Tungíase: doença negligenciada causando patologia grave

Tropical Medicine and International Health volume 15 no 7 pp 856–864 july 2010
L. Ariza et al. Rapid community assessment of tungiasis
(a)
60
True prevalence (%)
50
40
30
20
10
(b)
15
True severe prevalence (%)
12
0 0 10 20 30 40 50
9
6
3
0 0
y = 1.12x + 5.0
R 2 = 0.96
P < 0.0001
Prevalence on periungueal sites of any foot (%)
y = 0.24x – 3.4
R 2 = 0.76
P = 0.001
10 20 30 40 50
Prevalence on periungueal sites of any foot (%)
Figure 3 Linear regression analysis for estimating prevalence of
tungiasis (a) and of severe tungiasis (>20 lesions; b).
Disease (Heukelbach et al. 2001; Franck et al. 2003;
Heukelbach & Feldmeier 2004; Heukelbach &
Ugbomoiko 2007b; Feldmeier & Heukelbach 2009). It
occurs in many resource-poor communities in endemic
countries and causes considerable morbidity and loss of
quality of life, widely unnoticed by policy makers, the
pharmaceutical industry and health professionals (Feldmeier
et al. 2003; Heukelbach 2005; Joseph et al. 2006;
Heukelbach & Ugbomoiko 2007b; Ugbomoiko et al.
2007). Despite its obvious importance as a public health
problem, data on disease occurrence in endemic communities
and reliable data on the geographical distribution of
tungiasis are not available. As a consequence, control of
tungiasis has rarely been attempted (Heukelbach et al.
2001; Pilger et al. 2008).
Our data show that identification of tungiasis on
periungual areas of the feet can be used to estimate
prevalence of tungiasis and of severe disease in culturally
and geographically distinct communities in South America
and West Africa. The method is cheap, reliable and can be
rapidly applied, with minimal disturbance of affected
individuals. The assessment can be performed by para-
medical workers or community members, as diagnosis of
tungiasis can easily be performed by lay personnel living in
endemic areas (Heukelbach 2005). In fact, in endemic
areas, locals commonly affected by the disease diagnose
tungiasis usually with a higher degree of certainty than
health professionals (Heukelbach 2004).
The method is an alternative to time-consuming and
sophisticated analyses for the precise assessment of morbidity
used in a previous study on tungiasis (Kehr et al.
2007). As the number of lesions and morbidity are closely
co-related (Kehr et al. 2007), the estimation of prevalence
of individuals with more than 20 lesions indicates the
occurrence of severe morbidity in a community. However,
in our study, the strength of association was lower for the
estimation of prevalence of severe tungiasis than for the
overall prevalence. The rapid estimation method for severe
tungiasis cannot be applied in the case of low prevalence of
tungiasis at periungual sites, as in this case severe disease is
rarely observed in a community.
The delimitation of tungiasis-endemic areas based on
valid data is essential to highlight the epidemiological
situation in a country or region. It is also a prerequisite for
disease control at the population level. Thus, the rapid
epidemiologic assessment method proposed fills these gaps
in endemic areas.
In fact, rapid assessment tools were developed for the
diagnosis of lymphatic filariasis with similar objectives: to
determine the distribution of disease, identify high risk
communities, and raise the attention of health policy
makers (Gyapong et al. 1996, 1998a, b). As a result, about
a decade later the ‘Global Programme to Eliminate
Lymphatic Filariasis’ was implemented in collaboration
with WHO. On the other hand, rapid assessment methods
established for schistosomiasis and onchocerciasis were
required to plan and monitor mass interventions programmes
(WHO 1993, 1995; Red Urine Study Group
1995). In general, all rapid approaches provide valid data
quickly (Gyapong et al. 1996; Macintyre 1999). We
believe that our rapid assessment method for tungiasis will
be similarly helpful in launching, planning and monitoring
community control measures against the disease.
Rapid methods for other parasitic diseases, for example,
for schistosomiasis, onchocerciasis and lymphatic filariasis,
rely on the presence of indirect clinical or laboratory
markers (Lengeler et al. 1991; Ngoumou et al. 1994;
Gyapong et al. 1996; Kipp & Bamhuhiiga 2002; French
et al. 2007; Weerasooriya et al. 2008; Ugbomoiko et al.
2009). However, the objective of our study was not to use
an indirect marker for prediction of disease in an individual.
The proposed rapid assessment for tungiasis was based
on direct identification of the parasite as diagnosis of
tungiasis in an individual is easy to perform by clinical
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