How long does natural immunity last from having pertussis?

[Metasequoia]

I imagine it varies from person to person - but ball park? It only seems fair that it should be life-long, but I know it isn't.

[japonica]

I don't have the links here, but if you do a search under the vaccinations forum, someone answered this question there a few weeks ago, with study links. If I recall, it was something like "from 4-20 years." Still, the upper levels are higher than what you'd get from the vaccine, which generally has a top span of 10 years (if that).

We just had pertussis in our house in March. I must have had some residual immunity from my late teens (when I had a bad case of it), as I didn't become ill...and that was (ahem) over 20 years ago.

[tanyalynn]

I think that one's going to be really tricky to answer. I wish I'd bookmarked it, or maybe I did before I lost all my bookmarks, but IIRC, someone linked a study of nurses in a hospital, blood draws were done and showed that most had an increase in pertussis antibodies at least once in the 5-year period studied, and a solid percentage showed that increase 2 or 3 times. And the nurses didn't necessarily feel sick or think they'd had pertussis.

So it may be more an issue of: how frequently is someone being re-exposed, is there a time period when they are particularly rundown and more susceptible to a serious bout, and do they consider that a cough that lingers for 2 or 3 months w/o other more serious symptoms may be pertussis.

[Metasequoia]

I'm thoroughly confused now. I just heard that since it's bacterial, like say strep throat, there is no lasting immunity.

Why is it so tricky to find answers about pertussis??

The kids began showing symptoms on 7/26 (of course, we didn't know what it was because it was SO mild.) Then for Ds it morphed into something awful the following week. The ER did a chest x-ray & said it was pneumonia - which it could have been, but it began as pertussis.

Dd1 never had anything more than the mild dry cough for 4-5 days - she was fully vaxed for it.

Dd2 has it like I do, but hers started much earlier - back on 7/26 with a froggy voice, dry cough & runny nose.

My cough was definitely here on 8/9 when I took Ds to the Er, but I can't remember how long before that it showed up.

So if the contagious period is for 2-3 weeks after symptoms show up (& most definitely prior to symptoms showing up as well), then Dd2 shouldn't be contagious and I *might* still be through the rest of this week.

The doctor said that abx are most helpful *before* the horrendous cough sets in - but once the cough has set in, abx won't do much for the cough, but will prevent it being spread to others.
If it isn't going to help my cough, I don't see the point in taking abx when I can just stay home for 4 more days. My biggest concern is giving it back to Ds. Poor little bugger had SUCH a rough time of it - vomiting puddles of thick mucous, collapsing after coughing attacks, lips turning blue from lack of oxygen, etc.
My biggest complaints are not being able to sleep, peeing in my pants (I'm 6 months pregnant) and occasional sore throat from the coughing.
Sometimes the coughing attacks lead to contractions, but only right after coughing & they don't last. I have 3 more months of pregnancy, so nobody here should be contagious by the time baby comes.

Blah, pertussis sucks big time. I'll try to find the links in the vax forum - or maybe I'll just ask there...thanks mamas.