Microbiologic effectiveness of hand washing with soap in an urban squatter settlement, Karachi, Pakistan.

We conducted a study in a squatter settlement in Karachi, Pakistan where residents report commonly washing their hands to determine if providing soap, encouraging hand washing, and improving wash-water quality would improve hand cleanliness. We allocated interventions to 75 mothers and collected hand-rinse samples on unannounced visits. In the final model compared with mothers who received no hand-washing intervention, mothers who received soap would be expected to have 65% fewer thermotolerant coliform bacteria on their hands (95% CI 40%, 79%) and mothers who received soap, a safe water storage vessel, hypochlorite for water treatment, and instructions to wash their hands with soap and chlorinated water would be expected to have 74% fewer (95% CI 57%, 84%). The difference between those who received soap alone, and those who received soap plus the safe water vessel was not significant (P = 0.26). Providing soap and promoting hand washing measurably improved mothers' hand cleanliness even when used with contaminated water.

A low-cost intervention for cleaner drinking water in Karachi, Pakistan.

OBJECTIVE: To pilot test an inexpensive, home-based water decontamination and storage system in a low-income neighborhood of Karachi. METHODS: Fifty households received a 20-L plastic water storage vessel with a high-quality spout and a regular supply of diluted hypochlorite solution. Twenty-five control households were recruited. Water samples were collected at baseline and during unannounced follow-up visits 1, 3, 6, and 10 weeks later. RESULTS: Baseline drinking water samples among intervention households were contaminated with a mean 9397 colony-forming units (cfu)/100 mL of thermotolerant coliforms compared with a mean 10,990 cfu/100 mL from controls. After intervention the mean concentration of thermotolerant coliforms decreased by 99.8% among the intervention households compared with an 8% reduction among controls. Two years after vessel distribution, 34 (68%) of the families were still using the vessel. Thirteen of the households had stopped using their vessel because it had broken after more than 6 months of use, a pattern most consistent with ultraviolet radiation-induced degradation of the plastic. CONCLUSIONS: In a highly contaminated environment, a specifically designed water storage container and in-home water chlorination was acceptable and markedly improved water quality. Where plastic water vessels will be exposed to substantial sunlight, ultraviolet light stabilizers should be incorporated into the plastic.

Processes for obtaining nonmedical exemptions to state immunization laws.

OBJECTIVES: This study sought to determine the specific processes required for obtaining religious and philosophical exemptions to school immunization laws. METHODS: State health department immunization program managers in the 48 states that offer nonmedical exemptions were surveyed. Categories were assigned to reflect the complexity of the procedure within a state for obtaining an exemption. RESULTS: Sixteen of the states delegated sole authority for processing exemptions to school officials. Nine states had written policies informing parents who seek an exemption of the risks of not immunizing. The complexity of the exemption process, in terms of paperwork or effort required, was inversely associated with the proportion of exemptions field. CONCLUSIONS: In many states, the process of claiming a nonmedical exemption requires less effort than fulfilling immunization requirements.

Health consequences of religious and philosophical exemptions from immunization laws: individual and societal risk of measles.

CONTEXT: All US states require proof of immunization for school entry. Exemptions are generally offered for medical, religious, or philosophical reasons, but the health consequences of claiming such exemptions are poorly documented. OBJECTIVES: To quantify the risk of contracting measles among individuals claiming religious and/or philosophical exemptions from immunization (exemptors) compared with vaccinated persons, and to examine the risk that exemptors pose to the nonexempt population. DESIGN, SETTING, AND PARTICIPANTS: Population-based, retrospective cohort study of data from 1985 through 1992, collected by the Measles Surveillance System of the Centers for Disease Control and Prevention, as well as from annual state immunization program reports on prevalence of exemptors and vaccination coverage. The study group was restricted to individuals aged 5 to 19 years. To empirically determine and quantify community risk, a mathematical model was developed that examines the spread of measles through communities with varying proportions of exemptors and vaccinated children. MAIN OUTCOME MEASURES: Relative risk of contracting measles for exemptors vs vaccinated individuals based on cohort study data. Community risk of contracting measles derived from a mathematical model. RESULTS: On average, exemptors were 35 times more likely to contract measles than were vaccinated persons (95% confidence interval, 34-37). Relative risk varied by age and year. Comparing the incidence among exemptors with that among vaccinated children and adolescents during the years 1985-1992 indicated that the 1989-1991 measles resurgence may have occurred 1 year earlier among exemptors. Mapping of exemptors by county in California indicated that exempt populations tended to be clustered in certain geographic regions. Depending on assumptions of the model about the degree of mixing between exemptors and nonexemptors, an increase or decrease in the number of exemptors would affect the incidence of measles in nonexempt populations. If the number of exemptors doubled, the incidence of measles infection in nonexempt individuals would increase by 5.5%, 18.6%, and 30.8%, respectively, for intergroup mixing ratios of 20%, 40%, and 60%. CONCLUSIONS: These data suggest the need for systematic review of vaccine-preventable incidents to examine the effect of exemptors, increased surveillance of the number of exemptors and cases among them, and research to determine the reasons why individuals claim exemptions.

Impact of anti-vaccine movements on pertussis control: the untold story.

To assess the impact of anti-vaccine movements that targeted pertussis whole-cell vaccines, we compared pertussis incidence in countries where high coverage with diphtheria-tetanus-pertussis vaccines (DTP) was maintained (Hungary, the former East Germany, Poland, and the USA) with countries where immunisation was disrupted by anti-vaccine movements (Sweden, Japan, UK, The Russian Federation, Ireland, Italy, the former West Germany, and Australia). Pertussis incidence was 10 to 100 times lower in countries where high vaccine coverage was maintained than in countries where immunisation programs were compromised by anti-vaccine movements. Comparisons of neighbouring countries with high and low vaccine coverage further underscore the efficacy of these vaccines. Given the safety and cost-effectiveness of whole-cell pertussis vaccines, our study shows that, far from being obsolete, these vaccines continue to have an important role in global immunisation.

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.

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.

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.

Effect of urban versus rural residence and of maternal education on infant health in South Lebanon.

A sample of 253 women from rural and urban areas of south Lebanon were visited for 18 months after delivery. Information was collected on patterns of reproduction, infant feeding, and use of the health services. The findings indicate that educated women and women living in urban areas were better off in terms of family formation patterns, immunisation, and well-baby care. The importance of educating women, particularly in rural areas, as a policy that can be varied to improve child health and growth is thus emphasised. The study also indicates, however, the special need for health education programmes directed to all mothers to emphasise proper breast-feeding patterns and the importance of preventive health care for infants. The findings also indicate the need for a more diversified system of delivering health care in which properly trained paramedical personnel take part, particularly in rural areas.

Bottled beverages and typhoid fever: the Mexican epidemic of 1972-73.

A chloramphenicol resistant strain of S. typhi which caused a very large epidemic of typhoid fever in Mexico in 1972-73 survived in opened bottles of one carbonated drink with a pH of 4.6 for two weeks and in another such drink with a pH of 5.1 for six months. Bottled beverages are potential sources of large outbreaks of enteric disease, and deserve the same type of standards sand monitoring as comparable fluids such as milk.

Clinical features of types A and B food-borne botulism.

Medical records of 55 patients with type A and type B food-borne botulism reported to the Centers for Disease Control during 2 years were reviewed to assess the clinical features and severity of illness, diagnostic test results, nature of complications, amd causes of death. Some patients had features not usually associated with botulism including paresthesia (14%), asymmetric extremely weakness (17%), asymmetric ptosis (8%), slightly elevated cerebrospinal fluid protein values (14%), and positive responses to edrophonium chloride(26%). Several observation suggest that type A was more severe than type B disease. Although the case-fatality ratio was not significantly greater, patients with type A disease saw a physician earlier in the course of illness, were more likely to need ventilatory support, and were hospitalized longer. Patients who died were older than those who survived. Deaths within the first 2 weeks resulted from failure to recognized the severity of the disease or from pulmonary or systemic infection whereas the three late deaths were related to respirator malfunction.

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.

Infant mortality in Bekaa-Lebanon, 1979.

PIP: The study purpose was to determine the magnitude of infant mortality in the Bekka Mohafazat of Lebanon, to define its major causes, to try to correlate it with other possible influencing factors, and to determine whether the implementation of a new program for the treatment of diarrhea and prevention of its complications (sponsored by UN Agencies) should be a priority for Lebanon. The previously estimated birthrate for rural areas in Lebanon was 40/1000 and the estimated infant mortality rate was 60/1000. For this study to include around 60 cases of infant death, a sample of at least 25,000 was necessary. All newborns in the August 1976 to August 1979 period were studied; this meant 16 villages in 4 Qada's of Bekaa. A standard questionnaire was designed so that data could be obtained to record birthrate, infant mortality, causes of infant deaths and some other parameters. Parents were asked whether infants who died experienced diarrhea, respiratory symptoms, rash, or other major signs prior to death. The total sample size was 10,923. There were 997 newborns in the study period; 53 of these infants died within the 1st year of life. Data obtained for the whole Bekaa Mohafazat revealed a birthrate of 30.4/1000 and an infant mortality rate of 53.1/1000. Qada Baalbeck showed the highest birthrate (36.4/1000) as well as infant mortality rate (66.2/1000). The lowest infant mortality rate was found in Qada's Zahle (39.1/1000), and the lowest birthrate was noted in Qada's Hermel (18.9/1000). Of the total infant deaths, 47.1% had diarrhea prior to death and 43.4% had undefined conditions which reflects the parents' inability to assess objectively and to remember correctly the conditions of their infants before deaths. The remaining 9.5% cases had cough or rash prior to death. The study was conducted during July and August when diarrheal diseases are generaely more common, and this might have led to an overreporting of diarrhea as a condition prior to death. Prior to death, 50.8% of total deaths were treated in a hospital; 69.8% were treated by a physician at different levels of health care. No correlation was found between infant mortality and feeding habits of the newborns. No correlation was found between infant mortality and the mother's age and education, birth order, sex and age at death of the newborn.^ieng

Role of Norwalk virus in outbreaks of nonbacterial gastroenteritis.

Twenty-five separate outbreaks of nonbacterial gastrointestinal illnesses were studied serologically for evidence of infection with the Norwalk virus and the rotaviruses that affect humans. Eight of 25 outbreaks appeared to be related to the Norwalk virus. In one of the 25 outbreaks, there was evidence of rotavirus infection. These observations suggest that the Norwalk virus or serologically related agents play an important role in epidemic nonbacterial gastroenteritis in adults and older children.

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.