[Analysis of the monthly incidence of cutaneous leishmaniasis in Ceará (Brazil) between 1986 and 1990].
To determine the value of an epidemiological surveillance system, we evaluated the incidence rate and trends of American Cutaneous Leishmaniasis (ACL) in three health districts of Ceara state, Brazil. We used a retrospective time series analysis of ACL notifications in Ceara state between 1986 and 1990. The trend of this endemic/epidemic disease was analysed by using three types of modeling on the moving average graph: a linear, linear periodic and non linear periodic model. The study samples consisted of the 14,615 cases of ACL notified in Ceara state between 1986 and 1990. Males accounted for 54% of cases. Age was between 1 month and 19 years in 42% of cases. Most cases (81%) were diagnosed on clinical grounds only. After calculation of the moving average and application of a linear regression model to these means, the trend analysis revealed that 1) there was a significant trend towards an increase in two of the three health districts, with correlation coefficients of 0.31 and 0.49 (Student's t test = 2.24 and 3.88) and a significant trend towards a decrease in the remaining district (correlation coefficient = 0.51, t = 4.1). The linear periodic model showed a cyclic representation with a 36-month period and a base of 241. The non linear periodic model showed a cycle of 32 months and a base of 241, and was a better representation of the disease variations. Despite the limited study period, it appears that the 32-month cycle could be attributed to meteorological conditions. Field studies are underway to determine the precise causes of this periodicity.
Broutet
N
N
Hôpital Sao-José des maladies infectieuses, Fortaleza, Brésil.
Ingrand
P
P
Sousa
A de Q
Ade Q
Chabaud
F
F
Lima
J W
JW
D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001938:Brazil / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D016773:Leishmaniasis, Cutaneous / Q000453:epidemiology*; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D010507:Periodicity; D011159:Population Surveillance; D012189:Retrospective Studies; D014329:Tropical Climate
Analyse de l'incidence mensuelle de la leishmaniose tégumentaire dans le Ceará (Brésil) entre 1986 et 1990.