Rickettsial infections around the world, part 1: pathophysiology and the spotted fever group.

Background: The rickettsial diseases are an important group of infectious agents that have dermatological manifestations. These diseases are important to consider in endemic areas, but in certain suspicious cases, possible acts of bioterrorism should warrant prompt notification of the appropriate authorities.

Objective: In this two part review article, we review these diverse diseases by examining established and up-to-date information about the pathophysiology, epidemiology, clinical manifestations, and treatment of the ricksettsiae.

Biological and clinical basis for molecular studies of interferons.

The cytokine family of interferons (IFNs) has multiple functions, including antiviral, anti-tumor, and immunomodulatory effects and regulation of cell differentiation. The multiple functions of the IFN system are thought to be an innate defense against microbes and foreign substances. The IFN system consists first of cells that produce IFNs in response to viral infection or other foreign stimuli and second of cells that establish the antiviral state in response to IFNs.

Advances in antiviral therapy.

Infections with five of the herpesviruses (herpes simplex virus 1 [HSV-1], HSV-2, varicella zoster virus, Epstein-Barr virus, and cytomegalovirus) are treated with topical or systemic antiviral therapies. There are more than 100 genotypes of human papillomaviruses (HPVs), which may manifest as warts, skin cancers, cervical cancer, anogenital cancers, and upper digestive tract cancers. Molluscum contagiosum (MC) is a common, benign viral infection of the skin.

Selected sexually transmitted diseases and their relationship to HIV.

Although sexually transmitted diseases (STDs) are underreported and underrecognized, they are a major source of morbidity, mortality, and represent a major socioeconomic cost in developing and industrialized nations. Individuals who develop STDs are often coinfected with human immunodeficiency virus (HIV). Coinfection with HIV both facilitates the natural history of STDs and worsens the clinical picture.

Therapy of systemic fungal infections.

The incidence of both community-acquired and nosocomial fungal infections has significantly increased over the past several decades. The major factors for this increase are a heightened use of antibiotics, a growing population of the elderly and of immunocompromised patients as a result of HIV, cancer, and organ transplantation. In this article, we will review the indications, efficacy, and safety of the polyenes, imidazoles, triazoles, and other systemic antifungals in development that are used for systemic fungal infections.

Subcutaneous fungal infections.

Subcutaneous mycoses are caused by a variety of mostly tropical organisms, usually when they are implanted into the dermis or the subcutaneous tissue. They rarely disseminate or become systemic. Sporotrichosis, mycetoma, and chromoblastomycosis are more common subcutaneous mycoses than are rhinosporidiosis, zygomycosis, pheohyphomycosis, and lobomycosis.

Therapy of common superficial fungal infections.

Superficial fungal infections are common, especially onychomycosis, dermatophytoses, and superficial Candida infections. Most superficial fungal infections are treated with topical antifungal agents unless the infection covers an extensive area or is resistant to initial therapy. Onychomycosis often requires systemic therapy with griseofulvin, itraconazole, or terbinafine.

Emerging therapies for herpes viral infections (types 1 - 8).

There are eight members of the herpesviridae family: herpes simplex virus-1 (HSV-1), HSV-2, varicella-zoster virus, Epstein-Barr virus, cytomegalovirus, human herpes virus-6, human herpes virus-7 and human herpes virus-8. The diseases caused by viruses of the herpesviridae family are treated with and managed by systemic and topical antiviral therapies and immunomodulating drugs. Because these viruses establish a latent state in hosts, antiherpetic agents, such as nucleoside analogues, only control symptoms of disease or prevent outbreaks, and cannot cure the infections.

Vaccines and immunotherapies for the prevention of infectious diseases having cutaneous manifestations.

Although the development of antimicrobial drugs has advanced rapidly in the past several years, such agents act against only certain groups of microbes and are associated with increasing rates of resistance. These limitations of treatment force physicians to continue to rely on prevention, which is more effective and cost-effective than therapy. From the use of the smallpox vaccine by Jenner in the 1700s to the current concerns about biologic warfare, the technology for vaccine development has seen numerous advances.