Cyathostomin resistance to moxidectin and combinations of anthelmintics in Australian horses.

BACKGROUND: Cyathostomins are the most important and common parasitic nematodes of horses, with > 50 species known to occur worldwide. The frequent and indiscriminate use of anthelmintics has resulted in the development of anthelmintic resistance (AR) in horse nematodes. In this study we assessed the efficacy of commonly used anthelmintics against cyathostomins in Australian thoroughbred horses. METHODS: Two drug efficacy trials per farm were conducted on two thoroughbred horse farms in the state of Victoria, Australia. In the first trial, the horses on Farm A were treated with single and combinations of anthelmintics, including oxfendazole (OFZ), abamectin (ABM), abamectin and morantel (ABM + MOR), moxidectin (MOX) and oxfendazole and pyrantel (OFZ + PYR), at the recommended doses, whereas the horses on Farm B only received MOX, at the recommended dose. The faecal egg count reduction test (FECRT) was used to determine the efficacy and egg reappearance period (ERP) of anthelmintics. Based on the results of the first trial, the efficacies of MOX and a combination of ABM + MOR were reassessed to confirm their activities against cyathostomins. RESULTS: Of the five anthelmintic products tested on Farm A, resistance against OFZ, ABM and OFZ + PYR was found, with efficacies of - 41% (- 195% lower confidence limit [LCL]), 73% (60% LCL) and 82% (66% LCL) at 2 weeks post-treatment, respectively. The FECRT showed high efficacies of MOX and ABM + MOR (100%) at 2 week post-treatment and shortened ERPs for these anthelmintics (ABM + MOR: 4 weeks; MOX: 5 weeks). Resistance to MOX was found on Farm B, with a reduced efficacy of 90% (70% LCL) and 89% (82% LCL) at 2 weeks post-treatment in trials one and two, respectively. CONCLUSIONS: This study provides the first evidence of MOX- and multidrug-resistant (ABM and combinations of anthelmintics) cyathostomins in Australia and indicates the need for continuous surveillance of the efficacy of currently effective anthelmintics and large-scale investigations to assess the ERP for various anthelmintics.

Case Report: Atypical Presentation of Visceral Leishmaniasis: Two Cases from Northwest Ethiopia.

Human visceral leishmaniasis (VL) is a life-threatening disease caused by protozoan parasites belonging to the Leishmania donovani complex. Atypical cases of leishmaniasis and HIV coinfection have been documented in case reports, mostly associated with gastrointestinal tract, kidney, and skin involvement. We report two VL cases with atypical localizations not reported from east Africa before, both diagnosed and treated at the Leishmaniasis Research and Treatment Center, Gondar, Ethiopia. The first case was an HIV-infected patient with scrotal and penile involvement. Leishmania parasites were detected in the spleen and the scrotum. The second case was an immunocompetent individual with esophageal, laryngeal, and pharyngeal involvement and facial lesions. Leishmania parasites were detected in the spleen, skin, and esophageal biopsies. Current evidence suggests atypical presentation can occur in patients irrespective of their HIV status. Therefore, we suggest a high index of suspicion for VL among clinicians working in endemic areas of Ethiopia.

A case report of cutaneous leishmaniasis: a misleading clinical presentation.

BACKGROUND: The diagnosis of cutaneous leishmaniasis (CL) is often difficult because of the diversity of clinical presentations, its often-misleading appearance and the very long incubation period (time between the endemic stay and the onset of skin lesions). CASE: We report the case of an otherwise healthy 67-year-old man who presented with inflammatory skin lesions on the scalp and face for the past 7 years. The lesions were first mistaken as cutaneous sarcoidosis, mycobacterial infection, and cutaneous lymphoma. Finally, the diagnosis was made by RT-PCR analysis on a punch-biopsy specimen, which was positive for Leishmania infantum. DISCUSSION AND CONCLUSION: To date, the choice of treatment for complex cutaneous leishmaniases is based on the Leishmania species. Our patient successfully responded to liposomal amphotericin B.

[Investigation on Demodex infections among university students in Kunming City].

OBJECTIVE: To investigate the prevalence of Demodex infection among students in Kunming Medical University, and identify the factors affecting Demodex infections, so as to provide the evidence for the development of the strategy for the prevention of Demodex infections. METHODS: A total of 1 463 students from Grade 2014 who studied Medical Parasitology in Kunming Medical University were included in the survey. Demodex was examined in students'facial skin using the cellophane tape method, and the species was identified using microscopy. The students'gender, ethnicity, place of origin and skin type were captured using a questionnaire survey. RESULTS: The overall prevalence of Demodex infections was 19.07% (279/1 463) on the facial skin among the university students, and a higher prevalence was seen in girls (21.16%, 183/865) than in boys (16.05%, 96/598) (χ2 =5.965,P <0.05).TheprevalenceofDemodex infectionswas18.33%(66/360)amongminorethnicstudents,andnoethnicity-specific prevalence was seen (P > 0.05). Demodex folliculorum was the predominant species, with a prevalence of 50.54% (141/279), and mild infections were predominant among all infections (96.77%, 270/279), without severe infections seen. Multivariate nonconditional logistic regression analysis revealed that gender and roommates with Demodex infections were risk factors of Demodex infections, and the infection was not associated with ethnicity, place of origin or skin type. There were only 2.53% (37/1 463) of the subjects understanding the knowledge pertaining to the prevention and control of Demodex infection. CONCLUSIONS: A relatively low prevalence of Demodex infection is detected in the facial skin of students from Kunming Medical University, and Demodex infection is associated with gender and roommates with Demodex infections. Health education pertaining to the prevention of Demodex infections is suggested to be intensified among university students.

The Investigation of Prevalence of Demodex spp. in University Students: The Case of the Faculty of Health Sciences

Objective: The aim of this study was to determine the prevalence of Demodex spp. in college students, mostly adolescent individuals. Methods: A questionnaire including questions about the risk factors of Demodex spp. was administered to college students. Samples were taken with Standard Superficial Skin Biopsy method and examined under light microscope. Results: Presence of Demodex spp. was detected in 160 (42.7%) students out of 375 totally; 126 out of 291 nursing students (43.3%) and 34 out of 84 midwifery students (40.5%). It was detected in 47.3% of males and 40.2% of females. There was a statistically significant difference in terms of the prevalence of Demodex spp. between those who used foundation cream/make-up products and those who did not, and between those who removed hair and those who did not (p<0.05). There was no relationship between other variables and Demodex spp. prevalence. Conclusion: It is concluded that Demodex spp. is very common among college students in Kars. Dermatologists should also consider the existence of Demodex spp. in the etiology and pathogenesis of dermatoses which develops in the facial region of individuals in this group of age.

The Presence of Demodex Mites in Patients with Dermatologic Symptoms of the Face

Objective: The aim of the study was to investigate the Demodex prevalence in patients with dermatological complaints who were admitted to our hospital, and to evaluate the socio-demographic characteristics and risk factors of the patients. Methods: A total of 133 patients who were sent for Demodex screening were included and questionnaire for risk factors was administered. Samples were taken by standard superficial skin biopsy method and the different developmental stages were investigated under microscope. Results: Demodex species were found in 93 (69.9%) of the patients. Demodex folliculorum was found in 58 (62.4%) of the patients, Demodex brevis in 13 (14%), Demodex folliculorum and Demodex brevis in 4 (4.3%) and Demodex species in 18 (19.4%) of the patients. At least one of the Demodex species was found in 77.1% of patients with acne rosacea. No statistically significant relation was found between Demodex positivity and age, gender, number of weekly baths, use of makeup, and common towel use. Though statistically not significant, an increase of Demodex infestation with increasing age was observed. Conclusion: Demodex mite infestations are widespread worldwide without showing important racial and gender differences. In the present study, prevalence of Demodex infestation in patients with acne rosacea was high and this should be taken into consideration, when such patients are treated for their symptoms.

In vitro assessment of Argemone mexicana, Taraxacum officinale, Ruta chalepensis and Tagetes filifolia against Haemonchus contortus nematode eggs and infective (L3) larvae.

Argemone mexicana, Taraxacum officinale, Ruta chalepensis and Tagetes filifolia are plants with deworming potential. The purpose of this study was to evaluate methanolic extracts of aerial parts of these plants against Haemonchus contortus eggs and infective larvae (L3) and identify compounds responsible for the anthelmintic activity. In vitro probes were performed to identify the anthelmintic activity of plant extracts: egg hatching inhibition (EHI) and larvae mortality. Open column Chromatography was used to bio-guided fractionation of the extract, which shows the best anthelmintic effect. The lethal concentration to inhibit 50% of H. contortus egg hatching or larvae mortality (LC50) was calculated using a Probit analysis. Bio-guided procedure led to the recognition of an active fraction (TF11) mainly composed by 1) quercetagitrin, 2) methyl chlorogenate and chlorogenic acid. Quercetagitrin (1) and methyl chlorogenate (2) did not show an important EHI activity (3-14%) (p < 0.05); however, chlorogenic acid (3) showed 100% of EHI (LC50 248 µg/mL) (p < 0.05). Chlorogenic acid is responsible of the ovicidal activity and it seems that, this compound is reported for the first time with anthelmintic activity against a parasite of importance in sheep industry.

PREVALENCE OF DEMODEX ECTOPARASITES AMONG HUMANS IN ORDU PROVINCE IN TURKEY.

Demodex folliculorum and Demodex brevis are common ectoparasites in humans. Demodex parasite infestations have not been determined in the province of Ordu. We determined the prevalence of Demodex species among humans in Ordu Provience, Turkey. Seven hundred ninety-nine subjects (438 males and 361 females) aged ≥ 18 years living in the central districts of Ordu Province, Turkey, were selected using the World Health Organization cluster sampling method. A superficial skin biopsy of the face was obtained from each subject. Six hundred sixty-nine subjects (83.7%) had a Demodex parasite. Factors significantly associated with the presence of Demodex infestation were: female gender, employment in the private sector, people who only occasionally wash their face and district of residence. Since Demodex ectoparasites were common in Ordu Province, it is suggested that the diagnosis and treatment of this ectoparasite should be carried out in the hospitals of this region.

[The first case of Hypoderma tarandi-associated human myiasis in Greenland]. / Første tilfælde af Hypoderma tarandi-associeret myiasis på Grønland.

We present the first case of human myiasis in Greenland caused by the warble fly Hypoderma tarandi. Noticing a persisting, migrating, stinging facial sensation, a female patient eventually extirpated a larva from her upper eyelid, and the larva was confirmed to species level using DNA-based methods. A high prevalence of H. tarandi in reindeer, the main reservoir host, and increasing populations of musk ox may imply an increased risk of zoonotic transmission. Although diagnosis is challenging, rapid intervention is crucial to reduce the risk of ophthalmomyiasis.

Comparative genomic analysis reveals occurrence of genetic recombination in virulent Cryptosporidium hominis subtypes and telomeric gene duplications in Cryptosporidium parvum.

BACKGROUND: Cryptosporidium hominis is a dominant species for human cryptosporidiosis. Within the species, IbA10G2 is the most virulent subtype responsible for all C. hominis-associated outbreaks in Europe and Australia, and is a dominant outbreak subtype in the United States. In recent yearsIaA28R4 is becoming a major new subtype in the United States. In this study, we sequenced the genomes of two field specimens from each of the two subtypes and conducted a comparative genomic analysis of the obtained sequences with those from the only fully sequenced Cryptosporidium parvum genome. RESULTS: Altogether, 8.59-9.05 Mb of Cryptosporidium sequences in 45-767 assembled contigs were obtained from the four specimens, representing 94.36-99.47% coverage of the expected genome. These genomes had complete synteny in gene organization and 96.86-97.0% and 99.72-99.83% nucleotide sequence similarities to the published genomes of C. parvum and C. hominis, respectively. Several major insertions and deletions were seen between C. hominis and C. parvum genomes, involving mostly members of multicopy gene families near telomeres. The four C. hominis genomes were highly similar to each other and divergent from the reference IaA25R3 genome in some highly polymorphic regions. Major sequence differences among the four specimens sequenced in this study were in the 5' and 3' ends of chromosome 6 and the gp60 region, largely the result of genetic recombination. CONCLUSIONS: The sequence similarity among specimens of the two dominant outbreak subtypes and genetic recombination in chromosome 6, especially around the putative virulence determinant gp60 region, suggest that genetic recombination plays a potential role in the emergence of hyper-transmissible C. hominis subtypes. The high sequence conservation between C. parvum and C. hominis genomes and significant differences in copy numbers of MEDLE family secreted proteins and insulinase-like proteases indicate that telomeric gene duplications could potentially contribute to host expansion in C. parvum.

[PCR-based genotype classification of Blastocystis hominis isolates from college students of Guangxi].

Fifty-three Blastocystis hominis isolates were separated from the fecal specimens of carriers in college students from Guangxi and cultivated in vitro, and the genetic DNA was extracted. All the isolates were genotyped by PCR using seven pairs of known sequence-tagged site (STS) primers. The results showed there were five subtypes in the 53 isolates. Subtype 3 was the most popular one (32.1%, 17/53), followed by subtype 7 (9.4%, 5/53). Subtypes 1 (7.6%, 4/53), 4 (7.6%, 4/53), and 6 (1.9%, 1/53) were detected, while subtypes 2 and 5 were not detected. The genotypes of the other 22 isolates were unknown which were negative to all the STS primers.

Unexpected occurrence of Haemonchus placei in cattle in southern Western Australia.

Haemonchus placei is an abomasal parasite of cattle, primarily in tropical and subtropical areas of the world. In Australia, this nematode can be extremely pathogenic in summer rainfall areas, particularly in the hot, sub-tropical Kimberley region, in the far north of the state of Western Australia (WA). Although cattle are occasionally transferred to southern parts of WA, it was believed that H. placei did not occur in southern regions of WA, as it is less cold-adapted than Haemonchus contortus, and the free-living stages would not develop during the cold winter and dry summer periods. Here, we show that, although H. contortus is found in cattle in the temperate southern region of WA, it appears that H. placei also occurs in southern WA. While investigating the prevalence of anthelmintic resistance in nematodes of cattle in WA, the existence of H. placei was suspected on a range of participating farms, following the morphological examination of third-stage larvae cultured from faeces, and of adult worms recovered from sheep experimentally infected with these larvae. Genomic DNAs from individual worms as well as eggs from pooled faecal samples from seven farms in southern WA were subjected to PCR-based mutation scanning and sequence analyses of the second internal transcribed spacer (ITS-2) of nuclear ribosomal DNA. The results showed that both H. contortus and H. placei were harboured by cattle. This first record of H. placei in cattle in southern WA raises questions as to the prevalence and distribution of this parasite in other temperate and cool climatic regions of Australia. Although clinical disease due to H. placei has not yet been seen in southern WA, global, climatic trends might suggest an increased importance of this parasite in the longer term.

Trombiculiasis caused by chigger mites Eutrombicula (Acari: Trombiculidae) in Peruvian alpacas.

Trombiculiasis is an infestation caused by larvae members of the family Trombiculidae, common called chigger mites. In this study is presented the first case of trombiculiasis caused by the infestation of chigger mite Eutrombicula in alpacas from Peru. Twenty-two alpacas of a total of 130 animals were infested by Eutrombicula sp. The chigger mite location was only in the face skin folds and around the eyes. In addition, all alpacas infested had alopecia and dermatitis in the infected zone.

[Cervico-facial hydatidosis. Report of 17 cases]. / L'hydatidose cervico-faciale. A propos de 17 cas.

BACKGROUND: Cervico-facial hydatid cyst is rare. It accounts for 1 % of echinococcosis locations. AIM: To describe the epidemiological, clinical and therapeutic aspects of cervico-facial hydatid cysts based on our clinical experience and data in the literature. METHODS: A retrospective study was made concerning 17 patients with cervico-facial hydatid cyst treated surgically over a 25-year period from 1982 to 2006. RESULTS: Mean patient age was 27 years (range 2-79). Hydatid cyst localization was: cervical muscle (7 cases), thyroid gland (5 cases), parotid gland (2 cases), cervico-thoracic (1 case), larynx (1 case) and cheek (1 case). Hydatic origin of the cyst was suspected for 6 patients (35.3 %) preoperatively. Surgical treatment was used in all cases and adapted to each case. Diagnosis was always confirmed by macroscopic aspects and pathology. CONCLUSION: Hydatid cysts are rarely found in the cervico-facial region, even in highly endemic zone. The manifestation of symptoms depends on the location and the size of the cyst. Positive diagnosis can be difficult during preoperative period. Exclusively surgical treatment is indicated, ideally for total pericystic resection without rupture.

Influence of temperature and medium on viability of Demodex folliculorum and Demodex brevis (Acari: Demodicidae).

Demodex folliculorum and D. brevis are cosmopolitan, obligatory parasites. Epidemiological studies have established a clear association between these species and various facial diseases in humans. However, not much is known of the ecology of these mites, also because it has proven difficult to culture them. Here we report a laboratory study on the (combined) effects of temperature and culture medium on the viability of both species. Results showed significant differences in the survival time of D. folliculorum and D. brevis among different temperatures and media. Pair-wise comparisons revealed that both species survived longest in serum medium, at a temperature of 16-22 °C. Therefore, we conclude that these conditions allow preservation and maintenance of both Demodex mites.