Case Report Human Dirofilaria Repens Infection in Romania: a Case Report
Total Page：16
File Type：pdf, Size：1020Kb
Hindawi Publishing Corporation Case Reports in Infectious Diseases Volume 2012, Article ID 472976, 4 pages doi:10.1155/2012/472976 Case Report Human Dirofilaria repens Infection in Romania: A Case Report Ioana Popescu,1 Irina Tudose,2 Paul Racz,3 Birgit Muntau,3 Calin Giurcaneanu,1 and Sven Poppert3 1 Dermatology Department, Elias Emergency University Hospital, 011461 Bucharest, Romania 2 Histopathology Department, Elias Emergency University Hospital, 011461 Bucharest, Romania 3 Department of Clinical Diagnostics, Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht-Straβe 74, 20359 Hamburg, Germany Correspondence should be addressed to Sven Poppert, [email protected] Received 30 September 2011; Accepted 19 October 2011 Academic Editor: G. J. Casey Copyright © 2012 Ioana Popescu et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Human dirofilariasis is a zoonotic infectious disease caused by the filarial nematodes of dogs Dirofilaria repens and Dirofilaria immitis. Depending on the species involved, human infections usually manifest as one cutaneous or visceral larva migrans that forms a painless nodule in the later course of disease. Dirofilariae are endemic in the Mediterranean, particularly in Italy. They are considered as emerging pathogens currently increasing their geographical range. We present one of the few known cases of human dirofilariasis caused by D. repens in Romania. The patient developed unusual and severe clinical manifestations that mimicked pathological conditions like cellulitis or deep venous thrombosis. 1. Introduction from Romania, which produced an atypical and severe clinical picture. Human dirofilariasis is a zoonotic infectious disease caused by parasites of the genus Dirofilaria [1–3]. Dirofilariae are 2. Case Presentation a group of filarial nematodes infecting various carnivores as definitive hosts. The adult dirofilariae release microfilaria A male, 31-years-old patient, with no significant medical his- into the host’s blood, which may be taken up by various tory, presented in February 2011 with a cellulitis-like plaque mosquitoes that serve as intermediate hosts and transmit the on the right inner thigh (10 cm diameter) that, in about 12 disease. Humans may be infected as aberrant hosts, mainly hours, extended to almost the entire thigh. He was living in by Dirofilaria (D.) immitis and D. repens. The definitive hosts a Romanian suburban area (near Bucharest) and had a pet of D. repens and D. immitis are dogs, but other animals have dog. The patient denied recent or past travel abroad, except also been reported as reservoirs of the disease (cats, wolves, for France (Paris) for a weekend, 4 months earlier (in Octo- bears, foxes, etc.) [1, 3]. In human infections usually just one ber). The putative diagnosis at that time was cellulitis, and larva develops, which does not reach fertility [2, 3]. The larva antibiotic treatment was started with amoxicillin-clavulanic wanders through the human body and finally forms a nod- acid (for 5 days). All symptoms subsided rapidly within 24– ule. D. repens usually resides subcutaneously, while D. immi- 48 hours. tis frequently ends up in the human lung. In most cases One week later the patient developed severe muscle pain parasites cause few symptoms. D. immitis infections in par- in the lower right leg, and after a further two days he no- ticular are therefore frequently detected only incidentally and ticed a similar cellulitis-like plaque as before (red, edema- are initially often confused with malignancies. tous, warm with imprecise limits) in the popliteal region, D. repens has been reported from various regions of the with rapid extension to the adjacent areas, associated with world with warm to moderate climate, but only very rarely impaired walking ability due to extensive edema. Doppler from Romania [1, 4]. We report a human D. repens infection ultrasound showed no signs of thrombosis in the right leg. 2 Case Reports in Infectious Diseases (a) (b) (c) Figure 1: Clinical picture before and after surgery. Before the removal of the parasite, the patient showed erythematous plaques with mild edema in the lower right abdominal region (a). The ultrasound revealed a well-defined cystic lesion of 11.9 mm × 4.8 mm above muscular layer, which is seen on the right (b). After excision of the nodule the wound healed without complications and all symptoms resolved. The scar reveals the final location of the parasite (c). Laboratory investigations showed mild eosinophilia (7.2%; structures were the external longitudinal ridges, leading to a normal range 0–7%). All other investigations including com- cogwheel-like appearance in the transverse sections (Figures plete blood count, sedimentation rate, urinalysis, and liver 2(a), 2(b),and2(c)). Further typical features were the thick and renal function tests were normal. Because of the se- cuticula and the well-developed musculature (Figures 2(a) verity of symptoms, treatment with the macrolide antibiotic and 2(c)). Around the parasite a marked inflammatory azithromycin and the low-molecular-weight heparin enoxa- reaction had developed (Figures 2(d) and 2(e)). The histo- parin was administered for 7 days. Again the symptoms re- logical slides showed numerous eosinophils, neutrophils, solved quickly and completely. lymphocytes, plasma cells, and macrophages. (Figures 2(d) After about two further weeks, the patient developed and 2(e)). Occasionally, eosinophils and neutrophils, partly similar but less severe lesions on the lower right part of with pycnotic nuclei, were seen on the surface of the parasite the abdomen that were again associated with muscle pain (Figures 2(d) and 2(e)). Many IgE-positive plasma cells were (Figure 1(a)). present in the infiltration and near to the surface of the Infectious disease screening was performed and showed parasite (Figure 2(f)). positive serology for Echinococcus (E.) granulosus IgG To confirm the morphological diagnosis, DNA was iso- (ELISA) and negative tests for Borrelia burgdorferi, Toxo- lated from the tissue sample embedded in paraffin wax and plasma gondii, Toxocara canis, Trichinella spiralis,EBV,CMV, a PCR targeting the mitochondrial 12S rRNA was performed HBV, HCV, and HIV. Abdominal ultrasound and chest ra- as described before [7, 8]. Sequence analysis of the PCR pro- diography were normal. duct showed the highest similarity to Italian isolates of D. Because of the eosinophilia and the positive E. granulo- repens, thus confirming the morphological identification of sus serology, a parasitological cause was suspected and al- our isolate as D. repens. bendazole treatment was started (800 mg/day). During anti- Serum samples were investigated retrospectively for anti- parasitic therapy, the inflammatory abdominal plaque re- filarial antibodies using an ELISA composed of D. immitis solved, but a nodule developed deep in the subcutaneous antigen. The test was positive as expected. In addition, the tissue (Figure 1(b)). The nodule was excised, and all signs of presence of antibodies against E. granulosus was confirmed infection including the eosinophilia subsided, and no further by ELISA and indirect hemagglutination, but not by a west- symptoms developed (Figure 1(c)). ern blot confirmation test. The patient was thoroughly The excised material was investigated histopathologically screened for signs of an Echinococcus infection by sonography using hematoxylin-eosin (HE), Giemsa, and Masson’s tri- and CT scans, but no indications of a hydatid cyst were chrome stains, periodic acid-Schiff reaction, and immuno- found. histochemistry for IgE (Figure 2). The histopathology was In order to exclude the patient’s dog as a source of (fur- similar to that described for subcutaneous dirofilariasis in ther) D. repens infections, blood samples were obtained and previous reports [5, 6]. The parasite showed the typical fea- investigated for microfilaria using Giemsa stain and PCR. No tures of a nongravid female D. repens. The most indicative microfilaria or filarial DNA was found. Case Reports in Infectious Diseases 3 (a) (b) (c) (d) (e) (f) Figure 2: Histological sections of the parasite. Sections were stained using hematoxylin-eosin (HE) (a), Masson’s trichrome stain (b, c), Giemsa (d, e), and periodic acid-Schiff reaction and immunohistochemistry for IgE (f). Typical features of D. repens are the external longitudinal ridges, the thick cuticula, and the well-developed musculature (a, b, c). Around the parasite a marked inflammatory reaction with numerous eosinophils, neutrophils, lymphocytes, plasma cells, and macrophages is seen (d, e). Many IgE-positive plasma cells are present in the infiltration and near to the surface of the parasite (f). 3. Discussion infection. It could not be clarified whether the positive reactions with the E. granulosus tests were caused by an We present a case of human D. repens infection with an atyp- asymptomatic previous contact with Echinococcus or just by ical presentation that was most likely acquired in Romania. unspecific cross-reactions. The finding of Echinococcus anti- Human infection with D. repens usually presents as larva bodies with ELISA must be interpreted as an incidental find- migrans and later in the course of infection as a subcutaneous ing without relevance for the described case. nodule [2, 3]. However, infection may cause a wide variety The facts that the symptoms developed close to the site of symptoms