Investigating the etiology of Haff disease: Optimization and validation of a sensitive LC-MS/MS method for palytoxins analysis in directly associated freshwater and marine food samples from Brazil.

Haff disease typically develops after eating contaminated marine or freshwater species, especially fish. Despite still having an unknown etiology, recent reports have suggested its possible correlation with palytoxins. Therefore, the present work aimed to optimize and perform a validation of a sensitive method using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) for the analysis of palytoxin and some of its analogs, with the main purpose of investigating their presence in marine and freshwater food samples associated with Haff disease in Brazil. The method optimization was performed using a central composite rotatable design and fish samples fortified with the palytoxin standard. Then, the optimized method was validated for different food matrices, including freshwater and marine fish, mollusks, and crustaceans. The sample preparation involved a solid-liquid extraction using methanol and water, solid-phase extraction using Strata-X cartridges, and on-column palytoxin oxidation. The detection of the main oxidized fragments (amino and amide aldehydes) was achieved by LC-MS/MS with electrospray ionization in positive mode, using a C18 column, as well as acetonitrile and water as mobile phases, both acidified with 0.1 % of formic acid. After optimization and validation, the etiological investigation involved the analysis of 16 Brazilian Haff disease-related food samples (in natura and leftover meals) from 2022. The method was demonstrated to be appropriate for quantitative analysis of freshwater and marine species. So far, it has proven to be one of the most sensitive methods related to palytoxin detection (LOD 10 µg/kg), being able to work in a range that includes the provisional ingestion limit (30 µg/kg). Regarding the Haff disease-related samples analysis, there is a strong indication of palytoxin contamination since the amino aldehyde (common fragment for all palytoxins) was detected in 15 of the 16 samples. Selected results were confirmed using liquid chromatography coupled with high-resolution mass spectrometry (LC-HRMS).

La viruela de mono. ¿Una zoonosis emergente? / Monkeypox virus. An emergent zoonosis?

Resumen La viruela de mono es una enfermedad zoonótica propia de roedores y primates no humanos que producen casos esporádicos de monopox, el cual se caracteriza por lesiones exantemáticas en la piel. La viruela del mono es endémica en países del África Central y del Oeste, especialmente en la República Democrática del Congo. En 2003 se detectó por primera vez en el occidente y en el 2022 reaparece en Estados Unidos y otros países del mundo. Aunque cualquier persona que se exponga al virus puede desarrollar la enfermedad, este brote se ha caracterizado por presentar características epidemiológicas distintas ya que los grupos de riesgo más frecuente son los de los hombres que tienen sexo con hombres. Los nuevos brotes de esta enfermedad se han caracterizado por cambios importantes en la presentación clínica ya que el exantema no se presenta generalizado. Por el contrario, ha mostrado muchas variantes como la presentación de lesiones vesiculares únicas en la región genital, lo que hace difícil su diagnóstico clínico. Por ser una enfermedad emergente y presentar cambios en su comportamiento es importante estar consultando las recomendaciones de las organizaciones competentes para el manejo, tratamiento y diagnóstico de esta enfermedad.

Abstract Human monkeypox is a rare viral zoonosis endemic to central and western Africa. It was detected for the first time in the western Hemisphere in 2003. Recently it has re-emerged in USA and has spread rapidly to many countries of the world. Even though any person could contract the disease if expose to it, the populations most vulnerable to the infection are homosexuals, bisexuals and men that have sex with men. The virus produces an exanthem in the skin, which is clinically indistinguishable from other pox-like illnesses, particularly smallpox and chickenpox. Furthermore, clinical findings in recent studies have reported single vesicular lesions in the anogenital areas making the laboratory diagnosis an essential tool to be able to differentiate it from other venereal diseases. Since Human monkeypox is an emergent disease that presents very important epidemiological and clinical features, different from past outbreaks, it is recommended to be in constant communication with the competent health organizations and be aware of changes in case definitions, treatment and diagnostic procedures.

Outbreak of Oropouche Virus in French Guiana.

Oropouche fever is a zoonotic dengue-like syndrome caused by Oropouche virus. In August-September 2020, dengue-like syndrome developed in 41 patients in a remote rainforest village in French Guiana. By PCR or microneutralization, 23 (82.1%) of 28 tested patients were positive for Oropouche virus, documenting its emergence in French Guiana.

Of Pandemics and Zombies: The Influence of Prior Concepts on COVID-19 Pandemic-Related Behaviors.

We use a concepts and categories research perspective to explore how prior conceptual knowledge influences thinking about a novel disease, namely COVID-19. We collected measures of how similar people thought COVID-19 was to several existing concepts that may have served as other possible comparison points for the pandemic. We also collected participants' self-reported engagement in pandemic-related behaviors. We found that thinking the COVID-19 pandemic was similar to other serious disease outbreaks predicted greater social distancing and mask-wearing, whereas likening COVID-19 to the seasonal flu predicted engaging in significantly fewer of these behaviors. Thinking of COVID-19 as similar to zombie apocalypse scenarios or moments of major societal upheaval predicted stocking-up behaviors, but not disease mitigation behaviors. These early category comparisons influenced behaviors over a six-month span of longitudinal data collection. Our findings suggest that early conceptual comparisons track with emergent disease categories over time and influence the behaviors people engage in related to the disease. Our research illustrates how early concept formation influences behaviors over time, and suggests ways for public health experts to communicate with the public about emergent diseases.

Citizen Science Uncovers Phytophthora ramorum as a Threat to Several Rare or Endangered California Manzanita Species.

The Sudden Oak Death (SOD) Blitzes consist of yearly surveys led by citizen scientists designed to map the distribution of Phytophthora ramorum, cause of the forest disease called SOD, across northern California. During the 2017 Santa Cruz County SOD Blitz, six rare or endangered Arctostaphylos (manzanita) species were found to be possibly symptomatic for the first time. Symptoms included branch cankers and associated canopy mortality, and affected multiple individuals per species. Isolates of P. ramorum were obtained from each of the six species and, through a 30-day-long inoculation experiment on live plants, Koch's postulates were completed for each one of them, conclusively determining that they all are hosts of this pathogen. Two additional manzanita species were later found to be apparently symptomatic in Marin County. Inoculations on detached branches using an isolate of P. ramorum obtained from one of the six rare species from Santa Cruz County were successful, suggesting that these two species may also be hosts of P. ramorum. Detached leaves of all eight species were also successfully inoculated at the University of California-Berkeley in fall 2018 and then again in spring 2019. In these cases, the same isolate was used for all inoculations, in order to obtain information on the comparative susceptibility of the eight species in question. Both branch and leaf inoculations identified significant interspecific differences in susceptibility. The production of sporangia was low on all species but it was not zero, suggesting that sporulation may cause within-plant and limited across-plant contagion, especially in rainy years.

Natural Language Processing for Rapid Response to Emergent Diseases: Case Study of Calcium Channel Blockers and Hypertension in the COVID-19 Pandemic.

BACKGROUND: A novel disease poses special challenges for informatics solutions. Biomedical informatics relies for the most part on structured data, which require a preexisting data or knowledge model; however, novel diseases do not have preexisting knowledge models. In an emergent epidemic, language processing can enable rapid conversion of unstructured text to a novel knowledge model. However, although this idea has often been suggested, no opportunity has arisen to actually test it in real time. The current coronavirus disease (COVID-19) pandemic presents such an opportunity. OBJECTIVE: The aim of this study was to evaluate the added value of information from clinical text in response to emergent diseases using natural language processing (NLP). METHODS: We explored the effects of long-term treatment by calcium channel blockers on the outcomes of COVID-19 infection in patients with high blood pressure during in-patient hospital stays using two sources of information: data available strictly from structured electronic health records (EHRs) and data available through structured EHRs and text mining. RESULTS: In this multicenter study involving 39 hospitals, text mining increased the statistical power sufficiently to change a negative result for an adjusted hazard ratio to a positive one. Compared to the baseline structured data, the number of patients available for inclusion in the study increased by 2.95 times, the amount of available information on medications increased by 7.2 times, and the amount of additional phenotypic information increased by 11.9 times. CONCLUSIONS: In our study, use of calcium channel blockers was associated with decreased in-hospital mortality in patients with COVID-19 infection. This finding was obtained by quickly adapting an NLP pipeline to the domain of the novel disease; the adapted pipeline still performed sufficiently to extract useful information. When that information was used to supplement existing structured data, the sample size could be increased sufficiently to see treatment effects that were not previously statistically detectable.

Experimental Frog Virus 3 infection using Brazilian strain: amphibians susceptibility / Infecção experimental utilizando estirpe brasileira de Frog Virus 3: suceptibilidade de anfíbios

An alarming number of global warnings concerning amphibian mortality outbreaks have been released in recent years. Emerging diseases stand out as the main potential causes. Ranavirus is a worldwide-spread highly infectious disease capable of affecting even other ectothermic animals such as fish and reptiles. One major issue regarding this pathology is the lack of clinical signs before it leads up to death. Aiming at having a better understanding of anurans susceptibility, this study analyzed bullfrog (Lithobates catesbeianus) survival rate, when challenged with three doses of a Brazilian strain of Frog Virus 3 (FV3). The qPCR analysis indicated a low infectivity rate in these animals both as larvae and as adults. To elucidate the results, the following hypothesis was performed: 1) The amount of inoculum used on the frogs was insufficient to trigger an infection; 2) For the FV3 to produce clinical signs in this species, there is the need for a cofactor; 3) The animals did undergo FV3 infection but recovered in the course of the experiment, and 4) The inoculum utilized might have been low-virulence. Finally, the presence of actual clinical signs of ranavirus is discussed, with the more likely hypothesis.(AU)

Um número alarmante de notificações globais sobre surtos de mortalidade de anfíbios tem sido realizado nos últimos anos. As doenças emergentes destacam-se como as principais causas potenciais. O ranavírus é uma doença altamente infecciosa disseminada em todo o mundo, capaz de afetar até outros animais ectotérmicos como peixes e répteis. Uma questão importante em relação a essa patologia é a falta de sinais clínicos antes de levar à morte. Com o objetivo de compreender melhor a suscetibilidade dos anuros, o presente trabalho analisou a taxa de sobrevivência de rãs-touro (Lithobates catesbeianus), desafiadas com três doses de uma estirpe brasileira do Frog virus 3 (FV3). A análise de qPCR indicou baixa taxa de infectividade nesses animais, tanto como larvas quanto como adultos. Procurando esclarecer os resultados, foram formuladas as seguintes hipóteses: 1) A quantidade de inóculo aplicada nas rãs foi insuficiente para desencadear uma infecção; 2) Para que o FV3 dê sinais clínicos nesta espécie, é necessário um cofator; 3) Os animais sofreram infecção por FV3, mas se recuperaram no decorrer do experimento, e 4) O inóculo utilizado pode ter sido de baixa virulência. Finalmente, foi discutida a presença de sinais clínicos reais de ranavírus e levantada a hipótese mais provável(AU)

A Microsatellite Analysis Used to Identify Global Pathways of Movement of Phytophthora cinnamomi and the Likely Sources of Wildland Infestations in California and Mexico.

The genetic structure of a sample of isolates of the oomycete plant pathogen Phytophthora cinnamomi from natural and agricultural outbreaks and the long-distance movement of individual genotypes were studied using four microsatellite markers to genotype 159 isolates of Californian, Mexican, and worldwide origins. Allelic profiles identified 75 multilocus genotypes. A STRUCTURE analysis placed them in three groups characterized by different geographic and host ranges, different genic and genotypic diversity, and different reproductive modes. When relationships among genotypes were visualized on a minimum spanning network (MSN), genotypes belonging to the same STRUCTURE group were contiguous, with rare exceptions. A putatively ancestral group 1 had high genic diversity, included all A1 mating type isolates and all Papuan isolates in the sample, was rarely isolated from natural settings in California and Mexico, and was positioned at the center of the MSN. Putatively younger groups 2 and 3 had lower genic diversity, were both neighbors to group 1 but formed two distinct peripherical sectors of the MSN, and were equally present in agricultural commodities and natural settings in Mexico and California. A few genotypes, especially in groups 2 and 3, were isolated multiple times in different locations and settings. The presence of identical genotypes from the same hosts in different continents indicated that long-distance human-mediated movement of P. cinnamomi had occurred. The presence of identical genotypes at high frequencies in neighboring wildlands and agricultural settings suggest that specific commodities may have been the source of recent wild infestations caused by novel invasive genotypes.

Museum specimens of terrestrial vertebrates are sensitive indicators of environmental change in the Anthropocene.

Natural history museums and the specimen collections they curate are vital scientific infrastructure, a fact as true today as it was when biologists began collecting and preserving specimens over 200 years ago. The importance of museum specimens in studies of taxonomy, systematics, ecology and evolutionary biology is evidenced by a rich and abundant literature, yet creative and novel uses of specimens are constantly broadening the impact of natural history collections on biodiversity science and global sustainability. Excellent examples of the critical importance of specimens come from their use in documenting the consequences of environmental change, which is particularly relevant considering the alarming rate at which we now modify our planet in the Anthropocene. In this review, we highlight the important role of bird, mammal and amphibian specimens in documenting the Anthropocene and provide examples that underscore the need for continued collection of museum specimens.This article is part of the theme issue 'Biological collections for understanding biodiversity in the Anthropocene'.

Oropouche fever, an emergent disease from the Americas.

Oropouche virus is the aetiological agent of Oropouche fever, a zoonotic disease mainly transmitted by midges of the species Culicoides paraensis. Although the virus was discovered in 1955, more attention has been given recently to both the virus and the disease due to outbreaks of Oropouche fever in different areas of Brazil and Peru. Serological studies in human and wild mammals have also found Oropouche virus in Argentina, Bolivia, Colombia, and Ecuador. Several mammals act as reservoirs of the disease, although the sylvatic cycle of Oropouche virus remains to be assessed properly. Oropouche fever lacks key symptoms to be differentiated from other arboviral febrile illnesses from the Americas. Sporadic cases of aseptic meningitis have also been described with good prognosis. Habitat loss can increase the likelihood of Oropouche virus emergence in the short-term in South America.

Carp edema virus from three genogroups is present in common carp in Hungary.

Hungary is an important carp producer with intensive trading relationships with farms in other carp-producing areas in Europe. Carp in Europe were recently found infected with carp edema virus (CEV), a poxvirus which causes the koi sleepy disease (KSD) syndrome. Moribund carp were collected from 17 fish farms and angling ponds in different regions of Hungary. Histological analysis of gills from these carp revealed a proliferation of the interlamellar epithelium and an infiltration by eosinophilic cells. In 13 of 17 of these carp, CEV DNA was detected by qPCR and in seven fish more than 1 × 104 copies of virus-specific DNA sequences per 250 ng of DNA, which could be considered as clinically relevant and a cause of disease. A phylogenetic analysis of the sequences revealed that all three genogroups of CEV were present in Hungarian common carp with genogroup I being most abundant. These results support the hypothesis of a prolonged presence of CEV in European carp populations and suggest that previous outbreaks of KSD were not recorded or misdiagnosed. Hence, a testing of carp and koi for infection with CEV should be included into disease surveillance programmes to prevent further spreading of this disease.

Update on Senecavirus Infection in Pigs.

Senecavirus A (SVA) is a positive-sense single-stranded RNA virus that belongs to the Senecavirus genus within the Picornaviridae family. The virus has been silently circulating in pig herds of the USA since 1988. However, cases of senecavirus-associated vesicular disease were reported in Canada in 2007 and in the USA in 2012. Since late 2014 and early 2015, an increasing number of senecavirus outbreaks have been reported in pigs in different producing categories, with this virus being detected in Brazil, China, and Thailand. Considering the novel available data on senecavirus infection and disease, 2015 may be a divisor in the epidemiology of the virus. Among the aspects that reinforce this hypothesis are the geographical distribution of the virus, the affected pig-producing categories, clinical signs associated with the infection, and disease severity. This review presents the current knowledge regarding the senecavirus infection and disease, especially in the last two years. Senecavirus epidemiology, pathogenic potential, host immunological response, diagnosis, and prophylaxis and control measures are addressed. Perspectives are focused on the need for complete evolutionary, epidemiological and pathogenic data and the capability for an immediate diagnosis of senecavirus infection. The health risks inherent in the swine industry cannot be neglected.

Phenotypic interactions between tree hosts and invasive forest pathogens in the light of globalization and climate change.

Invasive pathogens can cause considerable damage to forest ecosystems. Lack of coevolution is generally thought to enable invasive pathogens to bypass the defence and/or recognition systems in the host. Although mostly true, this argument fails to predict intermittent outcomes in space and time, underlining the need to include the roles of the environment and the phenotype in host-pathogen interactions when predicting disease impacts. We emphasize the need to consider host-tree imbalances from a phenotypic perspective, considering the lack of coevolutionary and evolutionary history with the pathogen and the environment, respectively. We describe how phenotypic plasticity and plastic responses to environmental shifts may become maladaptive when hosts are faced with novel pathogens. The lack of host-pathogen and environmental coevolution are aligned with two global processes currently driving forest damage: globalization and climate change, respectively. We suggest that globalization and climate change act synergistically, increasing the chances of both genotypic and phenotypic imbalances. Short moves on the same continent are more likely to be in balance than if the move is from another part of the world. We use Gremmeniella abietina outbreaks in Sweden to exemplify how host-pathogen phenotypic interactions can help to predict the impacts of specific invasive and emergent diseases.This article is part of the themed issue 'Tackling emerging fungal threats to animal health, food security and ecosystem resilience'.

Liquid fat, a potential abiotic vector for horizontal transmission of salmonid alphavirus?

Viral diseases represent serious challenge in marine farming of Atlantic salmon (Salmo salar L). Pancreas disease (PD) caused by a salmonid alphavirus (SAV) is by far the most serious in northern Europe. To control PD, it is necessary to identify virus transmission routes. One aspect to consider is whether the virus is transported as free particles or associated with potential vectors. Farmed salmonids have high lipid content in their tissue which may be released into the environment from decomposing dead fish. At the seawater surface, the effects of wind and ocean currents are most prominent. The aim of this study was primarily to identify whether the lipid fraction leaking from dead infected salmon contains SAV. Adipose tissue from dead SAV-infected fish from three farming sites was submerged in beakers with sea water in the laboratory and stored at different temperature and time conditions. SAV was identified by real-time RT-PCR in the lipid fractions accumulating at the water surface in the beakers. SAV-RNA was also present in the sea water. Lipid fractions were transferred to cell culture, and viable SAV was identified. Due to its hydrophobic nature, fat with infective pathogenic virus at the surface may contribute to long-distance transmission of SAV.

Fiebre causada por el virus Chikungunya, enfermedad emergente que demanda prevención y control / Fever caused by Chikungunya virus, an emergent disease demanding prevention and control

En la región de las Américas, la fiebre causada por el virus chikungunya, ha sido notificada recientemente. Al ser una enfermedad emergente y ante la presencia del mosquito transmisor, el Aedes aegypti, en Cuba y casi toda el área geográfica, resulta necesario su prevención y control, para evitar que se registren brotes de la misma. Se realizó una revisión bibliográfica de los principales artículos publicados sobre el tema, resumiendo los aspectos fundamentales de este problema de salud.

In the region of the Americas, the fever caused by the Chikungunya virus has been notified recently. Being an emergent disease, and because of the presence of the transmitting mosquito, the Aedes aegypti, in Cuba and at around almost all the geographic area, it is necessary its prevention and control, to avoid disease outbreaks. We carried out a bibliographic review of the main articles published on the theme, reviewing the main aspects of this health problem.

Expected utility of voluntary vaccination in the middle of an emergent Bluetongue virus serotype 8 epidemic: a decision analysis parameterized for Dutch circumstances.

In order to put a halt to the Bluetongue virus serotype 8 (BTV-8) epidemic in 2008, the European Commission promoted vaccination at a transnational level as a new measure to combat BTV-8. Most European member states opted for a mandatory vaccination campaign, whereas the Netherlands, amongst others, opted for a voluntary campaign. For the latter to be effective, the farmer's willingness to vaccinate should be high enough to reach satisfactory vaccination coverage to stop the spread of the disease. This study looked at a farmer's expected utility of vaccination, which is expected to have a positive impact on the willingness to vaccinate. Decision analysis was used to structure the vaccination decision problem into decisions, events and payoffs, and to define the relationships among these elements. Two scenarios were formulated to distinguish farmers' mindsets, based on differences in dairy heifer management. For each of the scenarios, a decision tree was run for two years to study vaccination behaviour over time. The analysis was done based on the expected utility criterion. This allows to account for the effect of a farmer's risk preference on the vaccination decision. Probabilities were estimated by experts, payoffs were based on an earlier published study. According to the results of the simulation, the farmer decided initially to vaccinate against BTV-8 as the net expected utility of vaccination was positive. Re-vaccination was uncertain due to less expected costs of a continued outbreak. A risk averse farmer in this respect is more likely to re-vaccinate. When heifers were retained for export on the farm, the net expected utility of vaccination was found to be generally larger and thus was re-vaccination more likely to happen. For future animal health programmes that rely on a voluntary approach, results show that the provision of financial incentives can be adjusted to the farmers' willingness to vaccinate over time. Important in this respect are the decision moment and the characteristics of the disease. Farmers' perceptions of the disease risk and about the efficacy of available control options cannot be neglected.

Las epidemias de erisipela en Chile / Erysipelas outbreaks in Chile

Historical antecedents of erysipelas outbreaks in Chile, registered by national bibliography at years 1822 and 1873 are reviewed. The first one, after an earthquake, with numerous severe ataxo-adynamic manifestations and the second, more attenuated with few severe cases. Remembers of treatments utilized at XIX Century for the disease and the beginning of sulphamides prescription at the thirty decade are presented. Afterwards penicillin and other antimicrobial agents treatments were implemented. Finally, we comment the severe presentation of soft tissues streptococcal diseases that appeared in the end of XX Century.

Se revisa los antecedentes históricos de las epidemias de erisipela en Chile, que anota la bibliografía nacional, en los años 1822 y 1873. La primera, a continuación de un terremoto, con numerosas formas graves ataxo-adinámicas y la segunda, más benigna, con pocos casos graves. Se recuerda los tratamientos de la enfermedad utilizados en el siglo XIX y la iniciación de los antimicrobianos sulfamidados, en la década de los años 30. Posteriormente penicilina y otros antimicrobianos. Finalmente, se comenta la gravedad emergente de las infecciones estreptocóccicas de tejidos blandos, en los últimos años del siglo XX.

La peste, enfermedad infectocontagiosa reemergente / Re-emergence of the plague: an infectious and contagious disease

La peste es una enfermedad infectocontagiosa reemergente. Su reservorio natural en los vertebrados son los roedores silvestres. Los conejos y las liebres, los carnívoros silvestres y los gatos dométicos también pueden ser fuente de infección para los seres humanos. Es causada por la bacteria Yersinia pestis y transmitida por la pulga Xenopsylla cheopis que afecta tanto a animales como a humanos. Causó una devastadora pandemia que asoló Europa en el siglo XIV. Es una zoonosis muy virulenta y potencialmente letal enfermedad bacteriana. Sigue persistiendo en focos naturales que producen brotes recurrentes en muchos lugares del mundo La peste se contrae de manera natural por la intromisión de las personas en el ciclo zoonótico, o por la introducción de roedores silvestres o sus pulgas infectadas en el habitad de los seres humanos. La prevención y las medidas de control van encaminadas a la disminución y el control de roedores y pulgas(AU)

Plague is a re-emergent infectious and contagious disease. Its natural reservoirs in vertebrates are the wild rodents. Rabbits and hares, the wild carnivores and the domestic cats also may be an infection source for human beings. It is caused by Yersinia pestis and transmitted by the flea Xenopsylla cheopis affecting both animals and humans. In Europe during XIX century it caused a devastating pandemic. It is a zoonosis very virulent and a potentially lethal bacterial disease. It persists in natural foci producing recurrent outbreak in many world places. Plague is acquired in a natural way due to interference of people in the zoonosis cycle or due to introduction of wild rodents or their infected fleas in human beings habitat. Prevention and control measures must to be aimed to decrease and the control of rodents and fleas(AU)

La peste, enfermedad infectocontagiosa reemergente / Re-emergence of the plague: an infectious and contagious disease

La peste es una enfermedad infectocontagiosa reemergente. Su reservorio natural en los vertebrados son los roedores silvestres. Los conejos y las liebres, los carnívoros silvestres y los gatos dométicos también pueden ser fuente de infección para los seres humanos. Es causada por la bacteria Yersinia pestis y transmitida por la pulga Xenopsylla cheopis que afecta tanto a animales como a humanos. Causó una devastadora pandemia que asoló Europa en el siglo XIV. Es una zoonosis muy virulenta y potencialmente letal enfermedad bacteriana. Sigue persistiendo en focos naturales que producen brotes recurrentes en muchos lugares del mundo La peste se contrae de manera natural por la intromisión de las personas en el ciclo zoonótico, o por la introducción de roedores silvestres o sus pulgas infectadas en el habitad de los seres humanos. La prevención y las medidas de control van encaminadas a la disminución y el control de roedores y pulgas

Plague is a re-emergent infectious and contagious disease. Its natural reservoirs in vertebrates are the wild rodents. Rabbits and hares, the wild carnivores and the domestic cats also may be an infection source for human beings. It is caused by Yersinia pestis and transmitted by the flea Xenopsylla cheopis affecting both animals and humans. In Europe during XIX century it caused a devastating pandemic. It is a zoonosis very virulent and a potentially lethal bacterial disease. It persists in natural foci producing recurrent outbreak in many world places. Plague is acquired in a natural way due to interference of people in the zoonosis cycle or due to introduction of wild rodents or their infected fleas in human beings habitat. Prevention and control measures must to be aimed to decrease and the control of rodents and fleas

Comparison of gastropod mollusc (Apogastropoda: Hydrobiidae) habitats in two crater lakes in Nicaragua

The aquatic gastropod mollusc, Pyrgophorus coronatus, may perform an important role in the transmission of an emergent ocular pathology among fishes in Lake Apoyo, Nicaragua. This disease emerged after an introduction of tilapia (Oreochromis niloticus) and the subsequent loss of Chara sp. beds in the lake. We compared the mollusc population densities in three habitats (sandy/muddy substrates, rocks, and Chara vegetation) at varying depths (1.5, 10, 20, and 30 m) in two volcanic crater lakes in Nicaragua: Lake Apoyo and Lake Xiloa. where lower numbers of affected fishes were found and tilapia has not been introduced. Duplicate samples at 1.5 m depth were taken in each habitat monthly for a year, and triplicate samples for bathymetric analysis of snail populations were performed during August, 2005. Samples of fixed surface area were filtered in a 0.4 cm size screen and live snails were counted from each sample. The preferred snail habitat in both lakes, Chara beds, was vastly reduced in Lake Apoyo via consumption by introduced Nile tilapia (Oreochromis niloticus). Structureless sandy substrates (mean +/- standard error 3.1+/-1.3 ind/m2) had lower population densities than other habitats in Lake Xiloa (rocks 590.9+/-185.3 ind/m2; vegetation 3 686.5+/-698.2 ind/m2; ANOVA 1, p<0.01 in both cases) but this difference was attenuated in Lake Apoyo (sand 384.4+/-111.1 ind/m2; rocks 1 480.4+/-384.8 ind/m2: 0.0 1

El gasterópodo acuático, Pyrgophorus coronatus, podría jugar un papel importante en la transmisión de una patología ocular emergente entre los peces de la laguna de Apoyo, Nicaragua. Esta enfermedad surgió después de una introducción de tilapia (Oreochromis niloticus) y la subsecuente pérdida de lechos de Chara sp. en la laguna. Comparamos las densidades poblacionales del caracol en tres hábitats (substratos arenosos/lodosos, rocas y vegetación de Chara) en dos lagunas cratéricas volcánicas en Nicaragua: La laguna de Apoyo y la laguna de Xiloá, donde no se encuentraron grandes cantidades de peces afectados y donde no se han introducido tilapias. Mensualmente, por un año tomamos muestras duplicadas a 1.5 m profundidad mensualmente por un año, y durante agosto de 2005, muestreos triplicados de las poblaciones del molusco, para análisis batimétrico (1.5, 10, 20 y 30 m). Para determinar el número de individuos por unidad de área superficial, las muestras fueron filtradas en un colador de 0.4 cm de apertura de malla y contamos los moluscos vivos en cada muestra. El hábitat preferido de los caracoles en ambas lagunas fue la vegetación de Chara, que en la laguna de Apoyo fue vastamente reducida al ser consumida por las tilapias nilóticas introducidas (Oreochromis niloticus). Los substratos arenosos, menos estructurados que los otros sustratos estudiados, tuvieron densidades poblacionales más bajas (media ± error estándar 3.1±1.3 ind/m2) que en los otros hábitats en la laguna de Xiloá (vegetation 590.9±185.3 ind/m2; rocas 3 686.5±698.2 ind/m2; ANOVA I, p<0.01 en ambos casos) pero esta diferencia fue atenuada en la laguna de Apoyo (arena 384.4±111.1 ind/m2; rocas 1 480.4±384.8 ind/ m2; 0.01