JSTOR

Outbreak Report

In 2003, a 42 year‐old man was hospitalized with multiple organ failure in the 4‐bed MICU. He received a diagnosis of classic scabies on admission but was not given treatment. He died 4 days later. There were 36 healthcare workers (HCWs) who worked in the MICU and 10 patients who stayed in the MICU during this period. During the following 2 weeks, 3 nurses reported the development of pruritus, and active scabies surveillance was initiated. Of the 36 HCWs, 23 (63.9%) had symptoms (ie, pruritus) and/or signs (ie, papules). We obtained scrapings from suspicious scabietic papules from 22 HCWs, to look for mites and/or eggs; microscopy showed that 5 (22.7%) of 22 HCWs had scabies. The first symptoms and/or signs of scabies in HCWs were reported by nurses, followed by technicians and physicians. Of the 10 patients who were in the MICU during the index patient's 4‐day stay, 7 were evaluated; 3 of them had symptoms and/or signs of scabies, and 1 had a skin scraping that was positive for scabies. Nineteen (82.6%) of 23 HCWs and 7 (70%) of 10 patients with symptoms and/or signs received 1 dose of oral ivermectin (200μg/kg). Also, we requested that clothing, bedding, and room furniture be disinfected, both at the hospital and at HCWs’ homes. Items that could not be washed were stored in plastic bags for 5 days.

One week later, all HCWs were evaluated. Two nurses had new lesions, and they received another dose of ivermectin. One of the patients also had new skin lesions and a positive skin test result; this patient also received another dose of ivermectin. On evaluation 1 week later, no new lesions were detected on this patient. After the day of the initial evaluation and treatment, 2 additional HCWs reported symptoms and/or signs. They received the same treatment with ivermectin. One month later, no HCWs reported complaints related to scabies. None of the patients were evaluated further at this time. No cases suspected to be scabies were later reported by the HCWs.

Discussion

Scabies outbreaks are common in long‐term and acute care facilities and nursing homes around the world.^1‐3 However, particular circumstances contributed to this outbreak. First, the index patient did not receive proper treatment, although he received a diagnosis of scabies on admission. Second, infection control programs have not been implemented in Peruvian public hospitals. Infection control programs either do not exist or are not well implemented in 90% of Latin American hospitals⁵; this situation does not permit the implementation of measures to prevent most nosocomial infections, including scabies.

Another issue to consider with respect to this outbreak is that pruritus was reported by HCWs relatively soon after contact with the index patient. Scabies has been described as having a long incubation period, and symptoms usually start 3‐4 weeks after infestation.⁶ However, based on our findings, we should consider the possibility of scabies exposure for HCWs even if it has been less than 3 weeks since their contact with the possible index patient(s).

With respect to the medical management of scabies, oral ivermectin therapy was used to control this outbreak. The standard treatment for classic scabies consists of 5% permethrin cream left on overnight and repeated once per week for 1‐2 weeks. Benzene hexachloride and benzyl‐benzoate solution can also be used.⁷ However, oral ivermectin is easier to use, and, at least in Peru, it is cheaper than permethrin. Ivermectin is the only oral treatment for scabies, but it has not been approved for this use by the US Food and Drug Administration.⁸ However, lack of approval by the Food and Drug Administration does not mean that ivermectin is not an effective treatment for scabies. In addition, on the basis of its use of to treat microfilarial diseases in millions of people, ivermectin is considered a safe drug that rarely has adverse effects.⁹ Initial reports associated the use of ivermectin with an increased mortality rate in elderly people, but this linkage was not found in subsequent studies.^10,11

In conclusion, hospital patients with scabies should be promptly identified and treated, particularly in hospitals without an infection control program. Additionally, ivermectin offers major advantages for the management of institutional scabies outbreaks, compared with other topical agents.