Exposure to diagnostic x-rays and incident age-related eye disease.

OBJECTIVE: The purpose of this study was to evaluate whether a self-reported history of computed tomography or other x-rays of the head were associated with the incidence of age-related cataracts and maculopathy five years later. METHOD: A 5-year longitudinal follow-up of the Beaver Dam Eye Study cohort (n=3,684, 43-86 years at baseline). RESULTS: There was no evidence of a relationship between the x-ray exposures and the incidence of nuclear or cortical cataracts, or early maculopathy. There was a significant relationship to the incidence of posterior subcapsular cataract after adjusting for age only. CONCLUSIONS: Adult patients in whom medical conditions warrant diagnostic x-rays of the head appear to be at little or no increased risk of age-related cataract or maculopathy. However, research efforts with more precise measures of x-ray exposure, longer follow-up, and further attempts to define uncontrolled confounders are warranted.

Cutaneous leishmaniasis in Guatemala: people's knowledge, concepts and practices.

Ten rural communities in the northern area of Guatemala where cutaneous leishmaniasis (CL) is endemic were investigated to determine the residents' knowledge of the disease, their related concepts and practices, and their treatment preferences, and to identify the communication channels they use to acquire information. Of 425 heads of household interviewed, 96.7% could accurately describe a typical CL lesion. CL was found to be the fourth most frequently mentioned disease (in studies based on a free list format) and to be considered the sixth most serious (in studies based on paired comparisons). A series of three-way comparisons, used to analyse the subjects' concepts about the similarities of various discases, indicated that CL was considered to be most closely related to skin problems and to be different from any other group of diseases. All interviewees believed that it was necessary to receive treatment for CL, because without treatment the disease would progress, reach the bone, and take years to heal. More than half (55%) of the respondents knew about meglumine antimonate (Glucantime), the most commonly prescribed drug for treating CL in Guatemala. Only a few communication channels that were used by respondents to receive information were identified; the use of radio broadcasts and direct communication via the community leaders appeared to be the most effective.

The contrasting epidemiology of Cyclospora and Cryptosporidium among outpatients in Guatemala.

We compared epidemiologic characteristics of Cryptosporidium and Cyclospora in surveillance data from outpatient departments in Guatemala. Routinely-submitted stool specimens were screened by microscopy. Age, sex, and symptom data were collected. Cyclospora was detected in 117 (2.1%) and Cryptosporidium in 67 (1.2%) of 5,520 specimens. The prevalence of Cyclospora peaked in the warmer months, while Cryptosporidium was most common in the rainy season. Both affected children more than adults, but Cryptosporidium affected children at a younger age than Cyclospora (median age 2 years versus 5 years; P < 0.001). Cyclospora showed a stronger association with diarrhea than Cryptosporidium, even when data were stratified by age. These contrasts may reflect differences in the relative importance of transmission modes, the frequency of exposure, and the development of immunity.

Epidemiologic studies of Cyclospora cayetanensis in Guatemala.

In 1996 and 1997, cyclosporiasis outbreaks in North America were linked to eating Guatemalan raspberries. We conducted a study in health-care facilities and among raspberry farm workers, as well as a case-control study, to assess risk factors for the disease in Guatemala. From April 6, 1997, to March 19, 1998, 126 (2.3%) of 5, 552 surveillance specimens tested positive for Cyclospora; prevalence peaked in June (6.7%). Infection was most common among children 1.5 to 9 years old and among persons with gastroenteritis. Among 182 raspberry farm workers and family members monitored from April 6 to May 29, six had Cyclospora infection. In the case-control analysis, 62 (91%) of 68 persons with Cyclospora infection reported drinking untreated water in the 2 weeks before illness, compared with 88 (73%) of 120 controls (odds ratio [OR] 3.8, 95% confidence interval [CI] 1.4, 10.8 by univariate analysis). Other risk factors included water source, type of sewage drainage, ownership of chickens or other fowl, and contact with soil (among children younger than 2 years).

Consensus theory model of AIDS/SIDA beliefs in four Latino populations.

To describe Latino beliefs about AIDS (SIDA), Latino adults were sampled at two U.S. sites (Connecticut and Texas) and two international sites (Mexico and Guatemala). A 125-item questionnaire covered risk factors, symptoms, treatments, and sequellae of AIDS. The cultural consensus model was used to determine the cultural beliefs for each sample. Responses from 161 people indicated that a single set of beliefs was present at each site and that beliefs were shared across sites. Comparison of answers between samples indicated high agreement (p < .0007). The proportion of shared beliefs, however, decreased significantly between samples: .68 in Connecticut, .60 in Texas, .51 in Mexico, and .41 in Guatemala (p < .05). The proportion of positive answers similarly decreased from Connecticut to Guatemala (p < .001). Beliefs were stronger and more detailed in the higher prevalence areas. Furthermore, Latino beliefs tended to converge on biomedical beliefs about the disease.

Incident cataract after a five-year interval and lifestyle factors: the Beaver Dam eye study.

CONTEXT: A population-based study to investigate risk factors for age-related eye disease was begun in 1987 in a representative American community. Incidence of cataract was subsequently evaluated. SPECIFIC OBJECTIVES: To examine the relationships of cigarette smoking, alcohol, and caffeine intakes to incidence of age-related cataracts five years later. DESIGN: Observational epidemiologic incidence study of an adult population. PARTICIPANTS AND INTERVENTION: Adults 43-84 years of age were identified during a census in 1987-1988, and examined at baseline (1988-1990) and after a five-year interval (1993-1995). MAIN OUTCOME MEASURE: Standardized protocols were used at the baseline and follow-up evaluations for exposures and for objective identification of cataracts. RESULTS: Cumulative incidence of nuclear cataract in right eyes was about 12%, cortical cataract about 8%, and posterior subcapsular cataract about 3%. In multivariable analyses of the general estimating equations type, there were significant associations between nuclear cataract and: pack-years smoked (odds ratio [OR] 1.05, 95% confidence interval [CI] 1.01, 1.09 per 10 pack-years); and current alcohol intake (OR 1.01, 95% CI 1.00, 1.02 per 10 grams ethanol/week). Cigarette smokers were more likely to have had cataract surgery in the interval between baseline and follow-up examinations. CONCLUSIONS: Cigarette smoking and alcohol consumption were associated with modestly increased risks of incident nuclear cataract over a five-year interval.

Latino beliefs about diabetes.

OBJECTIVE: To describe Latino beliefs about diabetes and assess heterogeneity in beliefs across different groups. RESEARCH DESIGN AND METHODS: This study comprised a survey of 161 representative Latino adults from four diverse communities: Hartford, Connecticut; Edinburg, Texas; Guadalajara, Mexico; and rural Guatemala. A 130-item questionnaire covered causes symptoms, and treatments for diabetes. Information on demographics and acquaintanceship with someone with diabetes was also collected. The cultural consensus model was used to analyze the variation in responses to determine whether the degree of consistency within and between samples was sufficient to warrant aggregation and description as a single set of beliefs. RESULTS: Homogeneous beliefs were present within each of the four samples. Although variability in responses increased significantly from Connecticut to Guatemala (P < 0.00005), there was significant agreement between samples on the answers (P < 0.0005). Answers tended to be concordant with the biomedical description of diabetes. Greater acculturation, higher educational attainment, and higher diabetes prevalence were associated with greater cultural knowledge about diabetes. In Connecticut, greater knowledge correlated with longer mainland U.S. residency (P < 0.05). In Mexico, those with average educational attainment knew more (P < 0.05). Finally, average knowledge levels were higher in communities with greater diabetes prevalence. CONCLUSIONS: The cultural consensus model facilitated assessment of cultural beliefs regarding diabetes and diabetes management. Overall, Latino cultural beliefs about diabetes were concordant with the biomedical model. Variation in responses tended to characterize less knowledge or experience with diabetes and not different beliefs.

Predicting treatment-seeking behavior in Guatemala: a comparison of the health services research and decision-theoretic approaches.

This study attempts to identify and describe factors associated with the choice of a health care source in rural Guatemala. Because of limited choice options, rural Guatemala makes an excellent location for studying the factors that affect utilization patterns. Illness case histories were collected from a random sample of 270 households in six villages. Then, two different methodological approaches were used to predict treatment actions. First, a sociobehavioral model, which encompasses enabling, predisposing, and need factors, was used to predict treatment choices. Using discriminant analysis we identified factors associated with the use of home remedies, a pharmacy, the health post, a physician, or folk healer. In a second, parallel study, descriptive interviews were used to identify important factors in choosing a treatment strategy. From these interviews, and from responses to hypothetical illness cases, we developed a decision model of treatment actions. Both models were tested against the set of illness cases. Results indicate that both approaches identify similar variables (especially, severity), although selection of variables through the multivariate analysis was much more successful in predicting treatment actions.

Data and information requirements for determining veterans' access to health care.

The Department of Veterans Affairs (VA) is responding to changing requirements for decision-support data by maximizing the value of data contained in VA and non-VA sources. The data are used to answer questions relating to the accessibility and utilization of VA and non-VA health services. Access studies require accurate estimates of the number of persons served and the number of persons who could be served. To derive these population estimates, VA employs census data to develop projections of the veteran population at the national, state, and county levels. Data from many surveys are used to supplement the census data. Access studies also require quantitative and qualitative data on the characteristics of VA and non-VA health care delivery systems at the national, state, and local levels. The Department of Veterans Affairs obtains health care system data from external sources, including the US Department of Health and Human Services, the American Medical Association, and the American Hospital Association, and from internal sources, including VA surveys and the VA administration inpatient and outpatient files. Utilization studies need more detailed patient-level information than access studies. Data elements pertaining to the reason for health care encounters and the services rendered are obtained from survey data, the VA inpatient and outpatient administration files, the national Medicare database, and state Medicaid databases. The Department of Veterans Affairs'decision-support analyses for eligibility reform and health care system reform demonstrate the effectiveness of VA in analyzing data from many sources.

Knowledge, attitudes and practices during a community-level ivermectin distribution campaign in Guatemala.

Community acceptance and participation are essential for the success of mass ivermectin chemotherapy programmes for onchocerciasis (river blindness). To explore the local understanding of the purpose of ivermectin and willingness to continue taking the drug, we performed questionnaire surveys in four communities with hyperendemic onchocerciasis after each of three ivermectin treatment rounds. More than 100 respondents participated in each KAP survey, representing the heads of 30% of the households in each community. The respondents rarely stated that the goal of the ivermectin treatment programme was to prevent visual loss. Instead, they said they were taking the drug for their general well-being, to cure the onchocercal nodule (filaria), or to cure the microfilaria, a term newly introduced by agents of the treatment programme. The principal reason identified for refusal to take ivermectin was anxiety about drug-related adverse reactions, and there were marked differences between communities in acceptance of treatment. In one community over 50% of residents initially refused to take ivermectin, although participation rates improved somewhat after programmatic adjustments. We recommend that ivermectin distribution programmes establish surveillance activities to detect where acceptance is poor, so that timely and community-specific adjustments may be devised to improve participation.

Knowledge, beliefs, and practices in relation to malaria transmission and vector control in Guatemala.

As part of an effort to involve community members in malaria control activities, we studied knowledge, beliefs, and practices of residents of both the Pacific coastal plain and northeastern Guatemala related to malaria transmission and Anopheles albimanus control. Most residents recognized the role of mosquitoes in malaria transmission, but few knew how mosquitoes acquired their infections or understood the risk of having an untreated person in their midst. If this were more widely known, residents might put greater pressure on infected patients to seek timely and appropriate antimalarial treatment. Seventy-three percent of families owned one or more bed nets; however, even though most informants believed that bed nets help protect against malaria, the major reason for using them was to prevent nuisance mosquito bites. It is concluded that efforts should be made to promote bed net use by seeking ways to make them more affordable and by emphasizing their effectiveness as a barrier to nuisance mosquitoes. Although residents have a very positive opinion of the National Malaria Service spray teams, it is proposed that cooperation might be improved if malaria workers would emphasize the fact that house spraying reduces the numbers of nuisance mosquitoes and other pest insects, rather than focusing solely on malaria prevention, which most informants believed was less important. This study emphasizes the importance of understanding community beliefs and practices when planning or evaluating vector control activities.

Qualities of an ideal volunteer community malaria worker: a comparison of the opinions of community residents and national malaria service staff.

Since the late 1950s, most malaria surveillance and treatment in rural areas of Latin America has been carried out by networks of unpaid community malaria workers, known as Volunteer Collaborators, who are selected and supervised by staff of the national malaria services (NMSs) in each country. In spite of the free and readily accessible antimalarial treatment available at these Volunteer Collaborator posts, many residents continue to seek treatment elsewhere and in most cases take doses of antimalarials that are insufficient to cure their infections. To identify ways in which the Volunteer Collaborator Network could be made more attractive to residents and to improve the process of selection of new workers, we asked community residents and Guatemalan NMS workers to rank order, according to their importance, 11 qualities or characteristics of an 'ideal' volunteer malaria worker. Community residents preferred someone who is available to take care of patients at all times of the day, is a responsible person, and has a general knowledge of medicine. No significant differences were noted in the rank orders of male and female residents or literate and illiterate residents. National Malaria Service workers also preferred someone who takes care of patients at all times of the day, even when busy. In addition, they wanted individuals who recognize the importance of their work as a Volunteer Collaborator, but choosing volunteers who had a general knowledge of medicine was not important. By modifying the procedures used to select Volunteer Collaborators so as to identify candidates with the qualities preferred by residents, it should be possible to increase acceptance and improve the performance of these volunteer workers.

Effects of permethrin-impregnated bed nets on malaria vectors of northern Guatemala.

The authors evaluated the effects on malaria vectors of bed nets impregnated with permethrin over the course of a 16-month controlled study in four communities of Northern Guatemala. Anopheles albimanus and An. vestitipennis were the known malaria vectors in the area. Households were allocated to one of three experimental groups: those receiving bed nets impregnated with 500 mg/m2 of permethrin, those receiving untreated bed nets, and those where no intervention measures were taken. The impact of the treated and untreated bed nets on mosquito abundance, behavior, and mortality was determined by indoor/outdoor night-bite mosquito collections, morning pyrethrum spray collections, inspection of bed net surfaces for dead mosquitoes, and capture-release-recapture studies. The duration of the treated nets' residual insecticide effect was assessed by modified WHO cone field bioassays, and their pyrethrin content was estimated by gas-liquid chromatography analysis. The most important observation was that fewer mosquitoes were found to be resting in the households with treated bed nets. The treated nets probably functioned by both repelling and killing vector mosquitoes. Capture-release-recapture studies showed exit rates from houses with treated nets were higher (94%) than those from control houses (72%), a finding that suggests repellency. However, no significant differences were noted between the indoor night-bite mosquito collections at houses with and without treated nets. The horizontal surfaces of treated bed nets were nearly 20 times more likely to contain dead anopheline mosquitoes than were the comparable surfaces of untreated nets. the bioassays indicated that unwashed permethrin-impregnated bed nets retained their insecticidal activity for 6 months after treatment.

Community participation in malaria surveillance and treatment. III. An evaluation of modifications in the Volunteer Collaborator Network of Guatemala.

In most rural areas of Latin America, malaria surveillance and treatment is carried out by a network of unpaid village malaria workers, known as Volunteer Collaborators, who are trained and supervised by the National Malaria Service. To identify ways in which the performance of these volunteer workers could be improved and to test changes that would make the Volunteer Collaborator Networks (VCNs) a more attractive model for community participation in malaria case detection and treatment in other regions, we tested a series of modifications in the VCN of Guatemala. These modifications included improved methods for selecting, supervising, and evaluating the volunteer workers and for collecting blood smears and reporting results, and the use of volunteer workers, known as Volunteer Medicators, who administered presumptive antimalarial therapy without taking a blood smear. A cost-effectiveness analysis of the modified VCN was also carried out. Two years after the modifications were introduced, Volunteer Collaborators identified nearly twice as high a percentage (33% versus 17%) of patients with suspected malaria in their villages. Delays in examining blood smears were reduced from 23 days to 11 days and delays from blood smear examination to curative treatment were reduced from 21 days to 7 days. The Volunteer Medicators identified and treated only a slightly higher percentage of patients than the Volunteer Collaborators (36% versus 33%). However, the cost of maintaining a network of Volunteer Medicators ($0.61 per patient treated) was much lower than the traditional VCN ($2.45) or the modified VCN ($1.85). Thus, with a few, simple and relatively inexpensive modifications, the efficiency and cost-effectiveness of Volunteer Collaborators can be markedly improved. Additionally, the VCN can be modified to make it a more suitable model for community-based malaria control and surveillance networks in other malarious areas of the world, which differ in terms of their level of endemicity, the goals of the malaria program, or the available health care infrastructure.

Permethrin-impregnated bed nets for malaria control in northern Guatemala: epidemiologic impact and community acceptance.

Permethrin-impregnated bed nets were evaluated as a control measure for malaria in northern Guatemala. Twelve hundred forty participants were allocated to one of three experimental groups (impregnated bed nets [IBN], untreated bed nets [UBN], and controls) and followed up for a period of 13 months. The incidence density of malaria was significantly lower in both IBN (86 cases/1,000 person-years) and UBN groups (106/1,000) compared with that in controls (200/1,000). No difference in malaria incidence was noted between the IBN and UBN groups. Complaints of fever and chills were less frequent in the IBN group compared with controls. The participants were enthusiastic about the nets, which they saw as a means for avoiding nuisance insects more than for preventing malaria. Most (85%) wanted to wash their nets every 4-12 weeks, a practice known to shorten the duration of residual insecticide action. Larger studies are needed to determine whether or not impregnated bed nets offer an advantage over untreated nets in this setting.

Knowledge and beliefs about malaria on the Pacific coastal plain of Guatemala.

Surveys of residents of the Pacific coast of Guatemala revealed a lack of knowledge and many misconceptions about the transmission and treatment of malaria, which could adversely affect malaria control measures and antimalarial therapy. Although mosquitoes are known to play an important role in malaria transmission and are thought to become infected by biting individuals with malaria, 75% of people interviewed believe that the mosquitoes can also acquire infections from contaminated water or by biting snakes and frogs. Furthermore, most residents believe that malaria can be acquired in other ways, such as by bathing too frequently or by drinking unboiled water. Although self-treatment of malaria with oral and injectable drugs purchased at stores and pharmacies is very common, less than 10% of the respondents were aware of the correct curative dose of chloroquine. Chloroquine injections are preferred to tablets and believed to be approximately three times as potent as tablets of the same concentration. Nearly two-thirds of the interviewees believed that pregnant and lactating women with malaria should avoid the use of chloroquine because it may cause a spontaneous abortion or dry up breast milk. Similar surveys of National Malaria Service workers and village malaria workers revealed higher levels of knowledge, although the village workers had many misconceptions about malaria transmission. An educational campaign directed at correcting some of these misconceptions should result in more appropriate self-treatment of malaria and greater acceptance by residents of personal protection methods and vector control and drug treatment programs.

Community participation in malaria surveillance and treatment. II. Evaluation of the volunteer collaborator Network of Guatemala.

To evaluate the effectiveness of the Volunteer Collaborator Network (VCN) of Latin America as a community-based malaria case detection and treatment system, we conducted a study of the VCN of Guatemala. Volunteer Collaborators took 72.6% of all blood smears and identified 81.3% of all malaria cases reported by the Guatemalan National Malaria Service. The average volunteer treated 5.8 patients per month (range 0-32.8). In contrast, passive case detection (PCD) posts in government hospitals and health centers treated an average of 12.5 patients per month (range 0.5-91.4). The slide positivity rate of blood smears taken by Volunteer Collaborators was 16.2% compared with 9.7% for PCD posts in health centers and 10.3% for malaria workers during active case detection. The average delay between the date a blood smear was taken and examined ranged from 18.1 days on the Pacific coastal plain to 26.3 days in the less accessible northern region of the country. An additional 14.5 to 47.6 days elapsed before the radical treatments were initiated in these two regions. Seventy percent of the patients completed their radical treatments. In a survey conducted on the Pacific coastal plain of Guatemala, of 1,021 patients with chills and/or fever who believed they had malaria, 20.0% had visited a Volunteer Collaborator and 4.9% were treated at a government health center. Thus, the PCD network detected only 25% of all patients with symptoms suggestive of malaria. Most of the remaining patients treated themselves with antimalarial medications purchased in stores and pharmacies, but less than 15% of these patients used adequate courses of therapy. Furthermore, the rate of detection of symptomatic patients with malaria varied considerably from one community to another. Thus, data from the VCN are probably most useful when groups of communities or geographic areas are stratified for malaria control activities because at this level, variations between individual Volunteer Collaborator posts will be minimized. In spite of these problems, the VCN remains an excellent source of epidemiologic data for malaria control programs and the most practical means available for providing timely, appropriate antimalarial therapy to febrile patients in rural areas.