S89
Polio Eradication in the World Health Organization South-East Asia Region
by the Year 2000: Midway Assessment of Progress and Future Challenges
Jon K. Andrus, Kaushik Banerjee, Barbara P. Hull,
Jean Clare Smith, and Imam Mochny
Expanded Programme on Immunization, World Health Organization
Regional Office for South-East Asia Region, and Maternal Child Health
Division, Department of Family Welfare, Ministry of Health and Family
Welfare, New Delhi, India; Global Programme on Vaccines and
Immunization, World Health Organization, Geneva, Switzerland;
Centers for Disease Control and Prevention, Atlanta, Georgia
In the South-East Asia Region (SEAR) of WHO, paralytic poliomyelitis has decreased from
25,711 cases in 1988 to 3304 cases in 1995, representing an 87% reduction. By 1995, in 6 of
10 member countries-India, Bangladesh, Myanmar, Nepal, Indonesia, and Democratic People's
Republic of Korea- polio remained endemic. Two countries, Sri Lanka and Thailand, appear close
to polio eradication, and 2, Bhutan and Maldives, reported no cases during 1989-1995. Although
reported rates of acute flaccid paralysis and the percentage of cases virologically investigated are
low in some countries, no isolates of wild poliovirus type 2 have been reported outside India since
1993. By the end of 1996, all 8 countries in which polio is endemic will have conducted national
immunization days for polio eradication. The major challenge for polio eradication in SEAR will
be strengthening surveillance, because national immunization days alone cannot eradicate polio.
From 1988 to 1995, countries of the South-East Asia Region
(SEAR) of the World Health Organization (WHO) annually
reported more than half of the polio cases globally [1]. To
achieve the global goal of polio eradication by the year 2000,
it is of critical importance that countries of SEAR implement
and sustain the necessary strategies. Since the global polio
eradication initiative was first adopted by the World Health
Assembly in 1988, most of the global progress toward polio
eradication has been highlighted by the achievements of the
Americas and, more recently, of the Western Pacific Region
[1-4]. During 1994-1995, global progress was noteworthy for
the dramatic acceleration of polio eradication activities in
SEAR, particularly with the implementation of national immunization days (NIDs) and with efforts to strengthen stfrveillance
of acute flaccid paralysis (AFP) and wild poliovirus.
In SEAR, the strategies to eradicate poliomyelitis are similar
to those developed in the Americas [2]. These strategies, recommended globally by WHO [5], include strengthening routine
vaccination coverage, supplementing routine immunization services with NIDs in all countries in which polio is endemic,
expanding surveillance of AFP and wild poliovirus so that all
cases of polio are identified and investigated, and conducting
house-to-house "mop-up" immunization campaigns in the remaining areas sustaining transmission of wild poliovirus after
NIDs have been implemented.
This report summarizes the progress achieved in SEAR toward polio eradication from 1988 through 1995 and is based
on data reported to the SEAR office through 30 April 1996.
Coverage data are reported from 1988 through 1994. The 10
member countries of SEAR are Bangladesh, Bhutan, Democratic People's Republic of Korea (DPR Korea), India, Indonesia, Maldives, Myanmar, Nepal, Sri Lanka, and Thailand. When
reported, results of intratypic characterization of polioviruses
are included. The data source and date for country population
estimates is the United Nations Population Division, 1994.
OPV Immunization Coverage
In 1990, 8 member countries in SEAR reported that they
had reached the 1990 Universal Childhood Immunization goal
of coverage among children 1 year of age of > 80% with three
doses of diphtheria-pertussis toxoids-tetanus vaccine, three
doses of oral poliovirus vaccine (OPV3), and one dose of measles vaccine. Regionally, reported immunization coverage for
OPV3 by 1 year of age has been sustained above 80% since
1990. However, low-coverage areas exist in all countries, including those countries reporting coverage levels of >90%. In
1994, Bangladesh (95%), Bhutan (84%), DPR Korea (99%),
India (92%), Indonesia (91%), Maldives (97%), Sri Lanka
(88%), and Thailand (93%) reported a coverage of ;:,80% for
OPV3. Mongolia (77%) (now a member country of WHO's
Western Pacific Region), Myanmar (77%), and Nepal (64%)
reported coverage of <80% in 1994.
Presented at the 6th meeting on the Global Poliomyelitis Eradication Initiative, World Health Organization and Centers for Disease Control and Prevention, July 1995, Atlanta.
Reprints or correspondence: Dr. Jon Kim Andrus, South-East Asia Regional
Office for WHO, Indraprastha Estate, New Delhi-110 002, India.
Regional Progress
The Journal of Infectious Diseases 1997; 175(8uppl 1):889-96
© 1997 by The University of Chicago. All rights reserved.
0022-1899/97/7581-0017$01.00
From 1988 through 1995, the number of polio cases reported
in SEAR decreased by 87%, from 25,711 to 3304 (figure 1).
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Andrus et al.
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1987
1988
1989
1990
1991
1992
1993
1994
1995
Year of Paralysis Onset
Figure 1. Reported paralytic poliomyelitis by year of paralysis onset, India (rule) and South-East Asia Region (bars), 1987-1995.
Source: Ministry of Health, member countries.
However, in 1995, cases reported from SEAR accounted for
more than half of the cases of paralytic poliomyelitis reported
worldwide. In 1995, four subcontinent countries-India, Bangladesh, Myanmar, and Nepal-accounted for 99% (3283/
3304) of all the cases reported in SEAR. Other member countries in which polio is endemic are DPR Korea, Indonesia, Sri
Lanka, and Thailand.
By 1995, 6 of the 8 member countries in which polio is
endemic-Bangladesh, India, Indonesia, Nepal, Sri Lanka, and
Thailand-were conducting AFP surveillance (table 1). Of
these countries, Sri Lanka and Thailand routinely monitor and
evaluate AFP reporting rates, the timeliness of AFP reporting
and investigation, and the collection of 2 stool specimens
within 2 weeks of onset of paralysis. By May 1996, with the
exception of DPR Korea, all countries in which polio is endemic will have implemented AFP surveillance.
In 1993, the SEAR Polio Laboratory Network was established, consisting of three regional reference laboratories and
eight national laboratories. The reference laboratories are located in the National Institute of Communicable Disease
(NICD) in New Delhi; Medical Research Center in Colombo,
Sri Lanka; and Virus Research Institute (VRI) in Bangkok. The
eight national laboratories are located in India (King Institute of
Preventive Medicine in Madras, Enterovirus Research Center in
Bombay, Central Research Institute in Kasauli, and Pasteur
Institute of India in Conoor), Bangladesh (Institute of Public
Health in Dhaka), and Indonesia (National Institute of Health
Research and Development in Jakarta, Perum Bio Farma in
Bandung and Laboratory Health Services in Surabaya). Virologists at the national laboratories use traditional virologic cell
culture techniques for poliovirus isolation and typing. Polioviruses isolated at the national laboratories are sent to the appropriate regional reference laboratories for intratypic characterization using ELISA and nucleic acid probe hybridization
techniques.
In 1993, only 917 AFP cases were reported to have virologic
investigation, with a total of 1601 stool specimens being processed for viral culture. In 1995, provisional data indicate that
1287 AFP cases were reported to have virologic investigation,
with a total of 1802 stool specimens being processed for viral
culture. In 1995, 63% of all polioviruses isolated in the region
underwent intratypic differentiation.
Progress by Country
India (population 935,744,000). Most of the SEAR progress toward polio eradication primarily reflects achievements
Table 1. Rates of reported acute flaccid paralysis (AFP) per 100,000 persons aged <15 years in
countries in which polio is endemic, by year, South-East Asia Region, 1991-1995.
Country
1991
1992
1993
1994
1995
Bangladesh
DPR Korea
India
0.59
NR
NR
0.42
NR
NR
0.46
NR
NR
0.56
NR
NR
0.65
NR
2.2
Indonesia
Myanmar
NR
NR
NR
NR
NR
NR
0.014
NR
0.3
NR
Nepal
Sri Lanka
Thailand
0.15
1.2
NR
0.15
1.4
0.56
<0.05
1.6
1.01
0.05
1.4
0.84
0.05
1.4
0.74
% of reported cases in 1995
with stool specimens
collected for viral culture
29%
NA
NA, AFP surveillance
implemented in 1995
10%
NA, AFP surveillance to be
implemented in 1996
50%
94%*
55%*
NOTE. NR, not reported; NA, not available. Surveillance indicators are used to monitor performance of reporting
and investigation of AFP cases. Besides AFP reporting rates per 100,000 persons < 15 years old, indicators include
% of AFP cases virologically investigated and % of AFP cases with 2 stools collected for viral culture <2 weeks
after paralysis onset. India, Bangladesh, and Nepal target AFP surveillance toward children <5 years old, and rate
is expressed accordingly.
* % of cases with 2 stools collected <2 weeks after paralysis onset for viral culture.
Polio Eradication in South-EastAsia Region
JID 1997; 175 (Supp11)
in India, where reported polio cases declined 87% during 19881995, from 24,257 to 3142. Recently, this progress has leveled
(figure 1). In India, the number of polio cases decreased by
54% from 1992 (9203) to 1993 (4236), followed by a 13%
increase from 1993 (4236) to 1994 (4791), and then decreased
by 34% from 1994 (4791) to 1995 (3142).
Among cases with age information, the median age for polio
cases reported during 1992-1994 was 18.0 months for each
year and has remained relatively unchanged from reports 10
years previously [6, 7]. The proportion of cases <36 months
of age has ranged from 79% in 1992 to 82% in 1993 and 1994.
The proportion of cases < 48 months of age has ranged from
88% in 1992 to 91% in 1993 (table 2). In 1994, of the 2691
reported cases of paralytic poliomyelitis for which OPV immunization history was available, 64% had no doses ofOPV, 12%
had one or two doses, and 24% had three or more doses.
Analysis of polio cases reported by month suggests that India
is still reporting an episodic or seasonal pattern of disease
(figure 2). In 1994, outbreaks of polio occurred more focally
in the states of Gujarat and Karnataka (figure 3). From 1993
to 1994, Gujarat experienced a 6-fold increase in reported poliomyelitis cases, from 120 to 750. The number of poliomyelitis
cases more than doubled in Karnataka from 1993 (301) to
1994 (668).
In 1993, 14% (604/4236) of polio cases reported in India to
the SEAR WHO office had stools collected for viral culture;
of these, 32% (193/604) had polioviruses isolated. Of the 193
cases with polioviruses isolated, 24% (46/193) had type 1,24%
(46/193) had type 2,31% (59/193) had type 3, 18% (34/193)
had mixtures, and 4% (8/193) had unknown results.
In 1994, 22% (1075/4791) of polio cases reported in India
to the SEAR WHO office had stools collected for viral culture;
of these, 37% (397/1075) had polioviruses isolated. Of the 397
cases with polioviruses isolated, 75% (299/397) had type 1,
9% (35/397) had type 2, 11% (42/397) had type 3, and 5%
(21/397) had mixtures.
In 1995,32% (1004/3142) of polio cases reported in India
to the SEAR WHO office had stools collected for viral culture;
of these, 31% (313/1004) had polioviruses isolated. Of the 313
cases with polioviruses isolated, 57% (177/313) had type 1,
12% (38/313) had type 2, 22% (69/313) had type 3, and 9%
(29/313) had mixtures.
From 1993 to 1995, the proportion of poliovirus type 2
isolates was 24% in 1993, 11% in 1994, and 12% in 1995. Of
Table 2. Reported number of cases of paralytic poliomyelitis in
children <36 months and <48 months old, India, 1992-1994.
No. of polio cases reported
No. with age information
% <36 months
% <48 months
1992
1993
1994
8738
4650
79
88
4236
2035
82
91
4791
2671
82
90
S91
the 42 poliovirus type 2 isolates reported from the SEAR Polio
Laboratory Network in 1995, 38 were reported from India (6
Bombay, 26 New Delhi, 1 Kasauli, and 5 Madras). The other
4 (1 in Thailand, 2 in Sri Lanka, and 1 in Indonesia) were
characterized as vaccine-related.
The capacity for intratypic characterization of polioviruses
by the NICD Regional Reference Laboratory has expanded
since receiving the necessary reagents in 1993. In 1994, NICD
reported characterizing 28 poliovirus isolates selected from
specimens processed in 1993: 8 wild type 1, 8 wild type 2, 9
wild type 3, 2 vaccine-related type 1, and 1 vaccine-related type
2. In the first semester of 1995, NICD provisionally reported
characterizing 146 poliovirus isolates: 62 wild type 1, 21 wild
type 2, 42 wild type 3, 2 vaccine-related type 1, 5 vaccinerelated type 2, 4 vaccine-related type 3, and 10 polioviruses
pending.
In 1993, Kerala became the first state in India to conduct
statewide immunization days, targeting all children <3 years
of age on a single day, and in 1994 repeated this activity.
Kerala reported 59 cases of paralytic poliomyelitis in 1992, 80
cases in 1993, 7 cases in 1994, and 3 in 1995. The last cultureconfirmed case of paralytic poliomyelitis in Kerala was reported in July 1994.
In early 1994, Tamil Nadu became the second state to conduct statewide immunization days. Delhi, the seat of the nation's capital, became the third state, conducting statewide immunization days on 2 October 1994, Mahatma Gandhi's
birthday. Of note, Delhi authorities incorporated an extensive
social mobilization campaign, including the recruitment of hundreds of volunteers, schools, newspapers, radio, and television
networks [8]. Of the> 1 million children <3 years of age
targeted in the State, 92% received OPV.
After the success of statewide immunization days in Delhi,
Tamil Nadu, and Kerala, the central Government of India conducted its first NIDs in December 1995 and January 1996,
calling them Pulse Polio Immunization Days. More than 75
million children <3 years of age were targeted nationwide
to receive supplemental OPV. On 9 December 1995, health
authorities and volunteers immunized 87.8 million children
with OPV, of which 79.3 million (90%) were <3 years old.
Thirty-one of the 32 States and Union Territories reported firstround coverage to be >90% (Nagaland, population 1.3 million,
reported coverage of 86%). On 20 January 1996, the Government of India immunized 93.6 million children with OPV, of
which 85.4 million (90%) were <3 years old.
Bangladesh (population 120,433,000). In 1995, Bangladesh reported 108 cases of polio, an 80% decline from the 540
cases reported in 1988. In 1993, 26% (61/233) of the cases of
AFP had stool specimens collected for viral culture; of these,
28% had polioviruses isolated. Of the 17 cases with polioviruses isolated, 16 (94%) had poliovirus type 1 and 1 (6%) had
poliovirus type 2. In 1994,43% (123/289) of the cases reported
had stool specimens collected for viral culture; of these, 7%
(9/123) had polioviruses isolated. In 1994, of the cases with
S92
Andrus et al.
JID 1997; 175 (Suppl 1)
1,600 , - - - - - - - - - - - - - - - - - - - - - - - - - - - ,
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-
Figure 2. Reported cases of paralytic poliomyelitis cases by month and year of paralysis onset, India, January 1992- December 1995. Source: Ministry of Health and
Family Welfare, India.
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Jan
Feb
Mar
Apr
May Jun
Jul
Aug Sep
Oct
Nov Dec
Month of Onset of Paralysis
polioviruses isolated, 6 had type 1 isolated and 3 had type 3
isolated. In 1995, 53% (57/108) of the cases reported had stool
specimens collected for viral culture; of these, 4% (2/57) had
polioviruses isolated. Of the cases with polioviruses isolated,
both had type 1. During 1994-1995, no poliovirus type 2
isolates were reported.
In March 1995, Bangladesh became the second country in
SEAR to conduct NIDs, reaching 95% of the targeted 18.9
million children < 5 years of age in the country with at least
one dose of OPV and 83% with two doses of OPV. For the
first round, coverage ranged from being the lowest (47%) in
periurban areas of Dhaka to >90% in other cities. The input
of an evaluation conducted by independent observers during the
first round contributed to significant improvements in secondround performance 1 month later in April. In periurban areas
of Dhaka, coverage increased to 76% during the second round,
confirmed by Expanded Programme on Immunization (EPI)
cluster surveys.
Myanmar (population 46,527,000). In 1995, Myanmar reported 24 cases of polio, a 60% decline from the 60 cases
reported in 1988. In 1987, OPV3 coverage among children 1
year of age was only 10% compared with 77% reported in
1994. Concomitant with this progress has been the expansion
of the population covered by EPI and other primary care services. In 1991, 211 of 320 townships were covered by EPI
services. Over the next 2 years, the remaining 109 townships
not covered by EPI were targeted for inclusion. By 1995, only
17 townships remained not covered by some degree of
EPI services. Many of the 17 townships border the emerging
"polio-free" zones of China and Thailand.
The Government of Myanmar conducted its first NIDs on
10 February 1996 and 10 March 1996. Because China will be
conducting its third, and last, NIDs beginning in December
1995, the timing of the NIDs in Myanmar was epidemiologically critical for expanding polio-free zones of neighboring
countries. By May 1996, Myanmar will have implemented AFP
surveillance.
Nepal (population 21,918,000). In 1986,2 years before the
global polio eradication initiative was adopted, the Government
ofNepal intensified its immunization program by implementing
the Universal Childhood Immunization (UCI) project. By 1990,
coverage for OPV3 among children 1 year of age reached
almost 80%; however, coverage has gradually decreased since
then. By 1994, reported OPV3 coverage among children 1 year
of age in Nepal was 63%, similar to pre-UCI levels.
Nepal reported 9 cases of polio in 1995 and 9 cases in 1988.
Although Nepal conducts surveillance for AFP, the reported
rate per 100,000 children <5 years of age was 0.05 for 1994
(table 1). Of the 9 cases of polio reported in 1995, 6 were
culture-confirmed. Three cases were due to wild poliovirus
type 1 and 3 to wild poliovirus type 3.
Indonesia (population 197,588,000). In 1995, Indonesia
reported 12 cases of polio, a 98% decline from the 773 cases
reported in 1988. Because AFP reporting was not implemented
until 1994, estimated reporting rates of AFP through 1994 were
low (table 1). In 1993, 17% (4/24) of AFP cases had stool
specimens for virologic culture, of which 1 had poliovirus type
1 isolated. By 1995,90% (19/21) had stool specimens collected
for virologic culture; 10% (2/21) had 2 stool specimens collected within 2 weeks of paralysis onset. Of the 12 confirmed
polio cases, 2 were confirmed because of wild poliovirus type
1 isolation.
In September 1995, Indonesia became the third country to
conduct NIDs in the Region. Rather than conducting the NIDs
on a single day as was done in the Americas and more recently
in Thailand and Bangladesh, the Government of Indonesia de-
Polio Eradication in South-East Asia Region
JID 1997; 175 (Supp1 1)
cided to extend the campaign over a week (National Immunization Week). This was considered to be operationally necessary
because of the nature of the dispersed island population (inhabiting ~3000 islands). Preliminary administrative reports indicated that 85% of the nation's children <5 years of age received OPV on the first day of the campaign.
1992
1993
199.4
Gujarat
~
Karnataka
~
Figure 3. Reported cases of paralytic poliomyelitis, India, 19921994. Each dot represents 1 reported case.
893
Thailand (population 58,791,000). In 1995, Thailand reported 2 cases of polio, an 82% decline from the 11 cases
reported in 1988. From 1992 to 1995, AFP reporting rates per
100,000 persons < 15 years old in Thailand were consistently
>0.5 (table 1). In 1993, of the 161 AFP cases reported, 94%
had stool specimens collected for viral culture. In 1995, of the
118 AFP cases reported, 96% had stool specimens collected.
From 1992 to 1995, the percentage of AFP cases with at least
2 stool specimens collected within 2 weeks of paralysis onset
increased from 37% in 1992 to 55% in 1995.
Of the 11 culture-confirmed cases of poliomyelitis reported
in 1993, 5 were due to wild poliovirus type 1, 2 were due to
wild poliovirus type 2, and 4 were due to wild poliovirus type
3. No vaccine-related polioviruses were reported.
In June 1994, 1 culture-confirmed case of polio was reported
and was associated with wild poliovirus type 1. In 1994, 3
other AFP cases had poliovirus isolates-all vaccine-related
(1 each types 1, 2, and 3). In August 1994, Thailand become
the first member country in SEAR to conduct NIDs, reaching
>95% of the 6.8 million children targeted.
In 1995, 2 culture-confirmed polio cases were reported. The
first occurred in August, just before Thailand's second NIDs,
and was due to wild poliovirus type 3. Using molecular techniques similar to those developed for the polio eradication
initiative in the Americas [9, 10], the Bangkok VRI polio laboratory did genomic sequencing of the isolate to determine its
nucleotide sequence relatedness with other wild polioviruses
previously isolated in the area. This analysis revealed that the
virus had common ancestral origins with type 3 isolates from
India. Since the NIDs in August and September 1995, 1 cultureconfirmed case of polio has been reported. The case occurred
in November 1995 and was due to wild poliovirus type 1. VRI
did a similar analysis of the nucleotide sequence relatedness
with other type 1 isolates. This analysis revealed that the virus
had common ancestral origins with type 1 isolates from Laos,
Cambodia, and Thailand.
Although Laos is not a SEAR member country, the VRI
in Bangkok provides laboratory services to this neighboring
country for virologic surveillance of wild poliovirus. In 1995,
VRI reported characterizing 6 polioviruses isolated from specimens sent from Laos with dates of onset ranging from 1992
to 1995. One was wild poliovirus type 3 from a Lao case
with date of onset in 1992 and the rest were vaccine-related
polioviruses (1 each type 1 and type 2 and 3 type 3).
Sri Lanka (population 18,354,000). During 1994-1995,
Sri Lanka reported no cases of poliomyelitis compared with
16 cases reported in 1988. From 1992 to 1995, AFP reporting
rates have consistently remained> 1.0 per 100,000 persons
< 15 years old (table 1). From 1992 to 1995, the percentage
of AFP cases with 2 stools collected within 2 weeks ofparalysis
onset has dramatically increased, from 27% in 1992 to 94%
in 1995.
The last culture-confirmed case of polio occurred in November 1993 and was due to wild poliovirus type 1. From 1994 to
S94
Andrus et al.
1995, no wild polioviruses were isolated from 157 cases of
AFP investigated. In 1994, the only poliovirus isolated was
vaccine-related poliovirus type 2. In 1995, Sri Lanka reported
characterizing 14 polioviruses, all vaccine-related (4 type 1, 6
type 2, 2 type 3, and 1 mixture of type 1 and type 2).
DPR Korea (population 23,917,000). From 1988 to 1994,
DPR Korea reported no polio. In 1995, provisional data indicated that 7 cases of polio occurred in DPR Korea. In response,
DPR Korea conducted its first NIDs in April and May 1996,
achieving >90% coverage.
Bhutan (population 1,638,000) and Maldives (population
254,000). Two countries in the Region, Bhutan and Maldives,
have not reported cases of poliomyelitis for ~3 years, which
suggests that wild poliovirus transmission may have been interrupted. However, in addition to interruption of wild poliovirus
transmission for at least 3 years, certification of polio eradication requires criteria indicating adequate surveillance, which
has not been implemented in these countries [11].
Discussion
During 1988-1995, these data document substantial progress toward polio eradication in SEAR, with an 87% decline
in number of reported cases of polio. Bhutan and Maldives
have reported zero cases. Data from 1993 to 1995 also indicate
that Sri Lanka and Thailand may be close to polio eradication.
The last culture-confirmed case of polio reported from Sri
Lanka occurred in November 1993. After two NIDs, Thailand
may have only one remaining reservoir of wild poliovirus type
1. During 1994-1995, poliovirus infection caused by wild poliovirus type 2 in SEAR was not reported outside of India. By
1995, 6 of 8 countries in which polio is endemic were conducting AFP surveillance compared with 4 of 8 countries in 1993.
By May 1996, all countries in which polio is endemic, with
the exception of DPR Korea, will have implemented AFP surveillance. Both Sri Lanka and Thailand have achieved high
AFP reporting rates and percentages of reported AFP cases
that have 2 stools taken within 2 weeks of onset of paralysis
for virologic culture. By 1995, the three regional reference
laboratories were conducting intratypic differentiation of
polioviruses.
By 1995, wild poliovirus infection remained highly endemic
in 5 SEAR member countries: Bangladesh, India, Indonesia,
Myanmar, and Nepal. The subcontinent countries ofIndia, Bangladesh, Nepal, and Myanmar account for 99% of reported
cases in SEAR and 56% of the reported cases globally. To that
end, as recommended by WHO, NIDs remain a critical strategy
in eradicating transmission of wild poliovirus [1, 5]. With the
exception of Nepal, 7 of 8 countries in SEAR in which polio
is endemic will have conducted NIDs by April 1996. At the
time of this writing, Nepal planned to conduct its first NIDs
in December 1996. Of note, on 20 January 1996 (the second
round of India's first NIDs), Indian health authorities and vol-
JID 1997;175 (Suppll)
unteers immunized >93 million children with OPY, marking
the largest single-day immunization campaign ever.
In SEAR, essential strategies for mobilizing resources required
for polio eradicationhave been the formation in 1994 ofthe Technical Consultative Group on EPI-a group of international immunization experts that meets yearly to review the progress of disease
control activitiesand provide recommendations for improving strategies; the developmentof National Plans of Action for Poliomyelitis
Eradication-strategic plans prepared by all member countries that
include budget estimates for polio eradication and that are revised
annually to reflect progress toward eradication and to assist in
overcoming remaining obstacles; and the formation in 1994 of an
Interagency Coordination Committee of interested donors-a
group that meets periodically to review country plans of action to
galvanize financialsupportfrom both governmentaland nongovernmental donor agencies to cover potential shortfalls in resource requirements.
Eradication.of transmission of wild poliovirus in the Americas was largely accomplished by targeting NIDs in countries
in which polio was endemic to children < 5 years old during
the low season of transmission [1]. The Pulse Polio Immunization Days scheduled in India targeted all children <3 years
old. This decision was based on the experience of Kerala. Data
suggest that the target age of <3 years for a polio campaign
may work. Also, financial and operational concerns regarding
vaccine supply and administration resulted in the selection of
a lower age cutoff for the first year of NIDs in India, where
the size of one annual birth cohort is -25 million. However,
national data suggest that at least 18%-20% of the reported
polio cases occur in children ~3 years old. To that end, the
target age group will be increased in 1996 NIDs to include
children < 5 years old.
The major challenges confronting the polio eradication initiative in SEAR include sustaining and expanding coordination
of NIDs in all countries in which polio is endemic, ultimately
synchronizing NIDs in epidemiologic blocks of countries;
strengthening surveillance of AFP and wild poliovirus so that
the impact ofNIDs can be evaluated and ultimately polio eradication in SEAR can be certified; and using surveillance information to target remaining areas with reservoirs of wild poliovirus transmission for house-to-house immunization campaigns
with OPY.
Expanded coordination of NIDs among groups of adjoining
countries, such as was done previously in Central America, in
the Andean Region of South America, and more recently in
the 1995 NID initiative involving 18 countries of Eastern Europe, the Middle East, and central Asia [12], has been a remarkably useful global strategy. Clear-cut advantages to coordinating multicountry NIDs in contiguous epidemiologic blocks
include the following: increasing the level of national awareness and commitment of the political leaders, the general population, and the health personnel, which is further consolidated
by the development of a partnership of neighboring nations
working toward a common goal (this partnership of nations
TID 1997; 175 (Suppll)
Polio Eradication in South-East Asia Region
has the added benefit of having more global visibility and,
perhaps, of promoting global peace); achieving greater epidemiologic impact because regional immunization days cover
many more endemic areas at the same time, avoiding the risk
of reimportation of wild poliovirus from a nonparticipating
country to a participating one; increasing the likelihood that
otherwise difficult-to-reach migratory populations are fully
covered; and making the drive toward polio eradication faster,
more efficient, and less costly.
Accordingly, SEAR member countries Thailand, Myanmar,
Nepal, Bangladesh, and India and Pakistan of the Eastern Mediterranean Region were planning at this writing to synchronize
NIDs in December 1996 and January 1997. Bangladesh agrees
in principle to participate and has indicated that it will officially
endorse this activity soon.
In most SEAR member countries, AFP surveillance urgently
needs strengthening, particularly since the implementation of
NIDs has expanded so rapidly among the countries in which
polio is endemic. Underreporting of polio cases is a major
concern in countries that have reporting rates for nonpolio AFP
of < 1.0 per 100,000 persons < 15 years of age. Experience
shows that as AFP reporting improves, improvements in virologic surveillance follow, but usually not nearly to the same
degree [1, 13]. One challenge then is to link AFP and wild
poliovirus surveillance early in the program so reservoirs of
transmission by genotype of wild poliovirus can be more accurately defined. By integrating surveillance activities early in the
eradication program, the gains made by either epidemiologic or
virologic surveillance will be mutually beneficial.
To date, the expansion of virologic services, especially molecular characterization in India, has been impressive; however,
virologic surveillance in SEAR generally lags far behind what
will be required to eradicate transmission of wild poliovirus.
To eradicate polio in Latin America, which has half the population of India, a network of 8 laboratories processed, on average,
>6000 stools collected from investigations of -2000 AFP
patients and their contacts. In comparison, the SEAR Polio
Laboratory Network, consisting of 11 laboratories, processed
only 1802 specimens in 1995. There is a critical need to expand
the reporting of AFP cases so that virologic investigations,
starting with the collection of stool specimens in the field, can
be intensified.
Minimal criteria for certification of polio eradication in SEAR
require that countries demonstrate an AFP reporting rate of at
least 1.0 case of AFP per 100,000 persons < 15 years old and,
for at least 80% of the reported AFP cases, 2 stool specimens
collected within 2 weeks of paralysis onset for viral culture [11].
Achieving this level of surveillance performance will also allow
countries to target specific areas where the remaining reservoirs
of wild poliovirus transmission exist for house-to-house immunization "mop-up" campaigns, as was required in the final stages
in the polio eradication initiative of the Americas.
Enormous effort will be required to strengthen and maintain
surveillance [2, 5]; this is perhaps the greatest challenge [13].
S95
Unless it is done, huge sums of money directed to conducting
NIDs will be wasted. Because the majority of global poliomyelitis cases are reported from SEAR, the ability of SEAR member countries to strengthen integrated AFP and virologic surveillance may ultimately determine the success of the global
polio eradication initiative. Although recent progress by SEAR
member countries has been remarkable, the assessment of the
emergence of polio-free countries or of eradication of wild
poliovirus may be speculative until adequate surveillance has
been developed. Commitment, as reflected by the attitudes of
heads of state and agencies, now so amply demonstrated by
the implementation of NIDs in several SEAR member countries, must also be directed to the continued development and
expansion of integrated AFP and virologic surveillance.
To that end, in the first semester of 1996, the Danish Development Agency approved more than $11.5 million (US dollars)
and Rotary International is considering $2.7 million to
strengthen polio surveillance in India. Other governmental
agencies and governments, such as Japanese International Cooperation Agency, the United States Agency for International
Development, and Germany, are also demonstrating interest.
Efforts to galvanize additional resources in other SEAR countries must be continued.
Acknowledgments
We acknowledge the national staff of the Ministries of Health
of SEAR member countries who have dedicated their lives to
sustaining the progress of EPI. The success of polio eradication
by the year 2000 also depends on a partnership of technical, nontechnical, multilateral, governmental and nongovernmental, and
donor agencies. Although most of the total funds for poliomyelitis
eradication must be sought in individual countries, international
donor support is critical to accomplish the eradication objective.
Partners involved in substantially supporting the polio eradication
activities include UNICEF, Rotary International, bilateral agencies,
such as British Overseas Development Agency, German KFW,
Japanese International Cooperation Agency, World Bank, Australian Agency for International Development, United States Agency
for International Development, Canadian International Development Agency, Swedish International Development Agency, and
the Danish International Development Agency.
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