Question

medical mican uninvited party guest

An Uninvited Party Guest On a Monday morning in early July, Angela Thompson (31) and her c Natalie (9), Jason (6), and Marie (18 months) showed up in Dr. Jenkins's without an appointment. All complained of severe, smelly diarrhea, gas, and dominal cramping, which began Friday evening. Since these general sym are associated with dozens of self-limiting viral infections that are easily tra among family members, Dr. Jenkins was not overly concerned. He mended Imodium to stop the diarrhea, increased fluid consumption to preve dehydration, and diet modification, including yogurt as a probiotic. He colle ted Probiotie- Introduction of microbes into a host to balance normal flora cr to boost mucosal immunity a stool sample from little Marie, who had conveniently soiled her diaper their office visit. The next day Dr. Jenkins was surprised to examine six other patients with similar symproms. A few of these patients also complained of nausea, headache and mild fever. By Thursday morning Dr. Jenkins was truly concerned. Eighteen patients in four days had presented with the same symptoms and he had even admitted one to the hospital. Jake (38) had been diagnosed HIV seven yean earlier. Since he wasn't especially compliant with his prescribed antiviral therapy Jake had suffered from several opportunistic infections associated with his immu. nocompromised status. When he arrived at Dr. Jenkins's practice today, Jake was extremely dehydrated and had lost seven pounds in seven days due to the severe diarrhea. By late afternoon the results from Marie Thompson's stool specimen wetre back from the laboratory. The report confirmed giardiasis. 1. What microbe is responsible for this condition? Characterize tha 2. Where is this microbe commonly found? How is it transmitted to humans? 3. What is the infective dose for giardiasis? What is its incubation period 4. Outline the symptoms associated with this disorder. What is the duration organism of this illness? Are infected individuals always symptomatic? 5. Who is at greatest risk of infection? 6. How is giardiasis diagnosed? 7. How is this infection treated? Figure 1. Light micrograph of Glardia cysts Dr. Jenkins contacted the county health department to report a suspecned outbreak. With their help, stool samples were collected from all of his afficted patients and other local physicians were notified. Workers from the health depar ment were soon able to establish an epidemiological link between the patiens Ten days earlier everyone had celebrated the town's centennial, which includel a strawberry festival featuring shortcakes made with the locally grown berrics df the Taylor Family Farms. After a visit to the farms, it was determined that berries were irrigated using ditch water. Sampling water from various ditchs the vicinity of the fields yielded approximately half of the specimens positive the cysts of the suspected pathogen. The sale of produce from the Taylor Fane Farms was suspended, and the proprietors were ordered to use an approp ive water source for irrigation 70 Community Acquired infections

Answer 1

ANS 1 :  Giardiasis is caused by a microscopic parasite called Giardia lamblia.

Some of the characteristics of Giardia lamblia are-

• Giardia lamblia is a flagellated, microaerophilic microorganism
• Giardia reproduce by binary fission and must be attached to a surface for this to occur.
• Giardia lamblia has a characteristic tear-drop shape and measures 10-15 µm in length. It has twin nuclei and an adhesive disk which is a rigid structure reinforced by supelicular microtubules.
• There are two median bodies of unknown function, but their shape is important for differentiating between species.
• There are 4 pairs of flagella, one anterior pair, two posterior pairs and a caudal pair. These organisms have no mitochondria, endoplasmic reticulum, golgi, or lysosomes.
• The cyst is the reproductive form, and consists of a protective cyst wall as well as four nuclei.

ANS 2: Giardia lamblia is commonly found in contaminated water. It is also found on surfaces or in soil, food that has been contaminated with feces (poop) from infected humans or animals.

Giardia lamblia infection can occur through ingestion of dormant microbial cysts in contaminated water or food, or by the fecal–oral route

ANS 3:  The infectie dose for Giardiasis is about 10 cells.

Acute giardiasis develops after an incubation period of 1 to 14 days (average of 7 days)

ANS 4 : Common symptoms of Giardiasis are:  

• Watery, sometimes foul-smelling diarrhea that may alternate with soft, greasy stools
• Abdominal cramps
• Bloating
• Nausea
• Weight loss

Signs and symptoms of giardia infection may last two to six weeks, but in some people they last longer or recur.

Infected individuals are not always symptomatic. Some people with giardia infection never develops signs or symptoms but still carry the parasite and can spread it to others through their stool.

ANS 5 : Anyone may become infected with Giardia. However, those at greatest risk are-

• Giardia infection is far more common in children than it is in adults.
• Travelers to countries where giardiasis is common
• People in childcare settings
• Those who are in close contact with someone who has the disease
• People who swallow contaminated drinking water
• Backpackers or campers who drink untreated water from lakes or rivers
• People who have contact with animals who have the disease
• People who have anal sex

ANS 6 : Giardiasis is diagnosed by antigen testing of the stool. For antigen testing, a small sample of stool is tested for the presence of Giardial proteins. Giardia also can be diagnosed by examination of stool under the microscope for cysts or trophozoites; however, it takes three samples of stool to diagnose 90% of cases.

Other tests that can be used for diagnosing giardiasis are collection and examination of fluid from the duodenum or biopsy of the small intestine, but these require tests that involve expense and discomfort.