An outbreak of Norwegian scabies in a surgical ward

An outbreak of Norwegian scabies in a surgical ward of a teaching hospital was reported. The source of infestation was an elderly diabetic. The epidemic involved 28 of 32 medical personnel in the ward and 3 family contacts. All infected individuals were given a two-course treatment with hexachlorcyclohexane gel. Control of the outbreak was achieved by strict handwashing after patient contact, application of gowns and gloves for contact with skin lesions and the treatment of infected persons. Norwegian scabies in institutions is on the rise, vigilance for its occurrence is needed.

Resistance and immune response in scabies-infested hosts immunized with Dermatophagoides mites

Seventy-one percent of rabbits immunized with a mixed (50:50) Dermatophagoides farinae and D. pteronyssinus house dust mite extract were resistant to infestation by Sarcoptes scabiei var. canis. The resistance was evidenced by a marked reduction in parasite load. All immunized hosts developed similar immunogen-specific antibody titers that were independent of the levels of scabies infestation that developed when the hosts were infested with scabies. Resistant hosts exhibited significantly lower scabies-specific immunoglobulin titers and produced antibody to fewer scabies antigens than did nonresistant hosts. All infested hosts (resistant and nonresistant) showed a cellular infiltrate in the scabietic lesions that was composed of neutrophils, plasma cells, macrophages, and mononuclear cells. Resistant hosts were characterized by fewer plasma cells in the infiltrate than were observed for non-resistant hosts. Resistant hosts exhibited a gradual increase in the number of infiltrating neutrophils, followed by a decrease that correlated with a decrease in the mite burden. Nonresistant hosts exhibited an early rapid increase, a decrease, and then a gradual increase in the concentration of neutrophils as the mite load increased. These results clearly showed that D. farinae/D. pteronyssinus antigens/epitopes can sensitize the hosts to scabies mites and induce protective immunity. The lower circulating antibody levels and generally stronger inflammatory cell-mediated response of resistant hosts compared with nonresistant hosts suggested that the mechanism by which immunization with Dermatophagoides mites induces immunity to scabies mites involved a down-regulated T helper cell type 2 (Th2) response with reduced antibody production but an up-regulated and stronger Th1 (inflammatory cell-mediated) response to scabies.

Severe post-dipping dermatitis and subcutaneous fluid swellings associated with two outbreaks of sheep scab (Psoroptes ovis infestation)

Large subcutaneous fluid swellings developed on some of the sheep in two flocks infested with Psoroptes ovis during the two weeks after they had been plunge-dipped in phenol-based solutions. The swellings contained between 1 and 10 litres of exudate and affected 4 per cent of the sheep in each flock. The sheep with subcutaneous fluid swellings or exudative dermatitis had significantly lower serum albumin concentrations than the unaffected sheep (P < 0.05). In most cases secondary bacterial infections of the exudate occurred and these necessitated intensive antibiotic therapy. The severity of the skin lesions posed a serious welfare problem.

Sarcoptes scabiei: the circulating antibody response and induced immunity to scabies

Scabies is an important parasitic disease that continues to persist throughout the world despite the availability of acaricides to control it. The immune response mechanism to scabies and the possible development of a vaccine for control of scabies was investigated. This study demonstrated that hosts infested with scabies develop immunity (resistance) to reinfestation. All hosts developed scabies-specific elevated circulating antibody titers during scabies infestations that followed the classical pattern for primary and secondary infestations. Parallel elevated levels of complement C3 were also observed. The hosts that exhibited acquired immunity after their first infestations had antibody and complement levels during challenge infestations lower than those of the hosts that showed no immunity when reinfested. Induction of immunity coupled with generally elevated antibody levels for both immune and nonimmune hosts suggested that resistance to reinfestation was associated with a cell-mediated response. These data also suggested that vaccination with specific scabies tissue containing the relevant antigens or recombinant relevant antigens could enhance the cell-mediated response to protect the hosts against natural infestations.

Scabies outbreak on a spinal cord injury unit

This article describes an outbreak of scabies on a 30-bed acute spinal cord injury unit and the measures taken to eradicate the infestation. Because spinal cord injury patients have sensorimotor deficits, the sensation of itching often is absent, making an infestation of scabies more difficult to identify. A total of 30 patients and 38 employees were exposed and treated for scabies. Educational programs about scabies were instituted immediately for all employees. Routine daily activities and therapy schedules were severely hampered by the outbreak. Despite the efforts of staff to solve the problems associated with the outbreak, frustration and anger were sometimes displayed by many of the staff, patients, and families because of the difficulties they encountered. The outbreak was halted, however, and no further cases were reported, although several employees had to be treated twice.

Scabies: diagnosis and treatment

Scabies is a common, severely pruritic, contagious disorder. Treatment must be careful and methodical to avoid continuing infestation. Patients and their contacts must be treated, and clothing changed. Failure to discover all the contacts leads to continuing spread of the disease.

Alternative methods for the control of sheep scab

For nearly 17 years, plunge dipping has been the only method of scab control in the UK under a Government-controlled eradication campaign. Dipping is inconvenient and has been incriminated in the post-dipping illness of stockowners and contractors, and the disposal of large volumes of used dipwash is a potential hazard to the environment. Upon the deregulation of sheep scab in July 1992, stockowners are no longer obliged to dip and will seek alternative methods of scab control, ie, systemic injectables or synthetic pyrethroid pour-ons. Plunge dipping still offers the only fully effective method of controlling scab and it has a broad spectrum of activity against other ectoparasites of sheep. The present systemic pour-ons and oral drenches have little effect against scab, but double injections of systemic acaricides, ie, ivermectin, show great promise. The efficacy of systemic injectables is related to the initial mite burden and the second injection must not be omitted if complete control is to be achieved. The available synthetic pyrethroid pour-ons do not cover the entire sheep with a standard dose of acaricide, and leave the ventral surfaces unprotected and the sheep open to reinfestation.

Attack of the scabies: what to do when an outbreak occurs

Scabies remains a significant source of morbidity in nursing home residents because of its highly contagious nature. It is characterized by severe pruritus and papules, pustules, burrows, nodules, and occasionally urticarial lesions. Lesions are commonly found on the wrists, finger webs, antecubital fossae, axillae, areolae, periumbilical region, lower abdomen, genitals, and buttocks. Diagnosis is based on the history, physical examination, and demonstration of mites, eggs, or scybala on microscopic examination. Several topical scabicides are available, but permethrin cream appears to be less toxic and more effective in cases that are resistant to other agents. Successful management requires evaluation of individuals with close patient contact.

Knowledge, attitudes and practices (KAP) of human intestinal helminths (worms) in two rural communities in Nyanza Province, Western Kenya

Six common health problems prevalent in two rural communities-Buoye and Kanyawegi Sublocations--of Kisumu District, in Western Kenya, were selected and the knowledge, attitudes and practices (KAP) of the communities investigated with special reference to human intestinal helminths (worms). The selected diseases were malaria, diarrhoea, human intestinal helminths, scabies, schistosomiasis, and measles. The selection of the six health problems was based on a previous more general KAP study of health and disease at household level in the two areas and information from the Medical Officer of Health in the area. The specific objective was to assess the perceived importance of intestinal worms vis-a-vis other common and known health problems in the community. The study included an analysis of responses to questions on human intestinal worms broken down by sex, age and education level of respondents as well as identification and perceived health effects of a set of vectors and parasites of common diseases in the area. Compared with the other five health problems, intestinal worms did not rank highly in people's minds as an important health problem, although very high proportions of respondents knew of the problem, notably the young and educated. This high proportion of respondents who knew of the problem could describe the symptoms with some accuracy and could correctly identify the vectors and parasite samples. But the full implications of intestinal worms were not fully appreciated. Both communities reflected relatively poor comprehension of causes, treatment and methods of prevention.(ABSTRACT TRUNCATED AT 250 WORDS)

Scabies research: another dimension

The life cycle of canine scabies has been studied extensively. Currently studies are focusing on mite behavior, physiological requirements, host specificity, mite survival, and clinical complications of scabies. Investigations are giving insight into immunologic responses to infestation and cross-reactivity with house dust mites. A diagnostic blood test or vaccine may become a future reality, if a unique antibody response can be isolated. Can scabies transmit the human immunodeficiency virus (HIV)? This controversial area needs prompt definitive exploration.