What do physicians know about cryptosporidiosis? A survey of Connecticut physicians.

BACKGROUND: Cryptosporidiosis, an intestinal parasitic infection, has gained considerable media attention since a 1993 waterborne outbreak in Milwaukee, Wis, in which more than 400,000 persons became ill. However, the incidence of and risk factors for human cryptosporidiosis in the general US population are unknown. It has been suggested, but not documented, that physicians are generally unaware of the need to specifically request testing for this organism. OBJECTIVE: To assess physician awareness of cryptosporidiosis and knowledge of laboratory testing for Cryptosporidium oocysts. METHODS: A self-administered questionnaire was mailed to a stratified random sample of Connecticut physicians. Specialties were limited to physicians in internal medicine, gastroenterology, infectious disease, pediatrics, and family or general practice. Responses were compared among specialties. RESULTS: While most physicians were aware that cryptosporidiosis causes watery diarrhea (range, 67%-98%), particularly in patients with acquired immunodeficiency syndrome (> 85% of all specialties), many did not know the symptoms or failed to identify other groups at increased risk. More than 75% of gastroenterologists, general or family practitioners, internists, and pediatricians never or rarely order diagnostic testing for Cryptosporidium even when their patients have symptoms consistent with cryptosporidiosis. More than 30% of physicians assumed Cryptosporidium testing was included in a standard ova and parasite examination. CONCLUSIONS: Cryptosporidiosis is likely to be unrecognized and underdiagnosed in Connecticut. This may occur because many physicians are unaware of cryptosporidiosis, unsure of the symptoms, do not test for it, or do not order the appropriate test. Unless there is more widespread use of specific tests, it will be difficult to evaluate specific preventive initiatives to limit the overall health impact of cryptosporidiosis.

Smoking policies of licensed child day-care centers in the United States.

The authors analyzed data from a national survey of 2003 directors of licensed child day-care centers to determine employee smoking policies, measure compliance with state and local employee smoking regulations for child day-care centers and state clean indoor air laws, and to estimate the extent of exposure to environmental tobacco smoke in these settings. Forty states regulated employee smoking in child day-care centers, but only three states required day-care centers to be smoke-free indoors. More than 99% of licensed child day-care centers had employee smoking policies that complied with the appropriate state or local smoking regulations. Nearly 55% of centers were smoke-free indoors and outdoors, and 26% were smoke-free indoors only. The best predictors of more stringent employee smoking policies were location in the West or South, smaller size, independent ownership, or having written smoking policies. Despite the presence of strong smoking policies at the majority of licensed child day-care centers, more than 752,000 children in the United States are at risk for environmental tobacco smoke exposure in these settings. Health care professionals and parents should insist that child day-care centers be smoke-free indoors and, preferably, smoke-free indoors and outdoors.

A nationwide study of the risk of injury associated with day care center attendance.

OBJECTIVE: Because an increasing proportion of US children spends time in day care center environments, a national estimate of injury risks in day care centers is needed. METHODS: We interviewed directors of 1797 day care centers from every state and the District of Columbia from October to December 1990 and analyzed medically attended injuries and center characteristics reported by the directors. RESULTS: The centers were attended by 138,404 children. In the 2 months before the center directors were interviewed, 556 children sustained injuries requiring medical attention while attending the centers. The injury rate was 1.5 injuries per 100,000 child hours in day care. The most common injuries were cuts or lacerations (31%), bumps or bruises (15%), fractures (10%), and dental injuries (8%). Most injuries (51%) occurred on the playground. Many injuries (18%), and more than half of fractures and concussions (53%) were due to falls from climbing equipment. CONCLUSIONS: Day care center injury rates estimated by this study were relatively low. Many injuries that occur in this setting are probably minor. However, lowering the height of playground equipment and providing more resilient playground surfaces could further reduce injury risks in day care centers.

Cryptosporidiosis in child care settings: a review of the literature and recommendations for prevention and control.

Trends in child care have affected the epidemiology of many infectious diseases. Although once considered rare Cryptosporidium is now recognized as a significant pathogen in child care settings. Although the major impact of cryptosporidiosis in child care settings is economic in terms of parental time lost from work due to a child's illness, the possibility of transmission to immunocompromised individuals and health effects of cryptosporidiosis underscore the significance of this pathogen. Our understanding of the epidemiology of cryptosporidiosis in child care settings is hampered by the lack of information from both cross-sectional and prospective studies. Such studies coupled with the use of newer diagnostic techniques and methods that are currently under development for identifying Cryptosporidium in environmental samples are sorely needed. Information is also needed on the effectiveness of prevention and control strategies. Although prevention strategies may be based on findings from broad based studies that do not focus on any one agent, differences in duration of excretion, rates of asymptomatic infection, availability of treatment and survival in the environment suggest that control strategies for specific pathogens should be evaluated.

Impact of a massive waterborne cryptosporidiosis outbreak on child care facilities in metropolitan Milwaukee, Wisconsin.

OBJECTIVE: We describe the impact of the 1993 waterborne cryptosporidiosis outbreak on metropolitan Milwaukee child care homes and centers. METHODS: Information on outbreak-related illness and changes in policies and practices was collected from directors of 117 facilities. Stool specimens from 129 diapered children from 11 centers were screened for Cryptosporidium. RESULTS: Most (74%) facility directors reported children or staff with diarrhea during the outbreak; however, only 4 (3.4%) facilities closed because of illness among staff or children. During the outbreak child care homes were less likely to exclude children with diarrhea than were child care centers. Among diapered children attending centers the Cryptosporidium prevalence was 30%; 29% of infected children had no history of diarrhea associated with the Milwaukee outbreak. CONCLUSIONS: Facilities continued to operate during the outbreak despite considerable illness among children and staff. The news media were effective means for providing public health information to child care facilities. Although secondary transmission undoubtedly took place in child care facilities, the presence of children with asymptomatic Cryptosporidium infections did not result in an increased risk of diarrhea in infant and toddler rooms.

Giardia lamblia and Cryptosporidium infections in child day-care centers in Fulton County, Georgia.

Risk factors for the introduction, spread and persistence of Cryptosporidium and Giardia lamblia infections in child day-care centers are not well understood. In 1989 and 1990 stool specimens were obtained from 292 diapered children attending 17 randomly selected day-care centers in Fulton County, GA; 8 (2.7%) children in 2 centers were infected with Cryptosporidium and 21 (7.2%) children in 7 centers were infected with Giardia. In 1986 the prevalence of Cryptosporidium and Giardia in these same centers had been 0.4 and 11.0%, respectively; the prevalence of Cryptosporidium, but not Giardia, increased significantly (P = 0.04) between 1986 and 1989 to 1990. Risk factors for Giardia infection included day-care attendance for greater than 3 months, the presence of toddlers in the classroom and the presence of other children in the household. Day-care centers with a Giardia-positive child in 1986 were not more likely to have an infected child in 1989 to 1990. Cryptosporidium, like Giardia, may be endemic in day-care centers in Fulton County.

Chronic diarrhoeal illness in US Peace Corps volunteers.

Chronic diarrhoea of unknown aetiology is increasingly recognized as a problem in international travellers, and has been reported in US Peace Corps volunteers. In December 1987, we surveyed all Peace Corps medical officers to determine the magnitude of this problem and obtain preliminary data on potential risk factors. A rate of nine cases of chronic diarrhoea per 1000 volunteers per year was reported by medical officers representing 4607 volunteers in 43 countries. The highest rates were reported in Haiti, where one-third of the volunteers reportedly developed chronic diarrhoea during their two-year stay, as well as in Central and West Africa and Nepal. Volunteers were reported to drink unpasteurized milk routinely in eight (42%) of 19 countries with greater than or equal to one case of chronic diarrhoea during the previous two years, but in only two (11%) of 19 countries where none of the volunteers had chronic diarrhoea (odds ratio = 6.2, p = 0.06, Fisher exact test). Intensive prospective studies in areas of high incidence are needed to define this syndrome further.

Foodborne botulism: an international outbreak.

We report an outbreak of fishborne botulism caused by type E Clostridium botulinum. The eight cases, six in Israel and two in New York City, resulted from the consumption of ribbetz or kapchunka, a freshwater whitefish soaked in brine and air-dried, that was processed commercially in New York. Half the cases were males; the age range was 9 to 77 years. Five of the victims were hospitalized; the oldest died, and two others required ventilatory assistance. Laboratory confirmation of botulism was obtained in three cases. Prolonged lack of refrigeration during transatlantic flight and packaging contributing to an anaerobic environment were felt to be contributing environmental factors in the Israeli cases. Rapid communication and full cooperation between Israeli and US health authorities limited the extent of the outbreak. Despite adequate understanding of how foodborne botulism may be avoided, outbreaks still occur, particularly among people consuming certain high-risk or ethnic foods.

Injuries from falls on playgrounds. Effects of day care center regulation and enforcement.

OBJECTIVES: To measure the incidence of playground fall injuries among children attending licensed US day care centers and to evaluate how injury incidence varies with center characteristics and with the regulatory and enforcement climate in which centers operate. DESIGN: Telephone surveys of directors of day care centers and enforcement agencies and review of written day care regulations. SETTING: Probability sample of licensed day care centers in 50 states and the District of Columbia. PARTICIPANTS: Children attending day care centers with playgrounds. MAIN OUTCOME MEASURES: Medically attended playground fall injuries. RESULTS: Among the 1740 day care centers studied, a weighted total of 89.2 injuries occurred during the 2-month study period (0.25/100,000 child-hours in day care). The most important risk factor for injury was height of the tallest piece of climbing equipment on the playground in both bivariate (P = .01) and multivariate (P = .02) analyses. Neither regulations addressing playground safety or playground surfaces nor enforcement patterns were associated with lower injury rates. CONCLUSIONS: Additional effort is needed to develop and evaluate regulations and enforcement that reduce injury risks for children while minimizing burden on day care centers. In the meantime, limiting climbing equipment heights may reduce playground injury rates.

Evaluation of the whole blood filariasis ICT test for short-term monitoring after antifilarial treatment.

The immunochromatographic (ICT) filariasis test is a rapid screening tool that will be useful for defining the prevalence and distribution of Wuchereria bancrofti as part of the global program to eliminate lymphatic filariasis. To address questions about its usefulness for monitoring control programs, we used the ICT filariasis test to assess residual antigen levels following antifilarial treatment. Our results demonstrate that antigen levels persist in microfilaria-negative persons for up to three years after treatment. Different strategies for monitoring control programs may have to be considered.

Epidemiology of giardiasis in Wisconsin: increasing incidence of reported cases and unexplained seasonal trends.

Giardia lamblia is the most commonly reported enteric pathogen in Wisconsin. Since giardiasis became a notifiable disease, the annual number of cases reported to the Wisconsin Division of Health has increased more than 20-fold, from 2.2 cases per 100,000 population in 1981 to 49.1 cases per 100,000 population in 1988. To better understand the nature of this increasing trend, we reviewed records of G. lamblia infections reported to the Wisconsin Division of Health from 1981 to 1988. Although the increase in reported cases was a general phenomenon that was not limited to a few high-risk groups, the highest annual incidence and greatest increase occurred in children 1-4 years old; 34% of the cases in this age group occurred in children who attended day care centers. A remarkably consistent late summer (August) increase was observed across all demographic and risk groups, suggesting that G. lamblia may be more common in the environment during late summer, or that risk factors for transmission may differ during these months. Additional studies are needed to further explain the increasing incidence and seasonal nature of reported giardiasis and to identify opportunities for prevention.

Clearance of Wuchereria bancrofti antigen after treatment with diethylcarbamazine or ivermectin.

The present study was undertaken to assess the relationship between microfilarial clearance and clearance of circulating filarial antigen from the blood of Wuchereria bancrofti-infected persons following chemotherapy with either diethylcarbamazine or ivermectin. Patients received either 12 weekly doses of 6 mg/kg of diethylcarbamazine (DEC), a single dose of 6 mg/kg of DEC, a single dose of 420 microg/kg of ivermectin, or 20 microg/kg of ivermectin, followed by 6 mg/kg of DEC five days later. Microfilarial clearance was marked in all groups, but was significantly less in the single-dose DEC. In contrast, as monitored by the Og4C3 monoclonal anitbody assay, clearance of circulating filarial antigen was highly variable, not only between groups but within each group. As a result, there were few statistically significant differences in antigen clearance between groups. In no instance did the antigen level fall to zero, even in individuals that remained microfilaria negative during two or three years of follow-up. These results suggest that living adult worms persist in almost all persons treated with DEC and/or ivermectin.

A survey of knowledge, attitudes, and perceptions (KAPs) of lymphatic filariasis, elephantiasis, and hydrocele among residents in an endemic area in Haiti.

To assess knowledge, attitudes, and perceptions about bancroftian filariasis, 104 residents of an endemic area in Haiti were interviewed. Questions focused on 1) whether people understood the relationship between infection and disease, 2) recognition of the role that mosquitoes play in transmission, 3) perceived importance of hydrocele and elephantiasis in relation to other recognized diseases, and 4) the willingness of the community to participate in a control program. Fewer than 50% of residents had heard of filariasis and only 6% of those surveyed knew that it was transmitted by mosquitoes. In contrast, all persons knew of the clinical conditions of hydrocele and elephantiasis. Hydrocele was thought to be caused by trauma (60%) or trapped gas (30%); elephantiasis by walking bare foot on soil or water (37%) or by use of ceremonial powder that had been sprinkled on the ground (23%). Of 76 respondents, 53% and 38% thought that hydrocele could be treated through surgery or a drug, respectively, whereas 86 respondents, 85% and 15% believed that either surgery or a drug could be used to treat elephantiasis. In this context, persons were not referring to a specific drug; rather, they believed a drug existed (possibly in some other country) that could cure these conditions. Hydrocele and elephantiasis ranked second to acquired immunodeficiency syndrome as perceived health problems, most likely because residents believed treatment for conditions such as malaria, intestinal worms, anemia, and diarrhea was easily obtained. Responses were influenced by age, sex, and symptoms, but none of these effects were statistically significant except that persons with hydrocele or elephantiasis were more likely to have sought treatment than persons without these conditions (P = 0.0006). The survey results indicate that awareness of the causes of disease, the relationship between infection and disease, and goals of treatment must be heightened through community-based education campaigns to increase the possibility of acceptance and support of control programs.

Reduction of risk of watery diarrhea with point-of-use water filters during a massive outbreak of waterborne Cryptosporidium infection in Milwaukee, Wisconsin, 1993.

The occurrence of a massive waterborne outbreak of Cryptosporidium infection in Milwaukee, Wisconsin provided an opportunity to evaluate the effectiveness of point-of-use home water filters in preventing diarrheal illness associated with Cryptosporidium infection. Of 155 filter owners who responded to a televised request to contact the City of Milwaukee Health Department, 99 (64%) completed a self-administered questionnaire regarding their sources of drinking water, the characteristics of their home water filters, and diarrheal illness during the outbreak. Diarrhea among respondents was independently associated with residence in southern or central Milwaukee (the area served by the implicated South water treatment plant), having a home water filter with a pore diameter of greater than 1 micron, and drinking unfiltered tap water in a public building in southern Milwaukee. Among residents of southern and central Milwaukee, two (18%) of 11 persons who drank only submicron-filtered water at home and who did not drink unfiltered South plant water at work had watery diarrhea, compared with 50% (n = 2), 63% (n = 35), and 80% (n = 15) who reported drinking South plant water that was unfiltered or passed through a filter with a pore diameter > 1 micron at work only, home only, or both home and work, respectively (P = 0.02). The data indicate that use of submicron point-of-use water filters may reduce risk of waterborne cryptosporidiosis.

Comparative efficacy of clearing-dose and single high-dose ivermectin and diethylcarbamazine against Wuchereria bancrofti microfilaremia.

To compare the efficacy and tolerability of various combinations of low- and high-dose ivermectin and diethylcarbamazine (DEC), 59 persons with Wuchereria bancrofti microfilaremia were enrolled in a double-blinded six-arm clinical trial in Leogane, Haiti. On day 1, study participants were treated with low clearing doses of ivermectin, DEC, or placebo; on day 5 they received 200-400 micrograms/kg of ivermectin or 6 mg/kg of DEC. Adverse reactions, which were generally mild, occurred more frequently with ivermectin than with DEC. One year after treatment, the geometric mean microfilarial density returned to 0.9% of pretreatment levels for persons who received a total of 420 micrograms/kg of ivermectin. This rate was significantly lower than 5.6% for persons who were treated with 220 micrograms/kg of ivermectin (P = 0.02) and 9.3% for those receiving 6 or 7 mg/kg of DEC (P = 0.006). Persons treated with a clearing dose of ivermectin followed by 6 mg/kg of DEC also had low microfilarial densities (1.7% of pretreatment levels), suggesting an additive or synergistic effect of the two drugs. The addition of a clearing dose neither reduced the severity of adverse reactions nor improved the efficacy of high-dose ivermectin. Community-based intervention trials are now warranted to determine the feasibility and effectiveness of mass chemotherapy with single high-dose ivermectin for the prevention and control of lymphatic filariasis.

Assessment of combined ivermectin and albendazole for treatment of intestinal helminth and Wuchereria bancrofti infections in Haitian schoolchildren.

This randomized, placebo-controlled trial investigated the efficacy and nutritional benefit of combining chemotherapeutic treatment for intestinal helminths (albendazole) and lymphatic filariasis (ivermectin). Children were infected with Ascaris (29.2%), Trichuris (42.2%), and hookworm (6.9%), with 54.7% of children having one or more of these parasites. Wuchereria bancrofti microfilaria were found in 13.3% of the children. Children were randomly assigned to treatment with placebo, albendazole, ivermectin, or combined therapy. Combination treatment reduced the prevalence of Trichuris infections significantly more than either drug alone. Combination therapy also significantly reduced the prevalence and density of W. bancrofti microfilaremia compared with placebo or ivermectin alone. Only combination therapy resulted in significantly greater gains in height (hookworm-infected children) or weight (Trichuris-infected children) compared with the placebo group. Combined albendazole and ivermectin was a more efficacious treatment for intestinal helminth and W. bancrofti infections in children and resulted in nutritional benefits not found with either drug alone.

Short report: documentation of iodine deficiency in Haitian schoolchildren: implication for lymphatic filariasis elimination in Haiti.

In this study we documented unexpected moderate-to-severe iodine deficiency in Haitian schoolchildren although they live in a coastal community where presumably they have access to iodine-containing seafood. This fact combined with the lack of an iodized salt supply and endemic lymphatic filariasis makes community distribution of diethylcarbamazine-fortified, iodized salt an attractive strategy for elimination of lymphatic filariasis and iodine deficiency disorders in this area of Haiti. Combining lymphatic filariasis elimination with other public health interventions is one strategy to increase its public health benefit and maximize the impact of limited public health resources.

A community-based trial for the control of lymphatic filariasis and iodine deficiency using salt fortified with diethylcarbamazine and iodine.

To evaluate the effectiveness of salt fortified with diethylcarbamazine (DEC) and iodine for elimination of Bancroftian filariasis and iodine deficiency, all consenting residents of Miton, Haiti (n = 1,932) were given salt fortified with 0.25% diethylcarbamazine and 25 ppm of iodine for one year. Wuchereria bancrofti microfilaria prevalence and intensity, antigenemia, and urinary iodine were measured before and one year after salt distribution began. To measure the effect of DEC-fortified salt on adult worm motility, 15 microfilaria-positive men were examined by ultrasound of the scrotal area. Entomologic surveys were conducted to determine the proportion of W. bancrofti-infected Culex quinquefasciatus. After one year of treatment, the prevalence and intensity of microfilaremia were both reduced by more than 95%, while antigenemia levels were reduced by 60%. The motility of adult worms, as detected by ultrasound, was decreased, but not significantly, by DEC-fortified salt. The proportion of vector mosquitoes carrying infective stage larvae decreased significantly from 2.3% in the nine months before the intervention to 0.2% in the last three-month follow-up period. Iodine deficiency, which had been moderate to severe, was eliminated after one year of iodized salt consumption. The DEC-fortified salt was well accepted by the community and reduced microfilaremia and transmission to low levels in the absence of reported side effects. Based on these results, salt cofortified with DEC and iodine should be considered as a concurrent intervention for lymphatic filariasis and iodine deficiency elimination programs.

Malaria, intestinal parasites, and schistosomiasis among Barawan Somali refugees resettling to the United States: a strategy to reduce morbidity and decrease the risk of imported infections.

In 1997, enhanced health assessments were performed for 390 (10%) of approximately 4,000 Barawan refugees resettling to the United States. Of the refugees who received enhanced assessments, 26 (7%) had malaria parasitemia and 128 (38%) had intestinal parasites, while only 2 (2%) had Schistosoma haematobium eggs in the urine. Mass therapy for malaria (a single oral dose of 25 mg/kg of sulfadoxine-pyrimethamine) was given to all Barawan refugees 1-2 days before resettlement. Refugees >2 years of age and nonpregnant women received a single oral dose of 600 mg albendazole for intestinal parasite therapy. If mass therapy had not been provided, upon arrival in the United States an estimated 280 (7%) refugees would have had malaria infections and 1,500 (38%) would have had intestinal parasites. We conclude that enhanced health assessments provided rapid on-site assessment of parasite prevalence and helped decrease morbidity among Barawan refugees, as well as, the risk of imported infections.

Detection of IgM antibodies to Schistosoma mansoni gut-associated antigens for the study of the dynamics of schistosomiasis transmission in an endemic area with low worm burden.

For a period of 2 years, five follow-up measures of prevalence and incidence rates were estimated in a prospective study of S. mansoni infection in a group of schoolchildren who were living in a rural area of the Municipality of Itariri (São Paulo, Brazil), where schistosomiasis is transmitted by Biomphalaria tenagophila. Infection was determined by the examination of three Kato-Katz stool slides, and the parasitological findings were analyzed in comparison to serological data. In the five surveys, carried out at 6-month intervals (March-April and September-October), the prevalences were, respectively, 8.6, 6.8, 9.9, 5.8 and 17.2% by the Kato-Katz, and 56.5, 52.6, 60.8, 53.5 and 70.1% by the immunofluorescence test (IFT). Geometric mean egg counts were low: 57.8, 33.0, 35.6, 47.3 and 40.9 eggs per gram of feces, respectively. Of the total of 299 schoolchildren, who submitted five blood samples at 6-month intervals, one for each survey, 40% were IFT-positive throughout the study, and 22% were IFT-negative in all five surveys. Seroconversion from IFT negative to positive, indicating newly acquired S. mansoni infection, was observed more frequently in surveys carried out during March-April (after Summer holidays), than during September-October. Seasonal trends were not statistically significant for detection of S. mansoni eggs in stool. The results indicate that the use of IgM-IFT is superior to parasitological methods for detection of incidence of S. mansoni infection in areas with low worm burden.