Why polio is so hard to eliminate
DAKAR, 31 January 2012 (IRIN) - Poor-quality emergency immunization campaigns and low routine polio immunization coverage are helping the polio virus to spread in Chad, with 132 cases reported in 2011 - five times the number in 2010. More commitment is needed across the board, especially from local health authorities, to try to get immunizations right, say aid agencies.
The current outbreak in Chad has been ongoing since 2007, classifying Chad as a "re-established transmission zone" according to the World Health Organization (WHO). [ http://www.polioeradication.org/Dataandmonitoring/Poliothisweek.aspx ] Polio is endemic in Nigeria, Pakistan, India and Afghanistan - in other words, transmission of the disease in these places has never been broken.
While a dysfunctional health system is linked to poor routine immunization coverage, "the primary reason [for the upsurge] is operational," said Oliver Rosenbauer, spokesperson for the Global Polio Eradication Initiative at WHO in Geneva. "It is not to do with insecurity or lack of infrastructure. The outbreak response has not been sufficient to stop it [the outbreak]. They continue to miss too many children."
Why children missed
Immunizers have missed children for a variety of reasons: In some cases government and agency staff or volunteers inaccurately mapped out where they lived; or may have ordered too few vaccines or too few ice packs to cover each district, said WHO. Often communities are not well-sensitized in advance so families remain reluctant to bring their children forward, some resist on religious grounds, or they simply may not know that they can immunize a child even if he or she is sick, said WHO and UNICEF's West Africa communication for development specialist Irina Dincu.
Human error also plays a role, added Dincu, explaining that an ill-trained vaccinator may rest en route, breaking the cold chain, or a team may miss a few houses in a village.
An outbreak of the polio virus would not spread so far if routine polio immunization coverage was better, said Rosenbauer. Polio immunizations are rigorous to administer: vaccinators must go house-to-house, and must give each child four doses over a 6-12 month period, reaching 90 percent of all children to eliminate polio, according to WHO.
Coverage rates are estimated to be 60 percent at most in Chad, partly due to a poor-quality health system: Just 30 percent of health clinics are operational across the country; access to health care is poor; and routine immunization strategies are poorly planned.
The godmother approach
To ensure fewer children are missed, immunizers need to make better use of "social data" to find out why and where a campaign is not working, says Dincu. Agencies used to take a purely medicalized approach to polio immunization but this has now changed. "Immunization campaigns are not just a medical intervention. You need to address campaigns from a medical, political and societal angle," said Rosenbauer.
Social data has been used creatively in India and Nigeria to help vaccinators reach more children, according to UNICEF. In Nigeria's Kebbi State households were assigned "godmothers" who came regularly pre-immunization day to discuss the disease and why vaccination was important. When poring over the data afterwards to find missed children, the "godmothers" could identify them by place, name and age, making them much easier to re-trace.
These are the kinds of approaches that could be adopted in Chad, say practitioners, where despite its weak health system, polio should not be too challenging to control, says Rosenbauer. "We don't face the same high-population challenges that we do in Nigeria, or insecurity as is the case of Afghanistan and Sudan. Here it is more a question of political and societal will."
In his view, polio could be eliminated in six months if the government committed to doing so at all levels.
International efforts to combat polio are mounting: the Centers for Disease Control (CDC) [ http://www.cdc.gov/ ] has established an Africa-based emergency operations centre which will tackle public health crises, including polio.
Meanwhile, the Polio Eradication Initiative - made up of WHO, UNICEF, CDC, the Bill and Melinda Gates Foundation and the Rotary Foundation - has designated polio a "programmatic public health emergency" until eradication is achieved.
The Chadian government appears to be taking polio seriously: President Idriss Déby has emphasized the importance of fighting it, and catalyzed the development of a six-month polio emergency action plan (which will then be renewed for a further six months). This includes targeting high-risk areas and analyzing what is and is not working.
But commitment at the district and sub-district level in some parts of the country is weak, say aid agency staff. National authorities need to hold "sub-national" staff accountable for their performance, said Rosenbauer. "The virus doesn't respect district boundaries so we need high commitment in every single one," he told IRIN.
IRIN could not reach anyone in the Health Ministry for an interview.
Without local-level government commitment, elimination efforts will fail, says Rosenbauer. The number of cases in Nigeria rose from 21 to 57 between 2010 and 2011 partly due to local authorities focusing on presidential elections; while election-related violence also distracted from efforts to quash 36 cases that broke out in Côte d'Ivoire in 2011.
And until polio is eliminated in Nigeria and in Chad, all West African countries are at high-risk, according to WHO. "There are immunization gaps in many countries - it can strike in the most unexpected places. that is why it is such a dangerous disease."