Parasite Larvae Research Articles

A rapid, parasite-dependent cellular response to Dirofilaria immitis in the Mongolian jird (Meriones unguiculatus)

BackgroundThe Mongolian jird (Meriones unguiculatus) has long been recognized as a permissive host for the filarial parasite Brugia malayi; however, it is nonpermissive to another filarial parasite, canine heartworm (Dirofilaria immitis). By elucidating differences in the early response to infection, we sought to identify mechanisms involved in the species-specific clearance of these parasites. We hypothesized that the early clearance of D. immitis in intraperitoneal infection of the jird is immune mediated and parasite species dependent.MethodsJird peritoneal exudate cells (PECs) were isolated and their attachment to parasite larvae assessed in vitro under various conditions: D. immitis and B. malayi cultured separately, co-culture of both parasites, incubation before addition of cells, culture of heat-killed parasites, and culture with PECs isolated from jirds with mature B. malayi infection. The cells attaching to larvae were identified by immunohistochemistry.ResultsIn vitro cell attachment to live D. immitis was high (mean = 99.6%) while much lower for B. malayi (mean = 5.56%). This species-specific attachment was also observed when both filarial species were co-cultured, with no significant change from controls (U(9, 14) = 58.5, p = 0.999). When we replicated these experiments with PECs derived from jirds subcutaneously infected with B. malayi, the results were similar (99.4% and 4.72% of D. immitis and B. malayi, respectively, exhibited cell attachment). Heat-killing the parasites significantly reduced cell attachment to D. immitis (mean = 71.9%; U(11, 14) = 7.5, p < 0.001) while increasing attachment to B. malayi (mean = 16.7%; U(9, 15) = 20, p = 0.002). Cell attachment to both species was reduced when larvae were allowed a 24-h pre-incubation period prior to the addition of cells. The attaching cells were identified as macrophages by immunohistochemistry.ConclusionsThese results suggest a strongly species-dependent response from which B. malayi could not confer protection by proxy in co-culture. The changes in cell attachment following heat-killing and pre-incubation suggest a role for excretory/secretory products in host immune evasion and/or antigenicity. The nature of this attachment is the subject of ongoing study and may provide insight into filarial host specificity.Graphical

Variation in helminth infection prevalence, abundance, and co-infection in an intermediate host across a large spatial scale

Parasites are often distributed heterogeneously across host populations, but the controls of this heterogeneity across regional scales often remain unclear. Here, we test the relative importance of natural and anthropogenic environmental factors and biological attributes of host populations on the large-scale variability in infection probability and parasite abundance. We quantified a larval acanthocephalan parasite (Profilicollis altmani), as well as the trematodeMaritremasp. and the nematodeProleptussp., infection of mole crabsEmerita analogausing a hierarchical design at 8 sites spanning 500 km of the south-central shoreline of Chile. At each site, we measured the variables of beach size, morphodynamics, distance to nearest port, distance to tributaries, mole crab density, seagull density, and host body size. Using mixed-effects models, we analysed the associations of acanthocephalan infection probability and parasite abundance in mole crabs as functions of body size and the environmental site-level factors. Models accounted for 20 and 61% of variation in acanthocephalan infection probability and abundance, respectively, with mole crab body size exclusively accounting for nearly all of the model fits. Also, acanthocephalan abundance decreased with increasing mole crab density, suggesting a possible encounter-dilution effect. Co-infection was strong, with the 2 other larval parasite species correlated positively with acanthocephalan parasites. The low influence of environmental variables on acanthocephalan infection could be because spatial variability in these factors is relatively low or their influences are quick to saturate. Therefore, in this system, parasite infection is apparently more strongly related to the duration of host exposure than spatially variable environmental factors, even across large spatial scales.

Effect of short- and long-term immunization of recombinant disorganized muscle protein-1 (rDIM-1) against human filarial parasite Brugia malayi in rodents

Objective: To evaluate the effect of short-term and long-term immunization of recombinant disorganized muscle protein-1 (rDIM-1) in rodents against human filarial parasite Brugia malayi.Methods: Recombinant Brugia malayi DIM-1 (rDIM-1bm) protein was cloned, expressed and purified using a Ni-NTA affinity column. Mastomys coucha were immunized with rDIM-1bm in three immunization schedules: short-term (3-dose of rDIM-1bm), and long-term (booster doses till 3- and 6-week) and subsequently challenged with infective third-stage larvae of filarial parasite Brugia malayi (L3). Microfilaraemia was monitored in L3 exposed groups on day 90 post larval inoculation (p.l.i.) and continued till day 205 p.l.i. On day 205 p.l.i. all the infected animals were killed and total worm burden was estimated. Cellular proliferative response, macrophage activity, nitric oxide (NO) release, specific IgG and its subtypes, IgE, IgA and Th1 (IFN-γ, TNF-α and IL-2) and Th2 (IL-4, IL-5, IL-6, IL-10 and IL-13) cytokine release were determined.Results: Of the 3 different immunization schedules, short-term immunization (3-dose schedule) showed better reduction in microfilarial burden (36%-63%) in the peripheral circulation, adult worm load (52%), whereas long-term immunization (3- and 6-week schedule) exerted less effect on peripheral microfilariae count (9%-58%), and adult worm burden (9%-12.5%). Short-term immunization resulted in upregulation of cellular proliferation, macrophages activity, NO release, specific IgG, IgG1, IgG2a, IgG2b, IgE and IgA levels and both Th1 (IFN-γ, TNF-α and IL-2) and Th2 (IL-4, IL-5, IL-6, IL-10 and IL-13) cytokine release whereas long-term immunization (3- and 6-week schedule) exerted less effect on parasite burden and showed mixed immunological responses. None of the rDIM-1bm administration schedules induced any pathology in lymphoid tissues, or alteration in mast cell number and granularity.Conclusions: The short-term immunization with rDIM-1bm (3-dose schedule) induces robust immune responses and protects the host from filarial parasite infection.

Association of radioactivity of the monazite sands of the beaches of the Guarapari city with the presence of parasites of zoonotic potential.

The city of Guarapari, known as “Healthy City”, has as its main tourist attraction radioactive sands known as monazite sands. There are many studies aimed at quantifying radiation, but little is known about an influence of radiation levels on the life cycle of parasites with zoonotic potential, since many owners take their animals to beaches facilitating a maintenance of their cycle. The objective of the present work was to evaluate the association of the sand radiation of the beaches of the municipality of Guarapari and the presence of eggs and larvae of zoonotic potential parasites. To determine the influence of the radiation on the parasites, sand and faeces samples were collected from the beaches of Praia do Morro, Areia Preta, Castanheiras, Setiba and Santa Mônica, and how to analyze, use the simple centrifugal-flotation technique. The beaches of the present study were classified as low, medium and high radioactivity according to the dose limits that a human being can receive. The samples of sand and faeces were grouped according to a classification of the beaches where they were collected as samples. After obtaining the result, a Chi-square statistical test was performed at a significance level of 95% to evaluate an association between radiation classes and parasite presence. In general, monazitic sands have an influence on the maintenance of the cycle of zoonotic parasites found in beach sand, their correlation being inversely proportional.

Geospatial Artificial Intelligence Infused into a Smartphone Drone Application for Implementing &amp;apos;Seek and Destroy&amp;apos; in Uganda

This study provided important insights into new, real time, control measures at reducing larval, vector density [Macro Seek and Destroy (S&D) and blood parasite level [Micro S&D] in a malaria treated and suspected intervened population. Initially, this study employed a low-cost (< $1000) drone (DJI Phantom) for eco-geographically locating, water bodies including natural water bodies, irrigated rice paddies, cultivated swamps, ditches, ponds, and other geolocations, which are among the common breeding sites for <i>Anopheles</i> mosquitoes in Gulu district of Northern Uganda. Our hypothesis was that by integrating real time, scaled up, sentinel site, spectral signature, unmanned aerial vehicle (UAV) or drone imagery with satellite data using geospatial artificial intelligence [geo-AI] infused into an iOS application (app), a local, vector control officer could retrieve a ranked list of visually similar, breeding site, aquatic foci of <i>An.gambiae s.l. arabiensis s.s. fuentsus s.s.</i> mosquitoes, and their respective district-level, capture point, GPS indexed, centroid coordinates. We real time retrieved (hence, no lag time between seasonal, aquatic, <i>Anopheles</i>, larval habitat, mapping and treatment of foci) each georeferenced sentinel site signature which was subsequently archived in the drone dashboard spectral library using the smartphone app. Each georeferenced, UAV sensed, capture point was inspected using a mobile field team (i.e., trained local village residents led by a vector control officer) on the same day the habitats were geo-AI signature mapped, spatially forecasted and treated. A second hypothesis was that a real time, environmentally friendly, habitat alteration [i.e., Macro S&D] could reduce vector larval habitat density and blood parasite levels in treated and not suspected malaria patients at an entomological intervention site. A third hypothesis was: timely malaria diagnosis and treatment [Micro S&D] is associated with low population parasitemia and lower malaria incidences. In 31 days post-Macro S&D intervention, there was zero vector density, indoor, adult, female, <i>Anopheles</i> count as ascertained by pyrethrum spray catch at the intervention site. After a mean average of 62 days, blood parasite levels revealed a mean 0 count in timely diagnosed suspected and treated malaria patients. Implementing a real time Macro and Micro S&D intervention tool along with other existing tools [insecticide-treated mosquito nets (ITNs) and indoor residual spraying of insecticides (IRS)] in an entomological district-level intervention site can lower seasonal malaria prevalence either through timely modification of aquatic, <i>Anopheles</i>, larval habitats or through precisely targeted larvicide interventions.

Philornis infection in blue‐black grassquits: impact on nestlings and risk factors involved

Parasitic botfly larvae (Philornis ssp., Diptera: Muscidae) are found in nests of several bird taxa, although prevalence and impact on nestling survival vary considerably among species. Here we describe patterns of botfly infestation in blue‐black grassquit Volatinia jacarina nestlings. We identified the most typically affected nestling body parts and assessed parasite prevalence, impact on nestling survival, and changes in nestling body shape. Additionally, we tested whether climatic conditions, nest morphology and habitat characteristics are associated with larvae abundance. Blue‐black grassquits had low breeding success (16% of eggs/nestlings survived to fledged; 19% of the nests fledged at least one), but most failures resulted from predation by vertebrate predators. We estimated that 1% of nestlings died due to botfly infestation, and the number of subcutaneous larvae (range 1–18) in a nestling's body did not predict fledging success. Infected chicks exhibited higher tarsus asymmetry. Thus, we argue that although botflies had a small impact on offspring survival, they may reduce fitness in adulthood. There was no evidence that environmental conditions and nest morphology are linked to the number of larvae on nestlings. Nesting areas with higher food supply had lower infestation rates. Possibly, food‐rich habitats allow parents to invest more time in offspring care (brooding nestlings), thus protecting them from fly attacks. Alternatively, vegetation composition could influence local invertebrate diversity, which could provide a natural trophic buffer against adult Philornis. The present study brings to light new perspectives concerning bird–botfly interaction.

Gastrointestinal Helminths in Large Felines from a Zoo in Malaysia

In nature, wild animals live in an enormous space and usually have very low genetic resistance against parasitic infection mainly due to low exposure towards the parasites themselves. However, when herds of these wild animals are kept in captivity, or in zoological gardens, parasitic infections might be worse and pose a serious threat to endangered species. The present study was conducted to observe the occurrence of gastrointestinal parasites in large felines in a Malaysian zoo. Ten faecal samples were collected from pumas (Puma concolor, n = 5), African lions (Panthera leo, n = 3), a spotted leopard (Panthera pardus, n = 1), and a black panther (Panthera onca, n = 1). All faecal samples were examined for parasite eggs, larvae, and oocysts by simple faecal floatation and formalin – ether sedimentation technique. All large felines in the zoo were infected with gastrointestinal parasites. A total of six species of gastrointestinal parasites were recovered including four nematodes (Toxocara cati, Ancylostoma spp., Toxascaris leonina, and Oxyuris sp.), a cestode (Spirometra sp.), and a protozoan (Isospora sp.). Half (n=5/10) of the large felines had mixed infections with Toxocara cati and Ancylostoma spp.

Occurrence of Heilipus draco (Coleoptera: Curculionidae) in seeds of Ocotea puberula (Lauraceae) and its influence on germination

ABSTRACT This study aims to report the occurrence of Heilipus draco in seeds of Ocotea puberula, and to describe the main injuries caused to the seeds and the effects on germination, as well as the occurrence of parasitoid hymenopterans. To this end, fruits of seven trees were selected, in the extreme south of the Atlantic Forest, Brazil. Fruit collection was carried out weekly in the middle third of the canopy, forming lots, from the beginning of fruit formation until total dehiscence, for two years. In order to examine the damage caused by the granivorous insects inside the fruits, 100 fruits were sectioned taking into account the batch/year with the aid of a scalpel and analyzed using a binocular stereomicroscope. In the same way, 144 fruits from each lot/year were stored individually in transparent plates in order to verify the occurrence and identification of species of granivorous insects. The proof of the influence of the injury caused to the seeds by the granivorous insects was carried out by the germination test, with four replications of 25 seeds, comparing seeds with and without oviposition holes. The species H. draco was found to be associated with the fruits of O. puberula. The egg-layings are endophytic, carried out directly on the seed. Larval parasitism of Hymenoptera Bracon, Omeganastatus, Scambus and Triapsis was observed. It is concluded that the cycle from egg to adult takes place inside the seed of O. puberula, and the injuries caused by the larvae decrease germination.

Dermatobiosis in Panthera onca: first description and multinomial logistic regression to estimate and predict parasitism in captured wild animals.

Dermatobia hominis is a parasite widely distributed in neotropical regions. The parasitic phase of the cycle is characterized by the formation of a subcutaneous nodule in the host, which can promote infestation by other dipterans and skin infections. The aim of this report is to register parasitism by D. hominis in free-ranging Panthera onca captured in the Brazilian wetland and to determine significant biological and meteorological factors that are likely to influence the presence of larval parasitism in captured wild jaguars. Between 2011 to 2020, 34 jaguars were captured and examined manually by searching for lesions characteristic of myiasis. By manual compression in the subcutaneous nodules, larvae morphologically identified as D. hominis (first and third instars) were collected from 13 jaguars. A multinomial logistic regression showed that adult jaguars had 16.49-fold higher odds of being parasitized than subadults. Thus, jaguars captured in the season of July-September have 34.01- and 11.42-fold higher odds of being parasitized compared to the seasons of October-December and April-June, respectively, which is associated with high total monthly precipitation in the previous season. The present study is the first to describe parasitism by D. hominis larvae in jaguars.

АНАЛИЗ МЕТОДОВ И ТЕХНОЛОГИЙ БОРЬБЫ С ЭДЕМАГЕНОЗОМ И СИБИРСКОЙ ЯЗВОЙ СЕВЕРНЫХ ОЛЕНЕЙ

Reindeer husbandry is one of the leading branches of animal husbandry in the Far North of the Russian Federation and serves as the main source of life and employment for the local population. Anti-anthrax vaccinations of almost all deer are carried out annually, since immunity persists in the body for 12 months, and the spores of the pathogen of anthrax can persist in the external environment for many decades, especially in the “permafrost " zone. Therefore, vaccination of deer should continue as long as reindeer husbandry exists. Vaccination is carried out in early summer or autumn. At the same time, the pc vaccine has been successfully used recently.55 VNIIVViM. The purpose of the work is to conduct research to develop a method for creating a composition of therapeutic and prophylactic drugs against edemagenosis and anthrax of reindeer on the basis of new iver -, avermectins and anti-ulcer vaccine pcs. 55 VNIIVViM. Data on the results of screening of means and methods of combating the dominant diseases of reindeer are obtained from archival materials, publications of relevant scientific developments and research in recent years. The research is carried out in close creative cooperation and with the direct participation of employees of the VNIIVViM anthrax laboratory (Selyaninov Yu. O., Grekhova N. V.). Experiments on deer are carried out in reindeer breeding farms of the Komi Republic and the Nenets Autonomous Okrug. The results of all conducted tests of the association of drugs are issued by the relevant acts. Mass one-time antiepizootic treatment of deer provides 100% protection of livestock from an outbreak of anthrax. In addition, due to the destruction of parasitic larvae of the subcutaneous gadfly, the income of reindeer farms increases by 27-30% (up to about 3 thousand rubles per deer from the slaughter contingent). In the Komi Republic, this is determined by the amount of 6-8 million rubles annually.

АНАЛИЗ МЕТОДОВ И ТЕХНОЛОГИЙ БОРЬБЫ С ЭДЕМАГЕНОЗОМ И СИБИРСКОЙ ЯЗВОЙ СЕВЕРНЫХ ОЛЕНЕЙ

Reindeer husbandry is one of the leading branches of animal husbandry in the Far North of the Russian Federation and serves as the main source of life and employment for the local population. Anti-anthrax vaccinations of almost all deer are carried out annually, since immunity persists in the body for 12 months, and the spores of the pathogen of anthrax can persist in the external environment for many decades, especially in the “permafrost " zone. Therefore, vaccination of deer should continue as long as reindeer husbandry exists. Vaccination is carried out in early summer or autumn. At the same time, the pc vaccine has been successfully used recently.55 VNIIVViM. The purpose of the work is to conduct research to develop a method for creating a composition of therapeutic and prophylactic drugs against edemagenosis and anthrax of reindeer on the basis of new iver -, avermectins and anti-ulcer vaccine pcs. 55 VNIIVViM. Data on the results of screening of means and methods of combating the dominant diseases of reindeer are obtained from archival materials, publications of relevant scientific developments and research in recent years. The research is carried out in close creative cooperation and with the direct participation of employees of the VNIIVViM anthrax laboratory (Selyaninov Yu. O., Grekhova N. V.). Experiments on deer are carried out in reindeer breeding farms of the Komi Republic and the Nenets Autonomous Okrug. The results of all conducted tests of the association of drugs are issued by the relevant acts. Mass one-time antiepizootic treatment of deer provides 100% protection of livestock from an outbreak of anthrax. In addition, due to the destruction of parasitic larvae of the subcutaneous gadfly, the income of reindeer farms increases by 27-30% (up to about 3 thousand rubles per deer from the slaughter contingent). In the Komi Republic, this is determined by the amount of 6-8 million rubles annually.

Spatio-temporal variation of predatory hoverflies (Diptera: Syrphidae) and their relationship with aphids in organic horticultural crops in La Plata, Buenos Aires

Population variations of predatory hoverflies in agroecosystems depend mainly on the resources that crops and wild vegetation provides them as well as death caused by natural enemies. We identified I) aphidophagous hoverfly species in lettuce and broccoli crops in Buenos Aires, II) the seasonal variations of the immature stages and their larval parasitism, and III) the wild plants, surrounding the crops, visited by adults. Fortnightly, 30 leaves were randomly selected in both crops during 2018-2019 and immature stages of syrphids and aphids per leaf were recorded. Adults were manually collected in patches of the wild plants (during 10 min of direct observations), and plants visited by adults were determined. The hoverflies were Allograpta exotica Wiedemann and Toxomerus duplicatus Wiedemann. Only A. exotica was recorded in crops. The dominant aphids were Myzus persicae (Sulzer) in lettuce and Brevycorine brassicae (L.) in broccoli. Parasitism rates ranged between 8 and 100% and the species were Diplazon laetatorius (Fabricius), in both crops, and Pachyneuron aff. nelsoni only in broccoli. Galinsoga parviflora Cav. and Matricaria chamomilla L. were the wild plants most often visited by hoverflies. This work provides basic information for the control of aphids by hoverflies in the framework of conservation biological control

A triple-drug treatment regimen to accelerate elimination of lymphatic filariasis: From conception to delivery.

The Global Programme to Eliminate Lymphatic Filariasis (LF) is using mass drug administration (MDA) of antifilarial medications to treat filarial infections, prevent disease and interrupt transmission. Almost 500 million people receive these medications each year. Clinical trials have recently shown that a single dose of a triple-drug combination comprised of ivermectin, diethylcarbamazine and albendazole (IDA) is dramatically superior to widely used two-drug combinations for clearing larval filarial parasites from the blood of infected persons. A large multicenter community study showed that IDA was well-tolerated when it was provided as MDA. IDA was rapidly advanced from clinical trial to policy and implementation; it has the potential to accelerate LF elimination in many endemic countries.

Evaluation of Vegetable Contamination with Medically Important Helminths and Protozoans in Calabar, Nigeria

Aims: Vegetables are usually exposed to parasitic ova, larvae or oocyst during cultivation, irrigation, storage, transportation or while processing for consumption. Consumption of raw, unwashed and improperly cooked vegetables is considered a risk factor for transmission of intestinal parasites. This study assessed the parasitic contamination of vegetables and also determined factors associated with parasitic contamination of vegetables in selected markets in Calabar, Cross River State.&#x0D; Place and Duration of Study: Sample: Markets within Calabar, Cross River State, Nigeria between September and October, 2018.&#x0D; Methodology: A pre-tested semi-structured questionnaire was used for collecting data on factors associated with parasitic contamination of vegetables. 300 vegetable samples were purchased and processed from three different markets in Calabar for examination of parasitic contamination using direct wet mount and zinc sulphate floatation techniques.&#x0D; Results: 15.7% (47/300) of the vegetables sampled were positive for at least one parasite. The species and stages of parasites detected were larvae of Strongyloides, ova of Trichuris trichiura and Hookworm, and cysts of Entamoeba histolytica and Giardia lamblia. Larvae of Strongyloides (11.3%) were the most frequently detected followed by ova of T. trichiura (1.7%) and Hookworm (1.7%) (P = 0.000). Among the five vegetable types sampled, waterleaf (40%) had the highest level of parasitic contamination followed by pumpkin (21.7%). Washing vegetables before display and the means of display were significantly associated with parasitic contamination (P = 0.000).&#x0D; Conclusion: Prevention of contamination is important in reducing food-borne parasitic infections and can be achieved through improved personal hygiene practices of farmers, vendors and consumers, proper washing of vegetables and improved sanitary conditions especially around markets where these vegetables are sold.

The direct and indirect effects of copper on vector-borne disease dynamics

Metal pollution is a growing concern that affects the health of humans and animals globally. Copper is an essential insect micronutrient required for respiration, pigmentation and oxidative stress protection but can also act as a potentially toxic trace element. While several studies have focused on the negative fitness effects of copper on the aquatic larvae of mosquitoes, the effects of larval copper exposure on adult mosquito fitness (i.e., survival and fecundity) and their ability to transmit parasites (i.e., vector competence) remains unclear. Here, using a well-studied model vector-parasite system, the mosquito Aedes aegypti and parasite Dirofilaria immitis, we show that sublethal copper exposure in larval mosquitoes alters adult female fecundity and vector competence. Specifically, mosquitoes exposed to copper had a hormetic fecundity response and mosquitoes exposed to 600μg/L of copper had significantly fewer infective parasite larvae than control mosquitoes not exposed to copper. Thus, exposure of mosquito larvae to copper levels far below EPA-mandated safe drinking water limits (1300μg/L) can impact vector-borne disease dynamics not only by reducing mosquito abundance (through increased larval mortality), but also by reducing parasite transmission risk. Our results also demonstrated that larval copper is retained through metamorphosis to adulthood in mosquitoes, indicating that these insects could transfer copper from aquatic to terrestrial foodwebs, especially in urban areas where they are abundant. To our knowledge this is the first study to directly link metal exposure with vector competence (i.e., ability to transmit parasites) in any vector-parasite system. Additionally, it also demonstrates unequivocally that mosquitoes can transfer contaminants from aquatic to terrestrial ecosystems. These results have broad implications for public health because they directly linking contaminants and vector-borne disease dynamics, as well as linking mosquitoes and contaminant dynamics.

Geohelminths in the soil of the Laguna dos Patos in Rio Grande do Sul state, Brazil.

This study aimed at examining the prevalence of eggs and larvae of parasites - that may cause diseases to humans and other animals - in the soil of public squares located on the shore of Laranjal beaches, in the Laguna dos Patos, in Pelotas, Rio Grande do Sul state, Brazil. Four fieldwork trips - one per season - were taken to collect samples on six squares built on the shore of these beaches. Five samples of soil were collected on every square on every fieldwork trip. The material was processed by Caldwell & Caldwell's technique. Four squares (66.7%) were positive for helminth eggs and sample positivity was 8.3% (10). Toxocara spp. and Ancylostoma spp. were the main genera found in these places. Even though prevalence was lower than the one observed by other studies which were carried out in the area, helminths with zoonotic potential were found in the soil of the squares. It should be highlighted that measures to control dogs in these areas must be implemented and public policies must be put forth to make pets' owners and beach goers aware of the need to mitigate environmental contamination.

Prevalence of tracheopulmonary myiasis amidst humans.

Myiasis is a parasitic infestation of live vertebrates with the dipteran larvae that grow within the host while feeding on its living or dead tissue. Human myiasis is prevalent among individuals in close association of domestic animals and those inhabiting the unhygienic conditions. Open neglected suppurative wounds are the favourable sites that attract and stimulate the gravid female flies for oviposition. However, the poor personal hygiene, ignorance and the mental illness further add to it. Tracheopulmonary myiasis involves the infestation of foul smelling nasal and oral orifices or neglected wounds like tracheostomal incisions with the parasitic dipteran larvae which may extend up to the trachea, bronchi and lungs leading to serious health complications. Despite the incidence of human tracheopulmonary infestation is rare, the severe medical impediments and heterogeneous worldwide distribution signify the medical importance of this condition. The present manuscript reviews and summarizes the worldwide reported cases of human tracheopulmonary myiasis and the predisposing risk factors for onset of the same, as future reference for parasitologists and medical professionals.

Gastrointestinal helminth and protozoan infections of wild mammals in four major national parks in Sri Lanka

A cross-sectional, coprological survey of gastrointestinal (GI) parasites of wild mammals in four major National Parks in Sri Lanka: Wilpattu, Udawalawe, Wasgamuwa, and Horton Plains was carried out during November 2016 to August 2017. Fresh fecal samples were collected and analyzed using sedimentation technique, iodine &amp; saline smears, and Sheather’s sucrose flotation for morphological identification parasite eggs, cysts, and larvae. A modified salt flotation was carried out for egg counts. Seventy samples from 10 mammal species: Asian Elephant, Spotted Deer, Water Buffalo, Sambar, Indian Hare, Asian Palm Civet, Sloth Bear, Wild Boar, Grey Langur, Leopard, and four unknown mammals (two carnivores, one herbivore and one omnivore) were analyzed. Most were infected (94.3%) with more than one GI parasites. The highest prevalence of infection was recorded in Horton Plains (100%), followed by Wasgamuwa (92.8%), Wilpattu (90.4%) and Udawalawe (75.0%) with a significant difference among four parks (Chi square test; χ2=35.435; df=3; p&lt;0.001). Nineteen species of GI parasites were recorded, of which Entamoeba, Isospora, Balantidium, Fasciola, Moniezia, Dipylidium, strongyles, Toxocara, Trichiurus and hookworms were the most common. Strongyles (62.1%) and Entamoeba (80.3%) were the most prevalent helminth and protozoan infections, respectively. Overall, there was no difference in the prevalence of protozoans (84.3%) and helminths (87.1%; χ2=1.0; df=1; p=0.317). In carnivores, Entamoeba, Balantidium, Moniezia, strongyles and Strongyloides were common and in herbivores, Entamoeba, strongyles, Strongyloides and Toxocara were common. The quantitative analysis showed strongyles (17.639 EPG) and Isospora (18,743 OPG) having the highest infection intensity among helminthes and protozoans, respectively. This study provides baseline information of GI parasites and their distribution in wild mammals in the four national parks. Although the prevalence of GI infections was high, their intensity shows that they could be incidental infections. When the prevalence of an infection is high but the intensity is low, it is unlikely to be a major health problem leading to the endangerment of a species. Parasitic diseases can not only affect conservation efforts, but they are also natural selection agents and drive biological diversification, through influencing host reproductive isolation and speciation.

RNAi-mediated silencing of Trichinella spiralis serpin-type serine protease inhibitors results in a reduction in larval infectivity

Trichinella spiralis serpin-type serine protease inhibitors (TsSPIs) are expressed in adult worms (AW), newborn larvae (NBL) and muscle larvae (ML) of T. spiralis, with the ML stage demonstrating the highest expression level. This study aims to determine TsSPI functions in larval viability and invasion of intestinal epithelial cells in vitro, as well as their development, survival, and fecundity in vivo via RNAi. TsSPI-specific siRNAs and dsRNA were transfected into ML by incubation. The silencing effect of TsSPI transcription and expression was determined using qPCR and western blot, respectively. After incubation in 60 ng/μL dsRNA–TsSPI for 3 days, larval TsSPI mRNA and protein expression levels were reduced by 68.7% and 68.4% (P < 0.05), respectively. dsRNA-mediated silencing of TsSPI significantly impacted larval invasion into intestinal epithelial cells in vitro but did not affect the survival rate of larvae. After challenge with dsRNA–TsSPI-treated ML, mice exhibited a 56.0% reduction in intestinal AW burden and 56.9% reduction in ML burden (P < 0.05), but NBL production of female AW remained the same (P > 0.05). Our results revealed that RNAi-mediated silencing of TsSPI expression in T. spiralis significantly reduced larval infectivity and survival in the host but had no effect on the survival rate and fecundity. Furthermore, TsSPIs have no effect on the growth and reproduction of parasites but may be directly involved in regulating the interaction of T. spiralis and the host. Therefore, TsSPIs are crucial in the process of T. spiralis larval invasion and parasite survival in the host.

Adjuvanted Schistosoma mansoni-Cathepsin B With Sulfated Lactosyl Archaeol Archaeosomes or AddaVax™ Provides Protection in a Pre-Clinical Schistosomiasis Model.

Schistosomiasis threatens 800 million people worldwide. Chronic pathology manifests as hepatosplenomegaly, and intestinal schistosomiasis caused by Schistosoma mansoni can lead to liver fibrosis, cirrhosis, and blood in the stool. To assist the only FDA-approved drug, praziquantel, in parasite elimination, the development of a vaccine would be of high value. S. mansoni Cathepsin B (SmCB) is a well-documented vaccine target for intestinal schistosomiasis. Herein, we test the increased efficacy and immunogenicity of SmCB when combined with sulfated lactosyl archaeol (SLA) archaeosomes or AddaVax™ (a squalene based oil-in-water emulsion). Both vaccine formulations resulted in robust humoral and cell mediated immune responses. Impressively, both formulations were able to reduce parasite burden greater than 40% (WHO standard), with AddaVax™ reaching 86.8%. Additionally, SmCB with both adjuvants were able to reduce granuloma size and the amount of larval parasite hatched from feces, which would reduce transmission. Our data support SmCB as a target for S. mansoni vaccination; especially when used in an adjuvanted formulation.