Search

Ficus species are characterized by their unusual enclosed inflorescences (figs) and their relationship with obligate pollinator fig wasps (Agaonidae). Fig trees have a variety of growth forms, but true epiphytes are rare, and one example is Ficus deltoidea of Southeast Asia. Presumably as an adaptation to epiphytism, inflorescence design in this species is exceptional, with very few flowers in female (seed‐producing) figs and unusually large seeds. Figs on male (pollinator offspring‐generating) trees have many more flowers. Many fig wasps pollinate one fig each, but because of the low number of flowers per fig, efficient utilization by F. deltoidea's pollinators depends on pollinators entering several female figs. We hypothesized that it is in the interest of the plants to allow pollinators to re‐emerge from figs on both male and female trees and that selection favors pollinator roaming because it increases their own reproductive success. Our manipulations of Blastophaga sp. pollinators in a Malaysian oil palm plantation confirmed that individual pollinators do routinely enter several figs of both sexes. Entering additional figs generated more seeds per pollinator on female trees and more pollinator offspring on male trees. Offspring sex ratios in subsequently entered figs were often less female‐biased than in the first figs they entered, which reduced their immediate value to male trees because only female offspring carry their pollen. Small numbers of large seeds in female figs of epiphytic F. deltoidea may reflect constraints on overall female fig size, because pollinator exploitation depends on mutual mimicry between male and female figs., Blastophaga sp. pollinators routinely enter several figs of both sexes and generated more seeds per pollinator on female trees and more offspring on male trees. Pollinator offspring sex ratios in subsequently entered figs (circles) were often less female‐biased than in the first figs they entered (squares).

Rwanda has a fast growing pig production sector projected to continue expansion, due to rising local and regional demand. We undertook a value chain analysis to establish the flows of pigs and pork in Rwanda and the roles of various actors involved, and to understand governance and sanitary risks in the value chain. Cross-sectional qualitative data were collected through focus group discussions and key informant interviews with farmers, brokers, butchers, abattoir managers, and veterinarians. Data were collected on pig production methods and inputs, the source and destination of live and slaughtered pigs, value-adding infrastructures (abattoirs and processing factories), the people involved and interactions between them, governance, and challenges. Pig production in Rwanda is dominated by smallholders, mainly as a source of supplementary income and secondarily for manure. Emerging medium-sized and large pig farms were also identified, located mainly around urban areas. Live pig markets are the main mechanism allowing various actors to buy/sell pigs. Brokers have an important role in pig transactions: they are key in setting prices at markets, examining pigs for disease, organising the supply of pigs for abattoirs and for export. Only a few formal pig abattoirs were identified, which mainly supply to pork processing factories based in Kigali and/or export to customers. Local consumers rely on informal slaughtering at farm or bar/restaurant backyards, with irregular veterinary inspection. Formal abattoirs were attended by a veterinary inspector, however a lack of record keeping was noted. Sanitary risks identified were a lack of biosecurity throughout the chain and poor hygiene at slaughter places. Lingual palpation was practised in pig markets to identify cysticercosis infection, however cyst-positive pigs were not destroyed, but were sold for reduced prices in the same market or later informally sold by the owner. There are few veterinarians attending farms, with most services provided by less qualified technicians or self-treatment of pigs by farmers. Overall, this production system is characterised by a high degree of informality at all nodes, combined with the rapid growth trajectory in the sector. These findings provide a basis to plan interventions tailored to vulnerabilities identified in the Rwanda pig value chain.

Overabundant, free-roaming dog populations are associated with risks to public health, livestock losses, wildlife conservation, and dog health and welfare. Dog population management is conducted to mitigate these issues. Assessing dog population management strategies is important to determine their effectiveness, efficiency, and long-term impact. It is essential to also determine how the behaviour and outlook of local communities may influence the efficacy of dog population management. This study aimed to determine public attitudes towards free-roaming dogs and their management and describe dog ownership practices in three European countries using an online questionnaire survey. This study found that most surveyed respondents wanted to see a reduction in free-roaming dog numbers, and felt that this should be achieved through sheltering, catch-neuter-release, and by controlling the breeding of owned dogs. This questionnaire also identified significant associations between public attitudes and dog ownership practices with gender, religious beliefs, age, education level, reason for dog ownership, previous experience with free-roaming dogs, and country of residence. Respondents who identified as: (i) being male, (ii) holding religious beliefs, (iii) owning dogs for practical reasons, (iv) being young, and (v) having no schooling or primary education had a lower probability of neutering and a higher probability of allowing dogs to roam. Respondents who identified as: (i) being female, (ii) feeling threatened by free-roaming dogs, (iii) being older, and (iv) having more education had a higher probability of answering that an increase in free-roaming dog numbers should be prevented. These findings can help to inform future dog population management interventions in these countries and highlight the importance of considering local public attitudes and dog ownership practices in the development of effective dog population management approaches. Including these social factors will ensure that both the community and organisations involved in dog population management work cohesively towards a shared goal.

Growing interest in the use of microalgae as a sustainable feedstock to support a green, circular, bio-economy has led to intensive research and development initiatives aimed at increasing algal biomass production covering a wide range of scales. At the heart of this lies a common need for rapid and accurate methods to measure algal biomass concentrations. Surrogate analytical techniques based on chlorophyll content use solvent extraction methods for chlorophyll quantification, but these methods are destructive, time consuming and require careful disposal of the resultant solvent waste. Alternative non-destructive methods based on chlorophyll fluorescence require expensive equipment and are less suitable for multiple sampling of small cultures which need to be maintained under axenic growth conditions. A simple, inexpensive and non-destructive method to estimate chlorophyll concentration of microalgal cultures in situ from digital photographs using the RGB color model is presented. Green pixel intensity and chlorophyll a, b and total chlorophyll concentration, measured by conventional means, follow a strong linear relationship (R 2 = 0.985-0.988). In addition, the resulting standard curve was robust enough to accurately estimate chlorophyll concentration despite changes in sample volume, pH and low concentrations of bacterial contamination. In contrast, use of the same standard curve during nitrogen deprivation (causing the accumulation of neutral lipids) or in the presence of high quantities of bacterial contamination led to significant errors in chlorophyll estimation. The low requirement for equipment (i.e., a simple digital camera, available on smartphones) and widely available standard software for measuring pixel intensity make this method suitable for both laboratory and field-based work, particularly in situations where sample, qualified personnel and/or equipment is limited. By following the methods described here it should be possible to produce a standard curve for chlorophyll analysis in a wide range of testing conditions including different microalga cultures, culture vessel and photographic set up in any particular laboratory.

Nematodes can grow within the inflorescences of many fig trees (Ficus spp., Moraceae); however, the feeding behaviour of most nematodes is not known. Fig pollinating wasps (Hymenoptera: Agaonidae) transfer nematodes into young figs upon the wasps’ entry into the figs to deposit their eggs. Most Asian fig trees, however, are functionally dioecious, and the pollinating wasps that enter female figs are unable to reproduce. They fail to produce the offspring required to carry the new generations of nematodes. We examined whether female figs of F. hispida can nonetheless support the development of phoretic nematode populations. Nematodes were extracted from male and female figs sampled in Sumatra, Indonesia, to compare the growth of their populations within the figs. We found three species of nematodes that grew within figs of male and female trees of F. hispida: Ficophagus cf. centerae (Aphelenchoididae), Martininema baculum (Aphelenchoididae) and Caenorhabditis sp (Rhabditidae). The latter species (Caenorhabditis sp.) has never been reported to be associated with F. hispida before. Nematode populations peaked at around 120–140 individuals in both sexes of figs, at the time when a succeeding generation of adult fig wasps appeared within male figs. The female figs could support the growth and reproduction of the three nematodes species; however, the absence of vectors meant that female figs remained as traps from which there could be no escape.

Simple Summary Domestic dogs are abundant worldwide—as owned pets, unowned strays, and feral animals. High numbers of free-roaming dogs can be a concern because of the risks they pose to public health, animal welfare, and wildlife. Using a systematic review process, we investigated what the research published to date can tell us about the effectiveness of different dog population management methods. We found that management methods for dog populations have been researched in multiple countries worldwide, using a wide range of indicators to assess method effectiveness. We outline the results and suggest improvements to help guide future dog population management policy. Abstract The worldwide population of domestic dogs is estimated at approximately 700 million, with around 75% classified as “free-roaming”. Where free-roaming dogs exist in high densities, there are significant implications for public health, animal welfare, and wildlife. Approaches to manage dog populations include culling, fertility control, and sheltering. Understanding the effectiveness of each of these interventions is important in guiding future dog population management. We present the results of a systematic review of published studies investigating dog population management, to assess: (1) where and when studies were carried out; (2) what population management methods were used; and (3) what was the effect of the method. We evaluated the reporting quality of the published studies for strength of evidence assessment. The systematic review resulted in a corpus of 39 papers from 15 countries, reporting a wide disparity of approaches and measures of effect. We synthesised the management methods and reported effects. Fertility control was most investigated and had the greatest reported effect on dog population size. Reporting quality was low for power calculations (11%), sample size calculations (11%), and the use of control populations (17%). We provide recommendations for future studies to use common metrics and improve reporting quality, study design, and modelling approaches in order to allow better assessment of the true impact of dog population management.

Many species of fig trees (Ficus spp., Moraceae) have nematodes that develop inside their inflorescences (figs). Nematodes are carried into young figs by females of the trees’ host-specific pollinating fig wasps (Agaonidae) that enter the figs to lay their eggs. The majority of Asian fig trees are functionally dioecious. Pollinators that enter figs on female trees cannot reproduce and offspring of any nematodes they carry will also be trapped inside. The biology of the nematodes is diverse, but poorly understood. We contrasted the development of nematodes carried by the pollinating fig wasp Ceratosolen solmsi marchali into figs on male and female trees of Ficus hispida in Sumatra, Indonesia. Figs were sampled from both male and female trees over a six-month period, with the nematodes extracted to record their development of their populations inside the figs. Populations of three species of nematodes developed routinely inside figs of both sexes: Caenorhabditis sp. (Rhabditidae), Ficophagus cf. centerae and Martininema baculum (both Aphelenchoididae). This is the first record of a Caenorhabditis sp. associated with F. hispida. Mean numbers of nematodes reached around 120-140 in both male and female figs. These peak population sizes coincided with the emergence of the new generation of adult fig wasps in male fig trees. We conclude that figs on female trees can support development and reproduction of some nematode species, but the absence of vectors means that their populations cannot persist beyond the lifetime of a single fig. Just like their fig wasp vectors, the nematodes cannot avoid this routine source of mortality.

The collapse of mutualisms owing to anthropogenic changes is contributing to losses of biodiversity. Top predators can regulate biotic interactions between species at lower trophic levels and may contribute to the stability of such mutualisms, but they are particularly likely to be lost after disturbance of communities. We focused on the mutualism between the fig tree Ficus microcarpa and its host-specific pollinator fig wasp and compared the benefits accrued by the mutualists in natural and translocated areas of distribution. Parasitoids of the pollinator were rare or absent outside the natural range of the mutualists, where the relative benefits the mutualists gained from their interaction were changed significantly away from the plant's natural range owing to reduced seed production rather than increased numbers of pollinator offspring. Furthermore, in the absence of the negative effects of its parasitoids, we detected an oviposition range expansion by the pollinator, with the use of a wider range of ovules that could otherwise have generated seeds. Loss of top-down control has therefore resulted in a change in the balance of reciprocal benefits that underpins this obligate mutualism, emphasizing the value of maintaining food web complexity in the Anthropocene.

Many plants are grown outside their natural ranges. Plantings adjacent to native ranges provide an opportunity to monitor community assembly among associated insects and their parasitoids in novel environments, to determine whether gradients in species richness emerge and to examine their consequences for host plant reproductive success. We recorded the fig wasps (Chalcidoidea) associated with a single plant resource (ovules of Ficus microcarpa) along a 1200 km transect in southwest China that extended for 1000 km beyond the tree's natural northern range margin. The fig wasps included the tree's agaonid pollinator and other species that feed on the ovules or are their parasitoids. Phytophagous fig wasps (12 species) were more numerous than parasitoids (nine species). The proportion of figs occupied by fig wasps declined with increasing latitude, as did the proportion of utilized ovules in occupied figs. Species richness, diversity, and abundance of fig wasps also significantly changed along both latitudinal and altitudinal gradients. Parasitoids declined more steeply with latitude than phytophages. Seed production declined beyond the natural northern range margin, and at high elevation, because pollinator fig wasps became rare or absent. This suggests that pollinator climatic tolerances helped limit the tree's natural distribution, although competition with another species may have excluded pollinators at the highest altitude site. Isolation by distance may prevent colonization of northern sites by some fig wasps and act in combination with direct and host-mediated climatic effects to generate gradients in community composition, with parasitoids inherently more sensitive because of declines in the abundance of potential hosts.

1. Facilitation is recorded from diverse plant-insect interactions, including pollination and herbivory. 2. The significance of facilitation resulting from the behavior of males of multiple fig wasp species inside figs was investigated. Female fig wasps emerge from natal figs via exit holes dug by males, especially male pollinators. When no males are present, the females struggle to escape and may die. 3. Ficus microcarpa L. is a widely-established invasive fig tree from Southeast Asia. Its pollinator is absent in South Africa, so the tree cannot reproduce, but two Asian non-pollinating fig wasps (NPFW) Walkerella microcarpae and Odontofroggatia galili occupy its figs. Abundance patterns of the two NPFW and the proportion of male-free figs in South Africa, Spain (where the pollinator is introduced), and in China, where the native fig wasp community is diverse, were compared to determine the consequences of reduced species richness for insect survival. 4. Female fig wasps in male-free figs were found to be trapped, and small clutch sizes contributed to the absence of males in both species. The presence of pollinators in Spain allowed most NPFW to develop in figs containing males. Far more male-free figs were present in South Africa, elevating mortality rates among female NPFW. Facilitation of female release by males of other NPFW species nonetheless benefitted the rarer species. 5. Selection pressures in South Africa currently favour greater aggregation of NPFW offspring and/or less female biased sex ratios.

Natural enemies that reduce plant reproductive success are often utilized for biological control of invasive species. Reproduction in fig trees depends on host-specific fig wasp pollinators that develop in galled ovules, but there are also many species of non-pollinating fig wasps (NPFWs) that reduce seed and pollinator numbers. Fig wasps associated with an invasive Asian fig tree, Ficus microcarpa (Moraceae), were surveyed around the Mediterranean. Eight NPFW species are now known from the area, three of which are newly-recorded. The impacts of the two most prevalent ovule galling NPFW species (both Pteromalidae, Epichrysomallinae) on the tree’s reproduction were compared: Odontofroggatia galili Wiebes is widely-introduced, whereas Meselatus bicolor Chen has not been recorded previously outside its native range. Both gall-forming NPFWs significantly reduce seed and pollinator production, but M. bicolor has a far greater impact, entirely preventing seeds and pollinators from developing in the figs it occupies. M. bicolor has only been recorded from F. microcarpa and has the potential to be a valuable biological control agent in other countries outside the Mediterranean where F. microcarpa has become invasive.

Ficus and their species–specific pollinator fig wasps represent an obligate plant–insect mutualism, but figs also support a community of non-pollinating fig wasps (NPFWs) that consist of phytophages and parasitoids or inquilines. We studied interactions between Kradibia tentacularis, the pollinator of a dioecious fig tree species Ficus montana, and an undescribed NPFW Sycoscapter sp. Members of Sycoscapter sp. oviposited 2–4 weeks after pollinator oviposition, when host larvae were present in the figs. No negative correlation was found between the numbers of the two wasp species emerging from figs in a semi-natural population. However, in experiments where the numbers of pollinator foundresses entering a fig were controlled, Sycoscapter sp. significantly reduced the numbers of pollinator offspring. Consequently, it can be concluded that Sycoscapter sp. is a parasitoid of K. tentacularis (which may also feed on plant tissue). Sycoscapter females concentrate their oviposition in figs that contain more potential hosts, rendering invalid conclusions based on simple correlations of host and natural enemy numbers.

Fig trees ( Ficus spp., Moraceae) and their associated obligate pollinator fig wasps (Agaonidae) are partners in what is often a pair-wise species–specific association. Their interaction centres on the unique enclosed inflorescence of Ficus species – the fig. Among dioecious fig tree species, only pollinated ovules in figs on female trees develop into seeds. On male trees, galled ovules support development of the fig wasp offspring that will transport their pollen, but no seeds develop. Some fig wasp species actively collect and disperse pollen, whereas others are typical insect pollinators in that pollen is transferred passively. Active pollination is associated with improved larval survivorship in pollinated figs. Because active pollination is much more efficient, their host figs need to contain far fewer male flowers and across numerous Ficus species anther-ovule ratios are a good predictor of pollination mode. We examined variation in inflorescence size and floral ratios among male figs of the Asian Ficus montana and its consequences for the amounts of pollen that would be available for each pollinator to collect. Inflorescence size (total flower number) was highly variable, and female pollinator offspring production was higher in figs with more female flowers. Pollinator offspring numbers and anther-ovule ratios were also highly variable, and encompassed the range typical of both actively and passively pollinated fig tree species. In combination, this variation resulted in large differences in the extent to which pollinators were competing for access to pollen, with potential fitness consequences for both partners in the mutualism.

The interaction between the hundreds of Ficus species and their specific pollinating fig wasps (Agaonidae) presents a striking example of mutualism. Foundress fig wasps pollinate fig flowers, but also lay their eggs in (and gall) some of them. Only two cases of cheating fig wasps (that fail to pollinate) have been reported, from two continents, suggesting that there is a cost to abandoning pollination. Reasons for the rarity of cheating are a major question in fig biology, because persistence of the mutualism depends on fig wasps continuing to pollinate. A cost in terms of reduced reproductive success among cheaters could be one explanation. Here we compare the behavior and reproduction of an undescribed Eupristina sp., a cheater that coexists with the pollinator Eupristina altissima on Ficus altissima in southern China. Adult females of both species fought with conspecifics when they were seeking entry through the ostiole into receptive figs, but there was no fighting with heterospecifics. Despite a similar body size, female pollinators contained more eggs than female cheaters. Pollinators and cheaters produced similar number of galls, and although almost twice as many flowers were galled in figs entered by two compared to one foundress, larval mortality was greatly increased when two foundresses were present. Larval mortality was also significantly higher for cheaters compared to pollinators, independent of the number of foundresses. Ovules galled by the cheater were thus significantly less likely to result in adult offspring, suggesting that there are significant costs associated with abandoning the mutualism.

The interaction between figs (Ficus spp., Moraceae) and their pollinator fig wasps (Hymenoptera: Agaonidae) is anobligatemutualism,but females ofdioeciousfig treesexploitfig wasps withoutproviding rewards. Figs are closed inflorescences that typically trap pollinator females after entry, but some fig wasp species can re-emerge (although wingless) and subsequently oviposit in and pollinate further figs. Using glasshouse populations, we examined the sex ratios and clutches laid by single foundresses ofKradibia tentacularis (Grandi) in their first and subsequent malefigs ofFicus montana Blume, and how the probability of emergence and entering a second fig varied between seasons. A maximum of four figs were entered by any one foundress. Wingless foundresses were able to locate andenterfigsupto60 cm fromthefirstfigtheyentered,buttheprobabilityofentrydeclinedsharply with distance from thatfig. The foundresses that re-emerged produced slightly higher adultoffspring totals than those that failed to re-emerge. Clutch sizes of a single foundress in its first fig equalled those in all the subsequent figs combined, with clutch size per fig decreasing when more figs were

The host-specific relationship between fig trees (Ficus) and their pollinator wasps (Agaonidae) is a classic case of obligate mutualism. Pollinators reproduce within highly specialised inflorescences (figs) of fig trees that depend on the pollinator offspring for the dispersal of their pollen. About half of all fig trees are functionally dioecious, with separate male and female plants responsible for separate sexual functions. Pollen and the fig wasps that disperse it are produced within male figs, whereas female figs produce only seeds. Figs vary greatly in size between different species, with female flower numbers varying from tens to many thousands. Within species, the number of female flowers present in each fig is potentially a major determinant of the numbers of pollinator offspring and seeds produced. We recorded variation in female flower numbers within male and female figs of the dioecious Ficus montana growing under controlled conditions, and assessed the sources and consequences of inflorescence size variation for the reproductive success of the plants and their pollinator (Kradibia tentacularis). Female flower numbers varied greatly within and between plants, as did the reproductive success of the plants, and their pollinators. The numbers of pollinator offspring in male figs and seeds in female figs were positively correlated with female flower numbers, but the numbers of male flowers and a parasitoid of the pollinator were not. The significant variation in flower number among figs produced by different individuals growing under uniform conditions indicates that there is a genetic influence on inflorescence size and that this character may be subject to selection.

The leishmaniases comprise a complex of diseases characterized by clinical outcomes that range from self-limiting to chronic, and disfiguring and stigmatizing to life threatening. Diagnostic methods, treatments, and vector and reservoir control options exist, but deciding the most effective interventions requires a quantitative understanding of the population level infection and disease dynamics. The effectiveness of any set of interventions has to be determined within the context of operational conditions, including economic and political commitment. Mathematical models are the best available tools for studying quantitative systems crossing disciplinary spheres (biology, medicine, economics) within environmental and societal constraints. In 2005, the World Health Assembly and government health ministers of India, Nepal, and Bangladesh signed a Memorandum of Understanding to eliminate the life threatening form of leishmaniasis, visceral leishmaniasis (VL), on the Indian subcontinent by 2015 through a combination of early case detection, improved treatments, and vector control. The elimination target is

SUMMARYWe present a discrete time model for age-related changes in the mean and variance of the number of helminth parasites per host. We assess the degree of aggregation as the negative binomial parameter, k, and use the model to examine the influence of various factors on changes in aggregation with host age: discrete versus continuous infection; the degree of predisposition to infection; infection rate; parasite survival rate; and the variance in exposure to infective stages. The model can produce both increases and decreases in k with host age. However, with parameter values typical of many human helminth infections, a monotonic increase in k (decrease in aggregation) with age is predicted. With an age-dependent infection rate, convex relationships between k and age are possible. These predictions are consistent with data from field studies, but differ from those of previous models which have suggested that k is independent of host age in the absence of density dependence in parasite population dynamics. Differences between the models, and some difficulties in the interpretation of field data, are discussed.

Objective To evaluate the environmental and ecological factors associated with Leishmania transmission and vector abundance in Chaparral, Tolima-Colombia. Methods First, we compared the ecological characteristics, abundance of phlebotomies and potential reservoir hosts in the peridomestic environment (100 m radius) of randomly selected houses, between two townships with high and low cutaneous leishmaniasis incidence. Second, we examined peridomestic correlates of phlebotomine abundance in all 43 houses in the higher risk township. Results The high transmission township had higher coverage of forest (23%vs. 8.4%) and shade coffee (30.7%vs. 11%), and less coffee monoculture (16.8%vs. 26.2%) and pasture (6.3%vs. 12.3%), compared to the low transmission township. Lutzomyia were more abundant in the high transmission township 2.5 vs. 0.2/trap/night. Lutzomyia longiflocosa was the most common species in both townships: 1021/1450 (70%) and 39/80 (49%). Numbers of potential wild mammal reservoirs were small, although four species were found to be infected with Leishmania (Viannia) spp. In the high transmission township, the overall peridomiciliary capture rate of L. longiflocosa was 1.5/trap/night, and the abundance was higher in houses located nearer to forest (ρ = −0.30, P = 0.05). Conclusion The findings are consistent with a domestic transmission cycle with the phlebotomies dependent on dense vegetation near the house. Objectif: Evaluer les facteurs environnementaux et ecologiques lies a la transmission de Leishmania et l’abondance du vecteur a Chaparral, Tolima-Colombie. Methodes: Nous avons d’abord, compare les caracteristiques ecologiques, l’abondance des phlebotomes et les reservoirs potentiels dans l’environnement peri-domestique (rayon de 100 m) de maisons choisies aleatoirement, entre deux zones a incidence elevee et faible de la leishmaniose cutanee. Ensuite, nous avons examine les correlats peri-domestiques de l’abondance des phlebotomes dans toutes les 43 maisons de la zone avec le risque le plus eleve. Resultats: La zone avec une transmission elevee avait une plus grande etendue de foret (23 versus 8,4%) et de plants de cafe (30,7 versus 11%) et moins de monocultures de cafe (16,8 versus 26,2%) et de pâturages (6,3 versus 12,3%), comparee a la zone avec une faible transmission. Les especes Lutzomyiaetaient plus abondantes dans la zone avec une transmission elevee: 2,5 versus 0,2/piege/nuit. Lutzomyia longiflocosaetait l’espece la plus courante dans les deux zones: 1021/1450 (70%) et 39/80 (49%). Le nombre de mammiferes sauvages reservoirs potentiels etait faible, bien que 4 especes aient ete trouvees infectees par Leishmania (Viannia) spp. Dans la zone a transmission elevee, le taux global de capture autour des domiciles de L. longiflocosaetait de 1,5/piege/nuit et l’abondance etait plus elevee dans des maisons situees pres de la foret (RR= -0,30; p = 0,05). Conclusion: Les resultats sont compatibles avec un cycle de transmission domestique ou les phlebotomes sont dependants de la vegetation dense aupres des maisons. Objetivo: Evaluar los factores ambientales y ecologicos asociados con la transmision de Leishmania y la abundancia del vector en Chaparral, Tolima-Colombia. Metodos: En primer lugar comparamos las caracteristicas ecologicas, la abundancia de flebotominas y potenciales reservorios en el medio peridomestico (radio de 100m) de casas elegidas al azar, entre dos poblados con una incidencia alta y baja de leishmaniasis cutanea. En segundo lugar, examinamos factores peridomesticos correlacionados con la abundancia de flebotominas en las 43 casas del poblado con mayor riesgo. Resultados: El poblado con una alta transmision tenia una mayor cobertura de bosque (23 versus 8.4%) y cultivo de cafe bajo sombra (30.7 versus 11%), y un menor monocultivo de cafe (16.8 versus 26.2%) y pastos (6.3 versus 12.3%), comparado con el poblado con baja transmision. Lutzomyia era mas abundante en el poblado con alta transmision (2.5 versus 0.2/trampa/noche.) Lutzomyia longiflocosa era la especie mas comun en ambos poblados: 1021/1450 (70%) y 39/80 (49%). El numero de posibles reservorios mamiferos salvajes era pequeno, aunque se encontraron 4 especies infectadas con Leishmania (Viannia) spp. En el poblado con alta transmision, la tasa de captura peridomiciliaria de L. longiflocosa era 1.5/trampa/noche, y la abundancia era mayor en casas localizadas mas cerca del bosque (ρ=-0.30, p=0.05). Conclusion: Estos hallazgos son consistentes con un ciclo de transmision domestico, y con las flebotominas dependientes de una vegetacion densa cercana a la casa.

Peridomestic transmission of American cutaneous leishmaniasis is increasingly reported and dogs may be a reservoir of Leishmania (Viannia) in this setting. We investigated the prevalence of infection in dogs in Chaparral County, Colombia, the focus of an epidemic of human cutaneous leishmaniasis caused by Leishmania (Viannia) guyanensis. Two (0.72%) of 279 dogs had lesions typical of cutaneous leishmaniasis that were biopsy positive by kinetoplast DNA polymerase chain reaction–Southern blotting. Seroprevalence was 2.2% (6 of 279) by enzyme-linked immunosorbent assay. Buffy coat and ear skin biopsy specimens were positive by polymerase chain reaction–Southern blotting in 7.3% (10 of 137) and 11.4% (12 of 105) of dogs, respectively. Overall 20% of dogs (21 of 105) showed positive results for one or more tests. Amplification and sequencing of the Leishmania 7SL RNA gene identified L. guyanensis in one dog and L. braziliensis in two dogs. No association was identified between the risk factors evaluated and canine infection. Dogs may contribute to transmission but their role in this focus appears to be limited.

Background. Predisposition to heavy or light human hookworm infection is consistently reported in treatment-reinfection studies. A significant role for host genetics in determining hookworm infection intensity has also been shown, but the relationship between host genetics and predisposition has not been investigated. Methods. A treatment-reinfection study was conducted among 1302 individuals in Brazil. Bivariate variance components analysis was used to estimate heritability for pretreatment and reinfection intensity and to estimate the contribution of genetic and household correlations between phenotypes to the overall phenotypic correlation (ie, predisposition). Results. Heritability for hookworm egg count was 17% before treatment and 25% after reinfection. Predisposition to heavy or light hookworm infection was observed, with a phenotypic correlation of 0.34 between pretreatment and reinfection intensity. This correlation was reduced to 0.23 after including household and environmental covariates. Genetic and household correlations were 0.41 and 1, respectively, and explained 88% of the adjusted phenotypic correlation. Conclusions. Predisposition to human hookworm infection in this area results from a combination of host genetics and consistent differences in exposure, with the latter explained by household and environmental factors. Unmeasured individual-specific differences in exposure did not contribute to predisposition.

Toxoplasma gondii in sheep is important as a cause of lambing losses and as a food hazard. We aimed to assess the prevalence of infection in lambs via development of a standardised PCR technique applied to neonates together with follow-up serology at age 4 months. We measured the sensitivity of PCR targeting the T. gondii sequences B1, SAG1, 5'SAG2, 3'SAG2 and SAG3 in the presence of abundant sheep DNA. B1-PCR was the most sensitive protocol, achieving 50% positivity when 0.02 parasite genome copies were present in an assay testing 10 ng of template. Standardised B1-PCR, and serological follow-up using the modified agglutination test (MAT), were used to estimate infection prevalence in lambs from two flocks in Northern England. Neonatal prevalence detected by PCR on umbilical cord did not differ significantly between viable Charollais (16/243 (6.6%)) and viable Swaledale (30/264 (11.4%)). In contrast, at age 4 months seroprevalence was higher (P

In murine models of leishmaniasis, IgG subclass expression is a proxy measure for Th1/Th2 cellular immune response bias. However, in dogs, the reservoir of zoonotic visceral leishmaniasis, no consistent association has been described between IgG subclass ratios and disease resistance. Inconsistent results may reflect lack of specificity of commonly used commercial antibodies. Our aim was to measure IgG1 and IgG2 responses to crude Leishmania antigen using commercial polyclonal antibodies for comparison with a panel of commercially unavailable monoclonal antibodies, in a cohort of 60 naturally infected dogs, and to compare associations between subclass responses and clinical or parasitological outcomes. IgG1 and IgG2, measured by both antibodies, were higher in clinically symptomatic than in asymptomatic dogs (P

Summary Allergic diseases are rare in areas with high helminth parasite exposure and common where helminth exposure is lacking or significantly reduced, such as urban areas of developing countries and industrialized nations. Studies suggest that helminths induce a systemic immuno-modulatory network, including regulatory T cells and anti-inflammatory IL-10, which might play a key role in the protection against the allergic phenotype. Here, we review the current cross-sectional, birth cohort, and intervention study evidence for a protective effect of helminth infection on allergy. There is increasing evidence for a causal relationship between helminth infection and reduced skin prick test responsiveness to allergens. Cross-sectional studies have shown a consistent negative relationship, and these results have been confirmed in several, although not all, intervention studies. The immunological basis for this protective effect is less clear. Recent studies do not support the mast-cell IgE saturation hypothesis, but suggest that protection is associated with IL-10 production. As for allergic disease, cross-sectional studies support a negative relationship between clinical asthma and infection with some helminth species, particularly hookworm, but more studies are required to draw conclusions for eczema and rhinitis. In addition, none of the few intervention studies to date have demonstrated an increase in clinical allergy after helminth treatment, and further studies are needed. Furthermore, we are only beginning to understand the host genetic factors that are potentially involved. A genetically predetermined T-helper type 2 cell-dominated cytokine milieu reduces parasite burden and may enhance host survival in an environment where helminth parasites are prevalent. Lack of parasite exposure in such hosts might lead to hypersensitivity to seemingly minor environmental allergen stimuli. Large birth cohort studies in helminth-endemic areas that use epidemiological, genetic, and immunological tools are required to further examine how helminth parasites affect the development of atopy and allergic disease. Intervention studies with hookworm in parasite-naive allergic individuals are currently ongoing in the United Kingdom to test the above hypotheses further.

Previous studies have established a genetic component for susceptibility to malaria. Here we use a pedigree based approach, and transmission disequilibrium testing (TDT), to identify immune response genes that influence susceptibility to Plasmodium falciparum malarial phenotypes (parasite density and frequency of clinical episodes) in a Tanzanian population. Evidence for association was observed between markers in the TNF gene cluster and both the malarial phenotypes. There was weaker evidence for associations between HLA-DRB1*04, HLA-DRB1*10, and loci in the TCRBV region with parasite density. There was no evidence for association with polymorphisms in the IL10 promoter, IL1 gene cluster, or from the IL4/IL13 region.

A popular hypothesis to explain parasite survival in the presence of a pronounced T helper 2 phenotype in helminth-parasitized populations has been FcRI blockade by parasite-induced polyclonal IgE. To begin to test the hypothesis that FcRI-bearing cells would be refractory to activation in parasitized populations, we investigated basophil function in 43 individuals from a hookworm endemic area. Study individuals had high levels of total IgE and eosinophilia and a mean hookworm burden of 2,257 epg. Basophils from all members of this parasitized population were shown to release histamine to a number of agonists, including anti IgE and a hookworm allergen, calreticulin. These data would indicate that FcRI blockade at the level of the basophil did not occur in this parasitized population despite the presence of possible immunologic blocking agents. This would suggest that this effector arm of the T helper 2 phenotype remains operative in infected populations.

Background Geohelminth infection and poor hygiene may be protective against allergic sensitization. Objective To determine whether current helminth infection is associated with a reduced prevalence of allergen skin test sensitization in a Southeast Asian population of children with a high prevalence of hookworm infection. Methods A total of 1742 Vietnamese schoolchildren were invited to take part in a cross-sectional survey. Allergen skin sensitization to house dust mites ( Dermatophagoides pteronyssinus and Dermatophagoides farinae ) and American cockroach ( Periplaneta americana ) were measured and stool samples for qualitative and quantitative geohelminth estimation collected. Results A total of 1601 children age 6 to 18 participated. Sensitization to dust mites was present in 14.4% and to cockroach in 27.6% of children. In a mutually adjusted model, the risk of sensitization to dust mites was reduced in those with higher hookworm burden (adjusted odds ratio [OR] for 350+ vs no eggs per gram, 0.61; 95% CI, 0.39-0.96) and with Ascaris infection (adjusted OR, 0.28; 0.10-0.78), and increased in those using flush toilets (adjusted OR for flush toilet vs none/bush/pit, 2.51; 1.00-6.28). In contrast, sensitization to cockroach was not independently related to geohelminth infection but was increased in those regularly drinking piped or well water rather than from a stream (adjusted OR, 1.33; 1.02-1.75). Conclusion Geohelminth infection, sanitation, and water supply influence the risk of allergic sensitization in Vietnamese children. This is consistent with a protective effect against allergy by geohelminth or other gastrointestinal infection. Clinical implications If the inverse relationship between geohelminth infection, poor sanitation, and allergic sensitization proves to be causal, drugs derived from parasite products may help to alleviate clinical allergic disease.

Pentavalent antimony is the agent recommended for treatment of cutaneous leishmaniasis (CL). Its use is problematic, because it is expensive and because of the potential for drug-associated adverse effects during a lengthy and painful treatment course.We tested the efficacy of thermotherapy for the treatment of CL due to Leishmania tropica in a randomized, controlled trial in Kabul, Afghanistan. We enrolled 401 patients with a single CL lesion and administered thermotherapy using radio-frequency waves (1 treatment ofor=1 consecutive application at 50 degrees C for 30 s) or sodium stibogluconate (SSG), administered either intralesionally (a total of 5 injections of 2-5 mL every 5-7 days, depending on lesion size) or intramuscularly (20 mg/kg daily for 21 days).Cure, defined as complete reepithelialization at 100 days after treatment initiation, was observed in 75 (69.4%) of 108 patients who received thermotherapy, 70 (75.3%) of 93 patients who received intralesional SSG, and 26 (44.8%) of 58 patients who received intramuscular SSG. The OR for cure with thermotherapy was 2.80 (95% confidence interval [CI], 1.45-5.41), compared with intramuscular SSG treatment (P=.002). No statistically significant difference was observed in the odds of cure in comparison of intralesional SSG and thermotherapy treatments. The OR for cure with intralesional SSG treatment was 3.75 (95% CI, 1.86-7.54), compared with intramuscular SSG treatment (P.001). The time to cure was significantly shorter in the thermotherapy group (median, 53 days) than in the intralesional SSG or intramuscularly SSG group (median, 75 days and100 days, respectively; P=.003).Thermotherapy is an effective, comparatively well-tolerated, and rapid treatment for CL, and it should be considered as an alternative to antimony treatment.

Cytokine and proliferative responses to Necator americanus infection were measured in a treatment-reinfection study of infected subjects from an area of Papua New Guinea where N. americanus is highly endemic. Before treatment, most subjects produced detectable interleukin (IL)-4 (97%), IL-5 (86%), and interferon (IFN)- gamma (64%) in response to adult N. americanus antigen. Pretreatment IFN- gamma responses were negatively associated with hookworm burden, decreasing by 18 pg/mL for each increase of 1000 eggs/gram (epg) (n=75; P.01). Mean IFN- gamma responses increased significantly after anthelmintic treatment, from 166 to 322 pg/mL (n=42; P.01). The intensity of reinfection was significantly negatively correlated with pretreatment IL-5 responses, decreasing by 551 epg for each 100 pg/mL increase in production of IL-5 (n=51; P.01). These data indicate that there is a mixed cytokine response in necatoriasis, with worm burden-associated suppression of IFN- gamma responses to adult N. americanus antigen. Resistance to reinfection is associated with the parasite-specific IL-5 response.

Visceral leishmaniasis (VL), caused by Leishmania infantum, is an important disease of domestic dogs. Here, we present data on the IgG subclass antibody response to crude L. infantum antigen in a cohort of naturally infected Brazilian dogs. Specific IgG1-IgG4 responses could be detected in 98, 58, 70 and 82%, respectively of 57 dogs that were seropositive for specific IgG. Levels of all IgG subclasses were strongly inter-correlated. Levels of all IgG subclasses increased at the time of seroconversion, before reaching a plateau after several months. Levels of all IgG subclasses were higher in sick dogs than healthy dogs, and levels of all except IgG2 were higher in parasite-positive (by PCR) than parasite-negative dogs. However, levels of IgG2 relative to IgG1 were lower in sick or parasite-positive dogs compared to healthy or parasite-negative infected dogs. In contrast to previous studies, the results suggest that canine VL is associated with upregulation of specific antibody of all IgG subclasses, particularly IgG1, IgG3 and IgG4.

The elimination of seropositive dogs in Brazil has been used to control zoonotic visceral leishmaniasis but with little success. To elucidate the reasons for this, the infectiousness of 50 sentinel dogs exposed to natural Leishmania chagasi infection was assessed through time by xenodiagnosis with the sandfly vector, Lutzomyia longipalpis. Eighteen (43%) of 42 infected dogs became infectious after a median of 333 days in the field (105 days after seroconversion). Seven highly infectious dogs (17%) accounted for >80% of sandfly infections. There were positive correlations between infectiousness and anti-Leishmania immunoglobulin G, parasite detection by polymerase chain reaction, and clinical disease (logistic regression, r2=0.08-0.18). The sensitivity of enzyme-linked immunosorbent assay to detect currently infectious dogs was high (96%) but lower in the latent period (

Malignant hyperthermia (MH) and central core disease (CCD) are autosomal dominant disorders of skeletal muscle. Susceptibility to MH is only apparent after exposure to volatile anesthetics and/or depolarizing muscle relaxants. CCD patients present with diffuse muscular weakness but are also at risk of MH. Mutations in RYR1 (19q13.1), encoding a skeletal muscle calcium release channel (ryanodine receptor), account for the majority of MH and CCD cases. Fifteen RYR1 N-terminal mutations are considered causative of MH susceptibility, five of which are also associated with CCD. In the first extensive UK population survey, eight of 15 mutations were detected in 85 out of 297 (29%) unrelated MH susceptible cases, with G2434R detected in 53 cases (18%). Mutation type was shown to affect significantly MH phenotypes (in vitro contracture test (IVCT) response to caffeine, halothane, and ryanodine). RYR1 mutations associated with both CCD and MH (R163C, R2163H, R2435H) had more severe caffeine and halothane response phenotypes than those associated with MH alone. Mutations near the amino terminal (R163C, G341R) had a relatively greater effect on responses to caffeine than halothane, with a significantly increased caffeine:halothane tension ratio compared to G2434R of the central domain. All phenotypes were more severe in males than females, and were also affected by muscle specimen size and viability. Discordance between RYR1 genotype and IVCT phenotype was observed in seven families (nine individuals), with five false-positives and four false-negatives. This represents the most extensive study of MH patient clinical and genetic data to date and demonstrates that RYR1 mutations involved in CCD are those associated with one end of the spectrum of MH IVCT phenotypes.

Many of the genes within the Canine Major Histocompatibility Complex are highly polymorphic. Most of the alleles defined to date for DLA-DRB1, DQA1 and DQB1 come from the analysis of European or North American pure bred dogs. Little is known about DLA gene polymorphisms in other dog populations. We have studied Alaskan Husky dogs and Brazilian mongrel dogs and compared them with a panel of 568 European dogs and 40 Alaskan gray wolves. DNA sequence based typing was used to characterize a series of 12 Alaskan Huskies and 115 Brazilian mongrels for their DLA-DRB1, DQA1 and DQB1 alleles. Within these dogs, 22 previously undescribed DLA class II alleles were identified: 10 DRB1, 5 DQA1 and 7 DQB1 alleles. All these alleles were found in more than one animal, and, in some cases, as a homozygote. Several alleles initially observed in Alaskan gray wolves were found in these dogs. Each new allele was found in specific haplotypic combinations. Many new DLA class II haplotypes were identified. Several of the new alleles and haplotypes were also identified in the European dogs used for comparison. One new haplotype, containing a previously unknown DLA-DRB1 allele together with DQA1 and DQB1 alleles only seen before in gray wolves, was found in 20 Brazilian dogs, including three homozygous animals. It appears likely that the extent of polymorphism of the DLA genes will increase substantially as dogs from a wider geographic distribution are studied. This has major implications for the study of disease susceptibility and immune responsiveness in dogs.

The DLA class II genes in the dog major histocompatibility complex are highly polymorphic. To date, 52 DLA-DRB1, 16 DLA-DQA1 and 41 DLA-DQB1 allelic sequences have been assigned. The aim of this study was to examine the intrabreed and interbreed variation of DLA allele and haplotype frequencies in dogs, and to ascertain whether conserved DLA class II haplotypes occur within and between different breeds. One thousand and 25 DNA samples from over 80 different breeds were DLA class II genotyped, the number of dogs per breed ranging from 1 to 61. DNA sequence based typing and sequence specific oligonucleotide probing were used to characterize dogs for their DLA-DRB1, DQA1 and DQB1 alleles. The high frequency of DLA class II homozygous animals (35%), allowed the assignment of many haplotypes despite the absence of family data. Four new DLA alleles were identified during the course of this study. Analysis of the data revealed considerable interbreed variation, not only in allele frequency, but also in the numbers of alleles found per breed. There was also considerable variation in the number of breeds in which particular alleles were found. These interbreed variations were found in all three DLA class II loci tested, and also applied to the three-locus haplotypes identified. Within this data set, 58 different DLA-DRB1/DQA1/DQB1 three-locus haplotypes were identified, which were all found in at least two different animals. Some of the haplotypes appeared to be characteristic of certain breeds. The high interbreed, and relatively low intrabreed, variation of MHC alleles and haplotypes found in this study could provide an explanation for reports of interbreed variation of immune responses to vaccines, viruses and other infections.

We carried out a combination of field and laboratory experiments to investigate two possible mechanisms promoting the evolution of lekking in the sandfly, Lutzomyia longipalpis. Males in this species lek on or near hosts that females visit to mate and feed. To test whether the distribution of resources, lek size and female number were positively correlated (a prediction of hotspot models) we manipulated the availability of potential lek sites by varying the numbers of chickens, Gallus gallus domesticus, held in field cages. We then investigated the distribution of males and females across leks formed within these cages and measured males to assess the relationship between male size and lek size. The number of males attracted to a lek increased with the number of hosts present and on average males on larger leks had longer abdomens. The number of females was positively correlated with the number of males present, but the average number of females per male decreased with increasing lek size. In a second experiment, we introduced single females to laboratory leks of different sizes, and compared female latency to mate. Contrary to an explicit prediction of the black hole model, lek size had a direct effect on a female's latency to mate. Females at larger leks encountered and copulated with males sooner than those at smaller aggregations, but the length of time a pair spent courting did not vary with lek size. Our results suggest that the black hole model is unlikely to explain the evolution of lekking in this species. The data instead support the hotspot model as a possible mechanism promoting lekking in L. longipalpis but suggest that female preference for larger leks may need to be invoked to obtain the degree of aggregation observed.

Evaluating the risk of disease spill-over from domestic dogs to wildlife depends on knowledge of inter-specific contact rates and/or exposure to aetiological agents in dog environments. Here, contact rates of crab-eating foxes (Cerdocyon thous) with sympatric domestic dog populations were measured over 25months in Amazon Brazil. Foxes and dogs were serologically and clinically monitored for exposure to canine parvovirus (CPV-2) and canine distemper virus (CDV), pathogens known to have caused wildlife population declines elsewhere. Twenty-two of 24 (92%) tagged foxes visited one or more houses in a median 2 (range 1-3) villages per night where dog densities ranged from 7.2 to 15.4 per km(2) (mean 9.5 per km(2)). Foxes spent an average 6.4% (0-40.3%) of their 10h nocturnal activity period in villages, the equivalent of 38m (range 0-242) per night. The rate of potential exposure to disease agents was thus high, though varied by 3 orders of magnitude for individual foxes. Overall, 46% of the fox population was responsible for 80% of all contacts. None of the 37 monitored foxes however showed serological or clinical evidence of infection with CPV-2 or CDV. Seroprevalences for CPV-2 and CDV antibodies in the local domestic dog population were 13% (3/23) and 9% (2/23), respectively, and 89% of 97 monitored pups born during the study presented clinical signs consistent with active CPV-2 infection (haemorrhagic diarrhoea, vomiting, rapid morbidity and emaciation). Although there was no evidence for infection with either virus in foxes, the high level of contact of foxes with peridomestic habitats suggests that the probability of potential spill-over infections from dogs to foxes is high.

Reinfection with hookworm (Necator americanus) following chemotherapy was studied over 8 years in a rural village in Madang Province, Papua New Guinea. Faecal egg counts were performed on up to 202 individuals in July 1988, August 1990 and November 1996; the study population was treated after sampling in 1988 and 1990. Reinfection burdens in 1996 did not differ significantly from pretreatment burdens (in 1988), and were significantly higher than burdens in 1990. However, the prevalence of hookworm infection was significantly lower in 1996 than in either 1988 or 1990. There was significant predisposition to high or low hookworm burden between 1990 and 1996; this predisposition was stronger in children than adults. However, there was no detectable predisposition between 1988 and 1996 in individuals who had been treated 2 or more times between surveys. The mean weight of adult hookworms in individual hosts was measured in 1988 and 1990 using worms expelled after chemotherapy. There was a significant positive correlation between mean male hookworm weight in the 2 years, suggesting that individual hosts are predisposed to infection with heavy or light hookworms. These data suggest that differences in host susceptibility are involved in generating predisposition, but that longer-term variation in either exposure or susceptibility limits the period over which significant predisposition can be detected.

Calreticulin was recently identified as a hookworm (Necator americanus) allergen, implying secretion, and contact with cells of the immune system, or significant worm attrition in the tissues of the host. As human calreticulin has been shown to bind to and neutralize the haemolytic activity of the complement component C1q, and to be putatively involved in integrin-mediated intracellular signalling events in platelets, it was of interest to determine whether a calreticulin from a successful nematode parasite of humans, with known immune modulatory and antihaemostatic properties, exhibited a capacity to interfere with complement activation and to interact with integrin domains associated with cell signalling in platelets and other leucocytes. We can now report that recombinant calreticulin failed to demonstrate significant calcium binding capacity, which is a hallmark of calreticulins in general and may indicate inappropriate folding following expression in a prokaryote. Nevertheless, recombinant calreticulin retained sufficient molecular architecture to bind to, and inhibit the haemolytic capacity of, human C1q. Furthermore, recombinant calreticulin reacted in surface plasmon resonance analysis (SPR) with peptides corresponding to cytoplasmic signalling domains of the integrins alphaIIb and alpha5, in a calcium independent manner. SPR was also used to ratify the specificity of a polyclonal antibody to hookworm calreticulin, which was then used to assess the stage specificity of expression of the native molecule (in comparison with reverse transcriptase-polymerase chain reaction), to indicate its apparent secretion, and to purify native calreticulin from worm extracts by affinity chromatography. This development will allow the functional tests described above to be repeated for native calreticulin, to ascertain its role in the host-parasite relationship.

We experimentally investigated the fitness consequences of female mate choice in order to test the relative importance of three competing but non-exclusive hypotheses for the maintenance of pronounced female mating preferences on leks: that females benefit directly; that they gain indirect Fisherian benefits by producing more attractive sons; or that they benefit indirectly because preferred males possess 'good genes' that confer increased viability on their sons and daughters. We allowed lekking female sandflies, Lutzomyia longipalpis, to choose between males of varying attractiveness to females, and monitored the consequences for their own survival and reproductive success as well as for their offspring. In contrast to the predictions of the direct-benefits model, we found no clear sire effect on the fecundity or survival of the females themselves; females mating with more attractive males did survive longer after oviposition, but never long enough to undertake a second batch of egg laying. We also found no evidence that females gained good-genes benefits in terms of enhanced offspring survival. However, we did find that generally attractive males fathered sons who were then chosen when they in turn formed leks. Although not completely precluding other benefits, our results indicate that Fisherian benefits are at least partly responsible for maintaining female choice at L. longipalpis leks. These findings indicate the importance of testing all putative benefits concurrently in exploring the maintenance of female mate choice.

Amazonian localized cutaneous leishmaniasis (LCL) is caused by parasites of the subgenera Leishmania and Viannia. Respectively, these parasites may cause diffuse cutaneous leishmaniasis (DCL) and mucocutaneous leishmaniasis (MCL). This, together with differing skin test responses, suggests some species-specificity in cell mediated immunity. In this study, T cell responses (proliferative and interferon-gamma) to crude and defined antigens were examined in paired samples pre and post chemotherapy. Untreated L. (L.) amazonensis LCL patients showed lower responses to crude leishmanial antigens than the L. (V.) spp. group. L. (V.) braziliensis antigen was a more potent stimulator of T cell responses than L. (L.) amazonensis antigen in all patient groups. Few positive responses were seen to the L. (L.) amazonensis glycoprotein GP46. A substantial proportion of LCL patients did respond to the L. (L.) pifanoi amastigote antigens A2, and the surface membrane glycoprotein P8. DCL patients were poor responders to all leishmanial antigens, except GP46. In contrast, MCL patients were good responders to all antigens except GP46 and A2. A significant rise in the response to P8 and A2 antigen was seen post treatment across all LCL and MCL patients, indicating that these antigens might provide suitable vaccine candidates.

Background There is a need for sensitive and specific rapid diagnostic tests (RDT) for canine visceral leishmaniasis. The aims of this study were to evaluate the diagnostic performance of immunochromatographic dipstick RDTs using rK39 antigen for canine visceral leishmaniasis by (i) investigating the sensitivity of RDTs to detect infection, disease and infectiousness in a longitudinal cohort study of natural infection in Brazil, and (ii) using meta-analysis to estimate the sensitivity and specificity of RDTs from published studies. Methodology We used a rK39 RDT (Kalazar Detect Canine Rapid Test; Inbios) to test sera collected from 54 sentinel dogs exposed to natural infection in an endemic area of Brazil. Dogs were sampled bimonthly for up to 27 months, and rK39 results compared to those of crude antigen ELISA, PCR, clinical status and infectiousness to sandflies. We then searched MEDLINE and Web of Knowledge (1993–2011) for original studies evaluating the performance of rK39 RDTs in dogs. Meta-analysis of sensitivity and specificity was performed using bivariate mixed effects models. Principal Findings The sensitivity of the rK39 RDT in Brazil to detect infection, disease and infectiousness was 46%, 77% and 78% respectively. Sensitivity increased with time since infection, antibody titre, parasite load, clinical score and infectiousness. Sixteen studies met the inclusion criteria for meta-analysis. The combined sensitivity of rK39 RDTs was 86.7% (95% CI: 76.9–92.8%) to detect clinical disease and 59.3% (37.9–77.6%) to detect infection. Combined specificity was 98.7% (89.5–99.9%). Both sensitivity and specificity varied considerably between studies. Conclusion The diagnostic performance of rK39 RDTs is reasonable for confirmation of infection in suspected clinical cases, but the sensitivity to detect infected dogs is too low for large-scale epidemiological studies and operational control programmes., Author Summary Canine visceral leishmaniasis is a vector-borne disease caused by the intracellular parasite Leishmania infantum. It is an important veterinary disease, and dogs are also the main animal reservoir for human infection. The disease is widespread in the Mediterranean area, and parts of Asia and South and Central America, and is potentially fatal in both dogs and humans unless treated. Diagnosis of canine infections requires serological or molecular tests. Detection of infection in dogs is important prior to treatment, and in epidemiological studies and control programmes, and a sensitive and specific rapid diagnostic test would be very useful. Rapid diagnostic tests (RDTs) have been developed, but their diagnostic performance has been reported to be variable. We evaluated the sensitivity of a RDT based on serological detection of the rK39 antigen in a cohort of naturally infected Brazilian dogs. The sensitivity of the test to detect infection was relatively low, but increased with time since infection and the severity of infection. We then carried out a meta-analysis of published studies of rK39 RDTs, evaluating the sensitivity to detect disease and infection. The results suggest that rK39 RDTs may be useful in a veterinary clinical setting, but the sensitivity to detect infection is too low for operational control programmes.