Pulmonary dirofilariasis: restudy of worms reported gravid.

A worm in the lung of a man in Colombia, whose death was caused by lymphoid leukemia, originally reported as Wuchereria bancrofti with embryos in the uterus, was re-examined and identified as a Dirofilaria sp. and its gravid condition confirmed. A Dirofilaria sp. in the lung of a man in Japan, reported as gravid, was found to be nongravid with sloughed fragments of lining of the uterus mistaken for microfilariae. Noteworthy in the Colombia case is the association of lymphoid leukemia in the host and the gravid condition of the worm.

Zoonotic Brugia infections in North and South America.

Nine new zoonotic Brugia infections, 8 acquired in the United States and 1 in Brazil, are described. In each, a single worm was found in histological sections of lymph nodes or lymphoid tissues. In those from North America, 5 of the 8 worms were females, all were infertile, and only 3 were alive at the time the tissues were excised; all of the patients were male. A dead female worm was collected from a Brazilian male patient. In addition, 3 cases of filarial infections in the U.S., previously identified as Dirofilaria-, Dipetalonema-, or Brugia-like, are reviewed and reclassified as Brugia species on the basis of microscopic morphological features. Morphological features of male and female zoonotic Brugia species as they appear in the host tissues are described. The possible reservoirs of human infections are discussed.

Zoonotic Onchocerca in a Japanese child.

A female Onchocerca was found in histopathological sections of a nodule removed from the foot of a 2-year-old girl in southern Japan. As in previously reported cases in Switzerland, Crimea, Canada, and the USA, evident morphological features of the worm resembled those of Onchocerca gutturosa and O. cervicalis, which are known to exist in cervical ligaments of cattle and horses, respectively, in Japan and elsewhere.

Intraocular filariasis: a brief review.

Fifty-six cases of human intraocular filariasis have been reported. In 6, the objects interpreted as filariae may have been artifacts. In 8, a motile worm that apparently was not a filaria was observed. In the remainder, a motile filaria or filaria-like worm was observed, but in only 6 cases were the filariae removed from the eye, described, and identified. Three of these were identified as Dipetalonema spp., and one each as Wuchereria, Dirofilaria, and Loaina. In 10 cases, filariae were removed and identified as Loa loa (6) or Wuchereria bancrofti (4) but without a supporting description. A filaria was removed but not satisfactorily described or identified in 8 cases, spontaneously disappeared in 4, died following treatment in 4, and met unreported fates in seven. For 3 the original reports were inaccessible. Records of intraocular filariae that are not supported by morphological description are questionable.

Light, long-lasting Necator infection in a volunteer.

A Necator infection produced by percutaneous exposure of a volunteer to three larvae was followed with periodic egg counts for 4 months beyond 18 years when passage of eggs in the feces ceased permanently. During the 2nd year of infection, there was unintentional exposure to two additional larvae. Egg counts per gram of feces (EPG) were approximately 1,000 during the 1st year, 1,500 over the next 5 years, and less than or equal to 200 over the final 3 years, during which time there were 6 periods of approximately 1 month each when Kato thick-smear examinations revealed no eggs. During 6 of the 1st 14 years, when egg counts were done by the standard direct smear method, up to 37% of the eggs were infertile. Based on the assumption that two female worms were present during the 1st year, three during the next 3 years or more, and only one during the final 3 years, the estimated output per female in this light infection was 500 EPG in the worm's prime of life, and less than 200 EPG in the final year of the 17 or 18 year life span.

Invasive amebiasis in naturally infected New World and Old World monkeys with and without clinical disease.

Histopathological preparations of cecum and colon from monkeys naturally infected with invasive Entamoeba histolytica were examined to determine the distribution of amebae in the tissues and the types of lesions, if any, associated with them. Infections were studied in 3 New World species (10 Callicebus moloch, 1 C. torquatus, and 2 Aotus trivirgatus) and 3 Old World species (8 Macaca mulatta, 6 Erythrocebus patas, and 1 Cercopithecus aethiops). Amebiasis was recorded as the principal or a contributing cause of death of all of the 13 New World monkeys and in 6 of the 15 Old World monkeys; amebiasis was detected in the rest of the monkeys only after tissues were re-examined specifically for amebae. Amebae causing no apparent damage were found in the lamina propriae, mainly at the muscularis mucosae. Most frequent were colonies or aggregates of amebae in the crypts between the epithelium and basement membrane, causing either no evident necrosis or changes ranging from necrosis and disarrangement of adjacent cells to complete destruction of the epithelium and reduction of the cells to pyknotic bodies. A lesion interpreted as possibly characteristic of carrier-state invasive amebiasis was destruction of the epithelium in patches of mucosal crypts, not leading to ulceration. Uncommon but present in both New and Old World monkeys were typical areas of surface erosion and classical flask-shaped ulcers. The observations show that in some species of Old World monkeys amebiasis can be invasive without causing clinical disease.

A technique for removal of filariasis of the anterior chamber.

We describe a useful technique for removing filaria from the anterior chamber. In the case described, an immature female filaria approximately 15 mm in length was removed from the anterior chamber of a 32-year-old man in western Oregon and identified as a species of Dipetalonema. Features of four cases of filarial infection in the anterior chamber from the same geographic area are described. In three out of four cases, the worms were removed alive without difficulty by means of simple irrigation aspiration system.

Dirofilaria ursi-like parasites acquired by humans in the northern United States and Canada: report of two cases and brief review.

Two cases of subcutaneous dirofilariasis acquired in Ontario and Vermont are reported. The parasites in these and eight cases previously reported from the northern United States and Canada are classified as resembling Dirofilaria ursi, a primarily subcutaneous parasite of bears, or D. subdermata of porcupines, in the same region. A distinguishing morphological feature of the D. ursi-like group is the presence of distinct longitudinal cuticular ridges regularly and widely spaced on the outer surface, and usually evident even when the worms are necrotic. In the 10 known cases, all patients were women, and the usual location of nodules containing the worms was the scalp or a covered part of the upper body where blackflies, the intermediate hosts of D. ursi, normally feed.

Dirofilaria from the index finger of a man in Costa Rica.

A 4.5-cm male Dirofilaria indistinguishable from D. immitis was removed from the tip of the index finger of an 18-year-old farmer in Costa Rica. The case is reminiscent of a report of a larger (9-cm) but otherwise similar Dirofilaria, identified as D. spectans, a heartworm of otters, causing Raynaud's syndrome by occluding an artery of the fifth finger of a farm woman in Brazil. As in the present case, the worm was removed from a painful papule on the volar surface at the extreme tip of the affected finger.

Fly larva adherent to corneal endothelium.

Anterior ophthalmomyiasis is a rare condition in which a fly larva invades the globe, causing iridocyclitis and sometimes subluxation of the lens. Humans are accidental hosts in whom such larvae, after entering the eye, undergo little development. We report a case in which the first larval stage of a rodent or rabbit botfly, Cuterebra sp., invaded the anterior chamber, produced a transient iridocyclitis, and adhered to the posterior cornea where it remained as a dead, slightly atrophic body. Identification of the organism was made by slit-lamp and specular photomicrographs. Tapering doses of topical corticosteroids controlled the inflammation. During 27 months of observation the larva changed only slightly in appearance, the surrounding corneal endothelium remained normal, the cornea remained clear, and the visual acuity remained 20/20.

Zoonotic subcutaneous filaria of undetermined classification.

A necrotic adult male filaria was found in sections of a dense, fibrous, subcutaneous nodule excised from below the breast of a 61-year-old woman, resident of Mie Prefecture in Honshu, Japan. Owing to its necrotic condition, and to a lack of essential knowledge of the comparative micro-anatomy of filarial worms, a differentiation between Dirofilaria and Dipetalonema species, or member of a related group, was not possible.

Pulmonary dirofilariasis in a Costa Rican man.

In a 33-year-old male Costa Rican who died of undetermined cause 2 hours after admission to hospital, autopsy revealed a small female Dirofilaria causing a recent hemorrhagic infarct unlike the pale coin lesion usually seen in pulmonary dirofilariasis.

Macracanthorhynchus ingens from a child in Texas.

Nine acanthocephala recovered over a two-month period from the stools of a 10-month-old child in Texas were identified as Macracanthorhynchus ingens, a common intestinal parasite of the raccoon, Procyon lotor.

Subretinal nematode. An unusual etiology for uveitis and retinal detachment.

Retinal detachments are usually divided between rhegmatogenous and exudative. Many causes for exudative retinal detachments are described in the literature. Subretinal nematodes are a rare but well-known etiology for severe exudative retinal detachments and endophthalmitis. The case presented represents the first known infestation of human ocular tissue by the nematode Porrocaecum or Hexametra. Described are the presenting symptoms and medical and surgical management, including pars plana vitrectomy, retinotomy, and air-fluid exchange to salvage the eye.

A microfilaria of exceptional size from the ixodid tick, Ixodes dammini, from Shelter Island, New York.

Thirty or more microfilariae 0.70-1.32 mm in length were recovered from the hemocele of an unengorged adult tick, Ixodes dammini, that was collected from vegetation on Shelter Island, New York. Among approximately 500 I. dammini collected from the same area only 1 other was similarly infected. Outstanding features, in addition to size, were absence of a cephalic space and the presence of nuclei in 2 or 3 irregular rows extending to the end of a bluntly rounded tail. The microfilariae apparently were ingested in a blood meal that was taken when the ticks were larvae or nymphs, and had persisted alive without development.

Ascaridoid larva (Nematoda) from the eye of a child in Uganda.

A nematode measuring approximately 1.25 mm by 42 micron, excised in a granuloma from the eye of a child in East Africa, was identified as a third-stage ascaridoid larva of a type having no ventriculus or cecum and bearing conspicuous lateral alae.

Dioctophyma-like larval nematode in a subcutaneous nodule from man in Northern Thailand.

A nematode in a subcutaneous nodule from the anterior chest of a 12-year-old boy in Northern Thailand was identified as a third-stage larval dioctophymatid, possibly Dioctophyma renale, the second such larva to be reported from man.

Intraocular filaria, a Loaina species, from man in Colombia.

A 4.5-mm filarial worm was removed from the anterior chamber of the left eye of a 56-year-old man who had lost the sight in the right eye due to trauma some years earlier. The worm was removed intact through an upper scleral incision with a corneal based flap. Within 2 months vision was normal. The worm was identified as a sexually mature male of an undescribed species of Loaina Eberhard and Orihel 1984, a genus related to Loa and Dirofilaria.