Human gnathostomiasis is most frequently caused by the nematode Gnathostoma spinigerum. This disease is endemic to Southeast Asia, particularly Thailand and Japan. The clinical presentation is most commonly characterized by localized, intermittent, migratory swellings of the skin and subcutaneous tissues, often in association with localized pain, pruritus, and erythema. Since this worm can migrate to deeper tissues, any organ system may become involved. Characteristically, patients with gnathostomiasis have a moderate to severe elevation of the peripheral eosinophil count, with values not uncommonly exceeding 50% of the total white blood cell count. With modern-day travel and immigration, cases of gnathostomiasis are being diagnosed with increased frequency in the United States. Because of its rarity in this country, however, gnathostomiasis often is not included in an initial differential diagnosis despite the characteristic triad of intermittent migratory swelling, a history of travel to Southeast Asia, and eosinophilia. We report a case of cutaneous gnathostomiasis diagnosed in the United States, and we present a clinical review of the English-language literature on human gnathostomiasis.

https://www.jstor.org/stable/pdfplus/4456848.pdf

Clinical Gnathostomiasis: Case Report and Review of the English-Language Literature

Ancylostoma ceylanicum, a re-emerging but neglected parasitic zoonosis

Publisher Summary This chapter discusses the diethylcarbamatine and new compounds for the treatment of filariasis. Diethylcarbamazine is 1-diethylcarbamyl-4-methylpiperazine; it is also known as Hetrazan, Banocide, Notezine, Caricide, Carbilazine, Supatonin, and R.P. 3799. It was first put out as the chloride, but is now issued as the dihydrogen citrate, which contains only half its weight as base. In reports, it should be indicated whether the doses refer to a specific salt or to the base; unless otherwise stated, it can usually be assumed that the dose refers to the citrate. Diethylcarbamazine is a white powder, freely soluble in water, and has a slightly unpleasant sweetish taste. It is stable under all ordinary laboratory conditions. Furthermore, it is fully stable to autoclaving, even if mixed with diet (simulating cooking procedure). When diethylcarbamazine is given by mouth to either animals or man, it is rapidly absorbed from the alimentary canal. One dose of 10 mg base/kg produces a peak blood level of 4–5 μg/ml in 3 hours (when toxic symptoms are most prominent); the level gradually falls to zero within about 48 hours. Most of the excretion in the urine occurs in the first 24 hours during which time 10–26% of the dose may be recovered as diethylcarbamazine.

Diethylcarbamazine and new compounds for the treatment of filariasis.

Cestode worms, commonly also known as 'flat' worms or tapeworms, are an important class of endoparasitic organisms. In order to complete their life cycle, they infect intermediate and definitive hosts in succession, through oral ingestion of eggs or larvae, respectively. Serious disease in humans or other mammalian hosts is mostly caused by the larval stages. Echinococcus spp. and Taenia spp. have been extensively investigated in the laboratory due to the fact that they represent important veterinary medical challenges and also cause grave diseases in humans. In contrast, Hymenolepis spp. and Mesocestoides spp. infections are relatively rare in humans, but these parasites have been extensively studied because their life cycle stages can be easily cultured in vitro, and can also be conveniently maintained in laboratory animal hosts. Thus they are more easily experimentally accessible, and represent important models for investigating the various aspects of cestode biology. This review will focus on in vitro and in vivo models which have been developed for studies on the host-parasite relationship during infection with Echinococcus, Taenia, Hymenolepis, Mesocestoides and Spirometra, and will cover the use of these models to investigate the morphology and ultrastructure of respective genera, the immunological relationship with the host and the development of vaccination approaches, as well as applications of these models for studies on parasite metabolism, physiology and gene expression. In addition, the use of these models in the development of chemotherapeutic measures against cestode infections is reviewed.

Cestode parasites: application of in vivo and in vitro models for studies on the host-parasite relationship.

The course of primary infection with a hamster-adapted strain of Ancylostoma ceylanicum was studied in inbred DSN and randomly bred WO/GD and WO/CR hamsters. Infective larvae were administered orally and began to develop in the small intestine without embarking on a tissue migration. Only the occasional larva was detected in other organ sites. It was concluded that the developing larvae moulted on days 3-4 and again to the pre-adult stage about 9-11 days post-infection. Worm burdens in infected hamsters were stable for at least 11 weeks after infection. There was no sudden expulsive phase and some adult worms survived for over 200 days. Overall the sex ratio of worms in groups of hamsters killed concurrently was about 50% although occasionally the ratio was biased in favour of one sex in individual animals. The blood packed cell volume (PCV) was significantly depressed 2 weeks following infection and continued to decline until a point of stability was achieved 4-5 weeks post-infection. The PCV subsequently remained depressed throughout the period of observation. Infected hamsters lost weight if kept in groups, but not when housed in separate cages. Groups of animals which lost weight did not recover to normal values within 11 weeks of infection. It is suggested that this model of hookworm infection has scope for exploring aspects of the host-parasite relationship which the canine models cannot fulfill adequately.

/pdf/ancylostoma-ceylanicum-in-the-hamster-observations-on-the-375hhtkbbl.pdf

Ancylostoma ceylanicum in the hamster: observations on the host-parasite relationship during primary infection.

Litomosoides carinii: biogenic amines in microfilariae and adults.

The compound, 3, 5-dibromo-2'-chloro-4'-isothiocyanatosalicylanilide, has been tested against various nematode and cestode parasites in experimental and domestic animals. It shoved 100% activity against Ancylostoma ceylanicum, A tubaeformis, Syphacia obvelata, ascaridia galli, Toxocara spp., Toxascaris sp., Gnathostoma spinigerum, Hymenolepis nana, Raillietina spp. and Taenia spp. in doses 25-70 mg/kg given in single or multiple administrations.

3, 5-Dibromo-2'-chloro-4'-isothiocyanatosalicylanilide, a potent anthelmintic.

Ancylostoma ceylanicum is a new introduction as an experimental hookworm model. Information on the biology of this parasite in its laboratory host--the golden hamster, is meagre. Its infectivity, longevity and fecundity were studied to obtain relevant information especially on vulnerable points in the maintenance and continuation of the infection. 100% infectivity was obtained with an inoculum of 60 larvae per animal. Maximum numbers of parasites were harboured from day 15 to day 18 after infection and thereafter gradually declined. Approximately 10% of the worms were still present at the end of the third month of infection. The in vitro release of eggs in a 24-hour period by one female nematode peaked from day 25 to day 39, a second rise occurred in day 70 after infection.

Studies on infectivity, longevity and fecundity of Ancylostoma ceylanicum in golden hamsters *

The pattern of activity of certain membrane-associated enzymes was followed in the erythrocytes of Plasmodium berghei-infected Mastomys natalensis. Parasitized erythrocytes were separated from non-parasitized populations by percoll-density gradient centrifugation. The activity of adenylate cyclase was markedly increased while those of ATPase, acid phosphatase, beta-glucuronidase and N-acetyl-beta-D-glucosaminidase were considerably decreased in the membrane preparations of parasitized erythrocytes as compared to normal erythrocytes. There was a decrease in the activity of ATPase and an increase of adenylate cyclase in the membrane preparations of non-parasitized erythrocytes. However, other enzymes did not alter to a significant extent in non-parasitized erythrocytes. Chloroquine (in vitro) stimulated adenylate cyclase, Na+, K+-ATPase and Ca++Mg++-ATPase while acetylcholinesterase was significantly inhibited.

Erythrocyte membrane-bound enzymes in mastomys natalensis during plasmodium berghei infection

The synthesis and filaricidal activity of 1-iso-butoxycarbonyl-4-methylpiperazine against Litomosoides carinii in Sigmodon hispidus and Dipetalonema viteae in Mastomys natalensis is reported. At an intraperitoneal or oral dose of 3 mg/kg given for 6 days, the compound removed 91% of the circulating microfilariae but had no effect on adult L. carinii. However, it killed all microfilariae and adults of D. viteae at a subcutaneous dose of 50 mg/kg given for 6 days. The compound also possessed chemoprophylactic activity against the larvae of L. carinii and D. viteae at a dose of 30 and 50 mg/kg respectively.

A. B. Sen

Papers

Litomosoides carinii: biogenic amines in microfilariae and adults.

3, 5-Dibromo-2'-chloro-4'-isothiocyanatosalicylanilide, a potent anthelmintic.

Studies on infectivity, longevity and fecundity of Ancylostoma ceylanicum in golden hamsters *

Erythrocyte membrane-bound enzymes in mastomys natalensis during plasmodium berghei infection

Studies of potential filaricides: Part 14--Activity of 1-iso-butoxycarbonyl-4-methylpiperazine against experimental filariasis.