While the ebola virus continues its deadly spread, health experts, especially virologists have observed that travel restrictions could worsen West Africa's Ebola epidemic, limiting medical and food supplies and keeping out much-needed doctors.
The worst-ever outbreak of the haemorrhagic fever, which has hit Sierra Leone, Liberia, Nigeria and Guinea the hardest, has seen airlines cancel flights and several countries barring people from affected nations.
"If we impose an aerial quarantine on these countries, we undermine their fight against the epidemic: the rotation of foreign medical staff and distribution of supplies, already inadequate, will become even more difficult," said Sylvain Baize, head of the Pasteur Institute's viral haemorrhagic fever centre in Lyon, France.
This should be weighed against a "very limited" risk of infection for flight crews, given that the virus can only be passed on once symptoms appear and only through physical contact with the body fluids of someone who is ill, he told AFP.
The World Health Organisation has appealed for the reversal of flight cancellations to West Africa, where Ebola has killed more than half of the 3,000-plus people it has infected.
There is no vaccine or licenced cure.
Air France has suspended its service to Freetown, and British Airways its flights to Freetown and Monrovia.
Royal Air Morocco is now the only airline providing a regular service to the capitals of Sierra Leone and Liberia, while Brussels Airlines offer an irregular schedule.
South Africa has issued a ban on non-citizens travelling from Guinea, Liberia and Sierra Leone, Saudi Arabia has stopped granting visas to workers from these countries, and several West African neighbours closed their land borders with worst-affected states.
"Ebola virus is an infection that, understandably, provokes great fear and apprehension. So perhaps it is not surprising that some states or carriers are imposing travel bans," University of Nottingham virology professor Jonathan Ball told AFP.
"However, it's important to get the risk into perspective. Provided that the necessary airport exit and border monitoring takes place (for people displaying symptoms), then the risk of export of Ebola virus is limited."
"Even in the rare event of an exported infection, provided countries know how to identify a possible infection, then respond appropriately, the risk of wider infection...is low."
The current outbreak, the biggest since Ebola was first identified in the former Zaire in 1976, was detected in Guinea in March, from where it spread to Liberia, Sierra Leone, Nigeria and most recently Senegal.
An outbreak in the Democratic Republic of Congo is believed to be unrelated to the West African epidemic.
- Don't close your eyes -
Experts say the focus should be on helping affected countries contain the virus, and preparing themselves to deal with any cases that may arrive.
The best approach is to try and contain the epidemic by isolating as many infected people as quickly as possible and tracking down and monitoring everyone they had been in contact with.
"Closing the borders is like closing your eyes," said Michael Kinzer of the US-based Centers for Disease Control and Prevention (CDC), who led a recent surveillance and advisory Ebola mission to Guinea.
"It makes more sense for countries to spend their money and energy on preparing their health systems to recognise an Ebola case and respond correctly... so that the virus does not spread."
Liberia and Sierra Leone were in special need of assistance, added Baize. With not enough hospital beds available to isolate patients, the virus remain out there, passing from person to person.
"There are not enough teams on the ground to go out searching for patients in the furthest corners of villages and towns," he said.
On Tuesday, the UN's Food and Agriculture Organization warned of "grave food security concerns" through the disruption of cross-border trade.