Gert van der Hoek
In Memoriam - Editor, Senior Moderator
24 November 2015
Main conclusions
The increase in congenital microcephaly observed in Brazil is of concern. Its emergence a few months after the introduction of Zika virus (ZIKV) infection into the country raises questions about the possible role of the infection in congenital microcephaly. There is currently only ecological evidence of an association between the two events. A possible causative nature of the association cannot be ruled out with the evidence available. Further investigations and studies will contribute to a better characterisation of the association, and provide a better understanding of the possible role of other prenatal infections, genetic risk factors, environmental exposures to chemicals or consumption of teratogenic drugs. Studies of the ZIKV genome will provide information on possible changes that might influence ZIKV disease characteristics and vector competence.
As a precautionary measure, pending the results of the ongoing investigations, the Ministry of Health of Brazil emphasises the importance of recommendations that pregnant women should avoid the consumption of alcohol, drugs, medications without prescription and contact with people presenting with fever or infection. In addition, specific recommendations were issued about protection from mosquito bites, such as keeping doors and windows closed or screened, wearing trousers and long-sleeved shirts and using repellents authorised during pregnancy [1].
In the light of the current speculation regarding a yet to be established link between ZIKV and microcephaly, options for public health authorities in EU/EEA Member States to consider for mitigation of risks for travellers to and from Brazil include:
To enhance vigilance towards the detection of imported cases of ZIKV infection in EU Member States, EU Overseas Countries and Territories, and EU Outermost Regions, in particular where vectors or potential vectors are present in order to reduce the risk of autochthonous transmission.
To increase awareness of clinicians and travel health clinics about the evolution of the ZIKV outbreak and the endemic areas, especially in Brazil, Colombia, Suriname, Samoa and Cape Verde, in order for them to include ZIKV infection in their differential diagnosis for travellers from those areas. Fever and/or macular or papular rash not attributable to dengue or chikungunya infection among travellers returning from areas currently experiencing ZIKV outbreak should be considered indications for further investigation for ZIKV infection.
To ensure that advice on specific prevention measures, including information and education about mosquito bite prevention, is directed to pregnant women living in or travelling to areas where ZIKV outbreaks are ongoing.
Increase awareness among health professionals providing prenatal care of this possible association, and adapt prenatal monitoring according to the exposure of the pregnant women.
Advise travellers visiting affected areas, particularly pregnant women, to take individual protective measures to prevent mosquito bites all day round as ZIKV is transmitted by a daytime mosquito and consequently protective measures must be applied during the day (unlike malaria).
Strengthen the laboratory capacity to confirm suspected ZIKV infections in the European region in order to differentiate ZIKV infections from other arboviral dengue-like infections.
For blood safety authorities to consider deferral of donors with relevant travel history to areas with active ZIKV transmission, in line with measures defined for West Nile virus.
See also : Brazil investigates possible link between cases of microcephaly and Zika virus
Main conclusions
The increase in congenital microcephaly observed in Brazil is of concern. Its emergence a few months after the introduction of Zika virus (ZIKV) infection into the country raises questions about the possible role of the infection in congenital microcephaly. There is currently only ecological evidence of an association between the two events. A possible causative nature of the association cannot be ruled out with the evidence available. Further investigations and studies will contribute to a better characterisation of the association, and provide a better understanding of the possible role of other prenatal infections, genetic risk factors, environmental exposures to chemicals or consumption of teratogenic drugs. Studies of the ZIKV genome will provide information on possible changes that might influence ZIKV disease characteristics and vector competence.
As a precautionary measure, pending the results of the ongoing investigations, the Ministry of Health of Brazil emphasises the importance of recommendations that pregnant women should avoid the consumption of alcohol, drugs, medications without prescription and contact with people presenting with fever or infection. In addition, specific recommendations were issued about protection from mosquito bites, such as keeping doors and windows closed or screened, wearing trousers and long-sleeved shirts and using repellents authorised during pregnancy [1].
In the light of the current speculation regarding a yet to be established link between ZIKV and microcephaly, options for public health authorities in EU/EEA Member States to consider for mitigation of risks for travellers to and from Brazil include:
To enhance vigilance towards the detection of imported cases of ZIKV infection in EU Member States, EU Overseas Countries and Territories, and EU Outermost Regions, in particular where vectors or potential vectors are present in order to reduce the risk of autochthonous transmission.
To increase awareness of clinicians and travel health clinics about the evolution of the ZIKV outbreak and the endemic areas, especially in Brazil, Colombia, Suriname, Samoa and Cape Verde, in order for them to include ZIKV infection in their differential diagnosis for travellers from those areas. Fever and/or macular or papular rash not attributable to dengue or chikungunya infection among travellers returning from areas currently experiencing ZIKV outbreak should be considered indications for further investigation for ZIKV infection.
To ensure that advice on specific prevention measures, including information and education about mosquito bite prevention, is directed to pregnant women living in or travelling to areas where ZIKV outbreaks are ongoing.
Increase awareness among health professionals providing prenatal care of this possible association, and adapt prenatal monitoring according to the exposure of the pregnant women.
Advise travellers visiting affected areas, particularly pregnant women, to take individual protective measures to prevent mosquito bites all day round as ZIKV is transmitted by a daytime mosquito and consequently protective measures must be applied during the day (unlike malaria).
Strengthen the laboratory capacity to confirm suspected ZIKV infections in the European region in order to differentiate ZIKV infections from other arboviral dengue-like infections.
For blood safety authorities to consider deferral of donors with relevant travel history to areas with active ZIKV transmission, in line with measures defined for West Nile virus.
See also : Brazil investigates possible link between cases of microcephaly and Zika virus