%, respectively.Conclusion:Due to the lower frequency of infection in regular blood donors, younger individuals, and people with higher education levels, the selection of blood donors from these populations should be further considered.

Sensitivity of Oncomelania hupensis to niclosamide: a nation-wide survey in China.

Schistosomiasis japonica, transmitted by the intermediate host snail Oncomelania hupensis of the causative agent Schistosoma japonicum, remains a major public-health concern in China, and control of this snail is one of the major approaches used in attempts to interrupt the transmission of this neglected tropical disease. Niclosamide is currently the only commercial molluscicide available for the control of O. hupensis snails in China. The purpose of this study was to evaluate the current sensitivity of O. hupensis to niclosamide in China. O. hupensis snails derived from 17 sampling sites from eight schistosomiasis-endemic provinces of China were used for the molluscicidal tests. Active adult snails (10 for each drug concentration), were immersed in solutions of 1, 0.5, 0.25, 0.125, 0.063, 0.032, 0.016 and 0.008 mg/L of 50% wettable powder of niclosamide ethanolamine salt (WPN) for 24 and 48 h at 25°C, and then the snail mortality was estimated and LC50 values were calculated. All field-derived O. hupensis snails were dead following immersion in 0.5 and 1 mg/L WPN for 24 h, whereas no death was observed after immersion in 0.008 mg/L WPN for 24 h. Immersion in 0.5, 0.25, 0.125, 0.063, 0.032 and 0.016 mg/L WPN for 24 h resulted in 80%–100%, 63.33%–100%, 0%–85%, 0%–50%, 0%–15%, and 0%–5% snail mortalities, respectively. The 24 h WPN LC50 values for the O. hupensis snails derived from the 17 sampling sites in China ranged from 0.0743 to 0.2285 mg/L, and no significant difference was detected by the Kolmogorov-Smirnov test (p = 0.2). The results indicate that there is no regional variation in the current susceptibility to niclosamide in O. hupensis populations in China. It is suggested that the current sensitivity of niclosamide against O. hupensis remains high and has not changed after more than two decades of repeated, extensive application for snail control in the main endemic areas of China.

Human babesiosis, an emerging tick-borne disease in the People¿s Republic of China

Babesiosis is a typical zoonotic, emerging disease caused by a tick-borne intraerythrocytic protozoan of Babesia spp. that also can be transmitted by blood transfusion. Babesiosis imposes an increasing public-health threat. We reviewed and mapped epidemiological studies on Babesia in vectors and/or rodents in the People’s Republic of China (P.R. China) and found that B. microti was the predominant species detected in the investigated regions such as Heilongjiang, Zhejiang, Fujian provinces and Taiwan island. We reviewed a series of sporadic human babesiosis cases collected from 1940’s to 2013, in Yunnan, Inner Mongolia, Taiwan and Zhejiang and other regions including a main endemic area of malaria on the China-Myanmar border areas in P.R. China. Clinical manifestations of human babesiosis were also reviewed. Human babesiosis may have previously been overlooked in P.R. China due to a lack of medical awareness and the limitation of clinical diagnostic methods.

Temporal dynamics of areas of endemism under climate change: a case study of Mexican Bursera (Burseraceae)

ABSTRACTAimOur aim was to analyse the temporal dynamics of areas of endemism of Bursera species (Burseraceae), a dominant element of the Mexican tropical dry forest, between the Last Glacial Maximum (LGM) and the present day. We aimed to identify stable core sectors that have held permanent populations of endemic species.LocationMexican dry forest.MethodsWe modelled the geographical distributions of 81 species of Bursera and identified their areas of endemism at the LGM and at present. For each area of endemism, changes in time, species composition and distribution were analysed, and a spatially explicit temporal hypothesis was formulated.ResultsThree areas of endemism supported by geographically congruent elements were identified: the Central Mexican Pacific Coast, Western Balsas, and Eastern Balsas–Tehuacán/Cuicatlán–Tehuantepec. Within them we identified stable core sectors (refugia).Main conclusionsThe areas of endemism identified represent distinct evolutionary biotic components of the Mexican dry forest. Their stable core sectors may facilitate phylogeographical predictions at the level of species or species assemblages. The framework adopted allows us to formulate spatially explicit temporal hypotheses about biotic processes, based exclusively on geographical data.

Conservation priorities in the Southern Central Andes: mismatch between endemism and diversity hotspots in the regional flora

North western Argentina, the southernmost portion of the tropical Andes, contains one of the main areas of endemism within the Southern Cone, as well as one of the main diversity hotspots of the country. Historically its reserve area systems have been located in the richest ecoregion of the area; the Southern Andean Yungas. We evaluated the effectiveness of the current protected areas in preserving the endemic flora of the region. The distributions of 505 endemic species were either modeled or included as observed data to determine endemism hotspots in each ecoregion. The endemic species were mainly found in arid ecoregions such as the High Monte and the Central Andean Puna, as well as in the transition zones between these regions and the Southern Andean Yungas. We found that more than 1/3 of the endemic species are unprotected in their entire ranges by the current system, while nearly half of the species are protected in only 5 % of their distribution ranges. New priority areas were chosen to increase the effectiveness based on the irreplaceability concept. We show that adding 251 new cells of 100 km2 each would improve the protection values and convert the system to effective. The present paper highlights that priorities set on the basis of species richness may not successfully conserve areas of high plant endemism. However, zoologist would have to realize similar assessments in the endemic fauna in order to find the optimal designed of protected areas system to conserve both the endemic flora and fauna in the Southern Central Andes.

Co-infections with Babesia microti and Plasmodium parasites along the China-Myanmar border

BackgroundBabesiosis is an emerging health risk in several parts of the world. However, little is known about the prevalence of Babesia in malaria-endemic countries. The area along the China-Myanmar border in Yunnan is a main endemic area of malaria in P.R. China, however, human infection with Babesia microti (B. microti) is not recognized in this region, and its profile of co-infection is not yet clear.MethodsTo understand its profile of co-infections with B. microti, our investigation was undertaken in the malaria-endemic area along the China-Myanmar border in Yunnan between April 2012 and June 2013. Four parasite species, including B. microti, Plasmodium falciparum (P. falciparum), P. vivax, and P. malariae, were identified among 449 suspected febrile persons detected by nested polymerase chain reaction (PCR) assay based on small subunit ribosomal ribonucleic acid (RNA) genes of B. microti and Plasmodium spp.ResultsOf all the collected samples from febrile patients, mono-infection with B. microti, P. vivax, P. falciparum, and P. malariae accounted for 1.8% (8/449), 9.8% (44/449), 2.9% (13/449), and 0.2% (1/449), respectively. The rate of mixed infections of B. microti with P. falciparum or P. vivax are both 0.2% (1/449), and mixed infections of P. falciparum and P. vivax accounted for 1.1% (5/449).ConclusionsThis report supports the hypothesis that babesiosis caused by B. microti is emerging along the China-Myanmar border in the Yunnan province, P.R. China, but it was ignored because of low parasitemia or mixed infection with Plasmodium spp. More sensitive and specific diagnosis methods are needed to find the rapid response mechanism of emergency for babesiosis and malaria co-prevalence areas.

Analysis of Genetic Subtypes and Distribution of Hantavirus in Jilin Area

To investigate the subtypes and distribution of hantavirus in Jilin area. Rattus norvegicus were collected from the main endemic areas of Jilin area and hantavirus in the lung were identified by indirect immunofluorescence assay. M segments of positive samples were partially amplified with Nested RT-PCR and sequenced. Phylogenetic analysis was used for genotyping. All hantaviruses from R. norvegicus were Seoul virus in Jilin area. Phylogenetic analysis of M segments showed that Seoul hantaviruses carried by R. norvegicus in Jilin city were the S3 subtype,and there was no HTNV and PUUV found. The results showed that the subtype of Seoul hantaviruses in Jilin area was S3.

Incidence of Japanese encephalitis, visceral leishmaniasis and malaria before and after the Wenchuan earthquake, in China

The objective of this study was to investigate the incidence of insect-borne diseases from 2005 to 2011, before and after the 2008 Wenchuan earthquake in Longnan City, Gansu Province, China. The data include Japanese encephalitis, Kala-azar and malaria cases from 2005 to 2011 that occurred in Longnan City. We calculated the incidence rates and analyzed the epidemiological characteristics of the diseases before and after the Wenchuan earthquake. During 2005–2011, 212 Japanese encephalitis cases were reported in Longnan City, and the average incidence was 1.11/100,000. Compared with any year from 2005 to 2010 the incidence of Japanese encephalitis in Longnan City in 2011 was not significantly different (P≥0.05). From 2005 to 2011, there were 719 Kala-azar cases in Longnan City, the annual incidence was 3.77/100,000, and the incidence in males was higher than females (P<0.001). Compared with 2011, there was no significant difference in incidence of Kala-azar in 2009 or 2010 (P≥0.05). There were seven total cases of malaria from 2005 to 2011, and the annual incidence was 0.07/100,000. Wudu District and Wen County were the main endemic areas of insect-borne diseases in Longnan City. The results showed that Japanese encephalitis and Kala-azar were common insect-borne infectious diseases in Longnan City, and that the incidence of insect-borne disease did not increase after the Wenchuan earthquake. It is possible that vector control measures implemented after the earthquake prevented an increase in such diseases.

Echinococcus multilocularis in Svalbard, Norway: Microsatellite genotyping to investigate the origin of a highly focal contamination

Echinococcus multilocularis is a threatening cestode involved in the human alveolar echinococcosis. The parasite, mainly described in temperate regions of the Northern hemisphere was described for the first time in 1999 in the High Arctic Svalbard archipelago, Norway. The origin of this contamination could be due to an anthropogenic introduction from mainland Europe by domestic dogs or with the introduction of the sibling vole, perhaps from mainland Russia (St. Petersburg area), or with roaming Arctic foxes, known as the main definitive host of the parasite in Arctic regions. The genetic diversity of E. multilocularis in Svalbard was investigated here for the first time by genotyping using EmsB microsatellite and compared to other genotyped populations in the main worldwide endemic areas. We found low polymorphism amongst the 27 metacestode isolates from sibling voles trapped in the core of the distribution area of the vole on Svalbard. E. mutilocularis Arctic populations, using the Arctic fox as the definitive host, were genetically separated from European temperate populations that use the red fox, but closely related to St. Lawrence Island samples from Alaska. The result is inconsistent with the hypothesis of an anthropogenic introduction from mainland Europe, but can be seen as consistent with the hypothesis that Arctic foxes introduced E. multilocularis to Svalbard.

Primary health care in municipalities at high risk for malaria

This study aims to characterize aspects of Primary Health Care in the Amazon Region of Brazil, considered as the main endemic area for malaria in the country. The Ministry of Health recommends the expansion of Primary Health Care in endemic areas for malaria. A survey focusing on patients infected with malaria was conducted in 6 municipalities, in January and February 2007, to investigate specific aspects of Primary Health Care. Data was analyzed quantitatively and field records helped to give support to context and policy issues in the visited sites. Quality of access to health services and medicines, continuity of health care, system coordination and community orientation are still incipient in the visited areas. The study showed that there is little integration between Primary Health Care and malaria control in the region, which calls for development of joint strategies and for the strengthening of Primary Health Care per se, as a benefit to the population of this endemic area.

Lyme Borreliosis in Dogs and Cats: Background, Diagnosis, Treatment and Prevention of Infections with Borrelia burgdorferi sensu stricto

Lyme borreliosis (LB), synonymous with the often-used term Lyme disease, is an infectious disease caused by the spirochetal bacterium Borrelia burgdorferi. LB is the most frequent vector-borne disease in humans in the Northern Hemisphere. In animals, clinically apparent disease is found primarily in dogs. Severe polyarthritis, fever and lameness in dogs are reported from the main endemic areas of North America: the New England States, and eastern parts of the United States; several cases of LB are also seen in California and the Midwest. Because of the difficulties in finding sufficient indicative clinical signs, additional information (detailed case history, laboratory testing for antibodies) is especially important to make the clinical diagnosis of Lyme borreliosis. This article reviews the etiology, diagnosis, therapy, and prevention of LB.

Is there reduced susceptibility to praziquantel in Schistosoma japonicum? Evidence from China

Praziquantel is widely used for the treatment of human schistosomiasis. However, in recent years, there has been increasing concern about the resistance of Schistosoma species to praziquantel. The study described here was designed to evaluate the current susceptibility to praziquantel in S. japonicum in China. During the non-transmission period of schistosomiasis, a random sample of 4760 subjects from the main endemic foci of China were examined using parasitological stool examination. In total, 584 subjects were identified as being infected with S. japonicum, with a prevalence rate of 12.27%. Among them, 565 stool-egg-positive subjects were treated with praziquantel in a single oral dose of 40 mg/kg. Six weeks post-treatment, among the 505 villagers re-examined, 480 (95.05%) had no detectable S. japonicum eggs. Twenty-one subjects still excreting eggs after the first treatment were treated with praziquantel for the second time. All stool samples, including those from those participants with second treatment were re-examined 6 weeks after the second treatment, and no stool-egg-positives were found. The results indicate that the current efficacy of praziquantel against S. japonicum is still high and has not changed after more than 2 decades of repeated, expanded chemotherapy in the main endemic areas of China. It is suggested that no evidence of tolerance or resistance to praziquantel in S. japonicum was detected in China.

A statistical model for assessing the relationship between meteorological variables and the incidence of Plasmodium falciparum and Plasmodium vivax in a Peruvian endemic area

The objective of this study was to analyse, through a statistical model based on autoregressive procedures, the effect of the malaria incidence rate during the previous month and of meteorological variables (temperature, total precipitation and humidity) on the incidence of Plasmodium falciparum and Plasmodium vivax malaria in the observed month, in the main endemic areas Luciano Castillo and Colonna Health Region, Piura, Peru, during the period 1995?2002. The developed models captured an important part of the data variability. The coefficients of determination (R²) were 0.776 for P. vivax and 0.924 for P. falciparum. Similar models need to be validated in different ecological environments, such as the Peruvian jungle or other countries.

Ecological and historical factors affecting distribution pattern and richness of endemic plant species: the case of the Maritime and Ligurian Alps hotspot

ABSTRACTThe aim of this study was to test a method to locate all the foci, centres, and areas of endemism in a biodiversity hotspot in order to understand the influence of ecological and historical factors on the distribution pattern and to identify priority areas for future conservation projects. The study area was the Maritime and Ligurian Alps hotspot.Analyses were performed on the presence/absence matrix of 36 vascular plant taxa endemic to the study area. For each operational geographical unit, the number of endemic taxa present was counted. Additionally, the weighted endemism value was calculated. Areas of endemism were distinguished using cluster analysis and parsimony analysis of endemicity. The influence of ecological characteristics and historical factors was evaluated using Multi‐Response Permutation Procedure and the Nonparametric Multiplicative Regression. The Indicator Species Analysis (INDVAL) method was used to identify the species characterizing the areas of endemism. Our results show the importance and location of four main areas of endemism within the Maritime and Ligurian Alps and explain the distribution pattern of endemic plants. These areas are easily interpreted by historical and ecological factors, and INDVAL indicates which taxa took part in the history of each endemism area.

Detection and genetic characterization of rabies virus from human patients

Saliva and blood were collected from two patients who had not received post exposure prophylaxis in the cities of Wenzhou and Xinning respectively. Both patients were confirmed as positive for rabies by detection of rabies virus specific nucleoprotein antibodies in the sera by Western Blot. However, rabies virus specific RNA was only identified in the saliva collected from the patient in Wenzhou. Furthermore, the isolate Zhejiang Wz0 (H) was obtained by inoculating one-day-old suckling mice. Both nucleoprotein (N) and glycoprotein (G) genes from the isolate were amplified by RT-PCR and sequenced. Phylogenetic analysis indicated that the isolate belonged to classic rabies virus, and shared a higher homology with the street viruses from dogs in the main endemic areas in China and the street virus from dogs in Indonesia than with other known strains. Further comparison of the deduced amino acid sequences between the isolate and the vaccine strains used in China showed that the virus had a higher level of homology with the vaccine strain CTN than with the other vaccine strains (3aG, PV, PM and ERA). In particular, amino acid residues substitutions located in antigenic site III in the G protein, which could react with the neutralizing antibodies, were observed. These results suggested that the virus belonged to the classic rabies virus, and both N and G genes diverged from the current vaccine strains used in China at either the nucleotide or the amino acid level.

Échinococcose alvéolaire

Alveolar echinococcosis is caused by the larva of the cestode Echinococcocus ( E.) multilocularis. Carnivores, typically foxes, but also domestic dogs and cats are definitive hosts, harbouring the small adult tapeworms in their intestine. Many species of rodents act as intermediate hosts, allowing the liver development of the metacestode (larval stage) of E. multilocularis. Human is an aberrant host for the metacestode. Contamination occurs either by eating vegetables or wild berries tainted by the infected feces of the carnivores, or by touching these animals. This disease is observed only in the temperate northern hemisphere. The main endemic area are Alaska, Japan, China, Russia , Central Asia, Western Turkey and Central Europe. New factors seem to currently modify the epidemiology of alveolar echinococcosis and to cause an extension of the disease in new areas. Increasing fox populations, invasion of cities by foxes, probably contribute to these changes. The role of cellular immunity in the immune response against E. multilocularis larvae has been clearly established. A spontaneous secretion of IL-10 by the peripheral blood mononuclear cells and within the periparasitic granuloma is the immunological hallmark of patients with progressive forms of the disease. Genetic correlates of resistance or susceptibility to human alveolar echinococcosis have been indicated by analysis of human leucocyte antigen markers in a large group of European alveolar echinococcosis patients. Human alveolar echinococcosis is a potentially fatal, chronically progressive hepatic disease, that is characterized by a long asymptomatic period in which development of an invasive-tumour-like multi-vesiculated lesion occur. Vascular and biliary structures as well as adjacent organs may be involved in the parasitic process. There is, in addition, a risk of hematogenous spreading resulting in distant metastases. Unusually for a parasitic helminth infection, it is a life-threatening disease. Efficient drugs able to destroy the larva are currently lacking. A partial surgical resection is the only curative treatment in case of a rather limited disease, a situation which becomes more frequent due to the large use of abdominal ultrasonography. In case of large unresectable lesions, long-term administration of the parasitostatic benzimidazole derivates, albendazole or mebendazole and use of interventional radiology procedures are now able to stabilize the patients. Liver transplantation had been undertaken in some patients with very severe alveolar echinococcosis, mainly due to biliary complications. This ultimate therapeutic option must be preceded by a meticulous evaluation to identify extra-hepatic extension and need to be associated with long term benzimidazole therapy. Finally, the better comprehension of the immunopathogenesis of this disease allows to consider therapeutic immunomodulation for alveolar echinococcosis in the future.

The prevalence of antibodies against Sindbis-related (Pogosta) virus in different parts of Finland.

To study the occurrence of Sindbis-related (Pogosta) disease in Finland by serological means. A total of 2250 serum samples from five different areas were included in the study. Four hundred samples were collected from healthy blood donors and 1850 samples from patients who were suspected to have some viral infection. Antibodies of IgG and IgM classes against Pogosta virus were measured. Eleven per cent of 2250 samples were positive for IgG and 0.6% were positive for IgM class antibodies against Pogosta virus. The antibody prevalence in Finland was almost equally distributed, being highest in western Finland (17%) and lowest in southern and northern Finland (9%). Of all samples with IgG class antibodies, 25% were taken from children under 10 yr of age. The prevalence of antibodies against Pogosta virus was much higher than we expected. Additionally, they were detected from all locations studied and not only in eastern Finland, which has been thought to be the main endemic area for this disease. Pogosta disease has been considered to affect mainly middle-aged persons, but our results indicate a high prevalence also among children.