The World Health Organization (WHO) Director-General Margaret Chan declared on Monday that the Zika virus constitutes a Public Health Emergency of International Concern.

Chan had convened an Emergency Committee to collect advice on the severity of the health threat associated with the continuing spread of Zika virus disease in Latin America and the Caribbean.

Assessing the level of threat, eighteen experts and advisers examined in particular the strong association, in time and place, between infection with the Zika virus and an increase in the registered cases of congenital malformations and neurological complications.

The experts agreed that a causal relationship between Zika infection during pregnancy and microcephaly is strongly suspected, but has not yet been scientifically proven.

The committee concluded that there was urgent need to coordinate international efforts to investigate and understand the relationship better.

It also examined the patterns of recent spread and broad geographical distribution of mosquito species capable of transmitting the virus.

Among the other concerns were the lack of vaccines and rapid and reliable diagnostic tests as well as the absence of population immunity in the newly affected countries.

The committee concluded that the recent cluster of microcephaly cases and other neurological diseases registered in Brazil after a similar cluster had been registered in French Polynesia in 2014 constitutes an “extraordinary event” and a public health threat to the rest of the world.

WHO highlighted the need to coordinate international response to minimise the threat in affected countries and prevent its spread to other parts of the world.

Members of the committee agreed that the situation fulfills the conditions for a Public Health Emergency of International Concern.

WHO calls for coordinated international response in: improving surveillance; detecting infections, congenital malformations and neurological complications; intensifying the control of mosquito populations; accelerating the development of diagnostic tests and vaccines to protect people at risk, especially during pregnancy.

The committee established no public health justification for imposing travel or trade restrictions in order to prevent the spread of Zika virus.

At present, the most important protective measures are the control of mosquito populations and the prevention of bites among endangered individuals, especially pregnant women.

Brazilian authorities assured that there is no risk of the forthcoming Olympic Games in Rio de Janeiro being cancelled due to an outbreak of the Zika virus.

They said that there is no risk to athletes or spectators, except for pregnant women.

The Bulgarian health ministry imposed on Monday preventive measures against the possible spread of the Zika virus in the country.

Although at present the risk of the virus spreading in Europe is assessed as being low due to the absence of mosquito during the winter, there is a risk of transmission of the disease when traveling to Latin America.

The ministry called on Bulgarian health authorities to closely monitor the situation in Latin America and disseminate precise, timely and balanced information to population without causing panic and fear.

The ministry also highlights the need to increase awareness of the disease and readiness to prove potential cases especially among people who have stayed in the affected countries and display symptoms typical of the disease.

The health authorities are to publish instructions to people who are about to travel to the affected regions with concrete recommendations for preventing infection with the virus.

The ministry also highlighted the need for carrying out regular disinsection across the country on time and reinforcing the capacity of the transfusion hematology by diagnosing donated blood with nucleic amplification test (NAT).