Many parasitic diseases traditionally have been considered exotic and, therefore, frequently are not included in differential diagnoses of patients in the United States, Canada, and Europe. Nevertheless, a number of these organisms are endemic in industrialized countries, and overall, parasites are among the most common causes of morbidity and mortality in various and diverse geographic locations worldwide. Outside the tropics and subtropics, parasitic diseases particularly are common among tourists returning to their own countries, immigrants from areas with highly endemic infection, and immunocompromised people. Physicians and clinical laboratory personnel need to be aware of where these infections may be acquired, their clinical presentations, and methods of diagnosis and should advise travelers how to prevent infection. Table 3.40 gives details on some infrequently encountered parasitic diseases.

Table 3-40

Consultation and assistance in diagnosis and management of parasitic diseases are available from the Centers for Disease Control and Prevention (CDC), state health departments, and university departments or divisions of geographic medicine, tropical medicine, pediatric infectious disease, international health, and public health.

The CDC distributes several drugs that are not available commercially in the United States for Treatment of parasitic diseases. These drugs are indicated by footnotes in Table 4.11, Manufacturers of Some Antiparasitic Drugs . To request these drugs, a physician must contact the CDC Drug Service (see Appendix I, Directory of Resources) and provide the following information: (1) the physician's name, address, and telephone number; (2) the type of infection to be treated and the method by which the infection was diagnosed; (3) the patient's name, age, weight, sex, and if the patient is female, whether she is pregnant; and (4) basic demographic, clinical, and epidemiologic information. Consultation with a medical officer from the CDC is required before a drug is distributed.

Important human parasitic infections are discussed in individual chapters in Section 3; the diseases are arranged alphabetically, and the discussions include recommendations for drug Treatment. Tables 4.9, 4.10, and 4.11, reproduced from The Medical Letter (see Drugs for Parasitic Infections), provide dosage recommendations and other relevant information for specific antiparasitic drugs. Although the recommendations for administration of these drugs given in the disease-specific chapters are similar, they may not be identical in all instances because of differences of opinion among experts. Both sources should be consulted.