Re: BBC **LIES** About HIV TESTS

"Wolfgang G. Gasser" <[EMAIL PROTECTED]> schreef in bericht
news:[EMAIL PROTECTED]
>
> "Alex" in news:[EMAIL PROTECTED] :
> > Wolfgang wrote:
> > > "Alex" in news:[EMAIL PROTECTED] :
>
> > > > 3) HIV Screening in a Military Blood Transfusion Centers
> > > > This is Italian data from the general population (blood donors).
> > > > http://www.certi.org/CMA/newsletter/v03n01.pdf
> > > >
> > > > Table II
> > > >
> > > > Number of dontations: 25,562
> > > > Number of blood donations ELISA positive: 31
> > > > Number of blood donations after confirmation test: 2
> > > >
> > > > This means that of 25,562 people tested with a single ELISA,
> > > > 31 tested positive, and after further testing, only 2 *remained*
> > > > positive.
> > > > This means that in the field, ELISA had a ppv (positive predictive
> > > > value) of 2/31 or 6.45%.
> > >
> > > This means that there are  (31 - 2) / 25,562 = 0.11%  false
> > > positives.
> > >
> > > Only  2 / 25,562 = 0.008%  turned out to be HIV+.
> > >
> > > It IS relevant whether <0.008%> or <0.008% + 0.11%>, but it is
> > > totally irrelevant whether <around 20%> or <around 20% + 0.11%>.
>
> > The question has always been how many of the people
> > who test positive on their first ELISA remain positive after
> > further testing.
> >
> > The reason this is relevant, is because the "30%" number
> > you go on to quote, is based on these single ELISAs.
> >
> > So it is irrelevant that the majority of the population in Italy
> > doesn't test positive on ELISA. What is important is that
> > 93.55% who do, DO NOT REMAIN POSITIVE AFTER
> > FURTHER TESTING.
>
> No, your figure of 93.55% is a completely meaningless number.
>
> Let us test again the 25,560 Italians who are HIV-negative.
> We will again get around 30 false positives. So we could
> get for instance this result:
>
>  Number of dontations: 25,560
>  Number of blood donations ELISA positive: 29 (or 25, or 33)
>  Number of blood donations after confirmation test: 0
>  Percentage of non-confirmation: 29/29 = 100.0%
>
> In this case not a single person remains positive after
> further testing and your 93.55%-figure becomes 100%.
>
> If we add 1000 HIV+ persons to the above 25,560 HIV-
> negative persons, we get something like this:
>
>  Number of dontations: 26,560
>  Number of blood donations ELISA positive: 1029
>  Number of blood donations after confirmation test: 1000
>  Percentage of non-confirmation: 29/1029 = 2.8%

Nice, except that your number of true positives is completely
grabbed from thin air and the number of false positives
is kept the same.

The numbers I provided are from actual measurements
from an actual survey. There is no reason to assume that
just adding 1000 true positives is valid.

However, what is even less valid, is assuming is that when
you do, the number of false positives will stay (roughly) the
same (at 29).

The problem for Africa, is that there are many, many more
factors around that can cause false positive results, than there
are in Europe or North America.

1) Malaria. Almost unheard of in Europe and the US, while
90% of all malaria cases occur in Africa.
2) Tuberculosis. Almost extinct in Europe and the USA, but
rampant in places where living conditions are cramped.
3) DDT. Illegal in Europe and the USA, still frequently used
in Africa to the extent that the WWF made the following
statement:
"Investigations in Mexico and South Africa reveal that human
breast milk contains DDE (the breakdown product of DDT) at
concentrations that exceed the acceptable guidelines for infant
intake set by the WHO. "
http://www.worldwildlife.org/toxics/progareas/pop/ddt.htm

4) The near exclusive use of pregnant women in surveys.
The problem is that (multiple) pregnancy is one factor that
causes false positive tests (single elisa, of course).

In fact, there are about 70 known factors that can cause a
false positive single elisa. A couple of which are listed here
by the Paul Ehrlich Institut in München ("Bundesamt für Sera
und Impfstoffe" - another source of disinformation??):
http://www.pei.de/themen/hivdiasa.htm#stoer

They list as causes for false positive single elisas:

Antikörper gegen andere virale Erreger (z.B. anti-HAV-IgM , anti-HCV, anti-Rubella)
Proben mit Antikörpern gegen Herpesviren (anti-EBV, anti-HCMV, anti-HSV)
Bakterielle Infektionen
unspezifische B-Zell Stimulationen
Autoimmun-Antikörper
Rheumafaktoren
Proben mit Hypergammaglobulinämien
Proben von Schwangeren, besonders nach mehreren Schwangerschaften
vorangegangene Impfungen (z.B. HBV, Influenza)

> Why do "skeptics" believe in disinformation?
> (was: AIDS Claims 650,000 in Zambia in 1996-1999):
> http://groups.google.com/[EMAIL PROTECTED]

Estimated number of AIDS deaths.

Population of Zambia (divided by 1000):

1980        5,700
2000        9,799
2003       10,307

Source: US Census Bureau
http://www.census.gov/cgi-bin/ipc/idbsum?cty=za

In other words, between 1980 and 2000, the population of Zambia
increased 72%.

Alex