Friday, December 9, 2016

Zika and microcephaly

Long report on the CDC website about cases in Colombia.

The rate of microcephaly in women who were diagnosed with Zika was 4 times that of those without the virus.

But the "natural" rate is low so that means the actual number of case was low.

. Peak prevalence of microcephaly was registered in July 2016, when the prevalence was ninefold higher than in July 2015 (PR = 9.0). In 2016, among all microcephaly cases, 432 (91%) occurred in live born infants, and 44 (9%) occurred among pregnancy losses; in 2015, among 110 reported cases of microcephaly, 90 (82%) occurred in live born infants, and 20 (18%) occurred among pregnancy losses.

So all the hysteria was about a couple hundred cases of microcephaly out of tens of thousands of births.

Although the microcephaly prevalence in 2016 among infants likely exposed to Zika virus in utero (9.6 per 10,000 live births) in Colombia was not much higher than the median of microcephaly prevalence (6.6 per 10,000 live births) reported by passive surveillance in 17 U.S. states during 2009–2013 (4), the comparison with 2015 Colombia data indicates the magnitude of the increase.
Tranlation: chance of microcephaly was low, and higher among those affected but still the risk was low (6 out of ten thousand).

now, the question Why was the risk higher in Brazil than in Colombia?

In 2015, microcephaly prevalence in Brazil was 5.5 per 10,000 live births, representing an approximate ninefold increase over the average prevalence during the previous 14 years (5,6). 
In Colombia, the relative increase has been smaller (fourfold); however, the baseline microcephaly prevalence was 2.1 per 10,000 live births in 2015, at least three times higher than Brazil’s reported baseline.
Ah, so even the baseline was different. So does this mean that microcephaly was being missed in Brazil before the epidemic, making the statistics higher? or did altitude have something to do with it (Colombianos live mainly in the high plateaus).

 There are several possible reasons for differences between the reported baseline microcephaly prevalences in Brazil and Colombia, as well as the differences in increases of microcephaly in the context of the Zika virus outbreaks in the two countries. 
First, 50%–75% of the population of Colombia reside at altitudes above 2,000 meters, in areas without active, vectorborne Zika virus transmission (7). 

or maybe the difference is how the measurement is done

Second, microcephaly is a difficult birth defect to monitor because there are inconsistent definitions, obtaining accurate measurements is challenging, and terminology is inconsistent. Because of these challenges, prevalence estimates vary widely among countries and among surveillance systems within the United States (4). 

finally, how many women were frightened by the kerfuffle and either postponed pregnancy or aborted their babies in fear?

Third, the reports of microcephaly from Brazil might have served as an early warning. As evidence was emerging about the link between Zika virus infection and microcephaly, the Colombian Ministry of Health issued a recommendation in February 2016 advising women to consider delaying pregnancy for 6 months, which might have affected subsequent birth rates.§ The number of live births in Colombia during epidemiologic weeks 5–45 decreased by approximately 18,000 from 2015 to 2016.

and the dirty little secret: not all the cases of microcephaly were from Zika. Other viruses etc were also to blame: 476 cases, 306 tested for Zika but only half of them had blood tests positive for Zika. Toxoplasmosis was found in one fifth, and CMG, herpes simplex and syphillis were found in other cases.

Among the 476 infants and fetuses with microcephaly reported during epidemiologic weeks 5–45 in 2016, a total of 306 (64%) were tested for Zika virus infection; 147 (48%) had laboratory evidence of Zika virus infection by RT-PCR or immunohistochemistry on any placental, fetal, or infant specimen, and five of six tested had serologic evidence of infection by MAC-ELISA. Among 121 infants tested for other pathogens, 26 (21%) had evidence of infection with other pathogens, including toxoplasmosis (15 infants), herpes simplex (six), cytomegalovirus (four) and syphilis (one); among these 26 infants, 17 (65%) had evidence of coinfection with Zika virus (14 of 15 with toxoplasmosis, two of six with herpes, and one of four with cytomegalovirus). Neuroimaging results were available for 32% of all microcephaly cases. Among 476 infants or fetuses with microcephaly, mothers of 164 (34%) reported having symptoms compatible with Zika virus infection during pregnancy.

I am not saying this is not a serious disease: What I am saying is that the risk of malformation is low, compared to women infected with other diseases e.g. rubella in the first trimester.which is associated with an 80 percent chance of one of several devesstating problems.

Rubella infection in pregnant women may cause fetal death or congenital defects known as congenital rubella syndrome (CRS). Worldwide, over 100 000 babies are born with CRS every year. There is no specific treatment for rubella but the disease is preventable by vaccination.

usually rubella vaccine is given with measles and mumps vaccine as the MMR.

So compare the hysteria on Zika and the outcry to rush to get a vaccine, while everyone is ignoring the 100 thousand cases of fetal rubella syndrome, where there actually is a vaccine that will prevent babies from being born deaf, blind and/or retarded.

my sarcasm is twofold:

One, because the outbreak occured shortly before the Olympics, there was a chance that rich American yuppies might catch it, so hysteria.

Two: Zika can be used to push the abortion/population control agenda on poor women.

No comments:

Post a Comment