Leptospirosis,

Question 1

What is the prevalence rate of Leptospirosis?

Answer 1

10/100,000 prevalence rate

Question 2

What is the seasonal peak of leptospirosis?

Answer 2

— seasonal with a peak incidence during the
rainy months of July to October

Question 3

What is the etiology of Leptospirasos that causes pathology?

Answer 3

Leptospira interrogans
◦ Pathogenic strains

Question 4

What is the nonpathogenic strain of Leptospirosis?

Answer 4

— Leptospira biflexa
◦ nonpathogenic strains

Question 5

thin, coiled spirochetes (0.1 ×
6.0 to 20.0μm)
— hook at one or both pointed
ends

Answer 5

Leptospira

Question 6

The motility of Leptospira sp is by means of

Answer 6

?— Motility by means of two
periplasmic flagella

Question 7

What is the optimum growth of Leptospira?

Answer 7

— optimum growth at 28° C to
30° C

Question 8

Leptospirasos is an obligate aerobes. T or F?

Answer 8

T

Question 9

How is the sublclinal infection of Leptospirosis?

Answer 9

◦ mild influenza-like febrile illness

Question 10

What is the severe systemic disease of Leptospirosis?

Answer 10

— severe systemic disease (Weil disease)

• *◦ renal and hepatic failure**, extensive
• *vasculitis, myocarditis, and death**

Question 11

The pathogenesis of Leptospira is determined by?

Answer 11

— Determined by:

• *1. Number of infecting organisms
  2. host’s immunologic defenses
  3. virulence of the infecting strain influence**

Question 12

MOT of Leptospirosis?

Answer 12

penetrate intact mucous
membranes or skin through small
cuts or abrasions

Question 13

◦ spread in the blood to all tissues, including
CNS
– multiply rapidly and damage the endothelium of
small blood vessels
– meningitis, hepatic and renal dysfunction,
hemorrhage

Answer 13

L. interrogans

Question 14

Where is the early stage of Leptospirosis?

Answer 14

— Early Stges
◦ Blood, CSF

Question 15

Late stage of Leptospirosis?

Answer 15

— later stages
◦ Urine

Question 16

Clearance of Leptospirosis happens when?

Answer 16

Clearance
◦ When humoral activity develops

Question 17

2 type of host of Leptospirosis?

Answer 17

two types of hosts:
◦ reservoir hosts
– Rodents and small
mammals
◦ incidental hosts
– dogs, farm animals,
humans

Question 18

— asymptomatic infections

— colonize the renal tubules

— shed in urine in large numbers

— Streams, rivers, standing water, and moist soil can be contaminated with urine from infected animals

◦ organisms surviving for as long as 6 weeks

Answer 18

Reservoir hosts

Question 19

Most human infections of Leptospirosis

Answer 19

◦ Clinically inapparent

◦ detected only through the demonstration of specific antibodies

Question 20

Infection of Leptospirosis is introduced through

Answer 20

— Infection introduced through skin
abrasions or the conjunctiva

Question 21

What is the incubation period of Leptospirosis?

Answer 21

Incubation period 1-2 weeks

Question 22

What are the 2 phases of Leptospirosis?

Answer 22

— 2 phases:
◦ initial phase
◦ Severe disease

Question 23

— influenza-like illness
◦ fever and myalgia (muscle pain)
— Organisms isolated in CSF
— remit after 1 week, or the patient may
progress to the second phase

Answer 23

Initial phase

Question 24

What happens in the second phase of Leptospirosis?

Answer 24

Headache
— Myalgia
— Chills
— abdominal pain
— conjunctival suffusion
(i.e., reddening of the
eye)
— Can progress to:
◦ vascular collapse
◦ Thrombocytopenia
◦ Hemorrhage
◦ hepatic and renal
dysfunction

Question 25

acute febrile illness with headache, myalgia (particularly **calf muscle**) and prostration associated with any of the following symptoms/signs:

Answer 25

◦ Conjunctival suffusion ◦ Anuria or oliguria ◦ Jaundice ◦ Cough, hemoptysis, and breathlessness ◦ Hemorrhages (intestine, lungs) ◦ Meningeal irritation ◦ Cardiac arryhthmia ◦ Skin rash

Question 26

The CNS Disease of Leptospirosis is

Answer 26

— viral **aseptic meningitis** — course of the disease is generally **uncomplicated** **— low mortality rate** — **Negative CSF culture**

Question 27

— Icteric form of generalized disease ◦ 10% of all symptomatic infections — 10% to 15% mortality **— Hepatic necrosis not seen** —** most patients recover full renal function**

Answer 27

Icteric disease, or Weil disease

Question 28

— Sudden onset of ◦ Headache ◦ Fever ◦ Myalgias ◦ diffuse rash

Answer 28

Congenital leptospirosis

Question 29

Laboratory Diagnosis of Leptospirosis Microscopy \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ — Gram stain and silver stain \_\_\_\_\_\_\_\_ — Darkfield microscopy ◦ \_\_\_\_\_\_\_\_\_\_ ◦ Yields nonspecific findings — Fluorescein-labeled antibody ◦ \_\_\_\_\_\_\_\_\_\_\_\_\_

Answer 29

1. — cannot be seen by conventional light microscopy 2. not reliable 3. relatively insensitive 4. used to stain leptospires ◦ Not available in most clinical laboratories

Question 30

Laboratory Diagnosis:LEptospirosis Culture —media: — generation time: **6 to 16 hours** — 28° C to 30° C — Most cultures **positive within 2 weeks**

Answer 30

Fletcher, **EMJH [Ellinghausen- McCullough- Johnson-Harris], ** Tween 80-albumin

Question 31

Leptospirosis is present in the blood for present in blood or CSF

Answer 31

during the **first 10 days of** **infection** ◦ several specimens should be collected

Question 32

Leptospirosis is Present in urine after the \_\_\_\_\_\_\_\_\_\_\_\_

Answer 32

first week and for as long as 3 months Note : ◦ must be treated to neutralize the pH ◦ concentrated by centrifugation — Detected by darkfield microscopy

Question 33

Laboratory Diagnosis: Leptospirosis \_\_\_\_\_\_\_\_\_\_ — limited success — nucleic acid amplification (e.g., PCR) more sensitive than culture — technique is not widely available at this time

Answer 33

Nucleic Acid–Based Tests

Question 34

Laboratory Diagnosis: Leptospirosis Antibody Detection \_\_\_\_\_\_\_\_\_\_\_\_\_\_ ◦ reference method for all serologic tests ◦ measures the ability of the patient’s serum to agglutinate live leptospires ◦ serial dilutions of the patient’s serum are mixed with the test antigens and then examined microscopically for agglutination ◦ Agglutinins appear in the blood of untreated patients after 5 to 7 days of illness

Answer 34

— Microscopic agglutination test (MAT)

Question 35

Treatment, Prevention, and Control of Leptospirosis?

Answer 35

— usually not fatal in the **absence of icteric disease** — Treatment with **penicillin and doxycycline ◦ Doxycycline for** prevention — **vaccination of livestock** **and pets has proved** **successfu**l in reducing incidence of disease **— Rodent control**