Perspectives of public health and prevention.

The average life expectancy at birth of Americans has increased 30 years since the turn of the century and is mostly attributable to public health measures. Although death rates for cardiovascular diseases have declined in the past two decades, cardiovascular diseases still cause more deaths in the United States than all other causes combined. The major etiologies of heart disease, atherosclerosis and hypertension, are associated with modifiable risk factors--high blood cholesterol, high blood pressure, cigarette smoking, diet, and inactivity. Social status and access to medical care are also important contributors. Consequently, the greatest potential for reducing heart disease mortality and morbidity rests with prevention and public health practice. Recent directions in health-care reform emphasize fiscal management, medical care, and clinical medicine, and not general health. This emphasis exacerbates policy and financing imbalances between preventive and curative medicine. Consequently, the concept of a health system needs to be designed more rationally to allocate resources that include prevention and health promotion. The Bogalusa Heart Study provides understanding of the early origin of cardiovascular problems and the environmental and lifestyle factors that contribute to development of adult heart disease. To apply this information, public health models of intervention, like the school Health Ahead/Heart Smart program, are needed to address heart disease in the population. Changes in the true determinants of poor health, such as environmental factors and unhealthy behaviors, are the directions for prevention and future improvement in quality of life.(ABSTRACT TRUNCATED AT 250 WORDS)

Intestinal parasitism in the United States: update on a continuing problem.

To document patterns of intestinal parasitism in the United States, we analyzed results of 216,275 stool specimens examined by the state diagnostic laboratories in 1987; parasites were found in 20.0%. Percentages were highest for protozoans: Giardia lamblia (7.2%), Entamoeba coli and Endolimax nana (4.2% each), Blastocystis hominis (2.6%), and Entamoeba histolytica (0.9%). The most commonly identified helminths were nematodes: hookworm (1.5%), Trichuris trichiura (1.2%), and Ascaris lumbricoides (0.8%). Identifications of G. lamblia increased broadly from the 4.0% average found in 1979, with 40 states reporting increases and seven reporting decreases. Seasonally, Giardia identifications increased in the summer and fall, especially in the Midwest. Nine states reported hookworms in more than 2% of specimens; none were states with indigenous transmission. We analyzed similar, but abbreviated, data for 1991; parasites were found in 19.7% of the 178,786 specimens and Giardia was found in 5.6%. States reporting percentages of Giardia identification in the highest quartile for both 1987 and 1991 were located in the Midwest or in the Northwest. Cryptosporidium was identified in both the 1987 and 1991 surveys; it had not been identified in a previous survey. For each year, Cryptosporidium was reported from 25 states across the country (for both years in 17 states). We conclude that intestinal parasitism should not be overlooked as a cause of gastrointestinal illness in the United States and that the prevalence of Giardia may be increasing.

Recent trends in the prevalence and distribution of schistosomiasis in the Nile delta region.

In 1983, a survey of 71 villages in the Nile delta demonstrated that the overall prevalence of Schistosoma mansoni and S. haematobium infections was 39% and 5%, respectively. Recent increased availability of praziquantel, combined with Egyptian Ministry of Health-sponsored media efforts to educate the public about schistosomiasis, prompted us to determine the current status of S. mansoni and S. haematobium infections in the delta and evaluate any changes that may have occurred since the previous survey. The same villages that participated in the 1983 survey were resampled in 1990. Stool and urine samples were requested from all occupants over the age of two years in a 5% sample of houses within each village. Stool (Kato) thick smears and urine sediments were read qualitatively at the rural health station. Field-prepared Kato smears and a 20% sample of urine specimens were forwarded to the Ministry of Health Laboratory, where quantitative readings were also performed. Analysis of samples obtained from 17,310 persons revealed that S. mansoni prevalence had decreased to 23% and that S. haematobium prevalence had decreased to 3% (P < 0.001). The highest levels of schistosome infection were found in governates located in the eastern section of the delta. The observed changes in the prevalence of S. mansoni and S. haematobium suggest that control measures are having a favorable impact on schistosomiasis transmission in this region.

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.

Infectious diseases and injuries in child day care. Opportunities for healthier children.

OBJECTIVE: To provide pertinent background information on infectious diseases and injury in child day care and outline measures to address these health care needs. DESIGN: We reviewed published English-language literature identified through a MEDLINE bibliographic search, major literature summaries, and bibliographies from identified articles. SETTING: Child day-care settings reviewed included family child care homes, centers, special facilities for ill children, and facilities for children with special needs. PATIENTS OR OTHER PARTICIPANTS: Primarily children in a variety of day-care settings, often compared with children cared for at home. MAIN OUTCOMES: The occurrence of outbreaks and illness related to infectious disease and injury. RESULTS: Compared with preschool-aged children reared at home, among children in day care the risk of some infectious diseases was two to four times greater. Rates of both intentional and unintentional injuries in day-care settings were somewhat lower than those for children cared for at home. CONCLUSIONS: Because preschool-aged children spend increasing time in structured day-care settings, the risk for some infectious diseases has increased. At the same time, child day-care settings present opportunities for ensuring healthier children through enhanced development, safer environments, better nutrition, increased vaccination coverage, and health promotion.

Alterations in filarial antigen-specific immunologic reactivity following treatment with ivermectin and diethylcarbamazine.

The presence of circulating microfilariae has been associated with alterations in B and T cell functions. In this study, we compared the influence of diethylcarbamazine (DEC) and ivermectin on filarial antigen-specific immune responses in a Haitian population. Both drugs were effective at reducing microfilaremia levels to less than 10% of pretreatment levels for up to one year. This reduction in microfilaremia was associated with two phases of altered cellular responsiveness monitored with in vitro assays. Five days post-treatment, cellular proliferation in response to both filarial and nonfilarial antigens was significantly increased, as was the background response in the absence of any antigen. At both nine months and one year post-treatment, the filarial antigen-specific reactivity of both DEC- and ivermectin-treated patients was significantly increased over baseline levels. No differences were observed between the two treatment groups in terms of humoral or cellular reactivity to filarial antigens, despite evidence suggesting a role for DEC in adult worm killing. These results provide additional evidence that microfilariae modulate antifilarial immune reactivity.

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.

Evaluation of a commercially available enzyme-linked immunosorbent assay for Giardia lamblia antigen in stool.

The lack of a quick, simple, and inexpensive diagnostic test has limited the ability of public health officials to rapidly assess and control outbreaks of Giardia lamblia in child day-care centers. We evaluated the performance of a commercially available enzyme-linked immunosorbent assay (ELISA) for the detection of a G. lamblia-associated antigen in stool. Stool specimens were collected from the diapers of 426 children attending 20 day-care centers, fixed in 10% Formalin and polyvinyl alcohol, and examined by microscopy by Formalin concentration and trichrome staining techniques. Specimens were also tested visually and spectrophotometrically by ELISA. Of 99 tests positive by microscopy, 93 were visually positive by ELISA (sensitivity, 93.9%). Of 534 tests negative for G. lamblia by microscopy, 32 (6.0%) were ELISA positive. However, on the basis of examination of multiple specimens from the same child, none of these could be considered false-positive ELISAs; the specificity of the ELISA was therefore 100%. The sensitivity of both microscopy and ELISA improved as the number of specimens per child increased. An optical density value of greater than 0.040 was 98.0% sensitive and 100% specific for G. lamblia. This ELISA, which appeared to be more sensitive for G. lamblia than did microscopic examination of stool, should be useful as an epidemiologic tool, particularly in day-care settings, and may also have a role in confirming clinical diagnoses of giardiasis.

Comparison of high dose ivermectin and diethylcarbamazine for activity against bancroftian filariasis in Haiti.

This three-phase study was designed to compare high dose ivermectin with a standard diethylcarbamazine (DEC) regimen for patient tolerability, potential to kill adult filaria, and duration of microfilarial suppression in 30 Haitian subjects with Wuchereria bancrofti microfilaremia. All were first given a 1-mg oral dose of ivermectin (phase 1) to reduce microfilaria densities. Participants were randomized into three groups: Group 1 received DEC (6mg/kg per day for 12 days), Group 2 received 200 mcg/kg of ivermectin, and Group 3 received 400 mcg/kg of ivermectin (200 mcg/kg per day for 2 days). All drug regimens were well tolerated with few adverse reactions. Most reactions occurred during phase I and consisted primarily of headache, fever, and myalgia. At the end of phase 1, 27 of 30 (90%) patients were microfilaria negative. During phase 2, four of the six men receiving DEC developed scrotal reactions suggesting killing adult worms; no such reactions were noted in 10 men receiving ivermectin (p less than 0.05). At one-year follow up (phase 3), all treatment groups had less than 10% return to pretreatment microfilaria levels. The mean percent of baseline microfilaria counts were for Group 1, 0.9% (range 0-5%); Group 2, 8.2% (range 0-31%); and Group 3, 3.8% (range 0-25%). Seven individuals in Group 1 were microfilaria-negative, while only one and three individuals were microfilaria-negative in Groups 2 and 3, respectively. These results suggest that DEC causes more damage to the adult worms and greater reduction in microfilaria densities than ivermectin, but that high doses of ivermectin may suppress microfilaremia in lymphatic filariasis for periods much longer than previously reported.

Evaluation of UNICEF/Arab Republic of Egypt/WHO schistosomiasis Control Project in Beheira Governorate.

We evaluated the UNICEF/Government of Egypt/WHO Schistosomiasis Control project in 2 districts of Beheira Governorate of the Nile Delta during 3 weeks in February 1988. The project, begun in 1983, was focused on reducing prevalence, intensity, and morbidity due to schistosomiasis by providing diagnosis and treatment with praziquantel to schoolchildren. Schools were visited twice. Following the completion of the school surveys, the program was extended into the community. Chemotherapy was delivered by mobile and static teams. The evaluation indicated that, with respect to accuracy of diagnosis, record-keeping, and coverage of targeted populations, project tasks were performed exceedingly well by highly motivated, well-supervised mobile teams. Static teams in rural health centers were less successful in providing diagnosis and chemotherapy to village populations. We resurveyed 6 randomly selected schools to assess the impact of chemotherapy. Overall, the prevalence of Schistosoma mansoni infection was reduced from 60.3% to 24.8% between the first and second surveys (approximately 1 year apart) and was still lower (41.1%) than initial levels up to 3 years after the last treatment with praziquantel. The percentages of those with greater than or equal to 34 S. mansoni eggs/slide using the Kato-Katz technique showed a marked and prolonged decrease (17.1% to 0.3% to 2.2%). The prevalence of S. haematobium infection dropped from 37.6% to 5.5% and was still 9.9% at the time of the evaluation. The percentages of those with greater than or equal to 50 S. haematobium eggs/10 ml urine dropped less dramatically (17% to 4.4% to 11.9%). Mobile teams conducting vigorous chemotherapy programs targeted at schoolchildren can have long-lasting benefits in terms of prevalence and intensity.

The Saradidi, Kenya, rural health development programme.

A primary health care community development programme was initiated in 1979 by people living in Saradidi, Kenya. The community was involved in planning, organization, setting of priorities and objectives, implementation, evaluation and benefits. This paper describes the developmental process that occurred including how the programme began, how it was organized and what it attempted to accomplish.

Changes in sources of treatment occurring after inception of a community-based malaria control programme in Saradidi, Kenya.

To determine the changes in source of antimalarial treatment and perceptions about malaria after the initiation of a community-based malaria control programme in Saradidi, Kenya, two identical surveys were carried out; one in March 1982 (before the programme began in May 1982) and the other in December 1984. Three areas were involved: areas A and B had antimalarial treatment provided by village health helpers (VHH's) and area C had VHH's who did not provide treatment. Two groups of randomly selected women age 15 to 59 years were interviewed: 45 in survey 1 and 92 in survey 2. A decided change in the source of malaria treatment was observed. In the first survey, 52.9% of the respondents from areas A and B combined purchased antimalarial medicine from shops; other sources were government health facilities, mission clinics, and the Saradidi community clinic. By the second survey, 85.2% of the respondents in areas A and B obtained treatment from the VHH's; no significant change occurred in area C. In both surveys the leading reasons given for people purchasing drugs from shops was that the distance to health facilities was great, that no transport was available and that shops were open when emergencies occurred. The shopkeeper frequently advised which drug to take and the dosage as well as selling the drugs. For family illnesses of unknown aetiology most people (82.2% in survey 1 and 97.8%, in survey 2) went to a hospital or clinic. These results demonstrate that the malaria control programme in Saradidi has influenced both the source of antimalarials and the attitudes people have about malaria. In Saradidi, Kenya people chose to obtain antimalarial treatment and advice from community health workers.

Usage of community-based chloroquine treatment for malaria in Saradidi, Kenya.

A survey was done in June 1983 in Saradidi, Kenya, one year after the inception of a community-based malaria control programme to determine if people were obtaining malaria treatment from volunteer village health helpers (VHH's) chosen by the community. Ten of 36 villages were randomly chosen. From these ten villages, 100 households were randomly selected and 222 people ten years of age or more were interviewed; 113 (50.9%) had a history of malaria in the previous two weeks and 82 (72.6% of 113) had taken medicine for malaria in that period. Of these 82, 51.2% obtained drug from the VHH, 28% purchased it from a shop, 12.2% from a health facility, 4.9% from family members and 3.7% from a private practitioner or a shop outside Saradidi. Reasons given for not obtaining treatment from the VHH's among the 40 people who went elsewhere for treatment included: the VHH was not at home when needed (35%); the VHH had no drugs (22.5%); the patient was too sick for the VHH to treat (10%); had drugs already in the home (10%); 'not registered' with VHH (10%); VHH 'no good' (7.5%); and more 'convenient' to go elsewhere (5%). Similar results found on questioning the mother were obtained for 103 children under nine years old in these households; 67 (65.0%) children had a history of malaria in the previous two weeks and 59 (88.1%) of these 67 children had received antimalarial treatment. The VHH was the principal source of treatment (50.8% of 59), followed by health facilities (20.3%) and shops (18.6%).(ABSTRACT TRUNCATED AT 250 WORDS)

Consumption of chloroquine phosphate provided for treatment of malaria by volunteer village health workers in Saradidi, Kenya.

A community-based malaria control programme in Saradidi, Kenya provided chloroquine treatment for malaria in each village beginning in May 1982. Malaria was holoendemic in Saradidi. Treatment was provided by volunteer community health workers chosen and supported by the village. Consumption of the drug and characteristics of persons treated were recorded. Between 1 September 1982 to 31 August 1983, 40,649 treatments with chloroquine were given to village residents. The treatment rate per person in the mid-year population was 1.24. However, at least 41.8% of the mid-year population of 32,650 did not receive a single treatment. Multiple treatments were given to 50.5% of persons treated at least once and 13.4% of 13,879 persons treated at least once received five or more treatments during the year. Consumption patterns were not random: they were higher in females, in persons above 30 years of age and in the area with greater community organization and community participation. There is need to ascertain the reasons why so large a proportion of the population never received a single treatment in this highly malarious area and why adults who should not have had a high frequency of clinical malaria were treated so often. Nonetheless, the results demonstrate that volunteer community health workers can effectively provide treatment for malaria.

Symptoms associated with common diseases in Saradidi, Kenya.

A community-based malaria control programme was initiated in Saradidi, Kenya. One factor determining the utilization of treatment would be the symptoms felt to be diagnostic of malaria. The 12 most common diseases and 29 most common symptoms were identified by community members. Thirty-six randomly selected women were interviewed to determine association of the common diseases and symptoms; nine women were aged 15 to 29 years, nine women were 30 to 40 years, nine were 45 to 59 years and nine were 60 years or more. Women 60 years and older recognized a higher proportion of the diseases (P less than 0.0005) when compared with the other women of other ages. More than 90% of the women associated headache, fever, vomiting, joint pain, loss of appetite, tiredness and death with malaria. Measles and influenza were distinguished from malaria by rash and mouth ulcer for measles and by 'runny nose' and 'sneezing' for influenza. Analysis by average linkage hierarchical clusters revealed that malaria, influenza and measles were distinguished readily. The results suggest that if people in Saradidi do not obtain treatment from community health workers, it is not because they do not recognize the clinical symptoms of malaria.