| onchocerciasis, or river blindness, is a parasitic infection caused by the filarial nematode, onchocerca volvulus. It infects 18 million people worldwide, but is rarely seen in the united states. It is one of the leading causes of blindness in the developing world. Although onchocerciasis is also known as river blindness, it is not just a disease of the eyes, but rather a chronic multisystem disease. Clinically, onchocerciasis takes three forms: 1) eye disease; 2) subcutaneous nodules; and 3) a pruritic hypopigmented or hyperpigmented papular dermatitis. We present an 18-year-old African female with a 5-year history of asymptomatic, hypopigmented, slightly atrophic macules on her anterior tibiae. pathology revealed a scant perivascular inflammatory infiltrate with mononuclear cells, eosinophils, and rare microfilariae in the papillary dermis. ivermectin is the treatment of choice for onchocerciasis and was initiated in this patient. We present this interesting patient with onchocerciasis to expand our differential of hypopigmented macules, especially in the African population. In addition, we discuss both the diagnosis and the treatment of onchocerciasis in expatriate patients living in nonendemic areas. ( info) |
| Over the past 10 years, the status of human infection with guinea worm (Dracunculus medinensis) in the central african republic (CAR) has been difficult to ascertain. It is unclear if indigenous cases are occurring and whether cases are migrating into the CAR from surrounding countries. A team of investigators visited the CAR in July-August 2000, to attempt to ascertain the presence of indigenous transmission. No cases of true guinea-worm infection (i.e. dracunculiasis) were detected, but three cases of human infection with onchocerca volvulus, each of which had been misidentified as dracunculiasis, were detected. The unusual presentation of skin blisters and extraction of an intact female O. volvulus are described. As a result of this investigation, and the confusion of onchocerciasis being misidentified as dracunculiasis, the presence of endemic transmission of guinea worm in the CAR remains in question. ( info) |
3/36. A new focus of onchoceriasis in the sudan. A new focus of onchocerciasis is reported from Upper Atbara River area in the sudan. This river is a known seasonal breeding place of Simulium damnosum. The area was sparsely populated in the past but now, following agricultural development, is inhibited mainly by immigrants from Northern nigeria and chad. Clinically the common features are skin changes of the legs, thighs buttocks, arms and trunk. Other features are corneal opacities and small often deeply placed subcutaneous nodules. Choroido-retinal degeneration, genital elephantiasis and hydrocoele, commonly associated with onchocerciasis in other parts of the sudan, are absent. ( info) |
4/36. Intramuscular onchocercoma. Case report. onchocerciasis is characterized by the presence of numerous microfilariae in the skin, formation of subcutaneous nodules and eye lesions that can lead to blindness. We present a case, rather uncommon in our environment, in which an incomplete life cycle of the parasite, led to a single intramuscular nodule. The clinical symptoms and histological features are described, together with the treatment, using ivermectin. ( info) |
5/36. Cutaneous onchocercoma. onchocerciasis is a common, chronic multisystem disease with dermatologic, ocular, and systemic manifestations. Although the disease is endemic in Africa, latin america, and yemen, imported cases have been described in the united states. The causative organism, onchocerca volvulus, is transmitted by the bite of a black fly of the genus Simulium. There are a number of cutaneous manifestations of the disease, including onchocercomas, which are subcutaneous bundles of worms. The antiparasitic agent ivermectin is the drug of choice for both prophylaxis and treatment of active disease. ( info) |
| blindness affects approximately 42 to 52 million people worldwide. This article examines the major causes of blindness, including cataract, trachoma, glaucoma, onchocerciasis, nutritional deficiencies, and ocular trauma. Numerous case studies supplement the text. ( info) |
7/36. Zoonotic onchocerciasis caused by a parasite from wild boar in Oita, japan. A comprehensive analysis of morphological characteristics of the worms for its diagnosis. Histological examination of a nodule removed from the back of the hand of a 58-year-old woman from Oita, Kyushu, japan showed an Onchocerca female sectioned through the posterior region of the worm (ovaries identifiable) and young (thin cuticle). Six Onchocerca species are enzootic in that area: O. gutturosa and O. lienalis in cattle, O. suzukii in serows (Capricornis crispus), O. skrjabini and an Onchocerca sp. in Cervus nippon nippon, and O. dewittei japonica in wild boar (sus scrofa leucomystax). Diagnostic characters of female Onchocerca species, such as the cuticle and its ridges, change along the body length. tables of the histologic morphology of the mid- and posterior body-regions of the local species are presented. In addition, it was observed that transverse ridges arose and thickened during the adult stage (examination of fourth stage and juvenile females of O. volvulus). The specimen described in this report, with its prominent and widely spaced ridges, was identified as O. d. japonica. Four of the 10 zoonotic cases of onchocerciasis reported worldwide were from Oita, three of them being caused by O. d. japonica, the prevalence of which in local wild boar was 22 of 24 (92%). ( info) |
| onchocerca volvulus is usually associated with subcutaneous and ocular infections. infection of the breast is rare and there are only two previous case reports. We report a case of a thirteen-year-old Cameroonian female with a left breast mass, which had a microscopic evaluation consistent with O. volvulus. ( info) |
9/36. Cutaneous onchocerciasis in an American traveler. A case report of cutaneous onchocercias acquired during travels to Africa is presented. The salient epidemiologic, clinical, diagnostic, and therapeutic aspects are reviewed. Clinical and laboratory differences between onchocerciasis patients who are inhabitants of endemic areas and those who are occasional visitors to such areas are discussed. Parasitic infections, including onchocerciasis, should be considered in the differential diagnosis of pruritic eruptions in patients with a history of foreign travel to africa, central and south america. ( info) |
10/36. An Onchocerca species of wild boar found in the subcutaneous nodule of a resident of Oita, japan. Histological examination and dissection of a subcutaneous nodule removed from the right infraclavicular region of a 69-year-old woman from Oita, Kyushu, japan, revealed a young female of Onchocerca dewittei japonica, a common parasite of wild boar in the Oita region. Distinctive morphologic characteristics of this Onchocerca species include the thick cuticle with very prominent and straight transverse ridges overlapping at the lateral sides, the lack of inner striae (scalloping) of the inner cuticle layer, the dorso-ventral symmetry, and the thick somatic muscles. Jointed with previous reports in the past decade, this case confirms the occasional transmission of the parasite from wild boar to humans in Oita. ( info) |