Vol 12 No 3 (2017)

Review Article(s)

  • XML | PDF | downloads: 344 | views: 561 | pages: 312-322

    Background: Chemotherapy still relies on the use of pentavalent antimonials, amphotericin B, paromomycin, miltefosin, and allopurinol. In this study, we explained about the native plant that grows in different regions of Iran and used as anti-leishmanial in Iran and even many other countries.

    Methods: This narrative review covers all information about local herbal medicine in Iran that used in treatment of cutaneous leishmaniasis in all the worlds, published in local and international journals from 1996 to 2015 using various databases including PubMed, SID, Google Scholar, Scopus, and Science Direct.

    Results: Overall, 150 articles in databases were identified. Many local plants grown in some places of Iran were used to treat this endemic disease.

    Conclusion: The cutaneous leishmaniasis is also a major health problem in Iran, especially in Mashhad (Northeast of Iran). Therefore, many patients seek for herbal therapy that is cheaper and readily available. This review provides information regarding plant that exists in Iran and exhibiting effects on anti- Leishmania activity. Among the anti-leishmanial mentioned in this review, most have never been tested for cytotoxicity and very few have been tested for in vivo activity.

Original Article(s)

  • XML | PDF | downloads: 364 | views: 561 | pages: 323-331

    Background: Cystic echinococcosis (CE) is one of the most important zoonotic diseases; caused by different genotypes of Echinococcus spp. Camels have an important role in transmission cycle of E. granulosus especially, in desert areas. This study aimed to investigate molecular characterization of hydatid cysts isolates from one-humped camel (Camelus dromedarius) and to show its molecular and phylogenic status in this important CE host in the central part of Iran.

    Methods: Twenty hydatid cyst samples (14 fertile and 6 calcified) were collected from 56 slaughtered camels in Central part of Iran. Extraction of DNA from 14 fertile samples was achieved followed by molecular studies on two mitochondrial genes (nad1 and cox1).

    Results: Blast and phylogenetic analysis on sequenced genes showed the presence of G1 (28.6%), G3 (28.6%) and G6 (35.7%) genotypes in the samples. However, one sample was detected as E. ortleppi (G5) with 99% homology with G5 isolated from camel in Egypt (AB921055) and Sudan (JX912709).

    Conclusion: Presence of E. ortleppi, originally the cattle genotype, is reported for the first time in Iran. Due to the potential of infecting human by E. ortleppi; more attention should be paid to this zoonotic genotype in this region.

  • XML | PDF | downloads: 261 | views: 374 | pages: 332-338

    Background: Toxoplasma gondii, as a eukaryotic parasite of the phylum Apicomplexa, can infect almost all the warm-blooded animals and humans, causing toxoplasmosis. Rhoptry neck proteins (RONs) play a key role in the invasion process of T. gondii and are potential vaccine candidate molecules against toxoplasmosis.

    Methods: The present study examined sequence variation in the rhoptry neck protein 10 (TgRON10) gene among 10 T. gondii isolates from different hosts and geographical locations from Lanzhou province during 2014, and compared with the corresponding sequences of strains ME49 and VEG obtained from the ToxoDB database, using polymerase chain reaction (PCR) amplification, sequence analysis, and phylogenetic reconstruction by Bayesian inference (BI) and maximum parsimony (MP).

    Results: Analysis of all the 12 TgRON10 genomic and cDNA sequences revealed 7 exons and 6 introns in the TgRON10 gDNA. The complete genomic sequence of the TgRON10 gene ranged from 4759 bp to 4763 bp, and sequence variation was 0-0.6% among the 12 T. gondii isolates, indicating a low sequence variation in TgRON10 gene. Phylogenetic analysis of TgRON10 sequences showed that the cluster of the 12 T. gondii isolates was not completely consistent with their respective genotypes.

    Conclusion: TgRON10 gene is not a suitable genetic marker for the differentiation of T. gondii isolates from different hosts and geographical locations, but may represent a potential vaccine candidate against toxoplasmosis, worth further studies.

  • XML | PDF | downloads: 242 | views: 568 | pages: 339-347

    Background: The present study aimed to evaluate the effect of methotrexate (MTX) alone and in combination with meglumine antimoniate (MA, Glucantime) against sensitive and MA-resistant Leishmania tropica stages in vitro.

    Methods: The present study was carried out in 2014 in Leishmaniasis Research Center at School of Medicine, Kerman University of Medical sciences, Kerman, Iran. The effects of MTX alone and along with MA on promastigote and amastigote stages of sensitive (SS) and MA-resistant (RS) L. tropica strains have been evaluated using a colorimetric MTT assay and in a macrophage model, respectively. In addition, the inhibitory effect of MTX on the Leishmania invasion of murine macrophages was assessed in promastigotes of both strains of L. tropica. Sensitive and MA resistant L. tropica are referred to those isolates that are responsive or non-responsive to one or two courses of treatment by MA systemically and/or intralesionally, respectively.

    Results: The findings of OD and IC50 showed that MTX plus MA (SS: 16.1 μg/ml, RS: 39.8 μg/ml) had a higher anti-leishmanial effect than MA (SS: 52.2 μg/ml, RS: 170 μg/ml) or MTX alone (SS: 22.2 μg/ml, RS: 51.4 μg/ml) on promastigotes of both strains of L. tropica. The MTX plus MA caused a significant decrease (P<0.05) in the mean infection rate (MIR) and the mean number of amastigotes in each macrophage compared with positive control. Infectivity of promastigotes is significantly (P<0.05) reduced when it was preincubated with MTX.

    Conclusion: This study indicated high potency and a synergistic effect of MTX on MA in inhibiting the growth rateof promastigote and amastigote stages of sensitive and meglumine antimoniate-resistant L. tropica. Further works are needed to evaluate the anti-leishmanial effects of MTX on L. tropica using a clinical setting.

  • XML | PDF | downloads: 264 | views: 605 | pages: 348-354

    Background: This study was conducted to determine the prevalence of Giardia duodenalis in captive animals in a wildlife facility. This is the first study conducted in these animals from the facility.

    Methods: Eight captive tigers (Panthera tigris), two Palawan bearcats (Arctictis binturong whitei) and one Asian Palm Civet (Paradoxurus hermaphroditus) currently housed at a wildlife facility in Manila, Philippines were considered in 2012. These animals were apparently healthy with no signs of disease during the study. Sample collection was done twice at two months interval where freshly voided fecal samples were grossly examined, characterized and preserved in Sodium Acetate Formalin (SAF). The samples were used to determine the presence of G. duodenalis using modified flotation-sedimentation and commercially available immuno-chromatographic assay test kit.

    Results: All fecal samples tested were negative for the presence of G. duodenalis trophozoites, and cysts using the former. Furthermore, none of the samples tested positive for and G. duodenalis antigen using immune-chromatographic assay.

    Conclusion: There is no existing infection of G. duodenalis among captive tigers, Palawan Bearcats and Asian palm civet housed at the wildlife facility. 

  • XML | PDF | downloads: 276 | views: 387 | pages: 355-363

    Background: Acanthamoeba is an opportunistic amphizoic protozoan found in different fresh water sources. The aim of this study was to identify and characterize Acanthamoeba isolates from surface resting waters, in Northwest Iran.

    Methods: Samples were collected from twenty-two different areas, between May and Sep 2014. After filtration, samples were cultivated on non-nutrient agar. The extracted DNAs were amplified and sequenced using partial 18S rRNA in order to genotype and phylogenetic analyses.

    Results: Thirty-four (68%) out of 50 collected samples were positive for free-living amoebae based on both culture and morphological characterizations but 28 samples were identified as Acanthamoeba spp. by PCR. Sequentially, one isolate was identified as A. lenticulata, (T5) (AN: KP940443, identity 99.7%-100%, and divergence 0.3%) whilst other sequenced isolates identified Acanthamoeba spp. (AN: KP940444-45) as very similar to A. rhysodes and A. royreba with identity 100% and divergence 0%.

    Conclusion: Surface resting waters in Northwest Iran, were potentially contaminated with pathogenic amphizoic protozoan. Further studies will be required to determine other Acanthamoeba species and genotypes in the region.

  • XML | PDF | downloads: 269 | views: 412 | pages: 364-373

    Background: Intestinal parasitic infections are among the most common infections and health problems worldwide. Due to the lack of epidemiologic information of such infections, the prevalence of, and the risk factors for, enteric parasites were investigated in residents of Roudehen, Tehran Province, Iran.

    Methods: In this cross-sectional study, 561 triple fecal samples were collected through a two-stage cluster-sampling protocol from Jun to Dec 2014. The samples were examined by formalin-ether concentration, culture, and with molecular methods.

    Results: The prevalence of enteric parasites was 32.7% (95% CI 27.3–38). Blastocystis sp. was the most common intestinal protozoan (28.4%; 95% CI 23.7–33.0). The formalin-ether concentration and culture methods detected Blastocystis sp., Entamoeba coli, Giardia intestinalis, Dientamoeba fragilis, Iodamoeba butschlii, Entamoeba complex cysts or trophozoite, Chilomastix mesnilii, and Enterobius vermicularis. Single-round PCR assay for Entamoeba complex were identified Entamoeba dispar and E. moshkovskii. E. histolytica was not observed in any specimen. Multivariate analysis showed a significant association of parasites with water source and close animal contact. There was no correlation between infections and gender, age, occupation, education, or travel history. Protozoan infections were more common than helminth infections.

    Conclusion: This study revealed a high prevalence of enteric protozoan parasite infection among citizens of Rodehen. As most of the species detected are transmitted through a water-resistant cyst, public and individual education on personal hygiene should be considered to reduce transmission of intestinal parasites in the population. 

  • XML | PDF | downloads: 243 | views: 551 | pages: 374-381

    Background: Hookworm infection is one of the important Neglected Tropical Diseases (NTD) in the world. It was previously more prevalent in the northern and southern parts of Iran with a prevalence rate higher than 40% in some endemic regions; nevertheless, the infection rate has decreased to less than 1%. This study aimed to determine prevalence and molecular aspects of hookworm infections in rural inhabitants of Fouman County, Guilan Province, northern Iran

    Methods: This cross-sectional study was performed in 31 villages of Fouman district in Guilan Province, northern Iran during 2015-2016. Stool samples were collected from 1500 rural inhabitants and examined by formalin ethyl-acetate concentration as well as agar plate culture techniques. After treatment with albendazole, adult hookworms were isolated. FollowingDNA extraction,PCR amplification of ITS2-rDNA region was performed and the product was sequenced, followed by genetic variation analysis.

    Results: Of 1500 samples, one case was morphologically diagnosed as N. americanus. In addition, molecular characterization verified the presence of N. americanus, showing more than 95% similarity with sequences of N. americanus present in GenBank. The patient showed no clinical symptoms and a mild hypereosinophilia was the only laboratory finding observed.

    Conclusion: A reduced prevalence of human hookworms was demonstrated within Guilan Province located in north of Iran. The N. americanus originated from Guilan had  a high homology with the isolates found in Japan, Laos, Malaysia, and Australia.
  • XML | PDF | downloads: 280 | views: 485 | pages: 382-388

    Background: Majority of parasitic infections in rodents have zoonotic importance. This study aimed to determine the frequency and intensity of intestinal protozoa infections of rodents including Meriones persicus, Mus musculus and, Cricetulus migratorius.

    Methods: This survey was conducted in Meshkin Shahr district in northwestern Iran from Mar. to Dec. of 2014. Intestinal samples of 204 rodents including M. persicus (n=117), M. musculus (n=63) and C. migratorius (n=24) were parasitologically examined. Formalin-ether concentration method was done for all of rodents stool samples and observed with light microscope. All of suspected cases were stained with trichorome staining Method. Cultivation in dichromate potassium 2.5% was carried out for all of coccidian positive samples. Acid fast and aniline blue staining methods were used for detecting of coccidian oocysts and intestinal microsporidial spores, respectively.

    Results: About 121(59.3%) of the caught rodents were generally infected with intestinal protozoa. Entamoeba muris 14(6.9%), Trichomonas muris 55(27.0%), Chilomastix betencourtti 17 (8.3%), Giardia muris 19(9.3%), Eimeria spp. 46(22.5%), Isospora spp. 4(2%) and Cryptosporidium spp. 1(0.5%) were found from the collected rodents. Microsporidian spores were identified in 63 (31%) out of the 204 collected rodents using aniline blue staining method.

    Conclusion: Since some of the infections are zoonotic importance thus, control of rodents can be decreased new cases of the parasitic zoonoses in humans.
  • XML | PDF | downloads: 258 | views: 428 | pages: 389-397

    Background: The aim of this study was the seroepidemiological survey for detecting the status of human fasciolosis in Lorestan Province, western Iran.

    Methods: This cross-sectional study was conducted in 2015-16. Based on statistical estimations, 1256 serum samples were collected from different parts of Lorestan Province, western Iran, and stored at -20 °C until use. The collected serum samples were analyzed at Tehran University of Medical Sciences, Tehran, Iran using indirect ELISA method.

    Results: Anti-Fasciola antibodies were detected in 16 (1.3%) individuals. Regarding the seropositivity to fasciolosis, no significant differences were found between age groups, sex, level of education and occupation; however significant differences were observed regarding location, consuming local freshwater plants and water resources (P<0.02.)

    Conclusion: Local freshwater plants and unfiltered water resources were probably the main sources of the infection. Health education by local health centers to elevate awareness of people, and providing facilities for safer drinking water, especially in rural areas may help decrease the risk of fasciolosis infection in this region.
  • XML | PDF | downloads: 270 | views: 401 | pages: 398-407

    Background: Leishmaniasis is a parasitic disease that appears with a range of symptoms including cutaneous, mucocutaneous, and visceral leishmaniasis. The present study sought to determine the antileishmanial effect of the extract of Artemisia dracunculus (Tarragon) compared to control treatment with pentavalent antimony (meglumine).

    Methods: This experimental study was performed in 2014-2015. A. dracunculus were collected from West Azerbaijan Province, Iran and dried; then the ethanolic extract of the plant was prepared. The effect of different concentrations of Artemisia's extract was compared with Glucantime ® in the stationary phase by MTT colorimetric assay and Trypan blue staining. Human peripheral blood mononuclear cells (HPBMCs) treated with L. major and production of IFN- γ and IL-4 cytokines measured at concentrations of 25, 20, 10 and 5µg/ml A. dracunculus.

    Results: Treatment with the extract did not affect the survival of the parasites during the first 48 h; however, on the third day (72 h), all concentrations significantly reduced the number of parasites with an efficacy of more than 50% at 10 µg/ml (P<0.01), 20µg/ml (P<0.001), and 25 µg/ml (P<0.0001). Moreover, IFN-γ and IL-4 secretion from the HPBMCs was significantly affected in a dose-dependent manner, compared to the control (no extract). The IFN-γ/IL-4 ratio further confirmed this notion.

    Conclusion: A. dracunculus extract cannot only exert potent antileishmanial activity but may also enhance cellular immunity to this parasite. Further studies are required to determine the main compound(s) responsible for these effects of the plant.
  • XML | PDF | downloads: 218 | views: 349 | pages: 408-412

    Background: This study aimed to reveal the serological prevalence of Neospora caninum in large dairy farms in Isfahan Province, central Iran.

    Methods: Serum samples were collected from 1500 cattle living in four large dairy farms in Isfahan Province, Iran during 2014-2015 and examined for anti N. caninum IgG antibodies.  Overall, 113 serum samples were also collected from the dogs living in these areas; suspecting to be risk factors for this infection. All the serum samples were investigated to find IgG antibodies by using ELISA. Dogs' sera were also analyzed by indirect fluorescent antibody test.

    Results: Totally, 395 out of 1500 bovine samples (26.33%) were positive for N. caninum: 34%, 21.61%, 23.03% and 29.01% in four investigated clusters (farms). Infection rate was significantly more in cows with the history of abortion. The infection rate in dogs was 17.69%: (20 out of 113).

    Conclusion: The results show a high seroprevalence of the infection and possibly the role of the dogs in horizontal transmission of the infection. 

  • XML | PDF | downloads: 288 | views: 431 | pages: 413-422

    Background: The aim of this study was to compare between slow and rapid sand filters for the removal of free-living amoebae during drinking water treatment production.

    Methods: Overall, 48 water samples were collected from two drinking water treatment plants having two different filtration systems (slow and rapid sand filters) and from inlet and outlet of each plant. Water samples were collected from Fayoum Drinking Water and Wastewater Holding Company, Egypt, during the year 2015. They were processed for detection of FLAs using non-nutrient agar (NNA). The isolates of FLAs were microscopically identified to the genus level based on the morphologic criteria and molecularly confirmed by the aid of PCR using genus-specific primers.

    Results: The percentage of removal for FLAs through different treatment processes reached its highest rate in the station using slow sand filters (83%), while the removal by rapid sand filter system was 71.4%. Statistically, there was no significant difference (P=0.55) for the removal of FLAs between the two different drinking water treatment systems. Statistically, seasons had no significant effect on the prevalence of FLAs in the two different drinking water treatment plants. Morphological identification of the isolated FLAs showed the presence of 3 genera namely Acanthamoeba, Naegleria, and Vermamoeba (Hartmannella) confirmed by PCR.

    Conclusion: The appearance of FLAs especially pathogenic amoebae in completely treated drinking water may cause potential health threat although there is no statistical difference between the two examined drinking water filtration systems.
  • XML | PDF | downloads: 334 | views: 619 | pages: 423-432

    Background: Malaria outbreaks are common in Zimbabwe. They are common in Manicaland, which has the greatest burden of malaria in the country.

    Methods: A matched case control study was conducted to investigate the malaria outbreak in ward 13 and 14 of Chipinge district in Manicaland Province in Zimbabwe, week 30 to week 40 of year 2015. A sample size of 92 (46 cases and 46 controls) was used. Guided interviews were conducted with the aid of a structured questionnaire and a checklist. The investigation assessed factors associated with contracting malaria and the community knowledge levels on malaria.

    Results: Participants who stayed in houses with open eaves had 2.4 odds (95% CI=1.0; 5.6) of contracting malaria compared to those who lived in houses without open eaves. Staying within a radius of 3 km from the river or swamp also predisposed people to contracting malaria (OR =2.7, 95%CI=1.2; 6.3). People who had no insecticide treated mosquito nets hanged in their bed rooms had odds of 2.2 (95%CI=1.2; 6.4) of contracting malaria compared to those that hanged insecticide-treated mosquito nets in their bedrooms. Consequently, among people exposed to outdoor activities in the evening and at night, those that had insecticide-treated mosquito nets hanged in their rooms were more protected from malaria than those that did not.

    Conclusion: There is high need to intensify all pillars in the malaria prevention and control programs and maintenance of a strong surveillance system to prevent future occurrences of outbreaks.

  • XML | PDF | downloads: 289 | views: 413 | pages: 433-440

    Background: Dirofilaria immitis, a filarial nematode, is the most important parasite-affecting dogs, causing cardiopulmonary dirofilariasis. Current diagnostic tools for detecting D. immitis include morphological assays, antigen detection, and X-ray. Herein, we developed a method for the molecular detection of D. immitis in blood using polymerase chain reaction (PCR).

    Methods: The study was conducted at Eulji University, Republic of Korea in 2016. To detect D. immitis-specific gene regions, we aligned the cytochrome c oxidase subunit I (COI) genes of seven filarial nematodes and designed primers targeting the unique region. We used dog glyceraldehyde-3-phosphate dehydrogenase (GAPDH)-targeted primers as the internal control. We conducted PCR-amplified genomic DNA from canine blood samples. The products were confirmed by sequencing.

    Results: Gene alignment revealed a D. immitis COI-specific gene region, and the activity of designed primers was confirmed by PCR and sequencing. Plasmid DNA made from the PCR products was a positive control. The limit of detection for our method was 50 copies. The D. immitis COI and dog GAPDH genes could be discriminated from blood samples simultaneously.

    Conclusion: This study provides a method for highly specific and sensitive molecular diagnosis of D. immitis used as a diagnostic and therapeutic tool from the early stage of infection.

Short Communication(s)

  • XML | PDF | downloads: 237 | views: 336 | pages: 441-445

    Background: Leishmaniasis is a neglected disease affecting millions of people worldwide. The treatment of the disease is hampered due to high cost, toxicity and the crisis of drug resistance. Polytope approaches of genetic immunization could be a strategy for prevention of infectious diseases. Furthermore, the identification of Leishmania genome sequence and the application of bioinformatics assist us to devise an effective vaccine’s candidate.

    Methods: A linear sequence from predicted epitopes of GP63, LACK and CPC antigens was designed and was optimized using online available algorithms. The synthesized sequence (LAKJB93) was ligated to pEGFP-N1 plasmid.

    Results: The 264bp sequence was cloned at N terminal of GFP into pEGFP_N1 expression vector and transfect into CHO cell line. Construct was efficient expressed in CHO cells.

    Conclusion: The protein of LAKJB93 cosnstruct was expressed in CHO cells successfully.
  • XML | PDF | downloads: 309 | views: 419 | pages: 446-452

    Background: The development of new antischistosomal drug remains a pressing need and a vital challenge in front of many researchers through screening the natural or chemical substances for their potential activity as antischistosomal agents.

    Methods: Five groups of Schistosoma mansoni-infected mice (n=10) were enrolled in this study, the G1 was infected non-treated control group. G2 was infected treated with praziquantel 500 mg/kg for 2 consecutive days. G3 was given mirazid 500 mg/kg for 5 days. G4 was given Myrrh total oil 18 mg/kg for 3 days and G5 given nitazoxanide 100 mg/kg for 7 days. Mice perfusion was performed for worm ultrastructural morphology by scanning electron microscopy at 2 WPT.

    Results: Praziquantel was superior to any other tested substances as it caused extensive tegumental damages in male worms in the form of rupture of the tubercles and loss of spines followed by mirazid that resulted only in superficial tegumental damage with shrinkage of the outer surface of male tubercles with marked loss of spines. Nitazoxanide resulted in minor tegumental alterations of male worms while Myrrh total oil caused negligible effects on the teguments of perfused worms.

    Conclusion: PZQ showed more superior antiparasitic effects than all tested substances on S. mansoni worms. Mirazid was more effective than myrrh total oil and nitazoxanide.
  • XML | PDF | downloads: 250 | views: 391 | pages: 453-460

    Background: The reservoir and intermediate hosts of Echinococcus granulsus and human hydatidosis are more prevalent in the Alborz and Zagros Mountains slop due to rich pastures for sheep raising. Many cases of hydatid cysts operate in local hospitals annually. The present study aimed to review the epidemiologic characteristics of the hydatidosis patients.

    Methods: In this descriptive study, the medical files of 182 hydatidosis patients from main public and private hospitals in Hamadan Province, western Iran from 2006 to 2013 were reviewed. The data collected from eight general hospitals including demographic data, clinical and diagnostic measures, surgical approaches, and outcome were entered into the prepared checklist and analyzed by descriptive statistics.

    Results: All patients were diagnosed and operated giving an average of 26 cases per year, or 1.5 cases per 100000 inhabitants. The site of cysts was as follows: liver 70.9%, lung 24.7%, and in both these organs 2.2%. The ratio of male and female patients was approximately 1:1. Mean age of patients was 44.5±21.5 yr at range of 3 to 91 yr. The majority the patients were illiterate (32.2%) and resided in the rural areas (61.7%), and their occupations were housewives (36.8%). Almost 90% of patients diagnosed by imaging methods and 8% had history of surgery for cyst.

    Conclusion: Hydatidosis is a major health problem still in this region and more extensive epidemiological investigations of CE is necessary to better determine the prevalence, economic impact and risk factors for the disease control.

Case Report(s)

  • XML | PDF | downloads: 218 | views: 483 | pages: 461-465

    Echinococcosis is a multisystem disease and has propensity to involve any organ, an unusual anatomical site, and can mimic any disease process. The hydatid cyst of the mesenteries known to occur secondary to hepatic involvement but occasional cases of his primitive form has also been reported. We report here one such case of primitive mesenteric hydatid cyst herniated through inguinal canal in a 5-yr-old boy, admitted to our Pediatric Surgery Department of Children’s Hospital in Tunis, Tunisia in 2015.

  • XML | PDF | downloads: 229 | views: 423 | pages: 466-469

    Myiasis is an animal or human pathogenic condition initiated by parasitic dipterous fly larvae feeding in the host’s necrotic or living tissue. Here we report a case of external ophthalmomyiasis caused by Lucilia sericata in a 78-yr-old with a vascular tumor of the retina and surgery history, from Bijar City of Kurdistan Province, Iran in 2015. Associated symptoms included right eye pain with mucoid ocular discharge, headache, sensing the presence of a foreign body in the eye and itching. Examination revealed a L. sericata Larva in his right eye. Infestation of ocular tissue by fly larvae (ophthalmomyiasis) progresses after retinal surgery and can destroy orbital tissues within days, especially in patient with poor hygienic conditions. Treatment consists of removal of the larvae and surgical debridement. Following removal of larva, the symptoms completely resolved within a few hours and remained asymptomatic several weeks later.