Polio cases increasing

Yemen's polio epidemic has spread throughout the country, with 22 confirmed cases, and further suspected cases under laboratory analysis. The outbreak was first detected when four cases of type 1 polio virus were confirmed on 20 April in the Hodeidah governorate, on the western coast of Yemen. There are three types of polio virus and all are very similar but type 1 is the most common and the easiest to detect. The virus has now reached other parts of the country. Hodeidah has the heaviest outbreak with 16 confirmed cases. One case has been found in Makha, 250 km from Sana, on the southern part of the western coast and two more in Sayu in north-eastern Yemen. One was detected in Hajja, 80 km north-west of Sana, and another two other cases of polio were diagnosed in the capital itself. The head of the World Health Organization (WHO), David Heymann, described the outbreak as a "major epidemic" at a press briefing in Geneva earlier this week. Polio is a highly infectious viral disease. It invades the nervous system and can cause total paralysis in a matter of hours. In response, the WHO scheduled an extensive house-to-house immunisation campaign throughout the country from 30 May to 1 June and another round later in June, each at the cost of US $1.3 million. "For this immunisation, we will use a monovalent vaccine, a vaccine that specifically covers type 1 polio virus," WHO Country Representative, Dr Hashim Al-Zain, told IRIN in Sana. The recently developed monovalent oral polio vaccine type 1(mOPV1) provides better immunity to type 1 polio virus, with fewer doses required. The WHO in Yemen has also received genetic analysis results from the Centers for Disease Control (CDC) in the US confirming that the virus is of the same type that caused an epidemic in Sudan. The outbreak of polio in Yemen follows a precautionary immunisation round in April. "That round was planned because of the spread of the virus from Sudan. There were some cases in Ethiopia as well," WHO polio eradication officer, Dr. Rudi Tangermann told IRIN. "The virus was imported and circulated at the beginning of the year. This country has done so much, the most important thing now is to protect their investment," Tangermann added. "We are taking this very seriously. There probably will be more cases. We do have other suspected cases being followed up," he added. Yemen has a countrywide immunisation rate of approximately 69 percent, which is considered low. Moreover, immunisation is not spread uniformly throughout the country. "Some areas are 60 to 70 percent, which is routine coverage for Yemen but there are also pockets of very low coverage," Tangermann explained. The country is one of 16 previously polio-free nations to have been re-infected in the past few years. The virus has most recently reappeared in Indonesia, also considered polio-free for the past 10 years. The WHO's US $4 billion campaign to eradicate polio worldwide aimed to do so by the end of this year. "We still have a fighting chance. A lot is happening and there is a chance," Tangermann said. The west African country of Nigeria accounts for over half the polio cases worldwide. Cases have been reduced there, from 94 in 2004 to 54 this year. However, the disease spread from there to other African nations.