Parasites Worms

Blastocystis hominis is a common protozoan intestinal parasite, often identified in people with gastrointestinal complaints. While its pathogenic role is debated, it's associated with a range of digestive symptoms and is a frequent finding in stool tests worldwide....

Cryptosporidium spp. are a group of protozoan parasites that cause cryptosporidiosis, a gastrointestinal illness. Notable for their resilience in various environments, especially water, these parasites can cause outbreaks of diarrheal disease in both humans and animals....

Cyclospora cayetanensis is a microscopic protozoan parasite that causes cyclosporiasis, a gastrointestinal illness characterized by prolonged and relapsing diarrhea. Primarily found in tropical and subtropical regions, it has been responsible for various foodborne outbreaks globally....

Dientamoeba fragilis is a single-celled parasite that inhabits the human gastrointestinal tract. It is associated with dientamoebiasis, a condition that can cause a range of digestive symptoms. Its precise mode of transmission and role in the disease are still being researched.

Dwarf tapeworms, or Hymenolepis nana, are the most common tapeworms infecting humans, especially children. These parasites can complete their lifecycle within a single host, leading to direct transmission without the need for an intermediate host. Infections might be asymptomatic but can cause abdominal discomfort, diarrhea, and in severe cases, weight loss and malnutrition....

Entamoeba histolytica is a protozoan parasite that causes amoebiasis, a disease that can range from asymptomatic to severe dysentery and liver abscesses. It is a significant cause of morbidity and mortality in tropical countries with inadequate sanitation facilities...

Enterocytozoon and Encephalitozoon species are microsporidia — spore-forming unicellular parasites that can infect humans. They can cause gastrointestinal and systemic diseases, particularly in people with weakened immune systems. Symptoms vary depending on the site of infection but commonly include diarrhoea, weight loss, and fatigue.

Flatworms and tapeworms are parasitic worms that can infect the human digestive system, most commonly through the consumption of undercooked or contaminated meat. Tapeworms belong to the class Cestoda and can grow several metres long inside the intestines. Once inside the host, they attach to the intestinal wall and absorb nutrients, often causing symptoms such as digestive problems, weight loss, or fatigue. In many cases, however, the infection can be asymptomatic and remain undetected for long periods. Diagnosis typically involves stool sample analysis to detect eggs or worm segments.

Giardia lamblia is a protozoan parasite that causes giardiasis, a common intestinal infection. Notoriously resilient, it can survive in various environments, particularly in water, leading to outbreaks in communities with contaminated water sources....

Hookworms are parasitic worms that infect the small intestine, primarily in areas with poor sanitation. They attach to the intestinal wall, feeding on the host's blood, which can lead to anemia and protein deficiency. Symptoms include abdominal pain, diarrhea, and fatigue. Hookworms are transmitted through skin contact with contaminated soil....

Microsporidia are a group of microscopic, spore-forming parasites that primarily infect the intestinal tract but can also affect the eyes, muscles, and other organs, especially in individuals with weakened immune systems. These organisms are classified as fungi or fungus-like and are known to cause a condition called microsporidiosis. Transmission typically occurs through ingestion of contaminated food or water, or contact with infected animals or surfaces. Symptoms can include chronic diarrhea, weight loss, fatigue, and abdominal discomfort.

New World hookworms (Necator americanus) are a type of parasitic worm commonly found in the Americas. These parasites attach to the intestinal walls of their hosts, causing chronic blood loss, anaemia, and protein deficiency. The larvae can penetrate the skin from contaminated soil, putting individuals who come into contact with such environments at risk of infection.

Pinworms (Oxyuris), also known as threadworms, are common intestinal parasites, especially in children. These small, white worms cause itching around the anus, disturbed sleep, and irritability due to their egg-laying at night. Infection spreads via the faecal-oral route, often through ingesting microscopic eggs from contaminated hands, surfaces, or food.

Roundworms are a type of nematode that can cause infections in the human digestive tract. Typical symptoms include abdominal pain, diarrhea, and sometimes more serious conditions if left untreated. They are often transmitted through soil contaminated with human feces or improperly cooked food....

Tapeworms are intestinal parasites that can affect humans and animals. These flat, segmented worms can grow to considerable lengths. They typically enter the body through the consumption of contaminated food or water. While tapeworm infections may sometimes be asymptomatic, they can also cause abdominal discomfort, diarrhoea, and weight loss.

Threadworms (Strongyloides stercoralis) are tiny intestinal parasites that cause strongyloidiasis. They may be asymptomatic or cause a range of symptoms, including abdominal pain, diarrhoea, and, in severe cases, malabsorption. Transmission takes place through skin contact with contaminated soil. These worms are notable for their ability to reproduce within the host, which can lead to persistent, long-lasting infections.

Whipworms, caused by Trichuris trichiura, are intestinal parasites named for their whip-like shape. Infections often result from ingesting eggs found in soil contaminated with human feces. While many infections are asymptomatic, heavy infestations can lead to diarrhea, abdominal pain, and, in severe cases, rectal prolapse. Children are particularly susceptible to growth and cognitive development issues due to chronic infections....