Microbiology: Schistosomiasis Overview

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Questions and Answers

What is a key characteristic of the poliovirus that differentiates it from other viruses?

It is resistant to adverse environmental conditions. (correct)

It contains a DNA genome.

It has a complex structure with multiple lipid layers.

It is an enveloped virus.

Which of the following is NOT a method used to diagnose rabies?

Histopathologic examination of Negri bodies

Clinical evaluation of symptoms in the patient

Analysis of saliva for the virus presence

Detection of antibodies against viral capsid antigen (correct)

What is the primary method of transmission for hairy oral leukoplakia in AIDS patients?

Ingesting contaminated food or water

Direct contact with contaminated surfaces

Exchange of saliva, known as the kissing disease (correct)

Airborne droplets from infected individuals

Which of the following vaccines provides coverage against poliomyelitis?

Oral Polio Vaccine (OPV) or Inactivated Polio Vaccine (IPV) Signup and view all the answers

What is a common hematologic finding in patients diagnosed with hairy oral leukoplakia?

Lymphocytosis with Downey cells Signup and view all the answers

Which trematode is primarily associated with liver cancer?

Schistosoma japonicum Signup and view all the answers

Which treatment is considered the drug of choice for schistosomiasis?

Praziquantel Signup and view all the answers

Which laboratory method is specifically used to diagnose enterobiasis?

Scotch tape method Signup and view all the answers

What is a major symptom of hookworm infection?

Ground itch Signup and view all the answers

Which type of tuberculosis is characterized by multiple disseminated lesions?

Disseminated tuberculosis Signup and view all the answers

What characterizes the acute stage of bancroft filariasis infection?

Swollen lymph nodes Signup and view all the answers

Which method is commonly used for laboratory diagnosis of malaria?

Giemsa stained thick blood smear Signup and view all the answers

Which virus is strongly associated with Burkitt lymphoma?

Epstein-Barr virus Signup and view all the answers

What is the primary vector responsible for dengue transmission?

Aedes aegypti Signup and view all the answers

Which of the following is NOT a common symptom of acute HIV infection?

Chronic diarrhea Signup and view all the answers

Which hepatitis-causing agent is transmitted primarily through respiratory droplets?

Hepatitis A virus Signup and view all the answers

How is Zika virus most commonly transmitted to humans?

Mosquito bites Signup and view all the answers

What is the hallmark cancer associated with advanced AIDS?

Kaposi sarcoma Signup and view all the answers

Which organism is primarily responsible for causing trichuriasis?

Trichuris trichiura Signup and view all the answers

Study Notes

Schistosomiasis

Caused by trematodes known as blood flukes; dioecious with male and female forms.
Features two suckers: oral and ventral.
First intermediate hosts are mollusks such as clams and snails; undergo asexual reproduction.
Second intermediate host varies depending on the species, typically human.
Three main species: Schistosoma japonicum, Schistosoma mansoni, and Schistosoma haematobium.
Commonly found in freshwater; transmission via skin penetration by cercaria larvae.
S. japonicum primarily affects the inferior mesentery of the intestine; S. haematobium and S. mansoni affect the urinary bladder.
Geographic distribution: S. mansoni in South Africa, S. haematobium in the Middle East, and S. japonicum in Asia (Philippines, China, Indonesia).
Clinical disease: Schistosomiasis/Belharziasis. Can be asymptomatic or symptomatic with chronic infection.
Acute phase occurs 2-3 weeks post-exposure, may cause swimmer's itch or clam digger's itch; possible hematuria (blood in urine).
Katayama fever occurs 1-2 months post-exposure with swollen lymph nodes, hepatosplenomegaly, and fever.
Long-term effects include liver cancer (S. japonicum), colon cancer (S. mansoni), and urinary bladder cancer (S. haematobium).
Treatment options include artemisinin, praziquantel (drug of choice), and oxamniquine.

Ascaris

Ascaris lumbercoides is a large roundworm, creamy white in color.
Mature in the small intestine; eggs eliminated through feces, predominantly affecting children.
Disease: Ascariasis, often asymptomatic until adult worms are observed in stool.
Symptomatic cases may cause allergic reactions, asthma attacks, and eosinophilia (Löffler syndrome).
Laboratory diagnosis via detection of eggs and adult worms in feces or larvae in sputum.
Treatment includes mebendazole, albendazole, and pyrantel.

Enterobiasis (Pinworm)

Enterobius vermicularis, identifiable by yellow coloration, with females laying eggs in the perianal region at night.
Reinfection is common through hand-to-mouth transmission of eggs.
Symptoms include anal itchiness due to hypersensitivity reactions.
Laboratory diagnosis: Scotch tape method for egg detection.
Treatment includes mebendazole, albendazole, and pyrantel.

Trichuriasis (Whipworm)

Whipworm (Trichuris trichiura) features an anterior colorless end and posterior pink coloration.
Lives in the small intestine, migrating to the colon to lay eggs in feces.
Disease: Trichuriasis, which can mimic ulcerative colitis and lead to chronic dysentery with heavy infections.
Laboratory diagnosis through stool egg detection.
Treatment includes mebendazole and albendazole.

Hookworm Infection

Hookworms include Ancylostoma duodenale and Necator americanus.
A. duodenale has teeth, while N. americanus has cutting plates.
Infection occurs through skin penetration by filariform larvae.
Adult worms attach to the intestinal wall and feed on blood.
Disease: Hookworm infection, characterized by "ground itch," respiratory issues (eosinophilia), and anemia.
Laboratory diagnosis involves stool sample presence of thin-shelled eggs.
Treatment includes mebendazole, pyrantel, and iron supplementation.

Lymphatic Filariasis

Caused by Wuchereria bancrofti and Brugia malayi, both transmitted by mosquitoes.
Adult worms and larvae (microfilariae) appear creamy white with a delicate sheath.
Microfilariae migration can occur at night or during the day.
Symptoms include lymphatic obstruction, edema, flu-like symptoms, and chronic conditions like elephantiasis.
Laboratory diagnosis uses Giemsa-stained peripheral blood to detect microfilariae.
Treatment includes diethylcarbamazine, ivermectin, and albendazole (combination therapy).

Herpes Simplex Virus

Comprises HSV-1 and HSV-2, part of the herpesviridae family.
Transmission routes include oral contact (HSV-1) and genital contact (HSV-2).
Causes primary gingivostomatitis and herpes labialis (cold sores); can lead to herpes gladiatorum in wrestlers.
Laboratory diagnosis includes Tzanck smear for Cowdry type A inclusion bodies.
Treatment typically involves acyclovir.

Tuberculosis (Mycobacterium tuberculosis)

M. tuberculosis is the primary causative agent, with M. bovis affecting livestock.
Transmitted through respiratory droplets and potentially through contaminated milk.
Initial infection creates a Ghon complex; secondary infection may reactivate.
Extrapulmonary tuberculosis can affect lymph nodes and cause scrofula.
Laboratory diagnosis includes acid-fast staining of sputum and culture on Löwenstein-Jensen medium.
Treatment includes anti-TB drugs and BCG vaccination.

Mumps (Epidemic Parotitis)

Mumps virus from the paramyxoviridae family; primarily affects salivary glands.
Transmission occurs through respiratory droplets with an incubation period of 18-21 days.
Complications can lead to orchitis and meningitis.
Laboratory diagnosis includes urine, CSF, and sputum samples.
Prevention through MMR vaccination at 15 months.

Malaria

Caused by Plasmodium species, transmitted by Anopheles mosquitoes.
Symptoms manifest in cold, hot, and sweating stages, including severe headaches and splenomegaly.
Cerebral malaria may occur, resulting in kidney problems (black water fever).
Laboratory diagnosis involves Giemsa-stained thick blood films.
Treatment options include chloroquine and parenteral quinine.

Acquired Immunodeficiency Syndrome (AIDS)

Caused by human immunodeficiency virus (HIV), an RNA retrovirus.
Transmission methods include sexual contact, blood transfusion, and mother-to-fetus.
Asymptomatic for years; symptoms may include flu-like illness, lymphadenopathy, and opportunistic infections dominating later stages.
Hallmark features include hairy leukoplakia and Kaposi's sarcoma.
Laboratory diagnosis: ELISA followed by Western blot.
Treatment includes reverse transcriptase inhibitors and protease inhibitors.

Pediculosis Pubis (Pubic Lice)

Visible lice that attach to hair and feed on blood; primarily found in pubic hair.
Transmitted through sexual contact or shared linens.
Symptoms include itching and red spots from bites.
Diagnosis through lice identification.
Treatment typically includes insecticidal creams or permethrin.

Dengue

Transmitted by Aedes aegypti and Aedes albopictus mosquitoes.
Symptoms include high-grade fever, muscle and bone pain, and rash, with unique camel back fever pattern.
Dengue hemorrhagic fever leads to plasma leakage and severe bleeding.
Laboratory diagnosis via serology (MAC ELISA).
Vaccine available: Denvaxia (Sanofi Pasteur).

Zika Virus

Associated with microcephaly in newborns; transmitted primarily through Aedes mosquitoes.
Infectious via sexual contact, blood transfusion, and from mother to fetus.
Symptoms may be mild or absent, including headache, joint pain, and rash.
No specific treatment available.

Mononucleosis

Caused by Epstein-Barr virus (EBV), associated with B lymphocyte infection.
Transmission occurs through saliva (known as kissing disease).
Symptoms include lymphadenopathy and splenomegaly.
Diagnosis: hematologic examination revealing lymphocytosis and Downey cells.
Treatment is generally supportive, as no specific antiviral exists.

Poliomyelitis

From the picornaviridae family, known for its non-enveloped structure.
Symptoms transmitted via contaminated food, water, and nasal secretions.
Laboratory analysis through feces, CSF, and throat secretions.
Treatment includes pleconaril and vaccination with OPV (Sabin) or IPV (Salk).

Rabies

Caused by the Rhabdoviridae family (bullet-shaped RNA virus).
Primarily affects warm-blooded animals, especially dogs.
Transmitted through animal bites; virus travels from bite site to CNS.
Diagnosis involves histopathology for Negri bodies.
Post-exposure prophylaxis includes rabies immunoglobulin and human diploid cell vaccine (HDCV).

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Description

This quiz explores schistosomiasis, a disease caused by trematodes (blood flukes) such as Japonicum, Mansoni, and Haematobium. Participants will learn about the life cycle, intermediate hosts, and the specific anatomical sites affected by these parasites in humans. Test your understanding of this important microbiological topic.