Progress towards poliomyelitis erad

[OKKAR66129@xxxxxxx]

Subject: Progress towards poliomyelitis eradication,  Myanmar, 1999

The New Light of Myanmar
Friday, 24 December, 1999

Progress towards poliomyelitis eradication,  Myanmar, 1999 

The global polio eradication programme has made rapid progress, and is 
catering its final stages before reaching the eradication target by the end 
of 2000.

Myanmar is a country uniquely situated between polio-free countries (China, 
Lao PDR) and countries with widespread poliovirus transmission (India, 
Bangladesh). Myanmar began to intensify its efforts towards eradication of 
poliomyelitis in 1996, when for thc first time National Immunization Days 
were organized. Additional "mop-up" campaigns were implemented in October and 
November 1999, and will continued in the year 2000. Surveillance for Acute 
Flaccid Paralysis (AFP) was established in 1996, and has made rapid progress 
since. As one of the few countries in thc South-East Asian Region, Myanmar 
has had four cross-border meetings with its neighbouring country, China, 
aimed at coordinating polio eradication efforts. The current situation of 
poliomyelitis eradication in ,Myanmar will be highlighted with focus on 
surveillance and immunization strategies.

As most other countries, Myanmar is adopting four basic strategies to attain 
eradication of poliomyelitis: high levels of routine immunization coverage 
for 3 doses of Oral Polio Vaccine (OPV), National Immunization Days (NIDs), a 
sensitive AFP surveillance system, and Mop-up immunization campaigns.

EPI was launched in Myanmar in April 1978, and activities were accelerated in 
1986 to meet the goal of Universal Childhood Immunization (UCI) in 1990. 
Reported routine coverage for OPV3 has been around 80%90% since 1991, but 
surveys have shown that coverage rates were subs-stantially lower than the 
reported ones. Reported and surveyed routine OPV3 coverage was 84%, 75% 
respectively in 1995, and 90.3% and 81.6% respectively in 1997.

Such figures hide large differences between States and Divisions. Especially 
the border areas and hilly areas are affected by a below-average coverage. 
Low coverage in these areas can be explained by difficulties in access, 
cultural differences between health staff and populations, and lack of 
awareness among the population.

National Immunization Days were first organized in February and March 1996, 
and since then Myanmar has organized NIDs yearly in December-January, 
targeting all children aged 0-5 years. Reported coverage in the past years 
has been above 95%. Since the winter of 1996, NlDs have been synchronized 
with neighbouring countries, including Thailand, Bangladesh, India and China. 
The fifth nation-wide NIDs took place on 12 December 1999 and will be 
organized on 16 January 2000.

AFP Surveillance was established in 1996. Acute Flaccid Paralysis became a 
reportable condition, and intensive training and advocacy sessions were 
organized for clinicians and health basic staff. Reporting rates improved 
rapidly in 1997 and 1998. There are close to 2,000 zero-reporting sites since 
zero reporting has been introduced for all health centres and hospitals. In 
addition, some 30 large hospitals are visited weekly by public health staff 
who actively search for AFP cases.

Out of the 133 AFP cases reported between 1 January and 10 November 1999, 
(99%) had at least one stool specimen taken, and 95 (71%) had two stools 
taken within 14 days after onset. Out of the 52 cases for whom follow-up 
results (minimum 60 days after onset) were available, 3 had died, 27 were 
lost to follow-up, 33 had no residual paralysis, and 16 had residual 
paralysis. Up to now 20 cases are clinically confirmed as poliomyelitis. 
Since early 1999, AFP reporting forms have been adapted and can now also be 
used for reporting of measles and neonatal tetanus cases. In Myanmar, as in 
other SEAR countries, cases are classified using the clinical classification 
scheme. In 1999 wild poliovirus type 1 was isolated in 4 reported AFP cases, 
in children among the a group of minorities living in Rakhine State.

Stool specimens collected under the AFP surveillance system are cultured by 
the National Health Laboratory (NHL) in Yangon, which has been provisionally 
accredited as a National Polio Laboratory. Intra-typic differentiation is 
carried out by the Regional Reference Laboratory at the National Institute of 
Health (NIH) in Bangkok, Thailand.

Mop-up immunizations were carried out in high-risk areas in October and 
November 1999. These high-risk areas include areas with borders with 
neighbouring countries, areas with known low vaccination coverage, areas with 
circulation of wild poliovirus, and areas with indigenous races and migrating 
populations. More areas are planned for mop-up operation in early 2000. 
Mop-up operations are carried out by mobile teams over a period of about 5 
days, with focus on reaching the previously unreached children. Volunteers 
will also collect information on the number of children who have never 
received OPV ("zero dose" children) and on recent paralysis cases. For 
October/November 1999, 917,000 children were targeted. The age group for 
mop-up operations is in principle 0-5 years, with the exception of townships 
where a wild virus was found in older age-groups, in which case all children 
of that age-group are targeted in the concerned township, and to the extend 
possible also in neighbouring townships. Mop-ups in Ayeyawaddy Division are 
limited to Mawkyun township during the October and November rounds. As in 
other SERA countries, a National Certification Committee has been established 
and monitors on an on-going basis progress in the polio eradication programme.

Myanmar, situated between polio-endemic and polio-free countries, has 
recently isolated 4 wild P1 polioviruses, the proof of on-going poliovirus 
circulation since 1996.

Routine immunization coverage in Myanmar has achieved good overall levels, 
but coverage is not uniform across the country. In particular the border 
areas and hilly areas where access is difficult, are under-served, which 
results in the existence of pockets of children susceptible to polio 
infection. It is very likely that the same children who have not been reached 
by routine services are also not covered during the NIDs. The recent 
isolation of four wild P1 viruses illustrates that despite four NIDs (8 
rounds), poliovirus continues to circulate, especially on the 
Myanmar-Bangladeshi border. The mop-up operations in high-risk areas for 
polio are an appropriate response to the situation, making sure that mop-up 
campaigns succeed in achieving higher real coverage than the NIDs. To that 
extent, the mop-up operations have been planned over a period of 5 days, with 
emphasis on the mobility of the vaccination teams ("house-to-house" 
approach), detailed planning, and intensive supervision. The mop-up 
operations are also targeted at preventing spread of poliovirus into 
polio-free countries, in particular China.

The AFP surveillance system provides information on AFP and polio cases, 
including the clustering of cases, such as a non-polio outbreak of paralysis 
in teenagers in 1997 in Pyinmana Township and other townships in different 
age groups and the recent isolation of wild poliovirus. It has, however, not 
yet reached the level needed to provide the level of certification criteria. 
Non-polio AFP rates approached the target of 1 per 100,000 children under the 
age of 15 years in 1998, but rates have declined in 1999. Neither have 
reached certification-level targets of 80%.

The present level of AFP surveillance is therefore insufficient to precisely 
estimate the extent of wild poliovirus circulation. Blind spots continue to 
exist, and available information only provides a scattered picture. While 
mop-up campaigns and high-quality NIDs are needed to limit poliovirus 
circulation, AFP surveillance also needs to be further strengthened. Ongoing 
advocacy, supervision, feedback, and monitoring are needed to sustain the 
momentum achieved in the past two years.

With less than 14 months remaining to reach the target of polio eradication, 
Myanmar is stepping up efforts to immunize previously un-reached chi1dren. 
This effort must go hand in hand with high-quality surveillance.

During this year the importance of reaching the un-reached children should be 
stressed and no single children should be missed so that no pockets of 
children un immunized remained. 

Author: Dr Than Htain Win