In 1983-1984, in India, the prevalence of people with scabies was 4.7%. Today it is 40%.
Results showed that unsupervised home self-treatment was unsatisfactory, i.e. not done properly. So they devised an community project, Operation Dunking, where they compared the efficacy of treatment in two groups.
all members of a family were treated at one time. Each member of the family, including the index case, was examined by a doctor and the skin lesions were recorded on a chart. The patient was then made to take a bath with soap and water at the centre, and finally made to squat completely naked in 10% aqueous benzyl benzoate emulsion contained in an R.C.C. or a syntex tank. The tank measured 1 m x 1 m x 1 m and contained about 30 litres of 10% aqueous benzyl benzoate emulsion. Care was taken to see that the hips and the perineal area were immersed in the emulsion. The R.C.C. tank was fixed in the Health Centre whereas the syntex tanks were movable. While squatting in the tank, the patient scrubbed areas of skin lesions with a gauze piece to break open the lesions. The patient also smeared the emulsion all over the body. He/she then stood outside the tank to allow the body to dry. He/she then wore his/her clothes and was instructed not to remove them for the next 24 hours. The entire operation was supervised by the clinic staff, a male in the case of male patients and a female in the case of female patients.
The same emulsion was used over and over again; about 100 litres were required for 500 patients. No other treatment such as an antipruritic agent or an antibiotic was used in these patients.
In Group II, the patient was advised to bring all the family members to the hospital for treatment. Each infected person was given 300 ml of a 25% aqueous benzyl benzoate emulsion for three applications at home. Those with a bacterial infection were given an antibiotic in addition.
The patient was labelled as cured if all the skin lesions disappeared at the end of a week, as partially cured if 50% or more lesions disappeared; and as a failure if fewer than 50% lesions disappeared. A second treatment was given to failures as well as to those whose itching persisted beyond 7 days after the first treatment.
Results and concusions of the experiment:
The conventional treatment was found to be roughly 8 times as costly as the dip treatment, and just as effective, including repeats if it was necessary.
The same “Operation Dunking” described by a lay-person: