Measles cases in 2012 have surged by almost five times of that the previous year in Pakistan, leading to the deaths of hundreds of children, according to an international health body.
Maryam Yunus, a spokeswoman for the World Health Organisation (WHO) said on Tuesday that 306 children died in Pakistan because of the infectious disease in 2012, a dramatic surge from to the 64 children in 2011.
The WHO said the jump was most pronounced in southern Sindh province, where measles killed 210 children in 2012. Twenty-eight children died there the year before.
The organisation did not give a reason for the increase in deaths, but a provincial health official in Sindh said that the disease hit areas where poor families did not vaccinate their children.
A provincial health minister said 100 children died in Sindh province in December alone, mostly in areas where many people were not vaccinated.
He said health officials recently launched a campaign to vaccinate 2.9 million children in the affected areas of the province and urged parents to get their children vaccinated.
"We are vaccinating more than 450 patients per day. We are working on vaccination since the outbreak of measles in the area," Dr Shahid Hafeez Shahani, a government official, said.
Pakistan has a poor health care system, unsanitary conditions in many regions due to poverty, and a lack of education about how to prevent disease.
Pakistani officials believe that the worst-hit areas are poverty stricken areas where children did not receive vaccination.
Many Pakistanis, especially in rural areas, view vaccination campaigns with suspicion as a western plot to sterilise Muslims.
Sindh province, the area hardest hit by the measles outbreak, has also been battered by repeated floods in recent years that have damaged hospitals and clinics.
Measles is an extremely infectious disease spread by coughing and sneezing or personal contact. It causes a fever, cough and a rash all over the body.
Most people who contract the disease recover, but it can be fatal for malnourished children.
According to WHO, 139,300 people died of measles worldwide in 2010.