Day-care center attendance and hospitalization for lower respiratory tract illness.

To identify risk factors associated with hospitalization for acute lower respiratory tract illness, 102 children less than 2 years of age admitted to four Atlanta metropolitan area hospitals between December 1984 and June 1985 with the diagnosis of lower respiratory tract illness were studied. The most common causative agent associated with illness was respiratory syncytial virus, followed by other respiratory viruses, Haemophilus influenzae, and Streptococcus pneumoniae. The 102 case-patients were compared with 199 age- and sex-matched controls. A parent or guardian for each patient and control was interviewed by telephone regarding demographic data, care outside the home, breast-feeding, previous medical history, allergies, and smoking and illness in household members. Five factors were associated with lower respiratory tract illness in both a univariate analysis and a multiple logistic regression model (P less than .05). These factors were the number of people sleeping in the same room with the child, a lack of immunization the month before the patient was hospitalized, prematurity, a history of allergy, and regular attendance in a day-care center (more than six children in attendance). Care received outside of the home in a day-care home (less than or equal to six children in attendance) was not associated with lower respiratory tract illness. The suggestion made by our study and other studies was that for children less than 2 years of age, care outside of the home is an important risk factor for acquiring lower respiratory tract illness, as well as other infectious diseases, and that this risk can be reduced by using a day-care home instead of a day-care center.

Trends in hospitalizations for diarrhea in United States children from 1979 through 1992: estimates of the morbidity associated with rotavirus.

OBJECTIVES: To examine trends in the hospitalizations of children for diarrheal disease in the U.S. and to provide estimates for the burden of disease associated with rotavirus diarrhea. METHODS: Data for diarrheal hospitalizations among U.S. children ages 1 month through 4 years were compiled from the National Hospital Discharge Survey for the years 1979 through 1992. Between 1979 and 1992, 12% of all hospitalizations of U.S. children 1 month through 4 years of age had an International Classification of Diseases code for diarrhea listed in one of the top three positions on the discharge diagnosis. RESULTS: The annual rate of diarrheal hospitalizations, 97 per 10 000 persons (average, 185 742 per year), did not change substantially during the 14-year study period and accounted annually for 724 394 inpatient days (3.9 days per hospitalization). For most diarrheal hospitalizations (75.9%) no causative agent was specified in the National Hospital Discharge Survey records; of the remaining 24.8%, viruses were most commonly reported (19.3%), followed by bacteria (5.1%) and parasites (0.7%). The proportion of hospitalizations associated with viral diarrheas rose from 13% to 27% during the 14-year study period, whereas the proportion of hospitalizations for noninfectious diarrhea declined from 79% to 60%. Every year the number of hospitalizations peaked from November through April, the "winter" months, among children ages 4 through 35 months; this peak began in the West during November and December and reached the Northeast by March. CONCLUSIONS: Diarrhea continues to be a common cause of hospitalization among children in the United States and the winter seasonality estimated to be caused in large part by rotavirus would be expected to decrease if rotavirus vaccines currently being developed were introduced. Our analysis of temporal trends in diarrheal hospitalizations provides a unique surrogate with which to estimate the disease burden associated with rotavirus diarrhea.

Recent developments in diarrheal diseases.

Diarrheal diseases result from two different processes: toxin elaboration by pathogens such as Vibrio cholerae and some strains of Escherichia coli and invasion of tissue, eg, by shigellae and salmonellae. Intestinal motility serves as a normal cleansing mechanism of the intestine, and drugs that decrease this motility may facilitate replication of pathogens and their attachment to or invasion of the intestinal tissue. Therapy should not be aimed at suppressing the symptom of diarrhea. It is now known that the electrolytes lost in the course of diarrheal disease can be replaced orally if they are given in solution with glucose. Although commercial preparations are not readily available, an effective solution can be made from ingredients commonly found in the home. Oral rehydration has greatly simplified treatment and has significantly reduced the morbidity and mortality associated with diarrheal diseases.

Observations on the ecology of Salmonella waycross and Salmonella typhimurium on Guam.

A period of high incidence of human Salmonella infections on the island of Guam saw the emergence of S. waycross as the most commonly isolated serotype as well as a concurrent decreasing proportion of isolates due to S. typhimurium. Predation of local rodents by an introduced snake is believed to account for the decreased prevalence of S. typhimurium infections, but reasons for the increased prevalence of S. waycross infections are unknown.

A perspective on the global problem of enteric diseases.

Experience has shown that neither drugs nor vaccines can hope to solve the world's enteric disease problems. But oral-fluid therapy, which has sharply reduced cholera mortality, is proving effective in treating other enteric diseases as well. And most developing countries are making real progress in providing the safe water supplies and sanitary conditions that deny enteric pathogens an opportunity to flourish and spread.

Epidemiology of Escherichia coli in the United States.

Current evidence suggests that diarrheagenic E. coli are not important causes of disease in the sanitized urban centers of the United States at this time. However, enterotoxigenic E. coli are a leading cause of diarrhea among travelers who visit developing countries. The failure of diarrheagenic E. coli pathogens to gain a foothold in this country, despite problems with enteropathogenic E. coli in nurseries during the 1940s and 1950s and the more recent multiple introductions of enterotoxigenic E. coli by travelers returning from developing areas of the world, demonstrates the epidemiologic impotence of diarrheagenic E. coli in the relatively sanitized environment of the United States. Nondiarrheagenic E. coli seem to be major pathogens in community-acquired and nosocomial infections in extraintestinal sites.

Detection of Vibrio cholerae biotype El Tor by purging.

Previous studies have demonstrated the value of purging in detecting inapparent cholera infection, but the technique has not been generally accepted. The present study shows that the method can be recommended as a routine procedure to determine when convalescent cholera patients should be discharged from hospital. It may also be useful in detecting carriers of Vibrio cholerae and for evaluating chemotherapy. In this study, five of the eight patients who excreted vibrios after purging had been treated with 2 g of chloramphenicol daily for three days, a finding that throws doubt on the adequacy of this treatment. Purging with magnesium sulfate is simple, well tolerated and ideal for hospitalized patients or for subjects whose stools can be promptly cultured. Since magnesium sulfate is inhibitory to Vibrio cholerae, this purgative is not well suited for field studies, where there may be delays in culturing.

Salmonella typhi infections in the United States, 1967-1972: increasing importance of international travelers.

Isolates of Salmonella typhi from 3661 persons in the United States were reported to the Center for Disease Control from 1967 to 1972. Available case reports and carrier lists for the patients from whom the isolates were recovered were reviewed. During this period the yearly number of travel-associated cases rose 270% and, in contrast to indigenous cases, the number of travel-associated ones increased each year. This increase was largely due to cases associated in some way with Mexico. Furthermore, residents of the United States with Hispanic surnames were at higher risk of contracting typhoid in this country than was the rest of the population. Most indigenous cases were in children or young adults and were not linked to recognized outbreaks. Most known typhoid carriers in the United States are elderly women.

Search for a mass chemotherapeutic drug for cholera control. A study of Vibrio excretion following single and multiple dose treatment.

In a study designed to seek a suitable drug for mass chemotherapy during a cholera epidemic, four drugs were administered in single doses to patients with cholera in Iran. Streptomycin was administered orally; penicillin, parenterally; and chloramphenicol and a long-acting sulfa drug, both orally and parenterally. No drug consistently eliminated vibrios from the intestinal tract. Chloramphenicol was also administered in multiple doses for three days; this also failed to eliminate vibrios in one-third of 25 patients studied. The major problem with these drugs administered orally seems to be rapid elimination and poor absorption by patients with diarrhoea. The authors do not recommend any of these drugs for single-dose mass chemotherapy and consider that chloramphenicol cannot be recommended for multiple-dose mass chemotherapy.

Comparison of media for direct isolation and transport of Shigellae from Fecal specimens.

Xylose-lysine-deoxycholate (XLD) agar, SS agar, and MacConkey agar for isolating shigellae from fecal specimens were compared. XLD agar was superior to both SS agar and MacConkey agar for isolating Shigella sonnei, and both XLD and SS agar were superior to MacConkey agar for isolating S. flexneri. Direct plating of the fecal specimens in the field resulted in a greater yield of shigellae as compared to transporting specimens to the laboratory either in holding media or enrichment broth. Buffered glycerol saline was superior to other transport media evaluated, yielding 83% of shigella isolates when plated within 48 hr as compared to direct plating. The combination of XLD agar and SS agar is recommended for direct isolation of shigellae, and, whenever possible, these solid media should be taken to the bedside and inoculated directly.

Enhancement by sodium chloride of the selectivity of thiosulfate citrate bile salts sucrose agar for isolating Vibrio cholerae biotype El Tor.

In this study we utilized the salt-tolerant characteristics of vibrios to develop a more selective medium by addition of NaCl to thiosulfate citrate bile salts sucrose (TCBS) agar. The effect of adding salt to TCBS agar varied greatly among brands of TCBS agar and between lots of the same brand. The addition of salt at concentrations as high as 1.5% (2.5% total NaCl) caused the inhibition of growth of three species of commonly encountered normal bowel flora and one strain of classical Vibrio cholerae but did not compromise the use of TCBS agar for isolation of V. cholerae biotype El Tor.

Shigellosis in custodial institutions. V. Effect of intervention with streptomycin-dependent Shigella sonnei vaccine in an institution with endemic disease.

A double-blind controlled field trial of live, oral, streptomycin-dependent Shigella sonnei vaccine was begun in an institution with endemic S. sonnei disease. Considerable unexpected child-to-child transmission of the vaccine strains inadvertantly caused the field trial to resemble a mass vaccination campaign. Although S. sonnei accounted for 90% of shigella infections from 1968 to 1971 and three-fourths of the cases occurred in the seven study cottages, S. sonnei disease disappeared following vaccination; epidemiologic features suggest a causal relationship. Clinical S. sonnei disease did not occur despite the detection by bacteriologic surveillance of carriers of virulent S. sonnei. Levels of hygiene remained compatible with transmission of shigella since 43 cases of S. flexneri 6 were seen. If the interpretation is correct, the disappearance of S. sonnei disease resulted from inadvertent "mass vaccination" and oral shigella vaccines may prove useful for control of endemic shigellosis institutions. Nevertheless, a properly designed controlled field trial, taking into account transmissibility of vaccine, in an institutional setting similar to Sunland is necessary to substantiate the role of oral shigella vaccines in control of institutional shigellosis.

Studies on vaccination against bacillary dysentery. 6. Protection of children by oral immunization with streptomycin-dependent Shigella strains.

A field trial of oral streptomycin-dependent mutant Shigella vaccines in five hyperendemic areas of Yugoslavia in 1969 confirmed the findings of earlier studies by demonstrating the effectiveness of these vaccines against dysentery. For the first time, a high degree of protection was demonstrated in children. The vaccines induced serotype-specific immunity against Shigella flexneri 1 and 2a and S. sonnei. Postvaccinal reactions were minor and consisted of vomiting or diarrhoea, or both, in a small proportion of children within several hours of the administration of the vaccine. These reactions, seen mainly after the first dose, were dose-dependent and could be decreased by reducing the number of live organisms. Reactions to subsequent doses were much fewer. Pretreatment with sodium bicarbonate was necessary. Under the conditions of this study, the vaccines proved to be stable with no evidence of reversion of the mutant strains to the virulent parent.

Non-cholera vibrio infections in the United States. Clinical, epidemiologic, and laboratory features.

Non-cholera vibrios are organisms that are biochemically indistinguishable from Vibrio cholerae but do not agglutinate in vibrio 0 group 1 antiserum. Since 1972 there has been a dramatic increase in the number of these organisms referred to the Center for Disease Control for identification. Clinical, epidemiologic, and laboratory data were analyzed for 26 of 28 patients with isolates identified between January 1972 and March 1975. Thirteen (50%) of the isolates were obtained from feces of patients who had an acute diarrheal illness; no other pathogens were isolated from their feces, and all patients survived. Four (15%) patients had non-cholera vibrios isolated from other gastrointestinal or biliary tract sites; none of these patients had acute illness definitely attributable to non-cholera vibrios. Nine (35%) patients had non-cholera vibrios isolated from other tissues and body fluids; four deaths occurred in this group. Patients with acute diarrhea frequently had a history of recent shellfish ingestion or foreign travel, whereas some patients with systemic non-cholera vibrio infection had a history of recent occupational or recreational exposure to salt water.

International outbreak of Salmonella Eastbourne infection traced to contaminated chocolate.

Between Dec. 4, 1973, and Feb. 15, 1974, 80 cases of infection due to Salmonella eastbourne, previously a rare isolated serotype in the United States, were reported from twenty-three States. An additional 39 cases were reported from seven Provinces in Canada during a similar period. A telephone case-control study implicated Christmas-wrapped chocolate balls manufactured by a Canadian company as the vehicle of transmission. S. eastbourne was subsequently isolated from several samples of leftover chocolate balls obtained from homes where cases occurred. Investigation of the factory revealed that the contaminated Christmas and Easter chocolates, and a few chocolate items for year-round sale, had been produced between May and October, 1973. Bacteriological testing of samples taken at the plant implicated cocoa beans as the probable source of the salmonella organisms which, in the low-moisture chocolate, were able to survive heating during production. This outbreak and the finding of salmonella of other serotypes in chocolates produced by another manufacturer suggest that chocolate-related salmonellosis may be a significant public-health problem.