By Bernard Muthaka

A study by the KEMRI-Wellcome Trust says that a national programme where de-worming drugs are given to schoolchildren, in the hope that this will in time help control the worms in the larger community is unlikely to succeed.

 Kenya is part of a global initiative to deliver over 600 million doses of drugs against parasitic worms to schoolchildren, with experts expecting the benefits to spill over to the rest of the population.

In a recent study, KEMRI scientists based in Kilifi said that the infective stages targeted by such programmes have limited impact on the community. The Kenya National School-based Deworming programme was launched in 2009 and evaluation reports say it reached over 3.6 million children in 8,200 schools with deworming drugs. In addition, over 1,000 district officers and 16,000 teachers were trained during the programme.

The thinking behind school deworming programmes has been that in the long term, treatment of school children would have spill-over effects, meaning the entire community and those living near schools would benefit through what is known as the ‘herd immunity’ effect.

“While school-based programmes may have important health benefits, the community-level impact on transmission could be limited,” said the KEMRI study. 

Studies carried out prior to the programme to assess the prevalence of worm infections in school children showed that they affected about half of school children in Kenya, with those aged 13-14 years being most affected.

According to the national policy, mass deworming was selected as an important cost-effective activity that would improve the health status of the children, increase enrolment in public schools and improve academic performance.

     Cause of absenteeism

In Kenya, it is estimated that one-quartre of Kenyan student absenteeism is due to abdominal pains, which are most likely due to intestinal helminth infections.

Parasitic worms are among what are now known as neglected topical diseases, which health authorities hope to bring under control by the year 2020.  The diseases are seen as having little commercial attraction because poor countries, where the diseases prevail, cannot afford new drugs.

The World Health Organisation (WHO) has been pushing for innovative strategies to expand access to drugs for the diseases, with large drug donations from the pharmaceutical industry forming the backbone of those plans. Deworming for the soil-transmitted worms has often been targeted at school children because they are at greatest risk of morbidity and because it is cost-effective.

For instance, experts say primary schools have a much wider and deeper coverage than clinics.  Kenya has about 20,000 primary schools, four times more than clinics. The programme also takes advantage of a captive audience to link with other nutritional, health and education initiatives, thus minimising on delivery and logistic costs. 

The worms, which include hookworm, roundworm, schistosomiasis and whipworm, are prevalent among school-aged children in developing countries. They have a negative impact on education, hindering child development and school attendance.

 The parasites are transmitted through contact with or ingestion of faecal matter. This can occur if children do not have access to a latrine and instead defecate in the fields near their home or school, where they also play.

Schistosomiasis causes concern on infection

The parasitic infection that has been of most concern is schistosomiasis, which is caused by parasites found in water.

The parasites can be found either in the bladder or intestines.

People involved in subsistence farming or those who are frequently in contact with water are most at risk for schistosomiasis.

 

Occupations

Apart from people in these occupations, food handlers are also associated with spread of intestinal worms.

A study done in Nairobi last year found high presence of intestinal parasites among food handlers who possessed valid medical certificates.

The study said that limited health education in some food-handlers and lack of personal hygiene were the major causes of these infections.

Validity period

The authors suggested that the validity period of the health certificates be reduced. 

Currently the certificate is valid for six months, but the study warned that food handlers can be infected before the expiry of their medical certificates, thereby passing on infections to colleagues and clients.

This deworming programme is expected to help many families in terms of health to the children countrywide.