Infectious Diseases
Microorganisms that are capable of causing disease are called pathogens. Although microorganisms that cause disease often receive the most attention, it is important to note that most microorganisms do not cause disease.

Cryptosporidiosis
Intestinal infection with protozoa of the genus cryptosporidium. It occurs in both animals and humans. Symptoms include severe diarrhea.

Defenses Against Infectious Diseases
The human body has several general mechanisms for preventing infectious diseases. Some of these mechanisms are referred to as nonspecific defenses because they operate against a wide range of pathogens. Other mechanisms are referred to as specific defenses because they target particular pathogens and pathogen-infected cells.

Treatment of Infectious Diseases
In general, drugs that effectively inhibit viral infections are highly toxic to host cells because viruses use the host's metabolic enzymes in their reproduction. Antibiotic resistance appears as a result of changes in genes or the acquisition of genes that allow the pathogen to evade the action of antimicrobial drugs.

Rickettsiae
Rickettsia species cause Rocky Mountain spotted fever, rickettsialpox, other spotted fevers, epidemic typhus, and murine typhus.

Preventable Causes of Cancer
Our fforts to identify potential carcinogens still have a central place in our struggle with cancer. Prevention of the disease is not only better than a cure; for many types of cancer, it seems also to be much more readily attainable.

Diseases Transmissible Between Dogs and People
List of diseases that can be transmitted from dogs and cats to humans are rabies, roundworms, ringworm, and toxoplasmosis. It is always wise to minimize contact between wild animals and your dog or cat.

Toxoplasmosis and Associated Diseases and Disorders: The Growing Danger of Toxoplasmosis
Toxoplasmosis is a common parasitic zoonosis and an important cause of abortions, mental retardation, encephalitis, blindness, and death worldwide. Many diseases have been recently linked to this infection. Read about signs and symptoms of toxoplasmosis and its prevention.