The detected wild poliovirus (P1) resembles with Uttar Pradesh Virus of India. Bangladesh is now under a threat of further transmission of polio.

To combat the situation, Bangladesh has taken prompt initiative with the help of development partners like World Health Organisation (WHO), JICA, Rotary International, Unicef etc.

MOH&FW has announced 13th Special National Immunisation Days (NIDs) on 16th April, 13th May and 11th June 2006. All children up to 5 years of age will be vaccinated by 3 consecutive doses of oral polio vaccine.

A polio outbreak in Bangladesh once again

Since August 22, 2000 after the last incidence of Dolly, a female child of Mirpur slum area, Dhaka, Bangladesh was Polio free for more than 5 years. Children under 15 years of age attacked with Acute Flaccid Paralysis (AFP) have been being searched for poliomyelitis by collecting 2 stool samples. The stool specimens are examined in National Polio Lab at IPH, Dhaka for virological confirmation of Polio. This routine AFP surveillance is carried throughout all over Bangladesh as a part of Polio Eradication Programme.

During routine AFP surveillance, on January 26, 2006, a 9-year girl, Rahima D/O Quari Siddiqur Rahman of Bagdi village of sadar upazila of Chandpur district was detected as an AFP case. Two stool samples were collected on 28th and 29th January and sent to NPL, Dhaka. On February 20, the NPL confirmed presence of wild polio virus (P1) in Rahima's stool. On February 22, specimens were sent to Mumbai Polio lab, India for further confirmation. On March 8, they also confirmed the wild virus. Now there is a polio outbreak once again in Bangladesh.

Facts about polio?
Poliomyelitis (polio) is a highly infectious disease caused by a virus. It invades the nervous system, and can cause total paralysis within hours.

It can affect at any age, but affects mainly children under three (over 50 percent of all cases). The virus enters the body through feco-oral route.

Initial symptoms are fever, fatigue, headache, vomiting, and stiffness in the neck and pain in the limbs. One in 200 infections leads to irreversible paralysis (usually in the legs). Amongst those paralysed, 5-10 percent die when their breathing muscles become paralysed as well. Although polio paralysis is the most visible sign of polio infection, less than 1 percent of polio infections ever result in paralysis. Poliovirus can spread widely before cases of paralysis are seen.

As most people infected with poliovirus have no signs of illness, they are never aware they have been infected. After initial infection with poliovirus, the virus is shed intermittently in faeces for several weeks. During that time, polio can spread rapidly in the community.

Transmission
The virus enters the environment through faeces of people infected, then is passed to others especially in situations of poor hygiene.

The poliovirus can also infect persons who have been vaccinated and can be carried by them. Such individuals will not develop polio, but can carry the virus in their intestines and can pass it to others in conditions of sub-standard hygiene. The disease may infect thousands of people, depending on the level of sanitation, before the first case of polio paralysis emerges. Individuals can carry the virus in their intestines just long enough to transmit to others.

WHO considers a single confirmed case of polio paralysis to be evidence of an epidemic particularly in countries where very few cases occur.

Prevention
There is no cure for polio; it can only be prevented through immunisation. Polio vaccine, given at multiple times, almost protects a child for life. Full immunisation will markedly reduce an individual's risk of developing paralytic polio. Full immunisation will protect most people. However individuals can still get infected by the disease due to the failure of some individuals to respond to the vaccine.

Endemic countries and importation
Four countries in the world are polio-endemic: Nigeria, India, Pakistan and Afghanistan.

Nine countries had circulation of imported wild poliovirus in the past 6 months: Somalia, Indonesia, Niger, Chad, Ethiopia, Yemen, Angola, Nepal and Bangladesh.

Such importation and outbreaks in previously polio-free areas are not a new phenomenon. However, importations today tend to take on a much higher profile, as most of the world is polio-free. Since 2003, Nigerian poliovirus spread across the world, reinfected 18 previously polio-free countries. For the first time ever, in 2005, the number of polio cases in re-infected countries is higher than number of cases in endemic countries. 1045 cases were found in non-endemic countries in comparison to 206 cases in 2004.

After genetic sequencing of the recent poliovirus it has been confirmed by the experts that the Bangladesh virus found in Rahima is imported from the recent virus of Uttar Prodesh of India. In 2005, India's Polio Eradication programme recorded good indicators of progress, including its lowest ever level of poliovirus transmission reporting 66 cases (compared to 134 cases in 2004).

Let's stop further transmission in Bangladesh
In Bangladesh, authorities are following the ACPE (Advisory Committee on Polio Eradication) gold-standard outbreak guidelines, as the country will launch the first of the three National Immunisation Days (NIDs) on April 16. The second round will be on May 13 and third round on June 11.

To address the issue, Bangladesh is continuing its intensification of Polio eradication efforts by strengthening routine immunisation, strong AFP surveillance and intensified use of monovalent oral polio vaccine (mOPV) for type 1 during NIDs.

Be a part of the fight against polio
Please communicate the message to everyone you meet in your everyday life to vaccinate each and every child under 5 years of age with 3 consecutive doses of OPV once again during the upcoming NIDs.

Please inform the local health authority (Civil Surgeon at district level, UHFPO at upazila level or nearby hospitals) immediately if you know any case of acute flaccid paralysis (AFP) under 15 years of age anywhere in Bangladesh.

Please make sure that every child before reaching their first birthday is vaccinated in time against 7 deadly diseases through routine immunisation.

Let us make sure that our combined effort will stop further transmission of polio so that Rahima will be the last case of polio in Bangladesh.

Dr Md Iqbal Kabir is a public health specialist and epidemiologist.