Dengue fever - once bitten, twice shy?
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If one has kena dengue fever, does it mean that he will be more immuned/less immuned/the same in future?
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In simpler terms, the answer is NO.
There are four serotypes (letters A to D) or basically four types of dengue virus under the same heading or family.
Recovery from one does not render immunity to another serotype and reinfection with a different serotype compared to the initial infection will make condition worse and you may present with severe bleeding from the nose, the gums, urine and even your stools as compared to the first infection, where the typical presentation includes fever, joint pains, muscle aches, headache, eye pain, abdominal pain and pin-point rashes on the skin. These are mild and are collectively known as Dengue Fever. The second infection by a different serotype will cause a condition called Dengue Hemorrhagic (Bleeding) Fever which may progress to Dengue Shock Syndrome if not intervened early.
The cause of this is due to the suitability of the condition in the human body after the first infection for the second virus to settle quickly and spread faster leading to a more severe problem than the first. -
So scary.Originally posted by renorenal:In simpler terms, the answer is NO.
There are four serotypes (letters A to D) or basically four types of dengue virus under the same heading or family.
Recovery from one does not render immunity to another serotype and reinfection with a different serotype compared to the initial infection will make condition worse and you may present with severe bleeding from the nose, the gums, urine and even your stools as compared to the first infection, where the typical presentation includes fever, joint pains, muscle aches, headache, eye pain, abdominal pain and pin-point rashes on the skin. These are mild and are collectively known as Dengue Fever. The second infection by a different serotype will cause a condition called Dengue Hemorrhagic (Bleeding) Fever which may progress to Dengue Shock Syndrome if not intervened early.
The cause of this is due to the suitability of the condition in the human body after the first infection for the second virus to settle quickly and spread faster leading to a more severe problem than the first. -
I think ur immune if u have sickle type blood cells
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or was it immunity to AIDS?
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Only for malaria people.Originally posted by alexkusu:I think ur immune if u have sickle type blood cells -
Yeah like ndmmxiaomayi said, it's for malaria... same goes for thalassaemic patients... you can find that malaria is endemic in certain areas where thalassaemia and sickle cell disease is prevalent. Defective blood cells do not allow malarial parasites a chance to innoculate them and permit reproduction.Originally posted by alexkusu:or was it immunity to AIDS? -
thought thalassaemic patients are anemic? nothing to do with their defective red blood cells like sickle cell patients right?Originally posted by renorenal:Yeah like ndmmxiaomayi said, it's for malaria... same goes for thalassaemic patients... you can find that malaria is endemic in certain areas where thalassaemia and sickle cell disease is prevalent. Defective blood cells do not allow malarial parasites a chance to innoculate them and permit reproduction. -
Thalassaemic patients are indeed anaemic. Thalassaemia (or Mediterranean Sea anaemia, which is what that Greek term means) is a genetic condition resulting in a defect of globin chain production. Haemoglobin, the pigment in red blood cells that transports oxygen, is composed of haeme (which contains iron), alpha and beta globin chains. There are 4 alleles (copies) of the alpha globin gene and 2 of the beta globin gene. Inadequate production of the alpha and beta globin chains results in alpha and beta thalassaemia respectively. Depending on the degree of abnormality, the disease varies in severity:Originally posted by ndmmxiaomayi:thought thalassaemic patients are anemic? nothing to do with their defective red blood cells like sickle cell patients right?
Alpha thalassaemia:
1 or 2 allele defect: alpha thalassaemia trait (alpha-1 and alpha-2 thalassaemia)
3 allele defect: Haemoglobin H disease (fairly severe and may require occasional blood transfusions)
4 allele defect: Haemoglobin Bart's disease (incompatible with life, usually stillborn)
Beta thalassaemia:
1 allele defect: beta thalassaemia minor (asymptomatic or very mild)
2 allele defect: beta thalassaemia major (requires regular blood transfusions and death in teenage or young adult life)
As the name implies, thalassaemia is common in the Mediterranean Sea areas, as well as in South East Asia. However, the disease we see in Asia tends to be more severe. Whereas thalassaemic patients in the Mediterranean region tend to get a mutation of the globin chain genes, we tend to get a deletion of the entire allele(s).
As Reno said, thalassaemia confers some resistance to malaria like sickle cell anaemia does. The red cells in these conditions are defective and so malaria parasites tend to die within them, rather than replicating in them. However, the flip side of it is that haemolytic anaemia like thalassaemia may undergo massive haemolysis in the presence of infection by Parvovirus B19. -
Oh.... I understand now.Originally posted by oxford mushroom:Thalassaemic patients are indeed anaemic. Thalassaemia (or Mediterranean Sea anaemia, which is what that Greek term means) is a genetic condition resulting in a defect of globin chain production. Haemoglobin, the pigment in red blood cells that transports oxygen, is composed of haeme (which contains iron), alpha and beta globin chains. There are 4 alleles (copies) of the alpha globin gene and 2 of the beta globin gene. Inadequate production of the alpha and beta globin chains results in alpha and beta thalassaemia respectively. Depending on the degree of abnormality, the disease varies in severity:
Alpha thalassaemia:
1 or 2 allele defect: alpha thalassaemia trait (alpha-1 and alpha-2 thalassaemia)
3 allele defect: Haemoglobin H disease (fairly severe and may require occasional blood transfusions)
4 allele defect: Haemoglobin Bart's disease (incompatible with life, usually stillborn)
Beta thalassaemia:
1 allele defect: beta thalassaemia minor (asymptomatic or very mild)
2 allele defect: beta thalassaemia major (requires regular blood transfusions and death in teenage or young adult life)
As the name implies, thalassaemia is common in the Mediterranean Sea areas, as well as in South East Asia. However, the disease we see in Asia tends to be more severe. Whereas thalassaemic patients in the Mediterranean region tend to get a mutation of the globin chain genes, we tend to get a deletion of the entire allele(s).
As Reno said, thalassaemia confers some resistance to malaria like sickle cell anaemia does. The red cells in these conditions are defective and so malaria parasites tend to die within them, rather than replicating in them. However, the flip side of it is that haemolytic anaemia like thalassaemia may undergo massive haemolysis in the presence of infection by Parvovirus B19.
Deletion of entire alleles?
Then what is inside the gene without the alleles?
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Sorry, I mean there are 4 alpha-globin genes, 2 on each chromosome. So you receive 2 genes from your father (one allele) and 2 genes from your mother (one allele). A mutation of a gene may result in the formation of a truncated or abnormal protein which may still be functional whilst deletion of the entire gene will lead to a more severe phenotype.Originally posted by ndmmxiaomayi:Oh.... I understand now.
Deletion of entire alleles?
Then what is inside the gene without the alleles?
I should refrain from using the term allele (which means variant DNA sequence of a gene) in this context and confusing everybody and myself....tired when I typed my last post..
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Oh...Originally posted by oxford mushroom:Sorry, I mean there are 4 alpha-globin genes, 2 on each chromosome. So you receive 2 genes from your father (one allele) and 2 genes from your mother (one allele). A mutation of a gene may result in the formation of a truncated or abnormal protein which may still be functional whilst deletion of the entire gene will lead to a more severe phenotype.
I should refrain from using the term allele (which means variant DNA sequence of a gene) in this context and confusing everybody and myself....tired when I typed my last post..