Zika virus is a global public health emergency, declares WHO

BMJ 2016; 352 doi: (Published 02 February 2016) Cite this as: BMJ 2016;352:i657

Re: Zika virus is a global public health emergency, declares WHO

Microcephaly in Brazilian babies

Could maternal fever be a major contributing factor?

The chronology of events reveals some interesting observations.

According to Marco Caceres ( in October 2014 the Brazilian Ministry of Health’s Epidemiological Surveillance Center “Prof. Alexandre Vranjac” (CVE) in Sao Paulo announced a mandatory vaccination of pregnant women between the 27th and 36th week of pregnancy, from December 2014 with TDaP vaccine From early May 2015 a great number of babies were born with microcephaly . Most of the cases occurred in Pernambuco where most of TDaP vaccines were distributed.

Tens of thousands of pregnant women have been vaccinated with GlaxoSmithKline’s (U.K.) vaccine brand name Refortrix, or more commonly known as Boostrix, and which has been licenced in Brazil for more than a decade, and Adacel produced by Sanofi Pasteur (France). According to the package insert for Boostrix, “Animal fertility studies have not been conducted with Boostrix. There are no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, Boostrix should be given to a pregnant woman only if clearly needed.”

And, according to CDC,“Pregnant women should get a dose of TdaP during every pregnancy, regardless of whether a woman has already received one dose of TdaP to protect the newborn from pertussis… Tdap may safely be given at the same time as other vaccines.”

In December 2015, the Brazilian Government declared an emergency after 2,400 Brazilian babies were found to be born with “shrunken’heads (microcephaly) and damaged brains since October 2015.

The WHO came up with an answer: a little known Zika virus first described in the 1940s in Zika forests of Uganda, and allegedly spread by mosquitoes (Aedes aegypti) in the same way as is the West Nile virus.

The Zika virus has been known to infect people in Africa, South and Central Americas and Asia for more than 70 years without causing any birth defects. .

The Zika virus theory is largely based on the Zika virus allegedly found in a baby with microcephaly following an autopsy of the dead child and amniotic fluid of two mothers whose babies had the condition. No explanation has been given as to why suddenly it could be causing all these cases of microcephaly within the short period of time after, and not before, the mass vaccination of all pregnant women about 10 months before the first cases have appeared. The Brazilian government has accepted that as the cause.

Even if we disregard some of the above information as the cause of microcephaly in Brazilian babies, one effect of all vaccines is irrefutable: fever.

Product inserts of all vaccines, including the ones given to the Brazilian expectant mothers as above, list fever as a ubiquitous reaction.

According to “antimicrobe” ( hyperthermia in pregnancy causes a wide range of fetal structural and functional defects, with the central nervous system (CNS) being most at risk. While there is a greater incidence of neonatal morbidity and mortality with transmitted infections, not all maternal infections lead to transmission to foetus, nor does transmission to the fetus lead to disease or sequelae.

Somatic cell proliferation is adapted to, and proceeds optimally at the normal body temperature range of the species, and the deleterious effects of higher levels on mitotic cell proliferation and survival are widely recognised.

A hyperthermic episode during pregnancy can result in embryonic death, abortion, growth retardation, and defects of development. Maternal pyrexia, resulting from both microbial infection as well as non-infective causes such as epidural anaesthesia, could therefore augment the deleterious effects of hypoxia of the fetal brain, possibly by increasing the cerebral metabolism rate and demand for oxygen. Systemic fetal hypotension, endethelial injury and leukocyte aggregation may contribute to local tissue ischemia, especially in vulnerable areas, and many of these mechanisms could lead directly to cell death.

The above may also have an indirect neurotoxic effect by sensitising the brain and lowering the threshold at which hypoxia triggers apoptosis. The proinflammatory cytokines such as granulocyte colony-stimulating factor, tumour necrosis factor alpha, interleukin 1beta, C-reactive protein and interferon gamma, have a variety of effects. These include direct toxic effect on neurons and vulnerable oligodendrocyte precursor populations, gliosis with release of nitric oxide and mitochondrial dysfunction, as well as microglial activation in the brain. Animal studies reveal the direct correlation between increasing maternal temperature during gestation and the susceptibility to a variety of neurotoxic factors.

Graham et al. (1998. Teratogen update: gestational effects of maternal hyperthermia due to febrile illnesses and resultant patterns of defects in humans. Teratology; 58: 209-221.) demonstrated heat to be as significant that hyperthermia was the first teratogen in animals that was subsequently proven to be teratogenic in humans. They wrote, “These problems range from embryonic death and abortion to teratogenically induced anomalies, and are heavily dependent on the dose and timing of the exposure.

The range of defects induced by hyperthermia in experimental animals includes: anencephaly/exencephaly, encephalocele, microencephaly, talipes, arthrogryposis, abdominal wall defects and limb reduction defects. “

Perhaps, the traditional strict policy to not prescribe and administer any fever producing medication during pregnancy still applies.

Competing interests: No competing interests
Dr Viera Scheibner (PhD) retired
Blackheath NSW Australia

Competing interests: No competing interests

03 February 2016
Dr Viera Scheibner (PhD)
scientist/author retired
Blackheath NSW Australia