Question

PROTOZOAN GENUS NAMES TO MATCH TO THE CASE STUDY:      

Giardia                                                                                           Toxoplasma                                                      Trichomonas

Trypanosoma                                                                         Plasmodium

Case 4:

An 11-year-old boy in Thailand was admitted to the hospital due to a sustained fever for 10 days prior to admission. He presented with fever and chills. There were no symptoms of cough or other respiratory tract involvement. There was no jaundice, but two days before admission, there was a stomach-ache and vomiting, but no diarrhea. He complained about myalgia (muscle aches) but did not have any rash or hemorrhages.
His fever was 103^oF on admission, and his heart rate was 140 bpm. He had mildly enlarged tonsils, a swollen left submandibular lymph node and tachycardia. There was mild tenderness in the upper right quadrant of the abdomen, with mildly enlarged margins of the liver. His spleen was normal. He had drowsiness but was still oriented.
A peripheral blood smear showed normal-sized Red Blood Cells with a few ring-forms of a trophozoite inside the RBCs. On occasion, faint red dots were seen on the surface of the RBCs.
The patient was placed on Malarone and began to show signs of recovery within a few days.

Question 1: What is the name of this parasite?

Question 2: where is the trophozite of this parasite, usually reside?

_____________________________________________________________________________________________________________________________________________

Case 5

A pregnant woman who lived on a farm with many dogs and cats as outdoor pets presented to an urgent care clinic during the 15^th week of her pregnancy. She presented with fever, headache, enlargement of a lymph node on her neck, and symptoms of a common cold.   She was placed on the antibiotic Cefixime, but she remained symptomatic despite the prescription.
An ultrasound of the fetus was taken at week 17, and it showed no anomalies. But since the patient was still symptomatic, she was referred to an ENT (Ear-Nose-Throat) specialist. Fluid was extracted from a swollen lymph node which had continued to swell in size. No parasites were seen in a stain of the fluid. But a follow-up serological blood test was positive for antibodies to the suspected parasite. Under the microscope, the trophozoite of this parasite would be crescent-shaped, 6 micrometers in length, with a prominent nucleus, a pointed anterior end, and a rounded posterior end.
The patient was given pyrimethamine and sulfadiazine, but she could not tolerate them, developing a petechial rash. Spiromycin was then prescribed.
At the 24^th week of pregnancy, a fetal scan showed pronounced hydrocephaly and decreased amniotic fluid. The physician recommended termination of the pregnancy, and it was terminated at 178 days. The male fetus was covered in meconium and had developed the same petechia as the mother had during her drug reaction.

Question 1: what is the risk factor in this case?

Question 2:what is the caustive agent?

Answer 1

ANSWER

CASE 4

part 1. Parasite involved in case 4 is Plasmodium. It is an unicellular eukaryote which is known to cause malaria in the infected person. Transmission of this parasite occus through a vector which is a female anopheles (mosquito).

part 2. The trophozoite of plasmodium parasite resides in the RBCs (erythrocytes). After mosquito bites a person, it releases sporozoites in the bloodstream. These sporozoites move to the liver where they mature and become merozoites. These merozoites travel inside the RBCs and form a ring-like structure which are known as trophozoites. These trophozoites feed on globin component of RBCs and cause rupturing of RBCs. From this stage, symptoms of malaria begins to appear.

CASE 5

part 1. Cats are observed to be the risk factor in this case. Cats serve as definitive host for the parasite, Toxoplasma. When a cat feeds on an infected prey, the parasite enters the digestive tract of the cat. Here, parasite undergoes maturation and reproduction, thus, produces oocytes. These oocytes are eliminated in the form of faeces. Humans become infected with this parasite on eating the food contaminated with faeces.

part 2. Causative agent in case 5 is Toxoplasma gondii which causes toxoplasmosis, characterized by the presence of fever, cold, swollen lymph nodes. Its transmission occurs via eating contaminated food, exposed to the cat's faeces or transmits from mother to the foetus during pregnancy.