Question

Scenario
Tim is a 40-year-old sustainable farmer who works daily in his farm fields. After a long day getting his fields ready for planting, he comes in and falls into bed, exhausted.

The next morning as he’s taking a shower, he feels a small lump on the back of his leg, behind his knee. Since he can’t really see it, he dries off and asks his wife to look at it. Initially she thinks it looks like a scab, but upon closer inspection she notices it has legs!

She runs for the tweezers and pulls the tick off, and then notices that he actually has three more ticks embedded higher up on the back of his thigh.

Signs and Symptoms
Tim had been bitten by ticks and treated for Lyme disease before, so he decided to wait to see if a rash developed. After checking the spots daily for a week and not seeing anything other than a small, red, raised area around a few of the tick bite sites, he stopped worrying.

About 10 days later, Tim developed a fever and started to have bouts of extreme fatigue that were not alleviated by resting or sleep. The fatigue got to the point that he couldn’t get out of bed. When he started to act disoriented and confused, his wife drove him to the hospital.

Testing
Blood was drawn and sent to the hematology, clinical chemistry, and microbiology laboratories.

Question 1: What symptoms would indicate that Tim’s disease could be due to an infection involving the central nervous system?

Question 2: What is the significance of these findings in the peripheral blood smear?

While his attending physician struggled to figure out what was wrong, Tim became unresponsive. Additional samples were sent to serology to assess his exposure to viruses known to cause encephalitis, specifically West Nile Virus (WNV), Eastern Equine Encephalitis Virus (EEE), and Powassen Virus (POW), as well as tests for other tick-borne diseases common to his area.

Serology Test Results:
WNV, EEE, and POW—negative
Lyme disease serology—equivocal
Babesia microti and B. duncanii —negative
Ehrlichia monocytogenes—negative
Anaplasma phagocytophilium—positive

Question 3: Discuss the results of the collective laboratory tests— are the serology test results consistent with what the hematologist observed in the stained blood smear?

Question 4: Do you think Tim has Lyme disease?

Diagnosis
Tim was diagnosed with anaplasmosis, caused by Anaplasma phagocytophilium.

Question 5: Is it necessary for the hospital to report Tim’s case of anaplasmosis to the CDC for disease surveillance? Why?

Over the next two months, seven other people with Tim’s symptoms were admitted to the same regional hospital. Six tested positive for anaplasmosis and were successfully treated, but the seventh person died before a diagnosis could be reached. She subsequently was found to be positive for Anaplasma. In the previous year, there had been no cases of anaplasmosis diagnosed at the hospital.

Question 6: What epidemiological term(s) apply to this scenario?

Treatment
Once it was affirmed that Tim was infected with Anaplasma, treatment with IV ceftriaxone was immediately started via a peripherally inserted central catheter (PICC). After 2 days on the antibiotic he was alert but still overwhelmingly fatigued. After a week he was feeling well enough to be released from the hospital, but visited an infusion center daily for the rest of the month. He was also given oral doxycycline.

By the end of the year, a total of 26 cases of anaplasmosis were diagnosed at the hospital, which was the only medical facility in Tim’s county of residence. The county population (from census data) that year was 6,982 people.

Question 7: What is the incidence of anaplasmosis in Tim’s county?

Question 8: Is this also the prevalence of anaplasmosis in Tim’s county? Why?

Answer 1

1)Symptoms such as extreme fatigue, disorientation and confusion represents the involvement of neurologic system

2) in peripheral blood smear examiners look at the size ,shape and number of different blood cells these include Red blood cells which carry oxygen ,white blood cells to prevent infection,

morulae can detect ina granulocyte on a peripheral blood smear associated with A.PHAGOCYTOPHYILUM infection

3)the standard serologic test for diagnosis of anasplasmosis is the indirect immunofluorescence antibody (IFA)ASSAY FOR IMMUNOGLOBULIN G (IgG)using A.PHAGOCYTOPHILUM ANTIGEN.

antibody titers are frequently negative in the first weeks of illness.Anasplasmosis cannot be confirmed using single acute antibody results

Antibodies to phagocytophilum might remain elevated for many months after the disease has resolved

--DURING the first week of illness a microscopic examination of a peripherl blood smear might reveal moruale (microcolonies of anasplasmae) in the cytoplasm of granulocytes and is highly suggestive of a diagnosis

question 4

No, PATIENT WILL REPORT JOINT PAIN AND STIFFNESS IN LYME DISEASE

Question 5)It is necessary to report anasplasmosis -bacause it is a nationally notifiable condition and cases should be reported

cases are identified using a standard case definition estabilished by the council for state and territorial epidemologisis

The geographic range of anasplasmosis appears to be increasing ,which is consistent with black legged tick's expanding range

increasing ranges for blacklegged ticks have been documented along the Hudson River VALLY ,Michiganad Virginia

occasionally anasplasmosis cases are reported in other part of US