I read an article titled “Epidemiology meets evolutionary
ecology” a few weeks ago, but have not had a chance to fully digest it. I think
it’s potentially useful to think about viruses this way so I’m going to write
down a few points that I find interesting. Probably the most important point that this
paper makes is the definition of virulence, or “the extent of parasite-induced
reduction in host fitness.” (Although it still seems odd to me that virulence
is defined based on the host rather than the parasite itself....)
1. Optimal Virulence
-Viruses face a tradeoff between host survival and
fecundity. Hosts face a tradeoff between the cost of resistance and the risk of
infection.
-Estimates of R0 generally do not take into account vertical
transmission or multiple infections.
2. Transmission
Patterns
-Vertical transmission tends to reduce virulence compared to
horizontal transmission because vertical transmission depends on host survival
and reproduction. But vertical transmission and horizontal transmission are
usually related so it’s difficult to consider these transmission patterns
individually.
3. Spatial structuring
of disease transmission and dispersal mechanism
-Recent models that include spatial structuring tend to
predict lower virulence than those that don’t.
4. Host heterogeneity
-A host parasite that is optimally adapted to get around one
host’s immune system and not another, host heterogeneity selects for lower
virulence.
-The relationship between parasite virulence and host
resistance is more complex than was originally assumed.
5. Competition strains
and within-host dynamics
-Viral strains in the same host are competing to a limited
amount of resources, which leads to selection for greater virulence.
-Kin selection between related strains within one host is
predicted to reduce virulence.
6. Phylogenetic
analysis
-Phylogenetic analysis is useful in providing information
about emerging strains
7. Public Health
Policy
-Evolutionary ecology should be taken into account when
implementing public health interventions.
8. Sex and Virulence
-It is thought
that sex in parasites increases virulence and sex in hosts reduces virulence.
Phew! That just made my brain hurt a little bit more. And I
just discovered that there’s a great table in this article, which distills down
the major points better than I just did. (There’s a screen shot below, but you
should check out the original!) Also, the author makes the point that “the
misconception that parasites will ultimately evolve towards avirulence has only
been dispelled gradually from the medical literature.” (Proof of these “misconceptions” prevalence can be found in the abstract of the paper that Emi sent out on
HIV.)
By Olivia
References:
Galvani, A. “Epidemiology meets evolutionary ecology.” Trends in Ecology and Evolution Mar.
2003. Vol. 18(3): 132-139.
10 comments:
I has suffered for Human papillomavirus HPV) for 2years, I was given some tablets at the hospital but I refused to take it, They said I have to be on it for life so I don't want take a drugs everyday for life. No point in taking medicine everyday when u won't get cure from it and I was advice to seek for natural herbal cure, after some time I found dr onokun is the most trustful herbalist that have herbs to cure wicked symptom's,I emailed dr onokun, for 2weeks been his patient he cured my (HPV) with his herbal. I only used his natural herbs for two weeks it was 100% cure. I'm not (HPV) patient anymore. I'm happy about it i finally got cured out of this mess been in my body for 2years. I also recommend you if you're living with (HPV) or herpes symptoms i also want you to be free contact dr onokun with the email attach to my post. dronokunherbalcure@gmail.com
5 years ago I had warts, I was treated with some liquid applied to the warts they continued to grow and spread... The next 2 doctors did laser surgery to remove them. 1 year after the surgery, they grew back close to where the 1st ones were' so I was finally told it was hpv. I have had it for very long time, I contract it from my cheated boyfriend and I found out he was also infected and I end up the relationship between us. the warts was so embarrasses because it started spreading all over I have be dealing with this things for very long time the last treatment I take was About 2 years ago I applied natural treatment from Dr onokun herbal cure, a week after applying the treatment all the warts was gone. it's now 2 years and some months I don't have single wart or any symptoms of hpv. wow"" it's great, Dr onokun has finally cured me. Anyone living with hpv contact Dr onokun for natural treatment.
His email address: dronokunherbalcure@gmail.com
I was thinking that Illuminati is not real, But today with Mr david I now believe that Illuminati is real, when you come across wrong person’s you will think that life is not real but when you are with the real one you will experience the goodness of your life, To MR David has made me discovered my purpose of life. Welcome to the great brotherhood of Illuminati 666: WhatsApp Mr David +234-811-338-8018 Russia , and every other Country’s on how to join the Illuminati brotherhood to get rich and famous, You may be a politician, business man/woman ,musical artist, student, footballer or whatever occupation you do, you want to be rich, powerful and famous in life. Illuminati can grant all your heart desires join the Illuminati to become rich and famous in life, Illuminati will make you achieve your dream to become rich and protect you all the days of your life join the great illuminati brotherhood via email: lorddavid2345@gmail.com
Greatest thanks to Dr Oyagu for his herbal drugs that he prepared for me and when i start using it in just 2weeks i was completely cured and that ended my HERPES SIMPLEX 1&2 DISEASE i am so happy and grateful to Dr Oyagu . after reading about him on a testimony of Jason Cash on a blogger. i knew suddenly Dr Oyagu was the right Doctor to cure my HERPES SIMPLEX 1&2 DISEASE. i discuss with Dr Oyagu and he prepared a herbal medicine for me and when it got sent to me in south korean . i used the herbal medicine and 2weeks and i went to check up again. after 15years of suffering from HERPES SIMPLEX 1&2 at last i am smiling once again. Dr Oyagu also has remedy to others disease like COLD SORES,HIV/AIDS,DIABETES.CANCER,HIGH BLOOD PRESSURE AND MANY MORE. I oblige everyone to contact this powerful herbalist Dr Oyagu and be free from your suffering. contact his WhatsApp line:+2348101755322 or his Email via dr.Oyaguherbalhome@gmail.com
I’m here to testify about what DR. ISIBOR did for me. I have been suffering from (GENITAL HERPES VIRUS) disease for the past 3 years and had constant pain and inching, especially in my private part. During the first year, I had faith in God that i would be cured someday.This disease started circulating all over my body and I have been taking treatment from my doctor, few weeks ago I came across a testimony of Rose Smith on the internet testifying about a Man called DR. ISIBOR on how he cured her from 7 years HSV 2. And she also gave the email address of this man, advise anybody to contact him for help on any kind of diseases that he would be of help, so I emailed him telling him about my (HSV 2) he told me not to worry that I was going to be cured!! Well, I never doubted him I have faith he can cure me too,, DR. ISIBOR prepared and sent me Healing Oil, Soap, roots and herbs which I took. In the first one week, I started experiencing changes all over me, after four weeks of using his Roots/ Herbs, Oil and Soap, I was totally cured. no more inching , pain on me anymore as DR. ISIBOR assured me. After some time I went to my doctor to do another test behold the result came out negative. So friends my advise is if you have such disease or know anyone who suffers from it or any other disease like HPV, HIV, ALS, CANCER etc. you can contact DR. ISIBOR for help via email} drisiborspellhome@gmail.com or call +2348107855231
I have had HIV positive for 4 years,and I have taking different medications of drugs and injections all my effects to get cured was in vain, one day I came across testimony of someone who sheared how she was cured of Herpes virus from doctor James herbal mix, I thought it was a joke, but I picked up interest and gave it a try and contacted Dr James on his email drjamesherbalmix@gmail.comI told him my problem and he asked how long I was positive and how old I am, and I told him,he said I should not be worried that he will send me his powerful herbal mixed medicine that he believed will cure me from HIV, I said okay and sent him the amount he requested. 2 days later he told me the cure has been sent to me through UPS SPEED POST which got to me in 4 days time.I used the medicine morning and evening as he prescribed for me for 2 weeks I waited for 1 week then I went for a check up and I was tested HIV negative exactly as Dr James told me.I'm now free from HIV virus thank you so much Dr James. The happiness inside of me,made me to shear my testimony because I know there are still people out here with HIV positive and other diseases and don't know how to get cured contact Dr James for he is truly, trustworthy and a good herbalist man. Trust he's gonna cure you Email him on (drjamesherbalmix@gmail.com) WhatsApp him on +2348152855846 He also cures diseases like Herpes virus,Hiv/aids,Hepatitis,Cancer,Rectum effects,Diabetes,Inflammatory diseases and more
Hi, is a true life experience is not designed to convince you its a personal health experience, sometimes medical doctors take a different approach about herpes treatment. i has been stocked in bondage with herpes for two years and four months i has tried different means to eliminate this sickness because it surely has distract me even with the world, and i was told there is no cure, but only medicine for treatment all the possible ways i has tried was treatment, two months back i did some herpes research and i found amazing testimonies concerning natural herbal cure, and i go for it through the email address from the post just to give a try of herbal treatment, and i found it grate without delay i got cured with natural treatment from doc Onokun herbal cure his cure are powerful and shows out excellent result. and i think everyone suffering with herpes and others symptoms should also know about this cure from, Dronokunherbalcure@gmail.com
I was diagnosed of herpes virus, I have tried all possible means to get cure but all my effort proved abortive, until a friend of mine introduced me to a herbal doctor called Dr Agaba, who prepare herbal medicine to cure all kind of diseases including herpes virus (Herpes), when i contacted this herbal doctor via email, he sent me herpes virus herbal medicine via courier service, when i received the herbal medicine he gave me step by step instructions on how to apply it, when i applied it as instructed i was totally cured from the virus within 3 weeks of usage. Contact this great herbal doctor today to get your cure.
Via Email: Dragabasolutionhome@gmail.com or WhatApp: +2349074536486
Happiness is all i see now I never thought that I will be cured from HERPES virus again. I have been suffering from a deadly disease (HERPES) for the past 3 years now, I had spent a lot of money going from one places to another, from churches to churches, hospitals have been my home every day residence. Constant checks up have been my hobby not until this faithful day, I was searching through the internet, I saw a testimony on how DR agaba helped someone in curing his HERPES disease, quickly I copied his email which is Dragabasolutionhome@gmail.com just to give him a test I spoke to him, he asked me to do some certain things which I did, he told me that he is going to provide the herbal cure to me, which he did, then he asked me to go for medical checkup after some days after using the herbal cure, behold I was free from the deadly disease, he only asked me to post the testimony through the whole world, faithfully am doing it now, please brothers and sisters, he is great, I owe him in return. if you are having a similar problem just email him on : Dragabasolutionhome@gmail.com or WhatApp: +2349074536486
All thanks to Dr OLIHA for curing my herpes virus/hpv with his herbal medicine, i do not have much to say but with all my life i will forever be grateful to him and God Almighty for using Dr OLIHA to reach me when i thought it was all over, today i am happy with my life again after the medical doctor have confirmed my HERPES SIMPLEX VIRUS / HPV of 5 is gone,i have never in my life believed that HERPES SIMPLEX VIRUS could be cured by herbal medicine. so i want to use this means to reach other persons who have this disease by testifying the power of Dr OLIHA that all hope is not lost yet, try and contact him by any means for any kind of disease with his email: oliha.miraclemedicine@gmail.com add him on whatsapp line or call +2349038382931.
Post a Comment