Parasitologia

#### Módulo 2: Ascaridíase (*Ascaris lumbricoides*)

Módulo 2: Ascaridíase (Ascaris lumbricoides)

**Verso**: Ovo contendo a larva L3 (ovo embrionado).

1. **Frente**: Qual a forma infectante do *Ascaris lumbricoides*?

**Verso**: Luz do intestino delgado.

2. **Frente**: Qual o habitat do *Ascaris lumbricoides* adulto?

**Verso**: Intestino → Sangue/Fígado → Coração → Alvéolos → Faringe → Intestino.

3. **Frente**: Qual o trajeto simplificado do Ciclo de Loos no *Ascaris*?

**Verso**: Migração e ruptura das larvas de *Ascaris* nos alvéolos pulmonares.

4. **Frente**: O que desencadeia a Síndrome de Loeffler na Ascaridíase?

**Verso**: Tosse seca/com sangue, febre, dispneia e eosinofilia sanguínea.

5. **Frente**: Quais os sintomas clássicos da Síndrome de Loeffler?

**Verso**: Obstrução intestinal por enovelamento mecânico de vermes adultos.

6. **Frente**: Qual a principal complicação mecânica da Ascaridíase grave?

**Verso**: Espoliação proteico-calórica por consumo direto do chimo intestinal.

7. **Frente**: Qual a ação nutricional direta do *Ascaris* adulto?

**Verso**: EPF por Hoffman ou Kato-Katz (pesquisa de ovos mamilonados nas fezes)

8. **Frente**: Qual o método diagnóstico parasitológico padrão para *Ascaris*?

Mature Cyst (Giardia lamblia)

The infective form of Giardia lamblia, characterized by an oval shape, 2 to 4 nuclei, and a rigid cystic wall.

Trophozoite (Giardia lamblia)

The pathogenic form in the small intestine, featuring a piriform 'owl face' appearance, 2 nuclei, 4 pairs of flagella, and a ventral/suctorial disc that mechanically adheres to the duodenum and jejunum mucosa.

Secondary Lactose Intolerance (Giardiasis)

A condition caused by the mass attachment of trophozoites via their ventral disc, which flattens the microvilli of the brush border in the duodenum and jejunum, inhibiting local lactase enzyme production.

Steatorrhea (Giardiasis)

The presence of fat in feces caused by mechanical blockage and mucosal injury by Giardia lamblia, which prevents the digestion and absorption of lipids.

Micronutrient Malabsorption in Chronic Giardiasis

Impaired absorption of fat-soluble vitamins (A, D, E, and K), Iron, and Vitamin B12 due to lipid drag in steatorrhea, brush border epithelial damage, and accelerated diarrheal transit time.

Ciclo de Loos (Loos Cycle)

The larval migration process of Ascaris lumbricoides: ingested eggs hatch in the intestine, L3 larvae penetrate the mucosa into portal circulation, pass through the liver and right heart to lung alveoli, ascend the bronchial tree to the pharynx, and are swallowed back into the small intestine to become adult worms.

Loeffler's Syndrome

An acute pulmonary condition triggered by the migration and rupture of Ascaris larvae in pulmonary alveoli during the Loos Cycle, manifested by cough, fever, dyspnea, pulmonary eosinophilic infiltrate, and allergic reactions.

Cercaria (Schistosoma mansoni)

The infective form of Schistosoma mansoni with a bifurcated tail that infects humans through active transcutaneous penetration during contact with contaminated fresh water.

Biomphalaria

The genus of freshwater snails that serve as the intermediate host for Schistosoma mansoni.

Symmers' Fibrosis

Hepatic fibrosis resulting from Schistosoma mansoni eggs with lateral spines being carried by blood flow to liver sinusoids, triggering granulomatous reactions that obstruct portal flow and cause portal hypertension, splenomegaly, and ascites.

Iron Depletion in Schistosomiasis

The active consumption of host iron by Schistosoma mansoni, resulting in an estimated daily loss of $2.5\,\text{mg}$ of Fe and causing severe iron-deficiency anemia.

Tachyzoite (Toxoplasma gondii)

The arch-shaped, rapidly multiplying form of Toxoplasma gondii responsible for the acute phase of infection and host tissue cell destruction.

Bradyzoite (Toxoplasma gondii)

The slowly proliferating form of Toxoplasma gondii maintained inside tissue cysts (muscle and brain) during chronic latent infection.

Oocyst (Toxoplasma gondii)

The environmental resistance form of Toxoplasma gondii eliminated exclusively in the feces of cats (the definitive host).

Vector Transmission of Trypanosoma cruzi

Transmission occurring when a triatomine bug (barbeiro) bites and defecates, allowing metacyclic trypomastigotes in the feces to enter the host through the bite wound or mucous membranes during scratching.

Oral Transmission of Trypanosoma cruzi

Transmission caused by ingesting food contaminated with crushed triatomines or their feces (e.g., açai or sugarcane juice), allowing parasites to penetrate through the oral mucosa.

Myenteric Plexus Destruction (Chagas Disease)

The chronic destruction of neurons in Auerbach's and Meissner's myenteric plexuses, leading to dolicomegalesophagus (causing severe dysphagia and malnutrition) and dolicomegalocolon (causing chronic constipation and fecaloma).

Sporozoite (Plasmodium spp.)

The infective form inoculated into human hosts by the female Anopheles mosquito vector.

Gota Espessa (Thick Blood Smear)

A Giemsa-stained blood preparation considered the gold standard for diagnosing malaria and quantifying Plasmodium parasitemia.

Esfregaço Delgado (Thin Blood Smear)

A microscopic blood preparation used specifically for identifying the species of Plasmodium.

Culex quinquefasciatus

The mosquito species that acts as the primary vector for Wuchereria bancrofti.

Nocturnal Periodicity (Wuchereria bancrofti)

The biological phenomenon where microfilariae migrate to peripheral blood at night (peaking near midnight) to match the nocturnal feeding habits of Culex quinquefasciatus, while remaining in deep pulmonary capillaries during the day.

Elephantiasis (Lymphatic Filariasis)

Chronic lymphedema caused by adult Wuchereria bancrofti worms obstructing lymphatic vessels and triggering granulomatous inflammation, leading to extravasation of protein-rich fluid and increased basal metabolic expenditure.