Prevention of tungiasis and tungiasis-associated morbidity using the plant-based repellent Zanzarin: a randomized, controlled field study in rural Madagascar.
BACKGROUND
Tungiasis, a parasitic skin disease caused by the female sand flea Tunga penetrans, is a prevalent condition in impoverished communities in the tropics. In this setting, the ectoparasitosis is associated with important morbidity. It causes disfigurement and mutilation of the feet. Feasible and effective treatment is not available. So far prevention is the only means to control tungiasis-associated morbidity.


METHODS
In two villages in Central Madagascar, we assessed the efficacy of the availability of closed shoes and the twice-daily application of a plant-based repellent active against sand fleas (Zanzarin) in comparison to a control group without intervention. The study population was randomized into three groups: shoe group, repellent group and control group and monitored for ten weeks. The intensity of infestation, the attack rate and the severity of tungiasis-associated morbidity were assessed every two weeks.


RESULTS
In the repellent group, the median attack rate became zero already after two weeks. The intensity of the infestation decreased constantly during the observation period and tungiasis-associated morbidity was lowered to an insignificant level. In the shoe group, only a marginal decrease in the intensity of infestation and in the attack rate was observed. At week 10, the intensity of infestation, the attack rate and the severity score for acute tungiasis remained significantly higher in the shoe group than in the repellent group. Per protocol analysis showed that the protective effect of shoes was closely related to the regularity with which shoes were worn.


CONCLUSIONS
Although shoes were requested by the villagers and wearing shoes was encouraged by the investigators at the beginning of the study, the availability of shoes only marginally influenced the attack rate of female sand fleas. The twice-daily application of a plant-based repellent active against sand fleas reduced the attack to zero and lowered tungiasis-associated morbidity to an insignificant level.
Institute of Microbiology and Hygiene, Campus Benjamin Franklin, Charité University Medicine, Berlin, Germany.
Marlene
M
Thielecke
Vaomalala
V
Raharimanga
Christophe
C
Rogier
Manuela
M
Stauss-Grabo
Vincent
V
Richard
Hermann
H
Feldmeier
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007302:Insect Repellents / Q000627:therapeutic use*; D008270:Madagascar / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D010205:Pantothenic Acid / Q000031:analogs & derivatives* / Q000627:therapeutic use; D010936:Plant Extracts / Q000627:therapeutic use*; D010938:Plant Oils / Q000627:therapeutic use*; D015995:Prevalence; D012424:Rural Population; D012720:Severity of Illness Index; D016896:Treatment Outcome; D058253:Tunga / Q000187:drug effects*; D058285:Tungiasis / Q000453:epidemiology / Q000473:pathology / Q000517:prevention & control*; D055815:Young Adult
D007302:Insect Repellents; D010936:Plant Extracts; D010938:Plant Oils; C487210:zanzarin; D010205:Pantothenic Acid