Strigea robusta causes polydactyly and severe forms of Rostand's anomaly P in water frogs.

BACKGROUND: Cases of polydactyly in natural populations of amphibians have attracted great interest from biologists. At the end of the 1940s, the French biologist Jean Rostand discovered a polymorphic syndrome in some water frog (Anura: Pelophylax) populations that included polydactyly and some severe morphological anomalies (he called it 'anomaly P'). The cause of this anomaly remains unknown for 70 years. In a previous study, we obtained anomaly P in the laboratory in tadpoles of water frogs that developed together with molluscs Planorbarius corneus (Mollusca: Gastropoda) collected in the field. We thus proposed the 'trematode hypothesis', according to which the infectious agent responsible for anomaly P is a trematode species. METHODS: Metacercariae from tadpoles with anomaly P were identified using ITS2 gene sequencing as Strigea robusta (Trematoda: Strigeidae). To verify teratogenic features of the species, cercariae of S. robusta were tested for the possibility to cause anomalies. Identification of cercariae species was made using morphological and molecular methods (sequencing of ITS2 and 28S rRNA). The tadpoles were exposed to parasites at four doses of cercariae (control, low, medium and high) and divided into two groups: "early" (at 25-27 Gosner stages) and "late" (at 29-34 Gosner stages) exposure. RESULTS: A total of 58 (72.5%) tadpoles survived until metamorphosis under the dose-dependent experiment with the trematode S. robusta. Differences in the survival rates were observed between the exposed and unexposed tadpoles both in the group of "early" tadpoles and "late" tadpoles. The exposure of tadpoles to the cercariae of S. robusta induced anomaly P in 82% of surviving tadpoles. The severe forms developed only in "early" stages under all doses of cercariae exposure. Polydactyly predominantly developed in the "late" stages; under a light exposure dose, polydactyly also developed in "early" tadpoles. Laboratory-hatched tadpoles reared together with infected snails had different rates of survival and complexity of deformations associated with the period of coexistence. CONCLUSIONS: The experiments with direct cercariae exposure provide compelling evidence that S. robusta leads to anomaly P in tadpoles of water frogs. The manifestation of anomaly P turned out to be dependent on the stage of development, cercariae dose, and the location of the cysts.

[Two travellers returning from the tropics with persistent wounds on their feet]. / Twee tropenreizigers met persisterende voetwonden.

Two young tropical medicine residents returned from Zanzibar with multiple aching wounds on their toes that did not heal within 6 weeks. The clinical picture fit 'tungiasis', which is caused by Tunga penetrans, also known as jigger or sandflea. The ectoparasites were surgically removed and the status of tetanus vaccination was checked.

Tungiasis Outbreak in Travelers From Madagascar.

Seven patients from a group of 16 travelers were diagnosed at our institution with one or more sand fleas on their toes, 1 day to 3 weeks after returning from Madagascar. A questionnaire was sent to the whole group to collect clinical and epidemiological information, which showed that 9 of 13 (69%) had received pre-travel medical advice, but none were aware of sand flea; thus prevention measures were rarely applied. Five of seven (71%) patients wore open sandals throughout the trip. Overall, 10 sand fleas were extracted.

Clinical efficacy of botanical extracts from Eupatorium adenophorum against the Sarcoptes scabiei (Sarcoptidae: Sarcoptes) in rabbits.

The aims of present study were to evaluate the therapeutic efficacy of extracts from Eupatorium adenophorum against Sarcoptes scabiei. A 30-day experiment was performed using New Zealand rabbits that were naturally infested with S. scabiei in the toes (n=30) or artificially infected in the external ear margin with S. scabiei (n=30). Rabbits were randomly divided into five groups (6 animals per group, A-E groups for rabbits of naturally infested and F-J groups for artificially infected rabbits), respectively. All 60 rabbits were treated twice on days 0 and 7 successively. Animals in groups A/F, B/G, and C/H were treated on each toe/external ear margin with topical E. adenophorum ethanol extract at 1.0, 0.5 and 0.25 g/ml (w/v), respectively. Animals in groups D/I and E/J were treated with ivermectin by injections (positive controls) or by glycerol with water only rubbed onto the affected area (negative controls). After two treatments with extracts of E. adenophorum with relatively high concentrations of 0.5 and 1g/ml, the S. scabiei was completely eliminated in rabbits between days 14 and 30. Our results showed that rabbits treated with ivermectin (positive controls) and those treated with the extracts of concentrations of 1.0 or 0.5 g/ml achieved remarkable therapeutic efficacy; no mites were present in toes of rabbits in these groups on day 14, which confirmed a 100% therapeutic efficacy rate up to day 30 of the end of the trial. The clinical effects of treatment with 1.0 and 0.5 g/ml E. adenophorum extracts (groups A and B) were similar to ivermectin treatment. However, the therapeutic efficacy in group C and E rabbits only reached 43.25% and 7.13% by day 14. Furthermore, the therapeutic efficacy improved slightly by the end of the experiment on day 30, and rabbits in groups F, G and I also achieved good efficacy according to the recovery scoring criteria. These results indicate that E. adenophorum contains potent compounds for the effective control of sarcoptidosis.

[A woman with a painful toe]. / Een vrouw met een pijnlijk stekende teen.

A 64-year-old woman visited the surgeon because of an infected right hallux. After investigation we concluded she had myiasis caused by an infestation with Lucilia Sericata. This usually occurs in tropical regions in patients with low standards of hygiene, but is sometimes found in non-tropical countries, in patients with minor underlying lesions.

Imported tungiasis in a Japanese student returning from East Africa.

Ectoparastiosis by Tunga penetrans is becoming more common in non-tropical countries as people travel more to endemic areas. We present here a classic case of imported tungiasis including a history of visit to an endemic region and its typical presentation. Diagnosis with dermoscopy, treatment and prevention are discussed.

Tungiasis infestation in Tanzania.

Tungiasis is caused by the jigger flea Tunga penetrans. We describe a case of severe infestation from Kigoma region, Western Tanzania. A 19-year-old male with epilepsy and mental disability presented with ulcerated and inflamed toes. Clinical examination revealed the presence of approximately 810 embedded jigger fleas on the feet, and another 60 lesions on the hands. The patient presented with fissures on the feet, hands and soles. He had difficulty walking and erythematous, oedematous, ulcerated and inflamed skin around the feet. Living conditions were precarious. The patient was assisted to extract the embedded fleas and his feet were washed with disinfectants. Oral antibiotics were given. The case shows that the disease may reach high parasite loads in Tanzanian individuals, with consequently severe pathology. There have been single reports of returning tourists from Tanzania with tungiasis, but the epidemiological situation and the geographic occurrence of the disease in this country are not known. Systematic studies are needed to increase knowledge on the epidemiological situation of tungasis in Tanzania and to identify endemic areas.

[Tungiasis case after a trip to Kenya]. / Et tilfaelde af tungiasis efter rejse i Kenya.

Tungiasis is an ectoparasitic skin disease caused by infestation by the female sand flea, Tunga penetrans. Prevalence in endemic areas may reach 83%, while it is rare in non-endemic areas. However, an increase in international travel to and from the affected regions may lead to a rise in the number of cases in non-endemic countries. We present a Danish case of tungiasis contracted during a trip to Kenya.

A case of myiasis in a patient with psoriasis from Turkey.

Myiasis infestations caused by the larvae of flies mostly belonging to Cyclorapha suborders are frequently encountered in Turkey, which is located in the subtropical zone. The skin is a common site for myiasis, and the infestations are likely to develop in infected tissues and poorly attended wounds of the skin. The case, a 30-year-old male patient, was diagnosed with psoriasis 18 years ago. He had psoriatic scales on his right big toe and was receiving corticosteroid and immunosuppressive drugs. A total of 11 fly larvae were removed from the infected right first toe of the patient. Structures of the stigmas seen in the cross-sections taken from the final segments of these larvae were examined and determined as Sarcophaga spp. larvae. Patients with infected tissues should be extremely cautious about their wound hygiene and take required fly control measures especially during summer as flies can find a suitable environment for sustenance.

Tungiasis in the United States: a travel souvenir.

Tungiasis is a cutaneous infestation caused by the burrowing flea, Tunga penetrans. This infection typically results in the development of one or more wart-like fibrous papulonodules. The causative flea is endogenous to Central and South America, sub-Sarahan Africa and portions of India; consequently, tungiasis is rarely reported in North America. However, because of increasing air travel to and from endemic areas due to business and pleasure, it is imperative that this entity remain in the differential diagnosis when evaluating clinically suggestive lesions in a patient who also has a history of recent travel. We report a case of tungiasis in a 24-year-old Caucasian woman who presented with 7-week history of a non-healing, eroded nodule on the medial aspect of her left great toe. Significant history included travel to Tanzania during three months immediately prior to presentation. Following the presumptive clinical diagnosis of tungiasis, surgical removal of the flea and its contents was performed and the base of the lesion was curetted, without complication. The specimen was sent for histopathologic correlation which confirmed the diagnosis.

Tunga penetrans. A case report and review of the literature.

Tungiasis is an infection caused by infestation of Tunga Penetrans into the epidermis. Although, at the moment, presentation of this condition seems rare in Europe and Northern America, tungiasis is highly endemic in other parts of the world. We describe a case of Tunga Penetrans infection in the foot of a 22-year old Dutch female returning from Kenya, and present a review of the literature. Now that intercontinental travel is increasing, physicians in other parts of the world will be expected to recognize and treat this exotic infection. Knowledge of human tungiasis is mandatory in order to recognize the symptoms, achieve correct diagnosis and ensure adequate medical treatment to our patients.