Parasitic helminth infection

While he was living outside the country for 3 years, Mr. Evans became infected with a helminth. The parasite has been identified and the appropriate drug prescribed. Discuss the points you would include in a teaching plan for this patient. 

In some helminth infections, a migration through various body tissues is essential for maturation, as in ascarasis or schistosomiasis, whereas in other infections, the larva leaves the egg and simply matures in the intestinal tract, as in trichuriasis and enterobiasis. Host tissues involved vary depending upon the parasite. In severely immunocompromised patients, sites may be involved that are not involved in normal hosts. 

One likely reason for the prevalence of helminths is their undoubted ability to down-regulate the host immune system at both the antigen-specific and polyclonal levels [3], In many chronic diseases, such as schistosomiasis and lymphatic filariasis, peripheral blood T cells show dramatically impaired parasite antigen-specific responsiveness [4], as discussed in more detail below. Moreover, from early reports of immunosuppression in animal models of infection, to studies in Africa linking vaccine failure to heavy helminth infection, there is clear evidence that infections can diminish reactivity to bystander antigens, particularly with increasing intensity of... 

Recent developments in immunology now offer a conceptual framework to understand the link between helminth infection and immunomodu-lation. Parasites induce Treg populations which suppress antiparasite effector cells, as part of the parasites own strategy for survival in the host. At... 

IgG is the characteristic antibody of all internal secretions including blood and cerebrospinal fluid (CSF). Normal urine contains about 5-10 mg/day. In secondary immune responses like malaria and helminth infection, very large quantities of IgG are produced especially to soluble antigens and toxins. High values are found in many parasitic infections. 

Several benzimidazoles are in use for the treatment of helminthic infections. Three of these, mebendazole, thiabendazole and albendazole, are described in this section. They have a broad range of activity against many nematode and cestode parasites, including cutaneous larva migrans, trichinosis, disseminated strongyloidiasis, and visceral larva migrans. A fourth, triclabendazole, is considered as the drug of choice for Easciola hepatica therapy. 

Table 53-1 lists the major helminthic infections and provides a guide to the drug of choice and alternative drugs for each infection. In the text that follows, these drugs are arranged alphabetically. In general, parasites should be identified before treatment is started. 

The remarkable success that has been achieved with identification of protective, recombinant antigens against the Taenia and Echinococcus species has been in stark contrast to the general lack of success that has been achieved with vaccine development against other parasitic helminth infections (Dalton and Mulcahy, 2001). Hence, very little direction has been available from the experiences of others on how to translate a laboratory success with an anti-parasite vaccine into a practical (commercial) vaccine. First principles would suggest a host of issues that require investigation/opti-mization, for example ... 

The pharmacologic treatment of parasitic infections is a complex and extensive topic. In this limited space, it is difficult to describe the many species of each parasite, all the diseases caused by parasites, and the chemical methods currently available to selectively destroy various fungi, protozoa, and helminths in humans. Consequently, the general aspects of each type of parasitic infection are reviewed briefly, followed by the primary drugs used to treat specific fungal, protozoal, and helminthic infections. This discussion will acquaint physical therapists and occupational ther-... 

Infection from helminths, or parasitic worms, is the most common form of disease in the world.41,44 There are several types of worms that may invade and subsist... 

Some of the common anthelmintics used to kill the basic types of worms in humans are listed in Table 35-5. These agents are often very effective a single oral dose is usually sufficient to selectively destroy the parasite. Brief descriptions of the basic pharmacologic effects and possible adverse effects of the primary anthelmintic agents are presented below. Several authors have also extensively reviewed the pharmacologic treatment of helminthic infections.36,41,52,58,66... 

Three major groups of helminths (or worms), the nematodes, trema-todes and cestodes, infect humans. As in all antibiotic regimens, the anthelminthic drugs (Figure 36.1) are aimed at metabolic targets that are present in the parasite but are either absent from or have different characteristics than those of the host. Figure 36.2 illustrates the high incidence of helminthic infections. 

Mosquitoes, are the most notorious carriers, or vectors, of disease and parasites. Female mosquitoes rely on warm-blooded hosts to serve as a blood meal to nourish their eggs. During the process of penetrating a host s skin with their long, sucking mouth parts, saliva from the mosquito is transferred into the bite area. Any viral, protozoan, or helminth infections carried in the biting mosquito can be transferred directly into the blood stream of its host. Among these are malaria, yellow fever, W. bancrofti (filariasis and elephantiasis), and D. immitis (heartworm). 

Unlike helminth infections where a variety of drugs derived from arsenic, antimony, phosphorus, tin and lead have been used to eradicate intestinal and extrain-testinal parasites, only organo-arsenicals and -antimonials find use in the treatment of protozoal diseases [1-10]. 

This chapter discusses the major parasitic diseases, including protozoan diseases (amebiasis, malaria), helminthic infections (as-cariasis, enterobiasis), and ectoparasitic infestations (head and body lice). Emphasis is placed on diseases seen more frequently in the... 

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