The isolation of Leishmania braziliensis from sloths in Costa Rica.

Eight out of 47 Bradypus griseus and 14 out of 18 Choloepus hoffmanni yielded positive cultures for flagellates from blood, skin, liver or spleen. In some cases, more than one species of flagellate was isolated from one animal or site. Although amastigotes were obtained in tissue cultures from several isolates containing different types of promastigotes, only four of these strains (two from each species of host) were infective for hamsters and considered as Leishmania braziliensis. Infection with one of the strains was possible only after it has been passed through tissue culture.     

Diarrheagenic Escherichia coli in Children from Costa Rica

More than 5,000 diarrheal cases per year receive medical care at the National Children''s Hospital of Costa Rica, and nearly 5% of them require hospitalization. A total of 173 Escherichia coli strains isolated from children with diarrhea were characterized at the molecular, serologic, and phenotypic level. Multiplex and duplex polymerase chain reactions were used to detect the six categories of diarrheagenic E. coli. Thirty percent (n = 52) of the strains were positive, indicating a high prevalence among the pediatric population. Enteropathogenic E. coli and enteroinvasive E. coli pathotypes were the most prevalent (21% and 19%, respectively). Pathogenic strains were distributed among the four E. coli phylogenetic groups A, B1, B2, and D, with groups A and B1 the most commonly found. This study used molecular typing to evaluate the prevalence of diarrheagenic E. coli reported in Costa Rica and demonstrated the importance of these pathotypes in the pediatric population.     

Risk factors for childhood asthma in Costa Rica

BACKGROUND: Little is known about factors determining the pathogenesis and severity of asthma in Latin American countries. Costa Rica, one of the most prosperous Latin American nations, has a very high asthma prevalence. OBJECTIVE: To examine the relation between potential risk factors and childhood asthma in Costa Rica. METHODS: Cross-sectional study of 214 schoolchildren aged 10 to 13 years participating in phase II of the International Study of Asthma and Allergies in Childhood. RESULTS: After adjustment for age, gender, area of residence, maternal smoking during pregnancy, and airway responsiveness to hypertonic saline solution, sensitization to house dust mites was associated with asthma (odds ratio [OR], 2.2; 95% confidence interval [CI], 1.1 to 4.4; p = 0.02). In the multivariate analysis, parental education no higher than high school (OR, 3.0; 95% CI, 1.4 to 6.4; p < 0.01) and parental history of asthma (OR, 2.6; 95% CI, 1.3 to 5.2; p < 0.01) were also independent predictors of childhood asthma. CONCLUSIONS: Sensitization to house dust mites, low parental education, and parental history of asthma are associated with asthma in Costa Rica.     

Evolution of the measles vaccination program in Costa Rica

The vaccination program instituted in Costa Rica in 1967 has had a great impact on measles. Since 1973 the downturn in its incidence and in mortality due to the disease are due solely to the continued vaccination of susceptible children throughout the country. An epidemic outbreak occurred in 1977. Since the vaccine was given primarily to children of school age, this outbreak probably was the result of an accumulation of susceptible subjects. There was little change in the mortality rates. Programs resulting in a coverage of 70% attempted to prevent a new outbreak in 1979, but failed. Because the vaccine was routinely administered to children one year of age and older, most of the cases were in the group younger than that age. At present, the incidence of measles is minimal, and no fatalities occurred in 1981. Vaccination coverage for children two years of age exceeds 90%, and Costa Rica's goal is the complete eradication of the disease.     

Protected areas reduced poverty in Costa Rica and Thailand

As global efforts to protect ecosystems expand, the socioeconomic impact of protected areas on neighboring human communities continues to be a source of intense debate. The debate persists because previous studies do not directly measure socioeconomic outcomes and do not use appropriate comparison groups to account for potential confounders. We illustrate an approach using comprehensive national datasets and quasi-experimental matching methods. We estimate impacts of protected area systems on poverty in Costa Rica and Thailand and find that although communities near protected areas are indeed substantially poorer than national averages, an analysis based on comparison with appropriate controls does not support the hypothesis that these differences can be attributed to protected areas. In contrast, the results indicate that the net impact of ecosystem protection was to alleviate poverty.     

Endemoepidemic non-parenteral type B hepatitis in Costa Rica.

In an endemic area of Costa Rica nonparenteral type B hepatitis occurs at a yearly rate of 160/100,000, in an endemoepidemic pattern with periodic localized outbreaks. In a recent episode in the village of San Rafael, 23 clinical and 67 subclinical cases, all subtype adw, originated from two carriers living in opposite ends of the village. Contact transmission was identified as the mode of spread. In a coincidental outbreak in another village, San Juan, 17 clinical and 40 subclinical cases were observed. Thirty-seven cases of HBs Ag/ayw positive hepatitis occurred in the Western sector of the village, apparently originating from contact with three HBs Ag/ayw carriers found in that area. There were also 20 cases of HBs Ag/adw positive hepatitis, but these occurred almost exclusively in the Eastern sector, where subtype adw disease has been prevalent in previous years. The geographic distribution of antibody subtypes found in the two separated sectors of the village coincided fully with that of the antigen subtypes. These observations show that personal contact is definitely a mode of transmission of hepatitis B.     

Ecological study of Rocky Mountain spotted fever in Costa Rica

Since Rocky Mountain spotted fever (RMSF) was recognized in Costa Rica, ecological studies have been undertaken to discern its distribution and the natural cycle of Rickettsia rickettsii. The population of ticks parasitizing animals and vegetation was scarce. Rickettsiae were not isolated from pools of ticks nor from spleens of the animals studied. However, the active circulation of rickettsiae was evidenced through the demonstration of spotted fever group antibodies in humans, dogs, and wild rabbits. These findings concur with those in a number of fatal human cases as well as with the isolation of R. rickettsii from wild rabbit ticks.     

Rickettsia felis in Ctenocephalides felis from Guatemala and Costa Rica

Rickettsia felis is an emerging human pathogen associated primarily with the cat flea Ctenocephalides felis. In this study, we investigated the presence of Rickettsia felis in C. felis from Guatemala and Costa Rica. Ctenocephalides felis were collected directly from dogs and cats, and analyzed by polymerase chain reaction for Rickettsia-specific fragments of 17-kDa protein, OmpA, and citrate synthase genes. Rickettsia DNA was detected in 64% (55 of 86) and 58% (47 of 81) of flea pools in Guatemala and Costa Rica, respectively. Sequencing of gltA fragments identified R. felis genotype URRWXCal(2) in samples from both countries, and genotype Rf2125 in Costa Rica. This is the first report of R. felis in Guatemala and of genotype Rf2125 in Costa Rica. The extensive presence of this pathogen in countries of Central America stresses the need for increased awareness and diagnosis.     

Mass screening for gastric cancer performed in Costa Rica]

We performed mass screening for gastric cancer by means of X-ray in Costa Rica from 1996 through 1999. Screening was performed on 10,064 subjects and 69 gastric cancers were detected (screening group). During the same period 172 gastric cancer patients were referred to us (non-screening group). Results of screening in Japan (Japanese group) were quoted from the annual report of the Japanese Society of Gastroenterological Mass Survey. This study is a comparison of these 3 groups. The detection rate was 0.68% in the screening group, 0.11% in the Japanese group. The operability was 92.7%, 76.1%, 97.0%, the resectability 96.8%, 83.2%, 98.6%, the rate of early gastric cancer 64.5%, 30.3%, 65.9%, and the rate of curability A 79.0%, 38.5%. 82.6% in the screening group, non-screening group and Japanese group respectively. The results in the screening group were exactly equal to those in the Japanese group. These results show that the same results can be obtained in Costa Rica as in Japan, if screening is performed with the same diagnostic level and skill as in Japan.     

Infectious diseases in a Nicaraguan refugee camp in Costa Rica

Some Nicaraguans living in Costa Rica are in refugee camps. The types and rates of infectious diseases in the Pueblo Nuevo refugee camp were measured by examining medical records for 1985 and performing stool and blood testing. The incidence of infections was 320 episodes per 1000 persons per year. Respiratory infections represented 63% of all illnesses and pulmonary tuberculosis was high. Malaria was not found in blood samples and no childhood illnesses preventable by immunizations were recorded in the records. Intestinal parasites were found in 56% of the persons examined, considerably higher than the 15% prevalence noted in surveys of Costa Rica as a whole. Trichuris trichiura was found in 40% of the positive stool samples. The deficient hygienic conditions and overcrowding in the camp are responsible for the high rates of infections and the continued presence of infections many of which probably were acquired in Nicaragua. Improvement of hygienic conditions can be accomplished by involving the refugees in education, cleaning and identifying problem areas. Adequate sanitation and improved water supply, and reducing overcrowding are also recommended.