20 June 2008

Polio update and the current situation in Nigeria

An increase in cases of poliomyelitis in Nigeria raises concern for international spread of the disease. There are currently four countries that are considered endemic for polio: Afghanistan, India, Nigeria, and Pakistan. A further nine countries have reported imported cases in the last six months: Angola, Benin, Central African Republic, Chad, Democratic Republic of the Congo, Ethiopia, Nepal, Niger, and Sudan. 

Nigeria

On 18 June 2008, the World Health Organization (WHO) reported that northern Nigeria is affected by a new outbreak of wild poliovirus type 1 (WPV1) [1]. Since the start of 2008 there has been a nine-fold increase in the number of new cases caused by WPV1 compared to the same period in 2007 [2]. As of 17 June 2008 an overall total of 272 cases of polio have been reported. More than 20% of children in high risk areas have not been vaccinated against polio. Cases of WPV1 linked to Nigeria have already been reported from the neighbouring countries of Benin (17 April) and Niger (11 April). During 2003–2006 ongoing polio transmission in Nigeria led to international spread of polio with reinfection of 20 previously polio-free countries.

Nigeria is conducting large-scale polio immunisation campaigns, and disease surveillance is being heightened in at-risk countries.

The risk of a renewed international spread of the disease is increased by the intensity of the outbreak, but also by external factors, such as the forthcoming rainy season in northern Nigeria [3], and the expected vast population movements during the Hajj, which is due to take place from 6 to 9 December 2008. In 2007, the authorities in Saudi Arabia required proof of vaccination against polio for travellers from endemic countries and some travellers are required to receive an additional dose on arrival [4].

Afghanistan

Eight cases have been reported in 2008 (as of 17 June) [2]. Accessing populations in remote areas of the country continues to be the major hurdle to vaccination campaigns.

India

Ten new cases were reported in the week prior to 17 June, bringing the total number of cases for 2008 to 268 [2]. This compares with 62 cases for the same period in 2007. Emergency vaccination campaigns are planned for the states of Bihar and Uttar Pradesh, which  have been most affected by polio.

Pakistan

One new case was reported in the week prior to 17 June, bringing the total number of cases for 2008 to 12 [2]. Emergency vaccination campaigns continue to be planned and run in different areas of the country.

Non-endemic countries

Nine countries have reported importations in 2008. As of 17 June, cases have been reported in Benin, Central African Republic and Sudan (one case each), Democratic Republic of Congo and Ethiopia (two each), Nepal (three), Chad (four), Niger (nine), and Angola (16). With the exception of Democratic Republic of Congo (13 cases in 2007), all of these countries have had more cases in 2008 than were reported for the same period in 2007 [2].

Advice for travellers

Polio is transmitted through contaminated food and water. Travellers should practice strict food, water and personal hygiene precautions and have completed a primary vaccination course against polio according to the UK schedule. A booster dose of a polio-containing vaccine should be given to those who have not received a dose within the previous 10 years.

References

1. World Health Organization. Poliomyelitis in Nigeria and West/Central Africa. 18 June 2008. [Accessed 19 June 2008]. Available at: http://www.who.int/csr/don/2008_06_18/en/index.html

2. Global Polio Eradication Initiative. Weekly Update 18 June 2008. [Accessed 19 June 2008]. Available at: http://www.polioeradication.org/casecount.asp

3. BBC Weather Centre. Country Guide – Nigeria. [Accessed 19 June 2008]. Available at: http://www.bbc.co.uk/weather/world/country_guides/results.shtm

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4. World Health Organization. Health conditions for travellers to Saudi Arabia for the pilgrimage to Mecca (Hajj). 2007; 2 November; 44(82): 385-388. [Accessed 19.6.08]. Available at: http://www.who.int/wer/2007/wer8244.pdf

Links

NaTHNaC Poliomyelitis Health Information Sheet

 

Global Polio Eradication Initiative