Often our first take on the pathogenicity and burden of an emerging infectious disease is skewed by low sampling numbers, limited surveillance in regions where they tend to appear, and our tendency to only pick up the `sickest of the sick’ who present at local hospitals and clinics.
As a result, our initial impression is often one that exaggerates the threat or amplifies the mortality rate.
Less often the opposite is true, and over time we come to realize that a pathogen poses more of a threat than first thought. While the final verdict isn’t in – the Zika Virus – which has been described for years as generally producing `mild and self limiting’ illness (cite JAMA), appears to fall into this latter category.
Until the past couple of years outbreaks of Zika – a mosquito borne virus – have been relegated to remote regions with low populations and limited medical surveillance. It has only been since the outbreak last year in the South Pacific (see Zika, Dengue & Unusual Rates Of Guillain Barre Syndrome In French Polynesia) that enough data has been collected to suggest a link to neurological disorders.
Over the past two weeks we’ve seen evidence suggesting that maternal Zika virus infection (probably in the 1st or possibly 2nd trimester) can cause severe birth defects (see ECDC Risk Assessment: Microcephaly In Brazil Potentially Linked To The Zika Virus Epidemic).
Overnight the Brazilian MOH upped the ante by announcing `a confirmed relationship’ between the virus and the birth defects, and releases details on two adult deaths they believe are linked to the virus.
While one could argue the evidence for causation is still pretty limited, given the large population at serious risk here, the precautionary principal demands a substantially lower burden of proof when swift action is needed. Follow up studies will be needed to further nail down this link.
Registration Date: 11/28/2015 18:11:32
The finding strengthens the call for a national mobilization to contain the mosquito, Aedes aegypti, responsible for spreading disease
The Ministry of health confirms this Saturday (28) the relationship between the virus Zika and microcephaly outbreak in the northeastern region. The Evandro Chagas Institute, an agency of the Ministry in Belém (PA), sent the result of tests carried out on a baby, born in Ceará, with microcephaly and other congenital malformations. In samples of blood and tissue, was identified the virus Zika.
From that found the baby who came to death, the Ministry of health considers confirmed the relationship between the virus and the occurrence of microcephaly. This is an unprecedented situation in scientific research. The investigations on the subject should continue to clarify issues such as the transmission of this agent, his performance in the human organism, the infection of the fetus and period of greatest vulnerability for pregnant women. On initial analysis, the risk is associated with the first three months of pregnancy.
The finding reinforces the call of the Ministry of health for a national mobilization to contain the mosquito, Aedes aegypti, responsible for the spread of dengue fever, and chikungunya zika. The success of this measure requires national action, involving the Union, the States, the municipalities and the Brazilian society as a whole. The time is now to unite efforts to intensify even more the actions and mobilization.
The campaign launched this week warning that the dengue mosquito kills and, therefore, cannot be born. The idea is that every day are used for cleaning and verification of outbreaks that may be mosquito breeding sites. The result of the rapid Survey indices for Aedes aegypti (LIRAa) indicates 199 Brazilian municipalities at risk of outbreak of dengue, chikungunya and zika, requiring a mobilization of all immediate.
The Ministry of health has also been notified, on Friday (27), by the Instituto Evandro Chagas about two other deaths related to the virus Zika. The analysis indicates that the agent may have contributed to worsening of cases and deaths. This is the first call of death related to the virus Zika in the world, which shows a resemblance with dengue fever.
The first case was confirmed by the Instituto Evandro Chagas, in Belém (BA), this is a man with a history of Lupus and chronic use of medications steroids, a resident of São Luís, Maranhão. With suspected dengue fever, blood sample collection and fragments of viscera (brain, liver, spleen, kidney, lung and heart) and sent to the IEC. The laboratory test showed negative for dengue. With the RT-PCR technique, was detected the Zika virus genome in blood and guts.
Confirmed on Friday (27), the second case is a 16-year-old girl, in the municipality of Bala, in Pará, who died at the end of October. With suspicion of dengue, notified on 6 October, she presented a headache, nausea and petechiae (red dots on the skin and mucous membranes). The collection of blood was performed seven days after the onset of symptoms, on 29 September. The test was positive for Zika, confirmed and repeated.
All findings are being released as they are known. The goal is to provide transparency about the current situation, as well as issuing guidelines on population and to the public network. This is an important finding and deserves attention. The Ministry of health is deepening the analysis of the cases, as well as monitor other analyses that have been conducted by its organs for research and laboratory analysis. The initial Protocol for the care of possible worsening Zika is the same used for most serious dengue fever.
The Ministry of health retains the investigations on the occurrence of microcephaly in babies, as well as the evaluation of severe cases in adults, the clinical manifestation and the spread of the disease. This week, at the invitation of the federal Government, representatives of the CDC (Centers for disease control and prevention, in English), of the United States, will join the efforts of national authorities and partners in these analyses. The CDC is a reference to the World Health Organization (who) communicable disease.
The who and its representation in the Americas, PAHO, have been updated on the progress of the actions, the results and conclusions of the Ministry of health.
The Ministry of health has intensified its monitoring of the situation, as a priority, and disseminate guidelines for the public and for the population, according to the results of the investigations. Moreover, keep in touch with the State and municipal departments to articulate a joint response and, in particular, to mobilize action against the Aedes aegypti mosquito.
The Ministry of health reports that the President of the Republic ordered the convening of the GEI (Inter-ministerial Executive Group), involving 17 ministries, for the formulation of a national plan to combat the vector transmitter, the Aedes Aegypti mosquito. Are also being stimulated research for the diagnosis of disease and fronts of mobilization in critical regions. There are plenty of financial resources to support their actions.
The measures involve, finally, welfare support and communication actions, such as prenatal care, psychosocial care, physiotherapy, early stimulation and support of the babies.