Assessment Of Performance And Impact Of A Two-Year Nationwide Schistosomiasis Haematobia Control Programme In Burkina Faso (2004 - 2005)
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Date
2010-08
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University of Ghana
Abstract
Schistosoma haematobium infection or schistosomiasis haematobia or urinary
schistosomiasis is the most common form of schistosomiasis affecting more than 60
million people in 46 sub-Saharan Africa countries. Symptoms and signs include chronic
pain, anaemia, inflammation, haematuria, fibrosis and calcification of the bladder and the
urinary and genital tracts, and ultimately bladder cancer. The disease is spreading as a
result of increase in irrigation and water impoundment schemes that favours colonization
by Bulinus spp. snail vectors. Treatment with praziquantel can prevent the development
of chronic morbidity and forms the basis of the WHO-recommended preventive
chemotherapy strategy for control of schistosomiasis. With this strategy, populations
groups at-risk, especially school-age children, are treated at regular intervals, at
frequencies determined by the levels of disease transmission. Treatment activities are
usually carried out in schools which provide easy access to school-age children; nonenrolled
school-age children, which can be many especially in rural areas, might however
be left untreated. Issues of costs, manpower, expertise and the vast geographical areas
have limited the implementation of disease control interventions in many countries to
either small-scale or pilot projects. Most intervention programmes have also lacked a
monitoring and evaluation framework which is key to achieving sustainability of control
programmes. Thus most studies have reported on performance and impact extrapolated
from results of small scale interventions. In 2003 the Ministry of Health of Burkina Faso
opted to implement a nation-wide intervention to cover all school-age children
irrespective of educational status, with support from the Schistosomiasis Control
Initiative-Imperial College London, and the Bill & Melinda Gates Foundation. This
decision offered the opportunity, and the subject of thesis, to investigate the performance
and impact of a nation-wide programme relying on large-scale administration of
praziquantel to control urinary schistosomiasis. A characteristic of this programme was
its coordination by the Ministry of Health and use of only local human resources for its
implementation that combined both school-based and community-based channels. The
programme targeted each child eligible for treatment within a timeframe of 12 months
during 2004-2005 in all 13 administrative regions of Burkina Faso. The present study
investigated the programme's performance in terms of coverage and costs, and measured
infection and morbidity indicators to determine its impact using both longitudinal cohorts
and cross-sectional studies. Children aged 6-14 years were randomly selected from 16
sentinel schools in four regions located in the different ecological areas of Burkina Faso
and were recruited into the longitudinal cohort at baseline, approximately six months
before treatment. Infection indicators such as prevalence, intensity of infection and the
proportion of heavy-intensity infections, as well as morbidity indicators such as
haemoglobin concentration, anaemia status, microhaematuria and nutritional indexes,
were all measured using recommended protocols. The study also measured these
indicators cross-sectionally in newly enrolled children one year post-treatment to assess
the quality of the community-based delivery channel and in school children randomly
selected and matched by age and sex to those in the cohort in the second year, to validate
the results obtained for the longitudinal study. A total of 3,322,564 school-age children
were treated which was equivalent to a coverage of90.8% of the eligible population.
39.9% of the children were treated through schools whilst the majority, 60.1 %, through
the community delivery channel. The total costs of the programme amounted to
US$ 1,067,284, made up of delivery cost (US$ 325,936) and drug costs (US$ 741,348).
The delivery cost per child treated was US$ 0.098 and the full cost of treating each child
was US$ 0.32l.
Out of 1,727 children recruited in the original baseline longitudinal cohort, 1,131 and 763
were followed up in the first and second years respectively, thus 596 and 368 respectively
dropped out. Children that dropped out in the first year were mostly males (P<0.004),
older (P<O.OOl), more wasted (P<O.OOl) and more stunted (P<O.OOl) than those who
remained in the cohort. The parasitological parameters however did not differ
significantly between the two groups. Similarly, there were more male (P<0.05) and older
(P<0.01) children among the drop outs of the second follow-up. A significant increase in
Hb concentration from 109.7g/l at baseline to 112.5g/l, and a reduction in prevalence of
from 65.8% to 61.6%, were observed. Absence of haem aturi a increased from 50.4% to
89.5%. No significant changes were observed with nutritional indicators (wasting and
stunting). The prevalence of infection decreased significantly from 59.6% to 6.2% at the
first follow up and increased to 7.7% in the second year. Similarly the mean intensity of
infection decreased from 94.2 eggsllOml to 1.0 eggsllOml and increased to 6.8 eggsllOml
at the first and second follow-up respectively. The proportion of heavy-intensity
infections was reduced from 25% to 0.4% after year one and remained below 2% at the
end of the second year. A significant reduction of infection indicators 1 and 2 years posttreatment
was also registered by the two cross-sectional study components.
A combined school- and community-based drug distribution strategy was effective in
attaining high coverage rates of all school-age children in communities, and inclusion of
the community component did not significantly increase the budget. Drug costs were
significant and fluctuations in cost of praziquantel might have a significant impact on
overall costs of the intervention. The analysis of the recurrent costs suggests that delivery
costs are expected to decrease further with each subsequent round of treatment. A
calendar of retreatment with single administration of praziquantel every two years or
more would be sufficient to control morbidity associated with urinary schistosomiasis,
but will require further research. For sustainable intervention programmes, savings from
the reduction in treatment frequency should be invested into strengthening the monitoring
and evaluation of programme, which is usually not accorded the needed importance. This
would allow for fine-tuning of the intervention strategies as programme implementation
progresses. The monitoring and evaluation should be mainly based on cross-sectional
surveys conducted at biennial intervals and include all children irrespective of
educational status, with the aim of verifying that children in both school and communities
have actually been targeted by the disease control intervention.
Description
Thesis (PhD)
Keywords
Schistosomiasis Haematobia, Burkina Faso