Andrea Gustinelli

Sand flea (Tunga spp.) infections in humans and domestic animals: state of the art

Tungiasis is a parasitic disease of humans and animals caused by fleas (Siphonaptera) belonging to the genus Tunga. Two species, Tunga penetrans (L.) and Tunga trimamillata, out of 10 described to date, are known to affect man or domestic animals; the other eight are exclusive to a few species of wild mammals. Tunga penetrans and T. trimamillata originated from Latin America, although the first species is also found in sub‐Saharan Africa (between 20° N and 25° S). Hundreds of millions of people are at risk of infection in more than 70 nations, mostly in developing countries. The second species has been reported only in Ecuador and Peru. Males and non‐fertilized females of Tunga are haematophagous ectoparasites; pregnant females penetrate the skin where, following dilatation of the abdomen, they increase enormously in size (neosomy) and cause inflammatory and ulcerative processes of varying severity. The importance of Tunga infection in humans concerns its frequent localization in the foot, which sometimes causes very serious difficulty in walking, thereby reducing the subjects ability to work and necessitating medical and surgical intervention. Tungiasis in domestic animals can be responsible for economic losses resulting from flea‐induced lesions and secondary infections. Because tungiasis represents a serious problem for tropical public health and because of the recent description of a new species (Tunga trimamillata), it seems appropriate to review current knowledge of the morphology, molecular taxonomy, epidemiology, pathology, treatment and control of sand fleas of the genus Tunga.

The first report of Gyrodactylus salaris Malmberg, 1957 (Platyhelminthes, Monogenea) on Italian cultured stocks of rainbow trout (Oncorhynchus mykiss Walbaum).

The monogenean Gyrodactylus salaris Malmberg, 1957 is considered one of the most important parasites of wild salmonids in the European Community due to the heavy ecological and economical damage it has inflicted on Atlantic salmon (Salmo salar) parr populations. Rainbow trout (Oncorhynchus mykiss) is susceptible to G. salaris and can act as a suitable carrier host and, consequently, its trade in EU territory is restricted in relation to the status of recognized free zones. Despite the economic importance of rainbow trout farming in Italy, information on the Italian gyrodactylid fauna is lacking and prior to this study, G. salaris had not been officially reported. During a routine health examination of farmed rainbow trout stock throughout Central and Northern Italy in 2004-2005, five fish farms were found to be infected with G. salaris alongside three other gyrodactylids. Morphological and molecular characterisation confirmed the presence of G. salaris, Gyrodactylus teuchis Lautraite, Blanc, Thiery, Daniel et Vigneulle, 1999 and Gyrodactylus derjavinoides Malmberg, Collins, Cunningham et Jalali, 2007, while Gyrodactylus truttae Gläser, 1974 was identified by morphological analysis only. The findings from this study extend the distribution of G. salaris within Europe and highlight the importance of the rainbow trout trade in its dissemination.

Three new cases of human infection with Dirofilaria repens, one pulmonary and two subcutaneous, in the Egyptian governorate of Assiut

Abstract Human dirofilariasis caused by Dirofilaria repens is a parasitic infection, currently considered to be an emerging zoonosis, that has been observed in many areas of the Old World. Dogs are the main reservoir host. In humans, D. repens can cause inflammatory nodules, most commonly in the subcutaneous tissues or in the subconjunctival space. Lung involvement, which is the most common of the non-cutaneous and non-ocular manifestations, is frequently mis-diagnosed as a primary or metastatic lung tumour. Two new subcutaneous cases and one new pulmonary case, all observed in the Egyptian governorate of Assiut, are described here. This represents the first report of human pulmonary dirofilariasis caused by D. repens on the African continent. All the worms collected from the cases, including a living worm from the left lung of the pulmonary case, were identified morphologically, and the identity of the lung parasite was confirmed by PCR.

A Parasitological Survey of European Sea Bass (Dicentrarchus Labrax) and Gilthead Sea Bream (Sparus Aurata) Cultured in Italy

M.L. Fioravanti∗, M. Caffara, D. Florio, A. Gustinelli and F. Marcer Department of Veterinary Public Health and Animal Pathology, Faculty of Veterinary Medicine, University of Bologna, Ozzano Emilia (BO), Italy ∗Correspondence: Dipartimento di Sanità Pubblica Veterinaria e Patologia Animale – Facoltà di Medicina Veterinaria, via Tolara di Sopra, 50 – 40064, Ozzano Emilia (BO), Italy E-mail: fioravanti@vet.unibo.it

Human hepatic capillariasis: a second case occurred in Korea.

To the Editor: n nMonitoring the scientific literature on human cases of Dirofilaria infections worldwide, a topic that the first named author follows since more than 30 yr, our attention was drawn to the article by Kim et al. The first human case of hepatic dirofilariasis, issued in the Journal, vol.17, pp. 686-670 (2002). Reading the paper and analysing the figures, we noticed that the authors, unfortunately, misinterpreted the histological sections of the hepatic biopsy by describing some non-existent morphological details, and formulated a wrong parasitological diagnosis. Actually, from the histological sections shown in the four figures of the article, it was clearly visible that it was not Dirofilaria immitis, as claimed by the authors, but Capillaria (=Calodium) hepatica (Bancroft, 1893), Travassos, 1915 (Nematoda, Trichinelloidea, Capillariidae), a zoonotic infection of rather common occurrence in rats and mice but extremely rare in man. No more than 30 cases have been reported worldwide since the first case published by MacArthur in 1924 (1). Therefore, given this limited number of cases studied and still several unknown clinical and pathogenetic aspects of this infection in humans, it seems appropriate to record this new case in Korea, where the first case was reported a few years ago (2). Therefore, we would like to re-describe the case briefly using the information reported by Kim et al. The patient was a 39-yr-old man without any history of recent illness, who visited Guro Hospital in Seoul for a routine physical check-up. An ultrasonogram revealed a hepatic subcapsular hypoechoic nodule in the right lobe. After many hematological and serological tests, he agreed to have the resection of the liver segment to rule out any possibility of malignancy. He had no history of travelling abroad. n nFrom the photos of the histological sections, we could notice important morphological details, which have led us to a correct parasitological diagnosis. Fig. 4 showed several sections of the parasite, plunged in a necrotic liver parenchyma surrounded by an inner granulomatous rim and an outer zone of mixed inflammatory cell infiltrates containing plasma cells, lymphocytes, foreign body-type giant cells, and abundant eosinophils. Due to the limited field of the photo, the internal structures of the worm were not evident. Fig. 5 showed a cross-section of an adult worm, where the thin cuticle, the intestine, a sexual tube, and two bacillary bands were evident. Fig. 6 demonstrated a partial view of another adult worm in a strong regressive phase but where the fine striation of the cuticle was well visible. Fig. 7 involved the cross-section possibly of a female worm, with evident internal tubes. Unfortunately, the poor quality of the photos and the regressive conditions of the worm did not allow us to establish precisely whether the sexual tubes visible in the pseudocoeloma belonged to a male or to a female worm. More sections and other staining besides H&E would be necessary for an accurate identification of the worm. The diameter of the cross-sections of the adult of C. hepatica (female 78-184 µm, male 80 µm) (3) falls within the range measured by Kim et al. on the presumptive D. immitis sections. However, the presence of the bacillary bands, the fine striation on a thin cuticle, the diameter of the adult sections, the peculiar location of the worm, and the histological picture of the inflammatory reaction were sufficient for the diagnosis of C. hepatica. The absence of symptoms is also compatible with capillariasis. The positivity of the antibody test by ELISA using crude extracts of adult filarial worm should support the identification of the worm as a D. immitis, but we do not consider this test valid as a proof of an actual infestation by this nematode. Our opinion is also supported by many other qualified authors (4-6). n nIn the paper by Kim et al. no data were presented regarding the hygienic and environmental conditions relating to the patient, so it is difficult to ascertain the way of infection. Nevertheless, since C. hepatica represents the most common nematode parasite of the liver of house rats in Korea (88% out of 325 rats examined by Seo et al. [7]), it is possible that the patient was infected through foods contaminated by rat stools containing embryonated eggs of the nematode. The life cycle of the parasite, the list of previous human cases of liver capillariasis in the world, their clinical and histological characteristics, and the pictures of eggs and adults of this nematode are well descrived or presented in the papers by Pampiglione & Conconi (8), Attah et al. (9), Choe et al. (2), and the chapter on Capillaria spp. in the text-atlas by Orihel & Ash (3).