Epidemiological profi le of leprosy in children under 15 in Manaus ( Northern Brazil ) , 1998 – 2005

OBJECTIVE: To describe the epidemiological status of leprosy in children living in a metropolitan area. METHODS: There were studied 474 leprosy cases detected in children under 15 living in the metropolitan area of the city of Manaus, Northern Brazil, between 1998 and 2005. The endemic profi le and quality of care services were assessed based on data from the Notifi able Diseases Information System using epidemiological and operational indicators of the National Leprosy Elimination Program. RESULTS: Of all leprosy cases detected in the period studied, 10.4% were found in children under 15. The detection rates in this age group remained at hyperendemic levels between 1998 and 2003, and decreased from 2004 onwards but keeping on very high endemic levels. The most common clinical form was tuberculoid followed by dimorphous. Paucibacillary forms were seen in 70.7% of the cases. The level of disability at the time of diagnosis was assessed in 94.7% of patients and 2.9% of them had physical disabilities. Most children (99.4%) were treated with the multiple drug regimen recommended by theWorld Health Organization. CONCLUSIONS: Despite its decrease, detection rate of leprosy in children in the city of Manaus remains at a very high endemic level. DESCRIPTORS: Leprosy, epidemiology. Child. Adolescent. Endemic Diseases. Disease Notifi cation.


INTRODUCTION
Leprosy remains a public health concern in Brazil, the sole country in Latin America that has not attained the goal of eliminating the disease, i.e., reducing the prevalence rate to less than one case in every 10,000 inhabitants.From 1998 to 2005, the prevalence rate a in Brazil fell from 4.93/10,000 (1998) to 1.48 (2005) a but detection rate, which is an indicator of disease transmissibility, has remained at very high endemic levels (2.16/10,000 in 1998 and 2.09/10,000 in 2005).
The Brazilian National Program for Leprosy Elimination has developed together with state focal points a working plan for the year 2005.The program was intended to strengthen strategies for endemic elimination.The priority intervention a Brazilian Ministry of Heatlh.Situação epidemiológica da hanseníase no Brasil.Brasília; 2007.
[cited 2007 Apr 13].Available at: http://portal.saude.gov.br/portal/arquivos/pdf/situacao_hansen_2007.pdffocused on state capitals and cities reporting at least 50 cases in treatment in December 2003 as well as all cities that diagnosed on average 10 multibacillary cases and two cases in children under 15 over the last fi ve years.Manaus, the Amazon state capital, met all priority criteria for program actions with a very high detection rate a in children under 15, which accounted for most cases reported statewide during the period studied.
Leprosy in children can be an indicator of disease prevalence in the general population and its detection helps determining the disease transmissibility. 2,9Due to its long incubation period, leprosy characteristically occurs in adults but children can also be susceptible.Hence, they are at higher risk of developing the disease when living in endemic areas and when exposed to family contacts. 5,9,11 2005, the detection rate of leprosy in Brazilian children under 15 was 0.60/10,000.b During that same year, a hyperendemic rate b of 1.62/10,000 was seen in the Northern region, of 0.66/10,000 in the state of Amazonas c and of 0.53/10,000 in the city of Manaus.They all indicated very high endemic levels.
Ongoing high endemic levels of leprosy suggest children can be exposed to cases that go undetected in the health system.d With the purpose of providing input for disease control actions, the present study assessed the epidemiological status of leprosy in children living in a metropolitan area.

METHODS
This study is part of a larger research study, "Detection of leprosy cases in the city of Manaus through a geoprocessing approach," developed by Leônidas

RESULTS
Of 4,541 cases of leprosy detected during the study period, 474 (10.4%) were 0 to 14 years old.Table 1 displays the distribution of cases by age group and gender.It also shows tuberculoid was the most common clinical form of leprosy (50.2% of cases), followed by dimorphous, indeterminate, and lepromatous; and paucibacillary forms predominated (70.7%).Bacilloscopic examination was performed in 387 patients (81.6%) and a negative result was seen in 316 of them (66.7%).
The comparison of number of cases and detection rates (Table 2) show a reduction but remaining at hyperendemic levels between 1998 and 2003 and then falling to very high levels from 2004 onwards.Physical disability at the time of diagnosis was assessed in 94.7% of patients (Table 3 The number of lesions was not unknown in 63.1% of cases; 14.1% did not have any lesions; 19.6% had one to fi ve lesions and 3.2% had more than fi ve. Most cases (64.3%) were detected through spontaneous reporting, followed by referral (14.1%), contacts testing (12.7%) and global testing (3.2%).
Only 24.2% of patients had at least one contact examined and 71.3% had no contacts examined; and this information was missing in 4.6% of cases.
The proportion of new cases receiving the World Health Organization (WHO)-recommended multiple drug regimen was 99.4%.For the remaining, no information was available on treatment.
During the period studied, 441 patients ended their medical follow-up; 87.8% of them due to cure.Table 4 shows the main reasons for ending follow-up.Of those ending follow-up due to cure, 93.2% were assessed for physical disability: 3.0% of cured paucibacillary patients had physical disability compared to 7.3% of multibacillary patients.

DISCUSSION
Corroborating other studies, 3 the majority of children affected (64.8%) were between ten to 14 years of age, which could be explained by the long incubation period of leprosy. 11However, the number of children affected aged one to nine refl ects their early exposure to bacillipherous cases.
The literature 10,a describes higher prevalence of leprosy among male adults and the risk of exposure is a determinant for this gender difference.Among children, there is no gender difference, 11 although the present study found a slightly higher proportion of cases among males (50.2%).
The tuberculoid form was the most common clinical presentation, followed by dimorphous, indeterminate  and lepromatous, which corroborates other studies, 7,8 although in children paucibacillary forms (indeterminate and tuberculoid) are expected to be the most frequent ones due to the incubation period.
The indeterminate form is the early presentation of leprosy and it may progress to either spontaneous cure or polarized forms. 12In the present study, it was found a lower rate of indeterminate forms compared to polarized ones, which may suggest that the disease is not being diagnosed at its early stages.
The predominance of non-contagious forms is most often reported among children, 5,11 but multibacillary forms have also been detected in endemic areas. 11During the period studied, fi ve cases with dimorphous forms and two cases with lepromatous forms were reported in children aged one to four as well as 32 dimorphous and fi ve lepromatous cases in children aged fi ve to nine.The literature shows that the diagnosis of leprosy is usually made after the age of three. 5,11In the present study the two lepromatous cases in children aged one to four were seen in two-year-old and three-year-old children and the youngest case was found in an one-year-old child with an indeterminate form.
The predominance of paucibacillary forms may indicate that the actions for early diagnosis have been effective.
Spontaneous reporting is the main method of detection, followed by case referral, which may indicate that active search and contacts examination have not been implemented as recommended.This assumption is supported by the high number of cases with no contacts assessed (71.3%).But one should also bear in mind that missing information, such as underreporting of actions taken, can also have occurred.
According According to the Brazilian Ministry of Health variables, a the proportion of cured cases that were assessed for disability was adequate, with a low proportion of paucibacillary case with physical disability.Yet the proportion of multibacillary cured cases with disability (7.3%) was fair.This indicator suggests a need for disability prevention and rehabilitation after follow-up, despite the good quality of services and early diagnosis found in Manaus.
Another indicator that measures quality of care is the proportion of new cases receiving the WHO-recommended multiple drug regimen.Based on the current Leprosy Control Program criterion, it is defi ned as adequate when the number of patients receiving this protocol is equal to or greater than 98%.Thus, the fi nding of 99.4% of patients on this protocol shows full compliance with the recommended treatment.
In conclusion, despite a reduction seen over the period studied, detection rates remain at very high endemic levels among children in Manaus.Based on the indicators studied, quality of care and case detection at health services can be considered adequate.
Prevention and control actions should be taken to detect and treat cases as early as possible because children are very responsive to intervention at the early stages of disease. 9 by clinical form according to the Madrid classifi cation; (e) proportion of cases with bacilloscopic examination; (f) proportion of new cases with physical disability (level I -reduction or loss of sensation in both eyes, hands and/or feet; level II -disabilities or deformities in both eyes, hands and/or feet) assessed at the time of diagnosis; (g) proportion of cases with physical disability among new cases detected and assessed during the period study; (h) proportion of cured cases with physical disability assessed; (i) proportion of cured cases with physical disabilities (paucibacillary and multibacillary); and (j) proportion of new cases receiving the multiple drug regimen.EPI-Info program version 3.3.2was used for handling, management and analyses of data.

Table 3 .
Assessment of disability by age group at the time of diagnosis and end of follow-up in children under 15.Manaus, NorthernBrazil, 1998-2004.
Source: National System of Disease Notifi cation (SINAN) -State database.

Table 2 .
Leprosy cases in children under 15 and detection rates in the State of Amazonas and in the city of Manaus, NorthernBrazil, 1998-2004.
4,6Costa & Patrus, 4 the fi nding of disabilities at the time of diagnosis may indicate that diagnosis is being made late in the disease course as they tend to have a late development, and suggests ineffective leprosy control.Amador et al (2001)1argue that leprosy in children under fi ve can be potentially incapacitating due to its very early onset and higher risk of deformities but severe disabilities are uncommon in children.The proportion of children assessed for disability at the time of diagnosis is an indicator of the quality of services provided.In the city of Manaus, the quality was adequate according to the Leprosy Control Program criteria.aAsthe proportion of disabilities found (2.9%) was low, both these fi ndings may indicate that early diagnosis is being made.Though this proportion is not as high as in other studies,4,6disabilities are recognizably major factors of stigma associated with leprosy and they may impair children's social life and psychological development.

Table 4 .
Reasons for the end of follow-up of leprosy cases in children under 15 by age group.Manaus, NorthernBrazil,  1998 -2004.