54 Hemolytic Anemia resulting from Infections with Miroorganisms

Question 1

Mechanisms that may lead to hemolysis during infections

Direct invasion of or injury

Answer 1

Malaria, babesiosis, and bartonellosis

Question 2

Mechanisms that may lead to hemolysis during infections

Elaboration of hemolytic toxins

Answer 2

Clostridium perfringens

Question 3

The world’s most common cause of hemolytic anemia

Answer 3

Malaria

Question 4

Specialized invasion proteins that invade in Malaria

Answer 4

Erythrocyte binding-like (EBA) and reticulocyte homology (RH) protein families

Bind to receptors on the erythrocyte surface, including glycophorins A/B/C, CR1 (CD35), and basigin (CD147)

Question 5

All parasites bind to ________ and___________ found on endothelial surfaces

Answer 5

CD36 antigen (platelet glycoprotein IV)
Thrombospondin

**Some bind to the intercellular adhesion molecule-1 (ICAM-1), and a few bind to the vascular cell adhesion molecule (VCAM)

Question 6

TRUE OR FALSE

The anemia of falciparum malaria is characteristically a normocytic-normochromic anemia with a paucity of reticulocytes. If microcytosis is present, the concomitant presence of α- or β-thalassemia or iron deficiency should be considered.

Answer 6

TRUE

The anemia of falciparum malaria is characteristically a normocytic-normochromic anemia with a paucity of reticulocytes. If microcytosis is present, the concomitant presence of α- or β-thalassemia or iron deficiency should be considered.

Question 7

Disease conditions that interfere with invasion of erythrocytes by parasites (malaria) and their proliferation

Answer 7

G6PD deficiency, Southeast Asian ovalocytosis , CR1 deficiency, the thalassemias, sickle cell anemia, and other hemoglobinopathies

Question 8

Plasmodial species that are notably associated with hemolytic anemia

Answer 8

P. falciparum, P. vivax

Question 9

Plasmodial specie that invades only young red cells

Answer 9

P. vivax

Question 10

Plasmodial specie that attacks both young and old cells, more severe and is the most deadly type

Answer 10

P. falciparum

Question 11

The only plasmodium that infects humans that is zoonotic

It is not transmitted from human to human by a mosquito vector

Causes severe malaria with a frequency similar to P. falciparum, and this includes a high frequency of intravascular hemolysis

Answer 11

P. knowlesi

Question 12

Plasmodial species that decreases the erythropoietin response, resulting in less erythropoiesis than expected for the degree of anemia, reticulocytopenia, and, coincidentally, striking dyserythropoiesis with red cell stippling, cytoplasmic vacuolization, nuclear fragmentation and multinuclearity

Answer 12

Plasmodium falciparum

Question 13

Intravascular hemolysis in __________ malaria may be more frequent than in any other type of malaria.

Answer 13

P. knowlesi

Question 14

The fever associated with malaria, accompanied by rigors, headache, abdominal pain, nausea and vomiting, and extreme fatigue, is characteristically cyclic, varying in frequency according to the malaria type.

Answer 14

BLACKWATER FEVER

Question 15

Febrile paroxysms of malaria

P. vivax:
P. malariae:
P. falciparum:

Answer 15

Febrile paroxysms of malaria

P. vivax: every 48 hours
P. malariae: every 72 hours
P. falciparum: daily

Question 16

Mechanism of periodic fever in malaria

Answer 16

Schizont rupture

Question 17

Considered the standard of diagnosis in Malaria

Answer 17

Identification of the malarial parasite on the blood film

Involves examination of a thick and thin blood film preparation

Alternative and supplementary techniques involve polymerase chain reaction (PCR) to demonstrate the appropriate DNA sequences in the blood or the use of automated hematology analyzers to identify parasites as part of a routine complete blood count investigation.

Question 18

If more than______% of the red cells infected contain parasites, the infection is almost certainly with P. falciparum.

Answer 18

5%

Question 19

The finding of two or more rings within the same red cells is regarded as pathognomonic of (what species of malaria)

Answer 19

P. falciparum

Question 20

Approximately 15% of the cases were severe as indicated by one or more of the following:

Answer 20

Hemoglobin less than 70 g/L
Parasitemia of greater than 5% of red cells
Acute renal injury
Acute respiratory distress syndrome
Jaundice and requiring rapid treatment and intensive care

Question 21

Other names for Bartonellosis

Answer 21

Oroya Fever
Carrión disease.

Question 22

Human bartonellosis is transmitted by

Answer 22

Sand fly (Lutzomyia spp)

**The only reservoir for this organisms is human beings.

Question 23

Mechanism of Bartonellosis

Answer 23

Red cells are rapidly removed from the circulation, apparently both by liver and spleen.

The organism does not grow within the red cell but rather adheres to its exterior surface

The osmotic fragility of the red cells is normal.

Question 24

Bartonella protein that causes erythrocytes to acquire trenches, indentations, and invaginations has been purified from culture broths and has been called

Answer 24

Deformin

Question 25

Represents the early, invasive stage of a chronic granulomatous disorder of Bartonellosis

Answer 25

Oroya fever

Question 26

The second stage of B. bacilliformis infection characterized by a skin eruption of cutaneous vascular nodular tumors (hemangioma-like) often on the face and extremities

Answer 26

Verruca peruviana (also called verruca peruana)

Question 27

Diagnosis of Bartonellosis is established by

Answer 27

Demonstrating the presence of the organism on the erythrocytes

Giemsa-stained blood films reveal red-violet rods varying in length from 1 to 3 μm and in width from 0.25 to 0.2 μm.

Question 28

Treatment for patients with Oroya fever

Answer 28

Aminoglycosides, cephalosporins, macrolides, quinolones, penicillins, tetracyclines, and others (eg, rifampin)

Question 29

Babesiae are intraerythrocytic protozoa known as

Answer 29

Piroplasms

Question 30

Babesiosis is transmitted by the bite of

Answer 30

Tick:Ixodes scapularis

Question 31

Babesiae species that infect humans

Answer 31

Babesia microti, Babesia divergens, Babesia duncani, and Babesia venatorum

Question 32

Cases of babesiosis transmitted by transfusion are mostly caused by

Answer 32

Mostly caused by Babesia microti but also by Babesia duncani

Question 33

Morphology of Babesia in thin blood films

Answer 33

Darkly stained ring forms with light blue cytoplasm

Maltese cross tetrad: consists of four daughter cells of Babesia connected by cytoplasmic bridges

Question 34

TRUE OR FALSE

Most mild B. microti infections respond without treatment.

Answer 34

TRUE

Most mild B. microti infections respond without treatment.

Question 35

Treatment for Babesiosis

Answer 35

Clindamycin and quinine
Atovaquone and azithromycin
Tafenoquine

Question 36

Treatment for recalcitrant cases of Babesiosis

Answer 36

Whole-blood or red cell exchange

Question 37

Infection that most likely to occur in patients who have undergone septic abortion, after acute cholecystitis, as a result of an intrahepatic abscess, and, rarely, after amniocentesis (amnionitis)

Answer 37

Clostridium perfringens (formerly Clostridium welchii)

Question 38

Are gram-positive, encapsulated, spore-forming, anaerobic bacilli

Causes gas gangrene in soft tissues

Answer 38

Clostridium perfringens (formerly Clostridium welchii)

Question 39

Toxin that is the agent that causes intravascular hemolysis in Clostridium perfringens septicimeia

Answer 39

Lysolecithins

The α-toxin of C. perfringens is a lecithinase C that reacts with lipoprotein complexes at cell surfaces, liberating potent hemolytic substances, lysolecithins.

Question 40

Therapy for Clostridium perfringens septicimeia

Answer 40

Antibiotic therapy, fluid support, red cell transfusion, and when appropriate surgical debridement

Question 41

Pathogens that produce red cell agglutination in vitro

Answer 41

Haemophilus influenzae, E. coli, and Salmonella spp.

Question 42

Microorganisms may play a role in precipitating autoimmune hemolytic disease

Answer 42

Mycoplasma pneumoniae, measles, cytomegalovirus, varicella, herpes simplex, influenzas A and B, Epstein-Barr, human immunodeficiency virus, and coxsackievirus

Question 43

Microangiopathic hemolytic anemia may be triggered by a variety of infections:

Answer 43

Shiga toxin-producing E. coli, Shigella dysenteriae type 1, Campylobacter spp., and Aspergillus spp.