[NEW DELHI] Chikungunya virus can be transmitted from a pregnant woman to her baby if she becomes infected just before or after delivery, scientists report.
Public health officials should take the threat this poses to babies into account, researchers urge in their study, published in PLoS Medicine this week (17 March).
The team studied more than 7,500 women who delivered babies at the South Reunion Hospital Group (GSHR) on the Indian Ocean island of La Reunion during an outbreak of chikungunya virus between March 2005 and December 2006, when over one third of the population was infected.
They found that 700 women were infected with the virus between conception and three days before delivery, and 39 became infected between two days before and after delivery.
Mother-to-child transmission occurred only in babies born to mothers who were infected two days before or after delivery. Almost half of the babies born to mothers in this group were infected, and transmission occurred in mothers who had higher levels of virus in their blood.
Though healthy at birth, infected babies developed fever within 3–7 days.
"All the infected babies needed painkillers and feeding with a gastric tube," Patrick Gérardin, doctor at the GHSR and co-author of the study told SciDev.Net.
These findings should be considered by clinicians and public health authorities in the event of an outbreak, who should monitor babies exposed to chikungunya virus for a week after their birth, say the researchers.
Currently, there is no treatment that decreases the number of chikungunya virus particles in infected people's bloodstreams.
"If such a treatment was available, it would likely decrease the probability of transmission," says Marc Lecuit, a professor at the Department of Cell Biology and Infection at the Pasteur Institute, France, and co-author on the paper.
Chikungunya virus is spread by Aedes aegypti mosquitoes, mainly found in standing water in urban areas. It re-emerged on several islands in the Indian Ocean in 2005, caused a major outbreak in India in 2006–07, and was reported in Europe in 2007.
The researchers recommend that pregnant women should avoid contact with chikungunya-infected people by staying at home, using insect repellents and sleeping under mosquito nets in order to avoid bites.
PLoS Medicine doi 10.1371/journal.pmed.0050060 (2008)