Plasmodium and Babesia: Chapter 6 Flashcards
1
Q
Define the Following
- Sporozoa
- Macrogametocyte
- Microgametocyte
- Merzoite
A
- Sporozoa: A group of protozoa that have no obvious means of locomotion
- Macrogametocyte: Female sex cell of Plasmodium spp
- Microgametocyte: Male sex cell of Plasmodium spp
- Merozoite: Asexual sporoza trophozoite
2
Q
Define
- Ring form
- Schizogony
- Schizant
- Sporogony
- Sporozite
A
- Ring form
- Ringlike structure that appears initially after invasion of RBC by plasmodium spp
- Schizogony
- Asexual multiplication that occurs in humans prior to invasion of the RBCs
- Schizant
- Morphologic form responsible for the development and maturing of merozoites critical to parasite survival
- Sporogony
- Sexual multiplication that occurs in mosquitoes
- Sporozite
- Infective stage transferred by vector
3
Q
Health & Economic Burden of Malaria
A
- ~2.5 Billion (40% World’s Population) At Risk
- 400-800 million febrile infections/year
- 1 – 2 million deaths/year, >75% African children
- ~4 die per minute
- ~5000 die per day
- ~35,000 die per week
- <20% come to attention of the health system
- Pregnant women at high risk of dying, low birth weight children
- Children suffer cognitive damage and anemia
- Families spend up to 25% of income on treatment – (regressive tax)
- Major Impediment to Economic Growth and Development, as well as health
4
Q
Life Cycle of Plasmodium
A
5
Q
Occurence of Cyclic Paroxynsms (time required to burtst) in common plasmodium species
- P. vivax
- P. ovale
- P. malariae
- P. falciparum
A
- P. vivax
- Every 48hr
- P. ovale
- Every 48hr
- P. malariae
- Every 72 hr
- P. falciparum
- Every 36-48hr
6
Q
Clinical disease
A
- From the time of the original mosquito bite until a week or more later, the patient remains asymptomatic
- During this time the organisms are undergoing multiplication in the liver. This is the pre-erythrocytic or exo-erythrocytic cycle
- When the liver merozoites invade the RBCs, several broods begin to develop, however one will eventually dominate and suppress the other, thus beginning the process of periodicity
- Once the cycle is synchronized, the simultaneous rupture of a large # of RBC and liberation of metabolic waste byproducts into blood streams precipitate the paroxysms of malaria
7
Q
Clinical symptoms include
A
- Anemia
- Splenomegaly
- Classic paroxysms (with cold stage-fever-and sweats)
These symptoms are nonspecific and a diagnosis of malaria should always be considered in a patient with a travel history to an edemic area
8
Q
Paroxysms in cold stage
A
- Typical paroxysms begins with a cold stage and rigors lasting 1-2 hours. During the next few hours the patient will spike a fever that is high and will last for several hours marked by sweating and a subsequent drop in body temperatuer to normal or subnormal. Patients are usually exhausted and collaspse to sleep afterward
9
Q
Causes of Anemia in Malaria
A
- Direct RBC lysis as a function of the parasites lifecycle
- Splenic clearance of both infected and uninfected RBCs (coated with immune complexes)
- Automine lysis of coated infected and uninfected RBCs
- Decreased incorporation of iron into heme
- Increased fragility of RBCs
- Decreased RBC production from bone marrow suppression
10
Q
Host defenses against malaria
A
11
Q
Pathogenesis and Clincal Symptoms
A
- Paroxysms
- Periodicity varies by Plasmodium species
- Chacterized by chills
- Chills
- Fever
- Sweating
- Fatigue
- Relapses possible with P. vivax and P.ovale
- Additional possible symptoms:
- Ischemia-insufficient supply of blood to organ
- Anemia-decrease in RBC (healthy or unhealthy)
- CNS-involvement-can cause strokes
- Nephrotic syndrome-due to toxic degrad products
- Natural resistance due to some erythrocyte structural abnormalilites, certain hemoglobinopathies, and certain blood groups
- Example: individuals who are Duffy group negative showe greater resistance
12
Q
Morphologic Forms: Ring Forms (early trophozoites)
A
- Ringlike structure of parasite that develops after invasion of RBC
- Appears as blue cytoplasmic circle with red chromatin dot(s) on Giemsa stain
- Area within ring known as vacuole
13
Q
Mrophologic Forms: Developing trophozoites
A
- Appearance varies by Plasmodium species
- Ring form is much more pleomorphic and ameboid
- Circle of ring and chromatin dot(s) may still be present
- Brown pigment may be present
- Infected young, pliable RBCs are usually larege due to growing parasite
14
Q
Define of Schizant: Contrast immature & Matuer schizants
A
- Definition-A cell formed from a trophozoite during asexual stage of the life cycle of sporozoan protozoans, such as the malaria parasite.
- Immature schizants-
- Growing chromatin and cytoplasmic material
- Brown pigment granules may be present
- Parasite occupies more space within the RBC
- Mature schizants
- Mature and contains many merozoites (the maxiumum for that species before releasing into the blood stream
15
Q
A
Immature Schizonts
16
Q
Morphologic Forms: Mature schizants
A
- Fully developed merozoites emerge (asexual sporozoa trophozoites)
- Number and arrangement of merozoites vary with the malarial species
- Cytoplasmic material is presumed to be absent except with Plasmodium vivax
17
Q
Identify this: (Notice merozites in cells that vary in quanity according to species)
A
Mature Schizont
18
Q
Morphologic Forms: Microgametocytes
A
- Male sex cell
- Diffuse chromatin mass that stains pink-purple and surrounded by cytoplasmic material
- pigment may be present
-
Plasmodium falciparum
- Crescent-shaped
- Other Plasmodium species
- Round-oval
19
Q
Morphologic Forms: Macrogametocytes
A
- Female sex cell
- Compact chromatin material surrounded by cytoplasmic material
- pigment possibly present
- plasmodium falciparum
- Crescent-shaped
- Other plasmodium species
- Round to oval
20
Q
Identify
A
Plasmodium vivax
(notice the tiny granules)
21
Q
Identify
A
Plasmodium malariae
22
Q
Identify this
A
Plasmodium falciparum
(irregular to comma-shaped cytoplasmic dots seen in P. falciparum)
23
Q
Laboratory Diagnosis & perfered specimen
A
- Stained smear is still considered gold standard
- specimen of choice is mulitple sets of Giemsa-stained peripheral blood smears
- Thick smear for screening
- Thin smear for differentiation/morphology of Plasmodium species
24
Q
Laboratory Diagnosis: Timing of blood collection, & RDT
A
- Timing of blood collection
- Optimal time is between characterisitic cycles of fever and chills known as paroxysms
- Paroxysms vary by Plasmodium species
- RDT
- (Rapid Diagnostic Tests) such as plasmodium glutamate dehydrogenase testing; HRP II testing (Histidine rich protein) seen in P. falciparum; P.falciparum lactate dehydrogenase (pLDH); etc… are used in the field where expensive high technical testing like PCR and or microscopic detection by trained personnel are not practical.
25
Prevention of Malaria is based on using three types of drugs working together
* Chemoprophylaxis with the use of schizonticides against tissue schizonts
* Chemoprophylaxis with the use of a schizonticide directed to blood schizonts
* Chemoprophylaxis directed to the gametocyte stage of the plasmodium,
26
Plasmodium vivax (benign tertian malaria): Lab diagnosis, life cycle notes, and epidemiology
* Laboratory diagnosis
* All stages can be present in the blood film
* Life cycle notes
* Tends to invade **young, pliable RBCs-**results in distorted cells that are enlarged
* Epidemiology
* Most widley distributed of the *Plasmodium* species and found in tropical, subtropical, and temperate regions (C. &S America, India and S.E Asia)
27
Plasmodium vivax: Clincial symptoms, Treatment, & Preventaion
* Clincial symptoms: Benign tertian malaria
* Paroxysms occur every 48 hours
* Replase possible due to reactivation of dormant infected liver cells (hyponozoites)
* Treatment
* Numberous drugs available but resistance can exist
* Preventation and control
* Personal protection
* Prophylaxis
* Mosquito Control
28
Identify this
P. vivax ring trophs
29
Identify this
P. vivax ring troph
30
Identify this
P. vivax schizonts
31
Identify this
P. vivax schizonts
32
Identify
Plmasodium vivax
33
Identify this
Plasmodium Vivax gametocytes
34
Identify this
Plasmodium vivax gametocytes
35
Plasmodium ovale: little overview
* P. ovale and P. vivax infections are very similar yet P. ovale is **less severe,** tends to replase less frequently, and **usually ends with spontaneous recovery**, often with less than 6-10 paroxyms.
* Like P. vivax it infects only **young cells** (reticulocytes) and the parasitemia is generally limited to around 2-5% of available RBCs. **Thus RBCs' tend to be enlarged.**
36
Plasmodium ovale: Epidemiology & Clincial symptoms
* Epidemiology:
* Found primarly in tropical africa as well as Asia and S. America
* Clinical symptoms: **Benign teritan malaria:**
* ****48-hour paroxyms
* Replase possible due to reactivation of hypnozoites
* Without treatment, infection often lasts for only one year without treatment then spontaneous recovery compared to years with P. vivax
37
Plasmodium Ovale: Lab diagnosis & Life cycle notes
* Diagnosis
* All stages can be observed in blood firm
* Ring forms, microgametoctyes, and macrogametocytes are diffcult to distinguish from those P.vivax
* **Mature schizants with an average of 8 merozites differentiate it from P. vivax with an avg of 16 merozoites**
* Life cycle notes
* Targets and infects young, pliable red blood cells resulting in **distorted cells with ragged cell walls**.
38
Identifty this
Plasmodium ovale ring troph
39
Identify this
Plasmodium ovale ring troph
40
Identify this
Plasmodium ovale Schizonts
Note the oval shape and rough edges that the shape takes
41
Identify this
P. ovale microgametocyte
42
Identify this
P. ovale microgametocyte
43
Identify this
P. ovale microgametocyte
44
Plasmodium ovale: characterisictis of infected RBC and appearnce of RBCS
45
Table 6-3 tyical characterstics of P. Ovale
review table
46
Plasmodium malariae: Clinical symptoms, treatment, prevention and control
* Clincial symptoms: quartan malaria
* **Paroxyms occur every 72 hours**
* Spontaenous recovery can occur
* **There are no known relapses**
* Treatment
* Same as for P. vivax
* Prevention and control
* Similar to those for P. vivax
47
Plasmodium malariae: Overview
* P. malariae invades primarily the **older RBCs so the number of infected cells are somewhat limited**
* **Incubation period** between infection and symptoms may be much longer than that seen with P. vivax & ovale, raning from about **27-40 days.**
* Parasites can be found in the bloodstream several days before the initial attack. the prodromal symptoms may resemble those of P. vivax. A regular periodicity is seen from the beginning with a more severe parosxysm including a longer cold stage and more severe symptoms during the hot stage. collapse during the sweating stage is common
48
Plasmodium malariae: Symptoms and Geopgrahic distribution
* Nephrotic syndrome is common
* CNS involvement is rare
* **Anemia is mild to moderate**
* **Duration of untreated disease may be over 20 years**
* Symptom periodicty is **72 hrs**
* **Initial fever patterns are regular whereas in vivax and ovale it is irregular**
* 18-40 day incubation period
* Geographic distrubition
* Tropical and subtropical areas of C & S. America, Africa and S.E Asia
49
Plasmodium malariae: Lab diagnosis, Life cycle notes and Epidemiology
* Lab diagnosis
* Rings seen less often
* Developing trophozites and immature and mature schizants are more common
* **Life cycle notes**
* **Infects mature red blood cells**
* **Little red blood cell enlargment or distortion**
* **Noted for forming bands**
* Epidemiology
* Found in subtropic and tropic regions
50
Identifty this (illustration)
Plasmodium malariae
51
Identify this
P. malariae
| (notice the Band and Basket shapes)
52
Whats this? (Graphic)
Plasmodium Malariae
(note that there are 6-12 merozoites)
53
Identify this
Plasmodium malariae schizont forms
54
Plasmodium falciparum: Life cycle notes & Epidemiology
* Life cycle notes
* **Invades up to 50% of red blood cells of any age**
* Infections-in late summer and early fall
* Epidemiology
* Limited to tropical and subtropical regions (Tropical and Subtropical areas of C & S. America, Africa amd S.E Asia)
55
Plasmodium falciparum: Important points
* Nephrotic syndrome is rafe
* CNS involvement is very common (80% of fatal cases)
* Anemia is severe
* Parasitemia of all RBC regardless of age
* Duration of untreated infection is 6-17 months
* Symptoms are very severe
* Paroxysm is every 36-48 hours
* Incubation period is 8-11 days
* Relapses from the liver or recrudescences are rare
* Schizogony occurs in the internal organs (spleen, liver, bone marrow, etc) rather than circulating blood.
* Ischemia caused by plugging of vessels within these organs by masses of parasitized RBCs produces symptoms variying with the organ affected
56
Plasmodium falciparum: Clincial symptoms
* Symptoms: lack water fever, maligant tertian malaria
* Flu-like symptom early in infection
* **36-48 hr paroxyms**
* **Deadlist form of malaria**
* ****Large amount of toxic cellular debris
* May enter kidneys, brain, and liver
* May result in coma and death ( causes widespread ischemia due to capillary blockages) **Stick to sides of capiliary**
57
Plasmodium faliciparum: Lab diagnosis
* Typically only ring forms and gametocytes in blood firm
* Multiple infections can occur
* Red blood cells are neither enlarged nor distorted
* Other stages develop in capillaries of the viscera
* Relapses do not occur but infection can silenty persist and resurge
58
Identify this
Plasmodium falciparum
(Note the presence of mulitple rings and also the characteristic ear phone-ring form)
59
Identify these cells
Plasmodium falciparum
A. Ring form with double chromatin B, ring form. (a), schizont (b), and stain precipitate (c).
60
Identify this
Plasmodium falciparum ring forms
(noticed mulitply infected cells)
61
Identify this graphic
P. falciparum
(Notes-The most merozoites contained in a mature schizont of any other plasmodium schizont but can overlap with P. vivax to cause confusion)
62
Identify this
Plasmodium falciparum schizont
63
Identify this
Plasmodium falciparum schizont
64
Identify this
Plasmodium falciparum schizont
65
Identify this graphic
Plasmodium falciparum micro and macrogametocyte
(The very unique bana or crescent shapes gametocyte of plasmodium falciparum)
66
Identify this
Specifically (E) & (D)
E-Mature macrogametocyte
D-developing gametocyte.
67
Babesia life cycle
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