Handwashing to prevent diarrhea in day-care centers.

Diarrhea has been recognized as a frequent health problem among children enrolled in day-care centers. Thus, we evaluated the effect of a handwashing program in two day-care centers (HWC) on the incidence of diarrhea among children when compared to children in two control centers (CC). After the program was begun, the incidence of diarrhea at the HWC began to fall and after the second month of the study was consistently lower than that at the CC. The incidence of diarrhea in the HWC was approximately half that of the CC for the entire 35-week study period. Adenoviruses, rotavirus, Giardia lamblia, and enteropathogenic Escherichia coli were found in the stools of a small number of ill children, but not pathogen was identified in the stools of most children with diarrhea. These results suggest that a handwashing program will probably prevent at least some of the diarrhea in day-care centers.

Waterborne giardiasis: a communitywide outbreak of disease and a high rate of asymptomatic infection.

A communitywide outbreak of gastrointestinal illness due to Giardia lamblia infection occurred in the city of Berlin, New Hampshire, during April and May 1977. The clinical, epidemiologic, and laboratory aspects of this outbreak are described here. In 213 predominantly symptomatic cases of G. lamblia infection diagnosed at a local hospital laboratory in a 6-week period, illness was characterized by prolonged diarrhea (median duration 10 days) and 13% of symptomatic infections required hospitalization. Treatment with either quinacrine or metronidazole was generally followed by symptomatic improvement. A communitywide survey of the city residents revealed that the majority (76%) of G. lamblia infections occurring during the epidemic period were asymptomatic and ran a self-limited course without treatment. No significant secondary, person-to-person spread occurred and no enteric pathogens other than G. lamblia were implicated. Water was epidemiologically implicated as the most likely source of infection with Giardia cysts being demonstrated in samples of treated water as well as raw source water. Evidence supported the occurrence of two simultaneous outbreaks in this city which is supplied by two largely independent water supply systems. Inspection of the two water treatment facilities revealed several defects which permitted untreated (raw) water to mix with treated water. Human or beaver could have been responsible for contaminating source water with Giardia in this outbreak. A marked reduction in both clinical and subclinical giardiasis was apparent two months after onset of the outbreak, apparently as a result of measures applied to interrupt waterborne transmission of Giardia.

Shigellosis in the Marshall Islands: epidemiologic aspects of an outbreak.

An outbreak of diarrheal illness caused by Shigella flexneri 1b and associated with 11 deaths occurred in the Marshall Islands during June and July 1977. A house-to-house survey on Majuro indicated an attack rate of 6.2%. Neither the survey nor a case-control study uncovered a common source of exposure on Majuro, and it is believed that transmission was mainly person-to-person. Socioeconomic factors, type of water supply, distance to municipal water supply, and type of sanitary facility could not be related to the occurrence of illness, but a poor sanitary rating was associated with increased rate of household transmission. Absence of stool culturing for bacteria and false-positive identifications of amebae in stool specimens led to the outbreak's being attributed to Entamoeba histolytica. Subsequent parasitologic examinations and serologic studies indicated that E. histolytica played no role in the outbreak, and suggested that fecal leukocytes were being mistaken for amebae. Improved bacteriologic capabilities will be important in improving the approach to diarrheal illness in the Marshall Islands.

Giardiasis in American travelers to Madeira Island, Portugal.

A high incidence of diarrhea was reported in a group of approximately 1,400 Americans who traveled to the Portuguese island of Madeira in October 1976. A mail questionnaire survey revealed that 39% of the responding 859 travelers experienced diarrhea; in 42% of these diarrhea lasted for longer than 1 week. The most frequent accompanying symptoms were abdominal cramps (75%), abdominal distention (72%), nausea (70%), and weight loss (40%). Of all travelers surveyed, 33% developed an illness resembling giardiasis with a median incubation period of 4 days. Of 35 ill patients who had a stool culture, enteric pathogens were recovered from 4 (3 Shigella and 1 Salmonella). On the other hand, of 58 ill patients whose stools were examined for parasites, Giardia lamblia was recovered from 27 (47%). Analysis of the epidemiologic data showed that drinking tap-water on the island was significantly associated with illness; eating ice cream or raw vegetables on the island was also implicated. There was no evidence of continuing transmission of giardiasis in American tourists visiting Madeira 8--12 months after the outbreak.

Giardiasis in day-care centers: evidence of person-to-person transmission.

In August and September 1975, an outbreak of diarrhea occurred in children 1 to 3 1/2 years old attending a day-care center. An investigation revealed overlapping epidemics of shigellosis and giardiasis, with 54% of the children infected with Giardia lamblia. At two other centers 29% and 38% of the children had G. lamblia infection, but none had Shigella. The prevalence of G. lamblia in the day-care children was significantly higher than the 2% prevalence in age-matched children not in day-care centers. Epidemiologic data suggested fecal-oral transmission of the parasite from child to child in the centers and from infected children to other family members.

Epidemiology of an outbreak of head lice in Georgia.

An outbreak of head lice infestation (pediculosis) occurred in elementary school children in Barrow County, Georgia, in January 1974. An investigation was initiated to define the magnitude of the outbreak, determine factors that contribute to transmission, and disseminate information on control. All elementary school children in the county were examined for head lice and answered a questionnaire. Fifty-three (3%) of 1,783 white pupils were infested, but none of the 500 black pupils was infested. Distribution of infestation in the white pupils was influenced by grade, bed-sharing, socioeconomic status, infestation of other family members, crowding in the home, and family size; distribution was not influenced by hair length or the sex of the pupil. Recommendations for control based on the results of the investigation included procedures for identifying and processing cases, distributing free pediculicides, continuing surveillance, educating school personnel and parents on how to control the parasite.