Blastocystis is a protist that parasitizes the lower intestine of humans and a vast range of animals. Although Blastocystis has been implicated as a cause of various gastrointestinal tract symptoms, its role as a pathogen, mechanism of transmission, and life…
Balantioides coli originally was called Balantidium coli (synonym Neobalantidium coli ), but it has been renamed based on new phylogenetic observations. , This ciliate inhabits the intestine of several mammalian species, and it is the only ciliate known to infect…
Acknowledgment The author and editors remember the substantial contributions of Robert W. Tolan to pediatric infectious diseases and to this chapter in previous editions. Colleagues continue to mourn his loss. Babesiosis is an emerging tickborne zoonotic disease, clinically similar to…
Pediculosis The Parasites, Pathogenesis, and Epidemiology Pediculosis is an infestation by one of several species of sucking lice of the phylum Arthropoda, class Insecta, order Phthiraptera, suborder Anoplura, and family Pediculidae or family Pthiridae. The three types of lice that…
Although all infectious agents of humans are parasites, by convention, parasitic diseases are often defined as diseases caused by ectoparasites, parasites that live on the outside or within the skin of the host, and endoparasites, parasites that live on the…
Mycetoma (maduromycosis, Madura foot) is a neglected tropical disease that has its greatest impact on severely impoverished, remote rural communities. It is a noncontagious, localized chronic debilitating infection that affects skin, subcutaneous tissue, fascia, muscle, and bone. The foot is…
Superficial fungal infections of the skin, nails, and mucosa are mainly caused by three groups of fungi—the dermatophytes, Candida spp., and Pityrosporum spp. Non-dermatophytic molds form a fourth group that contributes a minority of such infections. Superficial fungal infections are…
Coccidioidomycosis is an infection caused by the dimorphic fungi Coccidioides immitis and Coccidioides posadasii . These fungi are endemic to the southwestern US, Mexico, Guatemala, and sporadic regions within Central and South America. Infection is caused by inhalation of highly…
Blastomyces , the etiologic agent of blastomycosis, can infect both people with healthy immune systems and those with impaired immune defenses. The Blastomyces genus consists of 7 different species, of which B. dermatitidis and B. gilchristii cause the majority of…
Description of Pathogen Pneumocystis jirovecii (formerly called P. carinii ) is an opportunistic human respiratory pathogen. Although Pneumocystis organisms share some of the common features of protozoa, molecular genetic comparisons have definitively placed Pneumocystis among the ascomycetous fungi. , Pneumocystis…