Why do people get the disease so differently?

[MozFan]

So a good friend of mine, who is 31 years old, has recently tested positive for coronavirus, she is an NHS nurse.
The only symptom she had was a loss of her sense of smell.
Her husband and DC have no symptoms over two weeks on. Although her DH had a bit of a sniffle.
Fortunately she’s the only person I know who has tested positive.
Although I myself think I’ve had it, as did my DS and DP. However me and my DS had coughs and mild fevers.
My DH lost his sense of smell and had diarrhoea.

I just wonder why she has presented with such mild, almost non existent symptoms, despite a possible higher viral load (being on the frontline) and other medical staff end up on ventilators.

It's an interesting question. I'm waiting for knowledgeable people.

I think viral load is imperative. But also systems. It affects your ACE system and some people's is already buggered because of high blood pressure (and meds).

But the asymptotic people are interesting. From the viruses POV it's great because it spreads it quicker. What's the mechanism though?

I've heard there are 20 or so different strains that its mutated into. So we might be getting a different strain than people in Wuhan for example.

There is an article in the guardian, a twin study, investigation of genetics playing a part.

It could be to do with viral load also.

It's very odd. My DD had it mildly, and didn't have a cough and was only ill for a few days. Her husband and children isolated for 2 weeks but had no symptoms. Yet other people including young and healthy people die. I feel the key to beating this virus will be understanding why the symptons vary so much and why some people have a mild version while others die.

But if it’s to do with viral load, I’d assume my friend would have had a serious illness (very fortunately she didn’t) that’s why I’m confused. She’s frontline NHS staff so she probably picked it up at work. But she had a loss of sense of smell as her only symptom.

You can't assume viral load.

And if it's only one factor, then it only contributes part of the story.

We don’t know but it’s fascinating. I think we will eventually find what mechanisms were involved but like anything, there will always be outliers

Don’t forget that people tend to get all viruses to different degrees. DD1 had really really awful chicken pox. DD2, who caught it from her, had 5 spots. DD2 had a serious case of scarlet fever. DD1 also had it, but just had red cheeks and a slightly sore throat. I tend to get colds really badly, DH gets a sniffle.

Could be genes. www.theguardian.com/world/2020/apr/27/study-of-twins-reveals-genetic-effect-on-covid-19-symptoms

Someone I know has a husband who is really ill with it, in hospital I’ll. she’s had nothing. I’ve been watching a programme on channel 4 and the doctor did an anti body test and had antibodies but hadn’t been ill at all so i guess some people have antibodies.

I don't believe the experts know yet and possibly won't do for a while yet. I expect there are quite a few variables at play and no one reason why one person's symptoms may be significantly different to anothers.

Well it’s the same as any disease. Take chicken pox for example, sone people get a single pox, others die. Some people are just healthier and some receive better treatment.

Can you provide a link please@eggandonion

genetics, ethnicity (the darker your skin the more difficult it absorbs vit D from the sun than lighter skin tones), health, age and gender (of which I hope this virus is confirming, there are only two!)

The doctor on C4 had been ill, they showed a picture of him at A&E. However, given there are no reliable antibody tests yet, I think it was an irresponsible programme.

Everyone is wired differently.

I have heart failure - classically my kidneys should be somewhat impaired, maybe my liver and other organs too. My heart bloods should be raised.

My kidney and liver function are some of the best they've ever seen and my heart bloods are merely borderline. I also have perfect oxygen levels, heart rate and blood pressure!

My heart failure nurse said that heart failure aside, on paper I look like a picture of health. My results shouldn't read as they do but they do. It's bizarre!

Some people's bodies, for whatever reason seem to be able to withstand more than others.

It seems strange when couples, family members all die. It doesn't seem to 'fit' the stats. There has been a sad case locally of a married couple who died from it,and the taxi driver who picked them up from the airport dies dies quite soon after. I believe they all had underlying health issues but still it seems odd to have all died

Viral load could also be correlative - i.e. higher viral load not due to higher exposure but lower initial resistance to the infection.

Someone else supplied the link! Gut bacteria seems to be important too, in a lot of ways.

Every immune system is unique, Influences start with genetics and then each exposure to illness we have, and every lifestyle choice we make, influences further.

Other, common viruses also manifest differently in different people.

Thanks for all the replies. It’s intersying to read them.

I guess you could say my Nan had a very ‘strong constitution’ she was 91 when she died, but was in hospital for quite some time before it happened. She had a nasty e-coli infection that turned into sepsis. She was laying on her deathbed for days, the doctors and nurses said they were very surprised she was still alive as they expected it to be fairly quick. Her body just a wasn’t giving up.
She had also recovered from a heart attack with minimal issue, a mild stroke and skin cancer when she was younger!

Aren't they investigating whether obesity is a factor. Although other issues would also be common with obesity such as diabetes, blood pressure and heart disease.

Ask your friend what blood type she is. Another poster had mentioned blood type may play a role O being less susceptible and less inclined to have serious issues and A being more likely to require hospitalization. I googled it and there was a small survey done in wuhan but as far as I'm aware it's not to be taken too seriously. Interesting though.

People respond differently to other viruses too. I had chicken pox in my 20s (a long time ago!). I wasn't particularly ill with it. Gave it to my flat mate and she wasn't particularly ill either. Gave it to my then boyfriend and he was very very ill with it. Temperature through the roof. Very painful joints. Very sensitive to light. Covered head to toe with pox. Should really have been in hospital.