Schistosomiasis is an infection caused by Schistosoma, a trematode. Schistosomiasis occurs in developing countries with poor sanitation Sanitation The development and establishment of environmental conditions favorable to the health of the public. Hepatitis E Virus. Freshwater snails are the intermediate host and are transmitted to humans through skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions contact with contaminated fresh water. The clinical presentation Presentation The position or orientation of the fetus at near term or during obstetric labor, determined by its relation to the spine of the mother and the birth canal. The normal position is a vertical, cephalic presentation with the fetal vertex flexed on the neck. Normal and Abnormal Labor occurs as a result of the host’s immune response to antigens from the eggs. Most patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship are asymptomatic, but others may develop acute schistosome dermatitis Dermatitis Any inflammation of the skin. Atopic Dermatitis (Eczema), acute schistosomiasis syndrome, or chronic schistosomiasis. The diagnosis can be made with microscopic evaluation of the urine Urine Liquid by-product of excretion produced in the kidneys, temporarily stored in the bladder until discharge through the urethra. Bowen Disease and Erythroplasia of Queyrat or feces, serology Serology The study of serum, especially of antigen-antibody reactions in vitro. Yellow Fever Virus, or PCR PCR Polymerase chain reaction (PCR) is a technique that amplifies DNA fragments exponentially for analysis. The process is highly specific, allowing for the targeting of specific genomic sequences, even with minuscule sample amounts. The PCR cycles multiple times through 3 phases: denaturation of the template DNA, annealing of a specific primer to the individual DNA strands, and synthesis/elongation of new DNA molecules. Polymerase Chain Reaction (PCR). The treatment for schistosomiasis is praziquantel Praziquantel An anthelmintic used in most schistosome and many cestode infestations. Anthelmintic Drugs.
Last updated: 3 May, 2021
Photomicrograph depicting a grouping of 3 different species of Schistosoma eggs: S. japonicum, S. mansoni, and S. haematobium.
Image: “21017” by CDC/Dr. Brodsky. License: Public DomainTransmission occurs through skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions contact with infected fresh water.
Schistosoma occupies freshwater environments in areas with poor sewerage management.
The life cycle Cycle The type of signal that ends the inspiratory phase delivered by the ventilator Invasive Mechanical Ventilation of Schistosoma
Image by Lecturio.Schistosoma mansoni cercaria
Image:“Schistosoma” by CDC/Dr. D.S. Martin. License: Public DomainClinical disease is caused by:
Most patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship are asymptomatic. Symptomatic individuals can present in several ways:
Also known as “swimmer’s itch”:
A papular
rash
Rash
Rocky Mountain Spotted Fever due to acute schistosome
dermatitis
Dermatitis
Any inflammation of the skin.
Atopic Dermatitis (Eczema):
The hypersensitivity reaction occurs when
skin
Skin
The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue.
Skin: Structure and Functions is penetrated by Schistosoma cercariae.
Occurs due to a systemic hypersensitivity reaction 3–8 weeks after the initial infection:
Presentation Presentation The position or orientation of the fetus at near term or during obstetric labor, determined by its relation to the spine of the mother and the birth canal. The normal position is a vertical, cephalic presentation with the fetal vertex flexed on the neck. Normal and Abnormal Labor can vary depending on the number of eggs in the tissues, the infection site, and the immune response of the host.
Intestinal schistosomiasis:
Hepatosplenic schistosomiasis:
Genitourinary schistosomiasis:
Neuroschistosomiasis:
Personal protection in endemic areas:
Control strategies:
Organism | Enterobius vermicularis Enterobius Vermicularis Enterobius/Enterobiasis | Toxocara Toxocara A genus of ascarid nematodes commonly parasitic in the intestines of cats and dogs. Toxocariasis canis | Ascaris Ascaris Ascaris is a genus of parasitic nematodes. The infection, ascariasis, is most often caused by A. lumbricoides. Transmission occurs primarily via ingestion of water or food contaminated with Ascaris eggs. Most patients with ascariasis are asymptomatic. Ascaris/Ascariasis lumbricoides | Strongyloides stercoralis Strongyloides stercoralis A species of parasitic nematode widely distributed in tropical and subtropical countries. The females and their larvae inhabit the mucosa of the intestinal tract, where they cause ulceration and diarrhea. Strongyloidiasis | Schistosoma mansoni |
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Characteristics | Nematode Nematode A phylum of unsegmented helminths with fundamental bilateral symmetry and secondary triradiate symmetry of the oral and esophageal structures. Many species are parasites. Toxocariasis | Nematode Nematode A phylum of unsegmented helminths with fundamental bilateral symmetry and secondary triradiate symmetry of the oral and esophageal structures. Many species are parasites. Toxocariasis | Nematode Nematode A phylum of unsegmented helminths with fundamental bilateral symmetry and secondary triradiate symmetry of the oral and esophageal structures. Many species are parasites. Toxocariasis | Nematode Nematode A phylum of unsegmented helminths with fundamental bilateral symmetry and secondary triradiate symmetry of the oral and esophageal structures. Many species are parasites. Toxocariasis | Trematode |
Reservoir Reservoir Animate or inanimate sources which normally harbor disease-causing organisms and thus serve as potential sources of disease outbreaks. Reservoirs are distinguished from vectors (disease vectors) and carriers, which are agents of disease transmission rather than continuing sources of potential disease outbreaks. Humans may serve both as disease reservoirs and carriers. Escherichia coli | Humans | Dogs | Humans |
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Transmission | Fecal–oral | Fecal–oral | Fecal–oral | Skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions contact with contaminated soil | Skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions contact with contaminated water |
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Stool analysis |
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Praziquantel Praziquantel An anthelmintic used in most schistosome and many cestode infestations. Anthelmintic Drugs |
Prevention | Good hygiene |
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Low-power, microscopic view of Enterobius vermicularis Enterobius Vermicularis Enterobius/Enterobiasis
Image:“Double bulb oesophagus of Enterobius vermicularis Enterobius Vermicularis Enterobius/Enterobiasis, under low power Power The probability that a test will correctly reject a false null hypothesis. Statistical Tests and Data Representation” by Kaniyarakkal V et al AL Amyloidosis. License: CC BY 4.0Adult Ascaris Ascaris Ascaris is a genus of parasitic nematodes. The infection, ascariasis, is most often caused by A. lumbricoides. Transmission occurs primarily via ingestion of water or food contaminated with Ascaris eggs. Most patients with ascariasis are asymptomatic. Ascaris/Ascariasis lumbricoides worm
Image:“An adult Ascaris Ascaris Ascaris is a genus of parasitic nematodes. The infection, ascariasis, is most often caused by A. lumbricoides. Transmission occurs primarily via ingestion of water or food contaminated with Ascaris eggs. Most patients with ascariasis are asymptomatic. Ascaris/Ascariasis lumbricoides worm” by CDC Division of Parasitic Diseases. License: Public DomainStrongyloides stercoralis Strongyloides stercoralis A species of parasitic nematode widely distributed in tropical and subtropical countries. The females and their larvae inhabit the mucosa of the intestinal tract, where they cause ulceration and diarrhea. Strongyloidiasis parasite
Image:“ Strongyloides Stercoralis Strongyloides stercoralis A species of parasitic nematode widely distributed in tropical and subtropical countries. The females and their larvae inhabit the mucosa of the intestinal tract, where they cause ulceration and diarrhea. Strongyloidiasis in sputum” by CDC Division of Parasitic Diseases. License: CC BY 4.0Adult Schistosoma mansonias seen on electron microscopy
Image: “Schistosoma mansoni, adult. SEM [Scanning electron microscopy] of worm, unstained” by Otis Historical Archives of “National Museum of Health & Medicine”. License: CC BY 2.0