Tungíase: doença negligenciada causando patologia grave

JAM ACAD DERMATOL
VOLUME 60, NUMBER 3
Table II. Cont’d
area can be considered representative for other
impoverished rural communities in the Brazilian
backlands. Housing is rather poor, income is generally
low, illiteracy is frequent, and social attitudes
and behavior facilitate the transmission of S scabiei.
In Feliz Deserto, scabies was mainly a disease of
children younger than 4 years, who accounted for
almost 30% of all cases diagnosed during the two
surveys. In Brazil, children of this age group usually
wear only diapers, slips, or shorts, independent of
their sex. They have frequent body contacts with
other children during playing and sleeping, and with
older siblings, their mothers, and other women, who
carry around babies and toddlers during the day.
In children aged between 10 and 14 years the
infestation was also very common, with the prevalence
ranging between 9.3% and 16.4%, according to
sex and season. Young age remained a significant
independent risk factor for the presence of scabies
and severe disease in the multivariate regression
analysis. Previous studies in resource-poor settings
also found that children are the most vulnerable
population group. 1,2,4,5,7,9,31
The overall prevalence did not vary between the
surveys, although 102 individuals with scabies were
treated in the first survey. We, therefore, cannot
exclude that without treatment the prevalence would
have been higher in the dry season. However, a clear
seasonal variation has not been detected. This corroborates
findings from other tropical areas, 9,20 but is
in contrast to observations made in industrialized
countries with a cold or moderate climate or developing
countries with a rather cold and dry winter
such as Malawi or Turkey. 4,21,29,43-46 Obviously, in
the hot climate of Northeast Brazil reduced off-host
viability of mites because of high environmental
temperatures does not impede continued
Presence of scabies (n = 151) Presence of severe scabies y (n = 68)
Exposure variable Examined n* Positive n (%) OR (95% CI) P value Positive n (%) OR (95% CI) P value
Sharing towel with others
Yes 532 85 (16.0) 1.60 (1.11-2.32) .01 44 (8.3) 2.03 (1.33-4.09) .001
No 585 62 (10.6) Ref. 22 (3.8) Ref.
Taking shower regularly
No 690 103 (14.9) 1.53 (1.04-2.28) .03 51 (7.4) 2.19 (1.19-4.25) .009
Yes 427 44 (10.3) Ref. 15 (3.5) Ref.
Using soap regularly
No 21 3 (14.3) 1.10 (0.21-3.84) .75 1 (4.8) 0.79 (0.02-5.12) 1.00
Yes 1096 144 (13.1) Ref. 65 (5.9) Ref.
CI, Confidence interval; OR, odds ratio; Ref., reference; WC, water closet.
*Data were not available in all cases.
y Individuals with $ 12 topographic areas affected.
z R$1 US$0.53.
Feldmeier et al 441
transmission throughout the year. 47,48 We suggest
that in impoverished communities in the tropics
reduced off-host viability of mites is compensated
by intense exposure through prolonged and intimate
body contact. In these settings, major parts of the
body are not covered with clothes during day and
night, irrespective of whether it is dry or raining, as
air temperature remains more or less stable. Babies
and small children are carried around on the hip by
their mothers and older girls for several hours during
the day. This should facilitate the transmission of
mites from person to person. 49
The high degree of transmission occurring within
households is best demonstrated by the fact that
individuals who had lived in the community for more
than 6 months had 3.6-fold higher odds for a diagnosis
of scabieseand a 4.2-fold higher odds for the
presence of severe scabieseas compared with individuals
who had recently arrived. In a study in rural
India an almost linear increase in the occurrence of
scabies with increasing household size was observed.
2 However, crowding (defined as [4 individuals/household)
was not associated with the
presence of scabies in this study. This suggests that
the risk of acquiring scabies in the household is not
directly linked to the number of persons living in that
household.
Illiteracy of adult household members was a very
good predictor for the presence of scabies and
severe disease, and remained a significant risk factor
in the multivariate regression analysis (odds ratio 2.8
and 3.2, respectively) (Table III). A low level of
education has been identified as a risk factor for
scabies in developing and industrialized countries.
20,50 Because illiteracy usually goes along with
a low socioeconomic status, the inability to read and
write can be taken as a proxy for poor living