Larval Forms Research Articles

Splenic hydatidosis with abdominal pain – a rare presentation in a developing nation

Introduction. Primary extrahepatic hydatid cysts are rare, and primary splenic hydatid cysts even rarer. Splenic hydatidosis constitutes 2% to 3.5% of all hydatid cysts. Aim. To present a case report of splenic hydatidosis with abdominal pain. Description of the case. We report here a case of isolated splenic hydatid cysts in a 23 year old female, who presented with dull dragging pain in the left hypochondrium. Diagnosis was made on computed tomography imaging of the abdomen and microscopic examination of the laminated hydatid cyst wall and supplemented with positive enzyme linked immunosorbent assay for hydatid antibodies. Conclusion. The incidence of splenic involvement by hydatid cysts is very low. Man is an accidental intermediate host, as entry of the larval forms into humans represents an end stage in its life cycle. Until recently the gold standard treatment for splenic hydatidosis was splenectomy, as medical therapy seems to be ineffective. However, the last two decades have shown a tendency towards splenic conservative surgery in suitable cases, to reduce opportunistic post splenectomy infection.

First report of Taenia pisiformis Cysticercus infestation in Domestic rabbits in Hajjah city Yemen

Cysticercus pisiformis is larval forms of Taenia pisiformis tapeworm. t has been observed in rabbits that are considered the intermediate host. In this study Cysticercus pisiformis was observed in domestic rabbits at routine necropsy examination.

Neurocysticercosis in a 14-year-old Nigerian: A case report and review of the literature

Neurocysticercosis (NCC), an infection of the brain by the larval form of Taenia solium tapeworm, has been described as the most common cause of acquired adult seizure and epilepsy in regions of the world where the worm infestation is endemic. It is acquired following ingestion of raw or partially cooked pork-containing cysts of T. solium. We report the case of a 14-year-old male patient, who presented with recurrent tonic–clonic partial seizures of 3 months duration, seizures, and progressive weakness of the left limb, while being fully conscious. He had a left facioparesis of the upper motor neuron type with plastic left hemiparesis. An impression of a right frontal cortical lesion was made. The laboratory investigations as well as the chest radiograph were reported as being essentially unremarkable. The magnetic resonance image of the brain revealed a circumscribed right parietal lesion which was circumscribed. A provisional diagnosis of intracranial tumor was then made. Surgery involved an en bloc resection of a cystic right parietal mass. The gelatinous fluid contained within was submitted for cytological examination. The latter revealed the presence of a cysticercus comprising the scolex, spiral canal, and the bladder wall. A diagnosis of NCC was made, and the patient was thereafter commenced on antihelminthics. The patient made an appreciable recovery thereafter. This report is to emphasize the continued existence of this disease, the need to improve diagnostic suspicion, and skill. This report further supports the proposal to declare NCC an international reportable disease.

Effects of geographical and climatic factors on cystic echinococcosis in south-western Iran.

Cystic echinococcosis (CE) is caused by the larval form of Echinococcus granulosus that can cause serious health and economic problems in the endemic foci. CE is globally distributed in various climatic conditions from circumpolar to tropical latitudes. Iran is an important endemic area with a spectrum of weather conditions. The aim of this study was to determine the effects of geo-climatic factors on the distribution of livestock CE in south-western Iran (SWI) in 2016 to 2018. Data of livestock CE were retrieved from veterinary organizations of four provinces of SWI. The geo-climatic factors, including mean annual temperature (MAT), minimum MAT (MinMAT), maximum MAT (MaxMAT), mean annual rainfall (MAR), elevation, mean annual evaporation (MAE), sunny hours, wind speed, mean annual humidity (MAH), slope, frost days and land cover, were analysed using geographical information systems (GIS) approaches. The statistical analysis showed that MAR, frost days, elevation, slope and semi-condensed forest land cover were positively and MAE, MAT, MaxMAT, MinMAT and salt and salinity land cover were negatively correlated with CE occurrence. MAE was shown to be a predictive factor in the stepwise linear logistic regression model. In short, the current GIS-based study found that areas with lower evaporation were the main CE risk zones, though those with lower temperature and higher rainfall, altitude and slope, especially where covered with or in close proximity of semi-condensed forest, should be prioritized for consideration by health professionals and veterinarians for conducting control programmes in SWI.

Cysticercosis of tongue in a 4-year-old child: Rare entity

Cysticercosis is a parasitic disease caused by larval form of tapeworm. Infestation of human tissues is uncommon, and affliction of the oral cavity and tongue is rare. We are reporting a case of 4-year-old male child with painless cystic mass on the right border of tongue 1 cm × 2 cm × 2 cm in size firmly attached to tongue for 2 months. Histopathology reveals cysticercosis of tongue.

Myiasis by <i>Cochliomyia hominivorax</i> (Coquerel, 1858): A Neglected Zoonosis in Brazil

Myiasis is the lesion resulting from the parasitism of diptera larval form in the living tissues of vertebrate animals. These are bloody conditions, causing severe damage to the welfare and the health of humans and animals. In Brazil, Cochliomyia hominivorax is the main responsible species for causing myiasis in humans and animals. The conventional treatment of these lesions in animals massively uses chemosynthetic products. The irrational use of these molecules has led to environmental degradation and has affected human health. The standard treatment of human myiasis is based only on larvae removal, surgically or not, supported by the use of antiparasitic drugs. Human myiasis is an important zoonosis, given its close relation with animal myiasis. However, this zoonosis has currently been neglected in Brazil and other developing countries in America. The One Health approach makes it possible to realize that the occurrence of myiasis in humans is directly related to the maintenance of stocks of this diptera in nature. Recognizing the direct relation that domestic and wild animals have as reservoirs in the human myiasis cycle is essential, in order to formulate strategies to control this ancient and important disease that still affects the population in Brazil.

Evolution of Feeding Shapes Swimming Kinematics of Barnacle Naupliar Larvae: A Comparison between Trophic Modes.

SynopsisA central goal in evolutionary biology is connecting morphological features with ecological functions. For marine invertebrate larvae, appendage movement determines locomotion, feeding, and predator avoidance ability. Barnacle larvae are morphologically diverse, and the morphology of non-feeding lecithotrophic nauplii are distinct from those that are planktotrophic. Lecithotrophic larvae have a more globular body shape and simplified appendages when compared with planktotrophs. However, little is known about whether and how such morphological changes affect kinematics, hydrodynamics, and ecological functions. Here, we compared the nauplii kinematics and hydrodynamics of a lecithotrophic Rhizocephalan species, Polyascus planus, against that of the planktotrophic nauplii of an intertidal barnacle, Tetraclita japonica. High-speed, micro-particle image velocimetry analysis showed that the Polyascus nauplii swam faster and had higher amplitude and more synchronous appendage beating than the Tetraclita nauplii. This fast swimming was accompanied by a faster attenuation of induced flow with distance, suggesting reduced predation risk. Tetraclita nauplii had more efficient per beat cycles with less backward displacement during the recovery stroke. This “anchoring effect” resulted from the anti-phase beating of appendages. This movement, together with a high-drag body form, likely helps direct the suction flow toward the ventral food capturing area. In sum, the tradeoff between swimming speed and predation risks may have been an important factor in the evolution of the observed larval forms.

Cysts that Still Persist: A Case Series of Cysticercosis on Histopathological Evaluation.

Cysticercus is the infective larval form of the cystode T. solium that causes cysticercosis. It is has been declared as one of the neglected endemic zoonoses by the WHO. Poor sanitation, and consumption of undercooked infected pork and raw vegetables contaminated by human feces are the potential sources. Cysticercosis can affect various organs. India is one of the endemic countries where the parasite is prevalent in many states. This study aimed to analyze and report cases of cysticercosis based on the histopathological diagnosis. This is a retrospective study that included cases which had been reported as cysticercosis on histopathology from 2010 to 2018 at a tertiary care hospital. The clinical presentation of these cases along with macroscopic and microscopic features were reviewed. There were six cases of cysticercosis that were diagnosed on histopathology during the study period. Among them, two cases were intramuscular lesions, three were subcutaneous, and one case was an intraventricular lesion in the brain. Three of the cases presented as cystic lesions. On histopathological evaluation, cysts were identified in four cases on macroscopy. Microscopically, the cross section of the cysticercus was seen in all six cases with associated inflammatory change. To conclude, cysticercosis can clinically present as a benign neoplastic or an inflammatory lesion. Microscopic findings dictate the diagnosis of cysticercosis, although histopathological evaluation is not common.

Combined cross-sectional and case-control study on Echinococcus multilocularis infection in pigs in Switzerland

The canid tapeworm Echinococcus multilocularis causes alveolar echinococcosis (AE) in humans and other intermediate hosts. Depending on the permissiveness of the intermediate host, the larval form of E. multilocularis (metacestode) may be either fertile, e.g. in rodents, and thus supporting the life cycle of the parasite, or infertile, e.g. in pigs, and thus interrupting the life cycle. Pigs have been shown to act as aberrant hosts for the metacestode and consequently develop liver lesions but represent a dead-end for the parasite. Routine liver inspection at slaughter provided the basis for a large-scale surveillance study on E. multilocularis infection in pigs. The aim of this combined cross-sectional and case-control study was to estimate the minimal prevalence of E. multilocularis in pigs in Switzerland, to find factors associated with infection, and to assess potential regional clusters of infection.During the 12-month-study period, approximately 85% of all pigs slaughtered in Switzerland were assessed. In total, 450 pig livers with macroscopic lesions suggestive of E. multilocularis infection were analysed. Of those, 200 samples were positive by E. multilocularis-PCR. Thus, the overall minimal prevalence detected by molecular means was 0.009% in all slaughter pigs (200 of 2'143'996), 0.008% in finishing pigs (177 of 2'123'542), and 0.11% in breeding pigs (22 of 20'454). Histology revealed the unique presence of a laminated layer in 105 cases, and an additional germinal layer detected in a single case. Protoscoleces could not be observed in any of the lesions. Factors positively associated with infection were "foxes seen in the pig shed", "foxes on premises", "presence of other animals in the shed", "absence of a hygiene barrier", "outdoor feeding", "feeding grass", "lack of rodent control", "not having own dogs on the farm" and "infrequent deworming of sows". Infection was present in all regions sampled and was representative of the important pig rearing areas of Switzerland, without evidence of any obvious geographical cluster.Conclusively, our study provided further evidence of widespread environmental contamination with E. multilocularis eggs in Switzerland. Furthermore, the absence of protoscoleces in any of the lesions supported the concept that pigs act only as a dead-end host and thus do not contribute to the life cycle of the parasite. Factors associated with E. multilocularis infection were in-line with parasite biology, and many can be addressed by increasing hygiene and management standards.

Ambient Illumination Influence on Photuris Firefly Larval Surface Movements is not Mediated by the Stemmata

Movements of fireflies visible on the surface of soil were measured under controlled laboratory conditions consisting of high and low ambient illumination. High illumination approximating the intensity of light prior to sunset constituted our light condition. Low illumination was consistent with ambient light levels after civil sunset, which we referred to as our dark condition. Surface movements were significantly more frequent during dark conditions compared to light conditions. Stemmata are the larval form of the insect eye and were the only identified visual organs present in Photuris larvae. We investigated whether stemmata provided larvae with the sensory information facilitating the light dependency of surface movements. We disrupted transmission of visual information from the larval eyes to the brain by severing the optic nerves. The amount of surface movement was compared between larvae with intact and severed optic nerves, under light and dark conditions. Light dependency of surface movements was preserved in larvae with cut optic nerves. The presence of the light dependency after cutting the optic nerves indicated that an alternative, extrastemmatal sensory pathway must be providing light intensity information to the animal. Light dependency was abolished upon removal of the head. Thus, these results suggested that the extraocular system providing light intensity information for regulating the frequency of surface movement was located in the head. The precise location of the suggested extraocular receptor and the nature of the associated sensory system remains unknown.

Incidental Detection of Microfilaria in Fine Needle Aspiration Cytology- A Report of Three Cases

Lymphatic filariasis, a major global health problem, is a mosquito-borne parasitic disease, encountered mainly in the tropics and subtropics. The disease is endemic in Southeast Asia, including the Indian subcontinent. It is transmitted by mosquitoes and is caused by the filarial nematodes Wuchereria bancrofti, Brugia malayi and Brugia timori. Usually, the infected person remains asymptomatic for years together and later manifests with features and consequences of lymphatic obstruction. The adult forms of the nematodes live in human lymphatics, whereas the infective larval form, the microfilaria circulates in the peripheral blood. The nocturnal periodicity of the microfilaria makes it challenging to detect in routine peripheral blood smear examinations. Also, it is quite unusual to find the microfilaria in fine needle aspirations. However, rare cases have been reported in certain unusual sites, like lymph nodes, cutaneous swellings, bone marrow, bronchial aspirate, breast, nipple discharge, cervicovaginal smears, pleural, pericardial, ascitic fluids, ovarian cyst fluids or even thyroid. Very few cases of microfilaria in thyroid aspirates have been reported till date. Also, it is unusual to find microfilaria in lymph node and breast aspirations. Herewith, three cases of microfilariasis are reported at three uncommon sites like thyroid, lymph node and breast.

Human hydatidosis in Alborz Province: a 5-year retrospective epidemiological analysis of hospitalized cases (2014-2019).

Hydatid cyst is a neglected zoonotic infection that is transmitted by the larval form of Echinococcus granulosus. It is widely distributed around the world and also it is endemic in many developing countries such as Iran. The aim of the current study is an assessment of the surgical cases in the general population of Alborz Province in Iran. The surgical cases of cystic echinococcosis were studied in the Educational and Therapeutic Centers or hospitals related to Alborz University of Medical Sciences from 2014 to 2019. Out of 26 records from patients with hydatid cyst surgery, 15 (57.7%) were female and 11 (42.3 %) were male. The age range was between 15-70 years old. The most infected organ was liver 21 (80.8%) followed by lungs 4 (15.4%) and one case of pelvic cyst 1 (3.8%). Based on residential status, 61.4% and 38.6% were living in rural and urban areas, respectively. The most and the least groups effected by hydatid cyst were housewives (38.46%) and employees (7.69%), accordingly. Twelve (46.15%) patients stated had a history of contact with dog. The prevalence of hydatid cyst in Alborz Province confirmed the importance of a proper protection plan against infection and it must be under control in main hosts. However, there is lack of data on status of parasitic infections in stray dogs in current region, as they play a key role in the transmission of the hydatid disease to humans.

Portal Cavernoma Complicating a Persistent Postoperative Bile Leak after Liver Hydatid Cyst Surgery: -a Report Case-

INTRODUCTION: Hydatid cyst is a parasitic infection caused by the larval form of Echinococcus granulosis. Portal hypertension is an unusual postoperative complication after a liver hydatid cyst surgery. CASE PRESENTATION: To illustrate this rare condition, we present the case of a 32-year-old patient operated for a liver hydatid cyst with late-onset postoperative complications. The patient suffered from secondary digestive bleeding because of portal hypertension and was therefore treated with a distal splenorenal shunt (Warren). CONCLUSION: Surgery of hydatid cyst may cause severe complications like portal hypertension and in certain cases, distal splenorenal anastomosis might represent an important treatment option that needs to be performed in specialised centres. Keywords: Liver cyst, Portal hypertension, Splenorenal shunt.

Investigation of the Genus Anisakis Among Atlantic Chub Mackerels (Scomber colias Gmelin, 1789) in Tripoli's Main Fish Markets, Libya

Parasitism is a common incident in the marine environment and all species of fish are susceptible to being infested by various parasites. Thousands of parasitic species of fish are described in adult or larval form, which mainly belong to the groups of protozoa, arthropods, plathihelminths (trematodes and cestodes) and nematohelminths (nematodes). Anisakidosis is a zoonosis caused by the intake of the nematode of the genus Anisakis in its third larval stage (L3). Atlantic chub mackerel (Scomber colias Gmelin, 1789), has great importance, both ecologically and economically in the Libya. From the economic point of view, it is possible to mean that Atlantic chub mackerel is the one of most abundant and frequent medium-sized pelagic species of fishing in the Libyan coastline. Atlantic chub mackerel is one of the most commercial significant species for the Libyan fishery. Consequently, in the period between 1st March to 28th April 2018, a total of 83 Atlantic chub mackerels were collected from two main fish markets in Tripoli, Libya to evaluate the parasitosis by infective larvae of the genus Anisakis spp. by the dissection method. Among the all examined fish, 15 (18.07%) were infested in the abdominal cavity with nematodes parasites, and identified as a third stage larvae, belonging to the Anisakis simples. Statistical analysis revealed there is no correlation between abundance of the infection by A. simplex with the host length. Furthermore, values of the infection intensity were significantly higher in the female of S. colias. However, this study indicates the need to continue efforts for in-depth investigate this metazoan parasite in different fish and cephalopod species in the coast of Tripoli, to represent the adequate risk of anisakidosis, and to alert the possible chance of the initial man case of anisakidosis in Libya, particularly among people who are more occupationally susceptible; like the fishmongers, fish processors, as well as to some residents population who prefer consume the raw or lightly cooked fish.

Retinoic Acid Signaling Regulates the Metamorphosis of Feather Stars (Crinoidea, Echinodermata): Insight into the Evolution of the Animal Life Cycle.

Many marine invertebrates have a life cycle with planktonic larvae, although the evolution of this type of life cycle remains enigmatic. We recently proposed that the regulatory mechanism of life cycle transition is conserved between jellyfish (Cnidaria) and starfish (Echinoderm); retinoic acid (RA) signaling regulates strobilation and metamorphosis, respectively. However, the function of RA signaling in other animal groups is poorly understood in this context. Here, to determine the ancestral function of RA signaling in echinoderms, we investigated the role of RA signaling during the metamorphosis of the feather star, Antedon serrata (Crinoidea, Echinodermata). Although feather stars have different larval forms from starfish, we found that exogenous RA treatment on doliolaria larvae induced metamorphosis, like in starfish. Furthermore, blocking RA synthesis or binding to the RA receptor suppressed metamorphosis. These results suggested that RA signaling functions as a regulator of metamorphosis in the ancestor of echinoderms. Our data provides insight into the evolution of the animal life cycle from the viewpoint of RA signaling.

HEMOPHAGOCYTIC LYMPHOHISTIOCYTOSIS (HLH) ASSOCIATED WITH SCRUB TYPHUS: REPORT OF 2 CASES

Hemophagocytic Lymphohistiocytosis (HLH) is a fatal hyperinflammatory syndrome characterized by histiocytic proliferation along with hemophagocytosis. HLH can be primary (inherited) or secondary, to any severe infection, malignancy or rheumatological disease. HLH, though rare, has also been noted in association with scrub typhus which is an acute febrile illness resulting from the bite of infected larval form of mite (also known as chigger). We hereby describe two cases of HLH associated with rickettsial infection (Oriental tsutsugamushi) in a 36-year-old male and in a 10-year-old male child. The former presented with high-grade fever and pruritic macular rash over abdomen. While the latter was presented with fever and decreased urinary output at the time of admission.

In vitro anti-echinococcal activity of octreotide: Additive effect of metformin linked to autophagy

Cystic echinococcosis (CE) is a worldwide zoonosis caused by the Echinococcus granulosus larval stage. The currently available therapy for this disease is based on benzimidazoles, which are rarely curative and cause several adverse effects. Therefore, new treatment options are needed. Octreotide (Oct) is a somatostatin analogue which exhibits anti-proliferative and anti-secretory effects over several cancer cell lines expressing somatostatin receptors. Here, we assessed the in vitro pharmacological effect of Oct against the E. granulosus larval stage. The drug caused a significant dose-dependent decrease in the viability of both protoscoleces and metacestodes. SEM and TEM analysis showed ultrastructural damage in both larval forms under drug treatment. Based on this, we investigated the possible presence of an Oct binding receptor in the parasite. The putative somatostatin/allatostatin-like receptor (Eg-s/ast) conserves the characteristic topology and signature sequences of the prototype somatostatin receptor common to vertebrates and is expressed in both metacestodes and protoscoleces. Moreover, Oct treated-parasites showed the presence of autophagic structures and a significant increase in transcriptional expression of autophagy key genes such as Eg-atg6, Eg-atg8, Eg-atg12 and Eg-atg16. In addition, by in toto immunolocalization assays, an increase in the punctate pattern and Eg-Atg8 protein expression was detected in Oct-treated metacestodes. Subsequently, the combination of Oct and Met had an additive effect on the viability of both larval forms. Our results provide additional evidence for the participation of PI3K/AKT/TOR/autophagy pathway in the Echinococcus survival and suggest the concomitant use of these drugs as potential therapeutic agents in treating of CE.

Paraphyly of Conodiplostomum Dubois, 1937

Adult trematodes of the genera Conodiplostomum Dubois, 1937 and Neodiplostomum Railliet, 1919 (Trematoda: Diplostomidae) parasitize the intestines of birds of prey, owls and, rarely, passeriform birds. Although the family is taxonomically unsettled, molecular phylogenetics have not been applied to analyze Conodiplostomum and Neodiplostomum and the reference DNA sequences from adult Diplostomidae are scarce and limit studies of their indistinct larval forms. We analyze the Conodiplostomum and Neodiplostomum spp. found during the examination of Czech birds performed from 1962 to 2017, and we provide comparative measurements and host spectra, including prevalence and intensity; we also provide and analyze the sequences of four DNA loci from eight diplostomid species. Molecular phylogenetic analysis suggested that Conodiplostomum spathula (Creplin, 1829), the type species of this genus, is nested in Neodiplostomum. Thus, we suggest the rejection of Conodiplostomum spathula (Creplin, 1829) and the resurrection of Neodiplostomum spathula (Creplin, 1829) La Rue, 1926 and reclassification of all species of Conodiplostomum with the neodiplostomulum type of metacercariae to Neodiplostomum as well. Conodiplostomum canaliculatum (Nicoll, 1914) is reclassified as Neodiplostomum spathulaeforme (Brandes, 1888). The molecular analysis suggested that Conodiplostomum perlatum (Ciurea, 1911), the species with the neascus type of metacercariae, belongs to Crassiphialinae Sudarikov, 1960. We erect the genus Ciureatrema gen. nov. Heneberg & Sitko and reclassify Conodiplostomum perlatum (Ciurea, 1911) as Ciureatrema perlatum (Ciurea, 1911) and establish it as a type species of Ciureatrema gen. nov. Further research should focus on the evolution of the neascus and neodiplostomulum types of metacercariae, as well as the evolution of the genital cone and pseudosuckers in Diplostomidae.

Muscle attachment site patterns for species determination in West Palaearctic Wohlfahrtia (Diptera: Sarcophagidae) of medical and veterinary importance

The flesh fly genus Wohlfahrtia Brauer & Bergenstamm contains at least six species of medical and veterinary importance. Traditional methods of species identification in specimens of Wohlfahrtia, however, are restricted mostly to adult forms. Muscle attachment site (MAS) patterns allow for species determination in larval forms. MAS patterns in third instar larvae of six common West Palearctic species of Wohlfahrtia have been analyzed for this study. As in previously investigated Calliphoridae and Sarcophagidae, MAS patterns were found to be species specific. A genus pattern was established to be used as base for comparison in further species determination. For the first time a tool is provided for species identification of such broad range in larvae of Wohlfahrtia species. Wohlfahrtia patterns are composed of a significantly higher number of MAS than patterns found in Sarcophaga. Specifics of the six species analyzed are explained in detail. The larvae of the well-known species W. magnifica, an obligate traumatic myiasis agent, had to be excluded from the analysis as a great number of spines on the outside obscure muscle attachment sites on the inside of the cuticle.

Lingual Cysticercosis: A Case Series with Review of Literature.

Cysticercosis is a condition in which humans are infected by the larval form of Pork Tapeworm Taenia solium. Isolated lingual cysticercosis is a rare entity due to the high muscular activity and metabolic rate of tongue which prevents the development of larva. We present a series of three patients with isolated lingual cysticercosis. One patient was treated by medical management while the other two were treated with surgical excision followed by medical therapy. All patients are asymptomatic after repeated follow ups.