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Learning objectives

  • Identify common parasites that cause infections of the circulatory and lymphatic systems
  • Compare the major characteristics of specific parasitic diseases affecting the circulatory and lymphatic systems

Some protozoa and parasitic flukes are also capable of causing infections of the human circulatory system. Although these infections are rare in the US, they continue to cause widespread suffering in the developing world today. Fungal infections of the circulatory system are very rare. Therefore, they are not discussed in this chapter.

Malaria

Despite more than a century of intense research and clinical advancements, malaria remains one of the most important infectious diseases in the world today. Its widespread distribution places more than half of the world’s population in jeopardy. In 2015, the WHO estimated there were about 214 million cases of malaria worldwide, resulting in about 438,000 deaths; about 88% of cases and 91% of deaths occurred in Africa. World Health Organization. “World Malaria Report 2015: Summary.” 2015. http://www.who.int/malaria/publications/world-malaria-report-2015/report/en/. Accessed July 28, 2016. Although malaria is not currently a major threat in the US, the possibility of its reintroduction is a concern. Malaria is caused by several protozoan parasites in the genus Plasmodium : P. falciparum, P. knowlesi, P. malariae, P. ovale, and P. vivax. Plasmodium primarily infect red blood cells and are transmitted through the bite of Anopheles mosquito es.

Currently, P. falciparum is the most common and most lethal cause of malaria, often called falciparum malaria. Falciparum malaria is widespread in highly populated regions of Africa and Asia, putting many people at risk for the most severe form of the disease.

The classic signs and symptoms of malaria are cycles of extreme fever and chills. The sudden, violent symptoms of malaria start with malaise, abrupt chills, and fever (39–41° C [102.2–105.8 °F]), rapid andfaint pulse, polyuria, headache, myalgia, nausea, and vomiting. After 2 to 6 hours of these symptoms, the fever falls, and profuse sweating occurs for 2 to 3 hours, followed by extreme fatigue. These symptoms are a result of Plasmodium emerging from red blood cells synchronously, leading to simultaneous rupture of a large number of red blood cells, resulting in damage to the spleen, liver, lymph nodes, and bone marrow. The organ damage resulting from hemolysis causes patients to develop sludge blood (i.e., blood in which the red blood cells agglutinate into clumps) that can lead to lack of oxygen, necrosis of blood vessels, organ failure, and death.

In established infections, malarial cycles of fever and chills typically occur every 2 days in the disease described as tertian malaria , which is caused by P. vivax and P. ovale . The cycles occur every 3 days in the disease described as quartan malaria , which is caused by P. malariae . These intervals may vary among cases.

Plasmodium has a complex life cycle that includes several developmental stages alternately produced in mosquitoes and humans ( [link] ). When an infected mosquito takes a blood meal, sporozoites in the mosquito salivary gland are injected into the host’s blood. These parasites circulate to the liver, where they develop into schizonts. The schizonts then undergo schizogony , resulting in the release of many merozoites at once. The merozoites move to the bloodstream and infect red blood cells. Inside red blood cells, merozoites develop into trophozoites that produce more merozoites. The synchronous release of merozoites from red blood cells in the evening leads to the symptoms of malaria.

Questions & Answers

what z microbiology
Mwelwa Reply
microbiology is all about the scientific study of microorganisms, their life changes, their life span, structural punctuality and their phenomenon.
Ridwan
thanks
micah
Best scope in microbiology
Rahul
wat abut skin
Elyas
whatis scope
Amare
what happened when someone died and what happened to the blood
Franca Reply
nice question
Attari
when you die you have no memory and the blood dry off
Falere
what microorganisms is all about?
Ridwan
And how many does the microorganisms is classified?
Ridwan
How are microbs organized
Saskia
what is endoparasites and exo parasite and their example
OGEDE Reply
Endo : inside the body Exo/ecto : outside or on the body
Paul
examples please
OGEDE
Louse for exo/ecto Helminths (worms) for endo
Paul
what's prokaryotic
mohaiminul Reply
A prokaryotic cell is a cell with no membrane bounds organelles
Paul
what are the main effect of parasite?
yunusa Reply
nutritional group of micro organism
Mana Reply
what are the charateristic bacteria, eukaryotes, and viruses have in commom
Ami Reply
what type of bacteria ismor serious
Amare
D N A ar purno rup ki
Ruba Reply
বাংলায় দেখবো DNA এর পূর্রন্যরুপ কি
Ruba
what's microbiology
micah
micro biology is the study of micro organisms,those being unicellular multicellular or a cellular
aniisha
deoxyribonucleic acid is a long molecule that contains our unique genetic code.
aniisha
Does the parasite/parasitology are under microbiology or not
yunusa
Define bacteria
Kainat
Bacteria are a type of biological cell & they constitute a large domain of prokaryotic microorganisms.
raisa
what kind of microbiology
Mira
hello what is main function of T and B cells
Ishaq Reply
T cells are involved in cell-mediated immunity while B cells are primarily responsible for humoral immunity (relating to antibodies)
Janet
what is hepatitis B
Sunday
it's viral infection that attacks the liver and can cause both acute and chronic diseases. the virus is most commonly transmitted from mother to child during birth and delivery, as well as through contact with blood or other body fluids...
Dejene
What are fundamental experiment of microbiology?
Lucky Reply
study of microscopic organisms, unicellular and multicellular
Falere
what are the characteristics of bacteria, viruses, and eukaryotes
Ami
bacteria-are living organism. contain a peptidoglycan/lipopolysaccharide cell wall. VIRUS-are considered as organic structure which interact with living organism don't have acell wall. they have many differents like bacteria size -large(1000nm) virus size-smaller(20-400nm). bacteria ribosomes presen
Dejene
virus ribosomes absence. bacteria living organism. virus b/n living and non-living things
Dejene
eukaryotic cell has a true membrane bond nucleus and has other membranous organelles that allow for compartmenalization of function
Dejene
This answer is wrong
Jeffrey Reply
who discovered the growth curve
Joy Reply
Example of coccus bacteria
Nweke Reply
staphylococcus aureus
Elton
MRSA any bew information
Satish
pl. read any new information about MRSA
Satish
Any stru tural finding about novel corona virus
Satish
Examples of spiral bacteria
Nweke Reply
Example of Bacillus bacteria
Nweke
pusals
manikanta
another one
Nweke
what is the desifection decontamination or sterilization
Sahra Reply
Is the removal of dangerous substances or germs from an area, objects or person
Florence
It is the removal of any pathogen, including their spores
Paul
removal of all forms of life including endospore
abdulbasid
I think there is a difference between disinfection and sterilization... we should consider those....
Mosimanegape
disinfection deals with removing harmful microbes at the surface level it doesn't destroy or kill spores ( it uses oxidizing agents ,alcohols , phenolic comp ,aldehydes etc) but sterilization deals with total elimination of all forms of lives.(this uses heat, steam, radiation and chemicals)
Onyinye
disinfecting is preventing microorganisms while sterilization is killing of microorganisms completely
Janet
what is the meaning of Papanicolaou smear
John
it's Pap smear A test to check for abnormal cells in the cervix.
Mabel

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Source:  OpenStax, Microbiology. OpenStax CNX. Nov 01, 2016 Download for free at http://cnx.org/content/col12087/1.4
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