Quote from: pallang on August 20, 2020, 01:18:51 PM

Quote from: criz2fer on August 19, 2020, 12:10:57 AM

~ ang mga nkakaloka is yung biglang pagtanggal ng barriers for the couple or magkasama sa bahay.

Magagamit pa naman nila mga barrier sa pagpriprito para di sila matalsikan ng mantika.

Pwede pa magamit barrier kay no. 2 Cool

Tungkol sa news being circulated ng mga iba't ibang stations tungkol sa mga milyones na unreported/undetected case sa Pinas ayon sa pag-aaral daw ng isang unibersidad, narito ang rebuttal ng former IATF consultant, isang spesyalista sa pagaaral ng infectious diseases, at siang molecular biologist.

Post link: https://www.facebook.com/edselmaurice.salvana/posts/10207985143221955

Quote

Ok let's address this study (preprint, not peer reviewed) that there are MILLIONS of undetected COVID-19 in the Philippines.

1. First of all, actual case counts are a function of testing and surveillance. For example, the ESTIMATED number of influenza cases in the US cases per year is extrapolated from sentinel sites, and the estimated deaths is also extrapolated using mathematical models. This is how infectious diseases are measured. There is NO WAY you can test everyone to know the actual number of cases because:

a. there simply aren't enough tests or testers available
b. you'll spend a ridiculous amount of money testing low risk individuals
c. your data will not be reliable by the time you finish testing (it may take the whole year) because some of those people who were negative are now actually positive.

This is why, very early on, those of us in the scientific community who understood infectious diseases thought that the whole idea of "mass testing" was not only ridiculous, it was dangerous. It diverted much needed resources for isolation, treatment and prevention and gave people a false sense of security if they tested negative. This was further magnified by the misguided use of rapid antibody tests which are notoriously inaccurate. We kept saying - the only thing worse than no test is a bad test - but very people were listening.

2. It is very difficult to estimate actual case numbers when your testing capacity is constantly changing. If you are only targeting severe and critical symptomatics, a public health practitioner ALREADY KNOWS that you are only capturing about 20% of the actual infected population. Therefore, in our minds, we ALREADY KNOW that you add another 80% to the cases to get close to the actual number. However, if you target even mild patients which we did as the testing capacity increased, then you get closer to the actual number and you only have to correct for those if the proportion of cases you are capturing is less than 80% milds. Finally, the CDC later on realized that 40% of cases may be asymptomatic, so now we need to factor those in. If we look at the current distribution of cases, 91.5% are mild, which means that we are most likely capturing a good number of the symptomatics across the board. 6.5% are asymptomatic, so we probably need to add another 33% or more to the estimate because it is VERY HARD to capture asymptomatic - the tests don't work very well due to low viral loads, and there isn't very much incentive to test asymptomatics other than those being contact-traced. Which brings me to another point - the increasing number of asymptomatics detected coupled with increasing positivity rate may also signal that contact tracing is getting better at capturing exposed people and testing them. Finally, you also take into account false negatives even with PCR so add another 40 or 50% to the confirmed number.

3. We also know that there are major backlogs and delays in testing, partially because everyone wants a test and the system gets overwhelmed - yet another reason why mass testing is a bad idea. It also kills your turn-around time and you will need to preemptively isolate people for days on end - some people get their negative test after they have already completed 14 days of quarantine. Antigen testing may help with this backlog, but ONLY IF IT IS PROPERLY USED UNDER CLINICAL SUPERVISION. Otherwise we will have a lot more haphazard testing and waste, as well as people who have a false sense of security and may take unnecessary risk.

4. The BEST way to find out how many people HAVE HAD COVID-19 in the community is with a highly sensitive and specific antibody test. The CLIAs and ELISAs (NOT the rapid antibody tests) are the best tool for this. You DO NOT NEED to test everyone, you just need to do a PROPER SAMPLING methodology. Former Health Secretary Manolet Dayrit is doing this in select communities already and this will be the BEST estimate of the extent of COVID-19 infection in the community since it will be rooted in REAL data.

5. Since COVID-19 is such a new disease, models of spread are constantly changing, along with testing targets and proportions of clinical disease. It is needless speculation bordering on alarmist to state that we have missed MILLIONS of cases. Even if that was true, the clinically relevant effect would still be the number of deaths and our healthcare capacity - which is near its limit, but hopefully continues to be manageable. This is where I would put limited funds - increasing healthcare capacity and not just more testing. In a way, if MILLIONS have ALREADY been infected and we have had under 3,000 deaths, that would actually mean that there is a growing proportion of the population who have developed some immunity and this will help slow down the spread. If a vaccine is not developed anytime soon, this is actually the best way forward - minimal deaths while building up immunity and eventually putting a stop to the surges that threaten to overwhelm our healthcare system. This also ensures our economy can remain open as long as we take good care of our patients and the healthcare system.

So don't let numbers scare you. Know that we have the tools to STOP this epidemic - mask, face shield and physical distancing. A new infectious disease agent will spread - that's what infectious diseases do. But the most important part is managing the infections and keeping deaths low. If a vaccine comes, great. If it doesn't, it's not the end of the world.