RESUMO
Background: Taeniasis and cysticercosis are major causes of seizures and epilepsy. Infection by the causative parasite Taenia solium requires transmission between humans and pigs. The disease is considered to be eradicable, but data on attempts at regional elimination are lacking. We conducted a three-phase control program in Tumbes, Peru, to determine whether regional elimination would be feasible. Methods: We systematically tested and compared elimination strategies to show the feasibility of interrupting the transmission of T. solium infection in a region of highly endemic disease in Peru. In phase 1, we assessed the effectiveness and feasibility of six intervention strategies that involved screening of humans and pigs, antiparasitic treatment, prevention education, and pig replacement in 42 villages. In phase 2, we compared mass treatment with mass screening (each either with or without vaccination of pigs) in 17 villages. In phase 3, we implemented the final strategy of mass treatment of humans along with the mass treatment and vaccination of pigs in the entire rural region of Tumbes (107 villages comprising 81,170 people and 55,638 pigs). The effect of the intervention was measured after phases 2 and 3 with the use of detailed necropsy to detect pigs with live, nondegenerated cysts capable of causing new infection. The necropsy sampling was weighted in that we preferentially included more samples from seropositive pigs than from seronegative pigs. Results: Only two of the strategies implemented in phase 1 resulted in limited control over the transmission of T. solium infection, which highlighted the need to intensify the subsequent strategies. After the strategies in phase 2 were implemented, no cyst that was capable of further transmission of T. solium infection was found among 658 sampled pigs. One year later, without further intervention, 7 of 310 sampled pigs had live, nondegenerated cysts, but no infected pig was found in 11 of 17 villages, including all the villages in which mass antiparasitic treatment plus vaccination was implemented. After the final strategy was implemented in phase 3, a total of 3 of 342 pigs had live, nondegenerated cysts, but no infected pig was found in 105 of 107 villages. Conclusions: We showed that the transmission of T. solium infection was interrupted on a regional scale in a highly endemic region in Peru. (Funded by the Bill and Melinda Gates Foundation and others).
Introducción: La teniasis y la cisticercosis son causas importantes de convulsiones y epilepsia. La infección por el parásito causal Taenia solium requiere la transmisión entre humanos y cerdos. La enfermedad se considera erradicable, pero faltan datos sobre los intentos de eliminación regional. Llevamos a cabo un programa de control de tres fases en Tumbes, Perú, para determinar si sería factible la eliminación regional. Métodos: Probamos y comparamos sistemáticamente las estrategias de eliminación para demostrar la viabilidad de interrumpir la transmisión de la infección por T. solium en una región de enfermedad altamente endémica en Perú. En la fase 1, evaluamos la eficacia y viabilidad de seis estrategias de intervención que incluyeron detección de humanos y cerdos, tratamiento antiparasitario, educación preventiva y reemplazo de cerdos en 42 aldeas. En la fase 2, comparamos el tratamiento masivo con la detección masiva (cada una con o sin vacunación de cerdos) en 17 aldeas. En la fase 3, implementamos la estrategia final de tratamiento masivo de humanos junto con el tratamiento masivo y vacunación de cerdos en toda la región rural de Tumbes (107 aldeas que comprenden 81.170 personas y 55.638 cerdos). El efecto de la intervención se midió después de las fases 2 y 3 con el uso de necropsia detallada para detectar cerdos con quistes vivos, no degenerados capaces de causar una nueva infección. El muestreo de necropsia fue ponderado de manera que incluimos preferentemente más muestras de cerdos seropositivos que de cerdos seronegativos. Resultados: Sólo dos de las estrategias implementadas en la fase 1 dieron como resultado un control limitado sobre la transmisión de la infección por T. solium, lo que destacó la necesidad de intensificar las estrategias posteriores. Después de que se implementaron las estrategias en la fase 2, no se encontró ningún quiste capaz de transmitir más la infección por T. solium entre los 658 cerdos muestreados. Un año después, sin más intervenciones, 7 de los 310 cerdos muestreados tenían quistes vivos, no degenerados, pero no se encontró ningún cerdo infectado en 11 de las 17 aldeas, incluidas todas las aldeas en las que se implementó el tratamiento antiparasitario masivo más la vacunación. Después de que se implementó la estrategia final en la fase 3, un total de 3 de 342 cerdos tenían quistes vivos, no degenerados, pero no se encontró ningún cerdo infectado en 105 de las 107 aldeas. Conclusiones: Demostramos que la transmisión de la infección por T. solium se interrumpió a escala regional en una región altamente endémica del Perú. (Financiado por la Fundación Bill y Melinda Gates y otros).
Assuntos
CisticercoseRESUMO
A longitudinal study of malariometric indicators and their association with potential risk factors was conducted during August 1997-July 1998 at Padre Cocha, a village of 1,400 residents in the Peruvian Amazon. The incidence of Plasmodium falciparum infections during the study year was 166/1,000 persons; that of P. vivax was 826/1,000 persons. The mean duration of symptoms prior to diagnosis was 2 days; presenting geometric mean parasite densities were 3,976 parasites/microl for P. falciparum infections and 2,282 parasites/microl for P. vivax. There were no malaria-associated deaths. Consistent with the epidemic nature of malaria in the area, the incidence of both parasite species increased with age and there were no age-specific differences in mean parasite densities. No specific occupational risks for malaria were identified. Activities significantly associated with malaria risk reflected local vector behavior and included strolling outdoors after 6:00 PM and arising before 6:00 AM for adults, and attending evening church services for children.
Assuntos
Malária Falciparum/epidemiologia , Malária Vivax/epidemiologia , Adolescente , Adulto , Fatores Etários , Animais , Anopheles/fisiologia , Antimaláricos/uso terapêutico , Criança , Pré-Escolar , Feminino , Humanos , Incidência , Insetos Vetores/fisiologia , Estilo de Vida , Estudos Longitudinais , Malária Falciparum/sangue , Malária Falciparum/parasitologia , Malária Falciparum/transmissão , Malária Vivax/sangue , Malária Vivax/parasitologia , Malária Vivax/transmissão , Masculino , Exposição Ocupacional , Parasitemia/epidemiologia , Peru/epidemiologia , Plasmodium falciparum/crescimento & desenvolvimento , Plasmodium vivax/crescimento & desenvolvimento , Prevalência , Fatores de Risco , Estações do Ano , Inquéritos e QuestionáriosRESUMO
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).
Assuntos
Coccidiose/epidemiologia , Surtos de Doenças , Eucoccidiida/isolamento & purificação , Parasitologia de Alimentos , Frutas/parasitologia , Enteropatias Parasitárias/epidemiologia , Vigilância da População , Adolescente , Agricultura , Animais , Estudos de Casos e Controles , Criança , Pré-Escolar , Coccidiose/etiologia , Guatemala/epidemiologia , Humanos , Lactente , Enteropatias Parasitárias/etiologia , Prevalência , Fatores de Risco , Estações do Ano , Abastecimento de ÁguaRESUMO
Los autores explican, desde la perspectiva de las necesidades del trabajador en salud el uso del GPS, enfatizando la necesidad de utilizar el GPS diferencial cuando se requiere localizar elementos (p. eje. casas, sitios de proliferación de insectos, etc.) en el espacio con un alto grado de exactitud, utilizando como ejemplo información correspondiente a un caso real
Assuntos
Epidemiologia , Saúde PúblicaRESUMO
Human abdominal angiostrongyliasis is a potentially fatal disease caused by Angiostrongylus costaricensis, a nematode found in the Americas. During the period of December 1994 through August 1995, an outbreak of this disease occurred in Guatemala. We identified 22 cases of abdominal angiostrongyliasis and conducted a matched case-control study to identify risk factors for illness. The median age of the 18 cases enrolled in the study was 37 years (range, 9-68 years), and 11 (61.1%) were male. Consumption of the following six raw food items was associated with angiostrongyliasis: mint (odds ratio [OR], 6.9; 95% confidence interval [CI], 1.5-66.0), shrimp (OR, infinite; 95% CI, 1.4 to infinite), and four kinds of ceviche that reportedly contained raw mint (OR for consumption of mint or ceviche that contained mint, 7.0; 95% CI, 1.0-315). We conclude that raw mint was the likely vehicle of infection for this outbreak. To our knowledge, this is the first reported outbreak of abdominal angiostrongyliasis and the first time that a specific food item has been epidemiologically linked to the disease.
Assuntos
Angiostrongylus , Surtos de Doenças , Infecções por Strongylida/epidemiologia , Abdome , Adolescente , Adulto , Idoso , Animais , Estudos de Casos e Controles , Criança , Estudos de Coortes , Meio Ambiente , Feminino , Microbiologia de Alimentos , Guatemala/epidemiologia , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Infecções por Strongylida/patologia , Infecções por Strongylida/fisiopatologiaRESUMO
BACKGROUND: Lymphatic filariasis and intestinal helminth infections are important disorders in tropical areas. Periodic treatment with albendazole is now used in many school-based intestinal helminth-control programmes. However, few such programmes exist for lymphatic filariasis, despite evidence that single-dose treatment with ivermectin can greatly reduce the concentration of Wuchereria bancrofti microfilariae in the blood for months to years. We aimed to assess the potential for school-based control of lymphatic filariasis by investigating the efficacy and tolerability or combined ivermectin and albendazole in Haitian schoolchildren. METHODS: In January, 1996, we collected 832 20 microL capillary blood samples for inclusion in a randomised controlled study from children aged 5-11 years, and examined them by microscopy for W bancrofti microfilariae. Infected children were randomly assigned treatment with placebo (n = 29), a single 200-400 micrograms/kg dose of ivermectin (mean, 273 micrograms/kg, n = 28), 400 mg albendazole (n = 29), or a combination of 200-400 micrograms/kg ivermectin and 400 mg albendazole (n = 24). Children with high concentrations of microfilariae in the blood were admitted to hospital and adverse reactions were monitored for 3-5 days, otherwise children were examined at school or during a visit to their home. 4 months after treatment, we examined blood samples again for microfilariae. FINDINGS: 113 microfilaraemic children were enrolled (mean age 7.8 years). 4 months after treatment, the proportion of children who remained positive for microfilariae was significantly lower in the ivermectin plus albendazole group (four [17%]), but there were no significant changes in the other three groups (20 [69%] placebo, 22 [76%] albendazole alone, 17 [61%] ivermectin alone remained positive; p = 0.004). Geometric mean microfilarial concentration decreased from 9.3 to 5.3 per 20 microL blood among children who received placebo; from 15.5 to 1.5 per 20 microL blood among those who received ivermectin only (p = 0.032); from 14.1 to 5.1 per 20 microL blood among those who received albendazole alone; and from 13.7 to 0.3 per 20 microL blood among those who received both ivermectin and albendazole (p = 0.0001). Systemic adverse reactions did not differ significantly between children who received ivermectin alone and those who were treated with ivermectin and albendazole [corrected]. INTERPRETATION: For children with W bancrofti microfilaraemia, combined treatment with ivermectin and albendazole was more effective than treatment with ivermectin only, with no measurable increase in severity of adverse reactions.
Assuntos
Albendazol/uso terapêutico , Filariose/tratamento farmacológico , Filaricidas/uso terapêutico , Ivermectina/uso terapêutico , Parasitemia/tratamento farmacológico , Wuchereria bancrofti , Animais , Criança , Pré-Escolar , Quimioterapia Combinada , Feminino , Filariose/sangue , Filariose/parasitologia , Haiti , Humanos , Masculino , Parasitemia/sangue , Parasitemia/parasitologia , Resultado do TratamentoRESUMO
A systematic, island-wide survey for schistosomiasis in Puerto Rico has not been conducted for more than 40 years. In 1974, a thorough survey of Boqueron de Las Piedras, a small community, showed a prevalence of 40%. No additional information on prevalence in Puerto Rico has been obtained during the ensuing 21 years. Concern for the public health of residents and visitors prompted the formation of the Bilharzia Commission in 1994 and the systematic serosurvey reported herein. Two thousand nine hundred fifty-five plasma samples from healthy donors were obtained randomly from the Red Cross in March and April 1995. Sex, resident municipalities, and age of the donors were recorded. The donors were from all but three of 79 municipalities in Puerto Rico. No sample was available from the three out island municipalities of Mona, Vieques, and Culebra. Male donors (n = 2,027) outnumbered females (n = 928) by more than 2:1, ages ranged from nine to 76 years with most (85.3%) between 19 and 51 years of age. All samples were tested with the Falcon assay screening test:enzyme-linked immunosorbent assay (FAST:ELISA) with microsomal antigens of Schistosoma mansoni. All FAST:ELISA+ samples were confirmed by enzyme-linked immunoelectrotransfer blot (EITB). Our data showed that 15.4% were FAST:ELISA+, and 10.6% were confirmed by EITB; 13.5% of the males and 4.1% of the females were EITB+. If we exclude those municipalities with fewer than five samples, the prevalence of EITB+ ranged from 0% to 38.5%, with the highest seroprevalence rates (21.1-38.5%) concentrated in 17 municipalities, which accounted for 48% of all seropositive samples. These 17 municipalities, however, contain only 18% of the total population of Puerto Rico. Two areas of high seroprevalence rates center around Jayuya (38.5%) and Naguabo (36.4%). The previously surveyed area of Boqueron is located in Las Piedras (35.3%), adjacent to Naguabo. In addition, we found 10% (21) of our total 215 donors less than 25 years of age to be EITB+ and all but two are residents of the high prevalence districts. These data strongly support the contention that schistosomiasis has been transmitted in a focal fashion during the past approximately 20 years.
Assuntos
Anticorpos Anti-Helmínticos/sangue , Schistosoma mansoni/imunologia , Esquistossomose mansoni/epidemiologia , Adolescente , Adulto , Distribuição por Idade , Idoso , Animais , Criança , Análise por Conglomerados , Coleta de Dados , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Immunoblotting , Masculino , Pessoa de Meia-Idade , Prevalência , Porto Rico/epidemiologia , Estudos Soroepidemiológicos , Distribuição por SexoRESUMO
Antigen detection assays serve as a useful adjunct to blood examinations for studies of filariasis, in terms of the diagnostic and epidemiologic information provided. We examined the utility of the Og4C3 antigen detection enzyme-linked immunosorbent assay for field studies and analyzed the distribution of Wuchereria bancrofti antigenemia in a Haitian population. Using serum samples collected following venipuncture, antigenemia levels were correlated with microfilaremia (P < 0.001). The microfilariae had a pronounced nocturnal periodicity while the sensitivity of the antigen assay was the same whether serum samples were collected during the day or at night. To determine whether the Og4C3 assay could be used in conjunction with fingerprick blood examinations, nocturnal blood surveys were conducted. Of 419 persons surveyed, 207 (49.4%) were antigen-positive with the Og4C3 assay. Serum specimens from all 121 microfilaremic individuals were antigen positive (100% sensitivity). The age prevalence of antigenemia increased from 24.5% for 1-5-year-old children to 70% for persons greater than 50 years of age. These results demonstrate that the Og4C3 assay is a sensitive tool for the detection of infection and raise questions about the expression of protective immunity in populations exposed to infection.
Assuntos
Antígenos de Helmintos/sangue , Filariose Linfática/epidemiologia , Parasitemia/epidemiologia , Wuchereria bancrofti/imunologia , Adolescente , Adulto , Fatores Etários , Idoso , Animais , Anticorpos Monoclonais , Criança , Pré-Escolar , Filariose Linfática/sangue , Ensaio de Imunoadsorção Enzimática , Haiti/epidemiologia , Humanos , Lactente , Microfilárias/imunologia , Pessoa de Meia-Idade , Parasitemia/sangue , Prevalência , Análise de Regressão , Sensibilidade e Especificidade , Estatísticas não ParamétricasRESUMO
Two groups of Wuchereria bancrofti-infected Haitians who had undergone treatment with diethylcarbamazine (DEC) were followed for up to five years after treatment to document the long-term effects of treatment on adult worms and microfilariae and on the recurrence of infection. One group of 69 persons who had received 12 daily treatments had a significant decrease in microfilaria levels until year 4, when a small number of individuals experienced a resurgence of this parasite stage in the peripheral blood. In a second group of 57 persons who had been treated weekly for 12 consecutive weeks, there was a greater reduction in the microfilaria levels following treatment, and for the full four years of followup, these levels remained more depressed than those of the group that received daily treatment. Our results indicate that DEC kills or permanently sterilizes adult W. bancrofti. Furthermore, these results demonstrate conclusively that in Haiti, the use of DEC provides long-term benefits to treated persons, even though they continue to reside in an area with endemic filariasis.
Assuntos
Dietilcarbamazina/uso terapêutico , Filariose Linfática/tratamento farmacológico , Wuchereria bancrofti , Animais , Dietilcarbamazina/administração & dosagem , Filariose Linfática/parasitologia , Seguimentos , Haiti , Humanos , Resultado do TratamentoRESUMO
Previous reports have demonstrated age-related shifts in antifilarial humoral immune responses in 6- to 10-year-old Haitian children; the responses consisted of elevated parasite-specific IgG2 and IgG3 in amicrofilaremic children and elevated IgG4 in microfilaremic children. In this study, the cell-mediated immune responses to soluble adult and microfilarial extracts of Brugia pahangi, determined by use of a microblastogenesis assay, were examined. Capillary blood samples were collected by finger prick from 176 Haitian children in an area with endemic Wuchereria bancrofti. Antigen-specific cellular responsiveness varied as a function of infection status but not age or sex; amicrofilaremic children had significantly greater responses to adult antigens than did microfilaremic children. Significant responses were detected in children less than 2 years of age; thus, correlations observed between filarial antigen-specific responses and infection status are established early in life.
Assuntos
Filariose/imunologia , Ativação Linfocitária , Adolescente , Fatores Etários , Animais , Brugia/imunologia , Criança , Pré-Escolar , Feminino , Filariose/sangue , Haiti , Humanos , Imunidade Celular , Lactente , MasculinoRESUMO
Ag-specific isotypic differences in immune response to Onchocerca volvulus Ag were assessed for 778 long term residents of endemic Guatemalan areas by quantitative ELISA with 5-min incubation steps and immunoblot. The study population was separated into five groups based on clinical status: N+F+, N+F-, N-F+, N-F-H+, and N-F-H-, where N = O. volvulus adults (nodule), F = microfiladermia, and H = history of O. volvulus infection. A subset of 44 individuals with high exposure to onchocerciasis from the N-F-H- group were critically evaluated and designated as "putatively immune." IgG1 reactivity to O. volvulus Ag was elevated in the majority of infected persons, but not in putatively immune individuals. Specific IgG3 levels, however, were equally elevated in all groups. The majority of N+F- persons also had elevated IgG1 levels, but they were lower than those found in F+ persons. IgG3 reactivities to a group of antigens at 20 kDa (GP20) were seen in many uninfected persons and some N+F- persons. In contrast, most F+ persons, react to this Ag with IgG1 and not IgG3. A mangabey inoculated with the infectious larval stage of O. volvulus (L3), but showed no signs of infection, began to recognize GP20 at 2 wk postinoculation. Early recognition of GP20 was possibly elicited by the larval stage. Purified nodule Ag from N+F+ individuals contained GP20, however, identical nodule Ag prepared from N+F- individuals did not. These data suggest that GP20 Ag may be common to both uterine microfilaria and the infectious larval stages. The fact that GP20 is predominantly recognized by IgG3 in putatively immune persons and some N+F- persons suggests that this increased IgG3 activity may be important in acquired immunity to onchocerciasis.
Assuntos
Anticorpos Anti-Helmínticos/análise , Antígenos de Helmintos/análise , Imunoglobulina G/análise , Isotipos de Imunoglobulinas/análise , Oncocercose/imunologia , Adolescente , Adulto , Animais , Criança , Pré-Escolar , Densitometria , Humanos , Immunoblotting , Imunoglobulina G/imunologia , Lactente , Camundongos , Pessoa de Meia-Idade , Onchocerca/imunologiaRESUMO
Previous studies of antifilarial antibodies in a pediatric population residing in an area with endemic Wuchereria bancrofti filariasis have demonstrated age related shifts in antifilarial immunity. To further characterize humoral responses in Haitian children, serum samples from 129 patients (3 months-15 years of age) were analyzed by ELISA for isotype-specific antifilarial antibody responses. Age-stratified analysis of geometric mean antibody titers showed significant increases in antibody titers of all isotypes with age in the amicrofilaremic population. Antifilarial IgG1, 2, and 3 levels were higher in amicrofilaremic children than in microfilaremic children, significantly so for IgG2 and IgG3. In contrast, IgG4 antibody levels were higher in microfilaremic subjects than in amicrofilaremic subjects. A multivariate, unconditional, logistic regression model was developed from these data to predict infection status. The model correctly classified 91.6% of the amicrofilaremic subjects, but only 55.6% of the microfilaremic subjects.
Assuntos
Anticorpos Anti-Helmínticos/sangue , Brugia/imunologia , Filariose/imunologia , Imunoglobulina G/análise , Adolescente , Animais , Criança , Pré-Escolar , Filariose Linfática/diagnóstico , Filariose Linfática/epidemiologia , Filariose Linfática/imunologia , Filariose Linfática/parasitologia , Ensaio de Imunoadsorção Enzimática , Feminino , Filariose/diagnóstico , Filariose/epidemiologia , Filariose/parasitologia , Haiti , Humanos , Lactente , Masculino , Microfilárias/imunologia , Microfilárias/isolamento & purificação , Modelos Estatísticos , Análise MultivariadaRESUMO
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.
Assuntos
Dietilcarbamazina/uso terapêutico , Filariose Linfática/tratamento farmacológico , Ivermectina/uso terapêutico , Wuchereria bancrofti , Adolescente , Adulto , Animais , Método Duplo-Cego , Tolerância a Medicamentos , Filariose Linfática/sangue , Feminino , Seguimentos , Haiti , Humanos , Masculino , Microfilárias/efeitos dos fármacos , Microfilárias/crescimento & desenvolvimento , Pessoa de Meia-Idade , Wuchereria bancrofti/efeitos dos fármacos , Wuchereria bancrofti/crescimento & desenvolvimentoRESUMO
We performed a population-based case-control study of risk factors for primary invasive Haemophilus influenzae type b (Hib) disease in metropolitan Atlanta from July 1, 1983, through June 30, 1984. Active surveillance identified 102 cases in children less than 5 years of age, 89 of whom lived in households with telephones. We used random digit dialing to select 530 controls who were postmatched to cases by age. Multivariate analysis showed a significant association between Hib disease and two independent exposure factors, household crowding (odds ratio (OR) 2.7, 95% confidence limits (CL) 1.3 to 5.6) and day-care attendance. For day-care attendance, relative risk was highest in 2- to 5-month-old infants (OR 17.7, 95% CL 5.8 to 54.4) and declined to 9.4 (4.3 to 20.9) at ages 6 to 11 months, 5.0 (2.7 to 9.3) at 12 to 23 months, 2.7 (1.3 to 5.5) at 24 to 35 months, and 1.4 (0.5 to 4.0) in 36- to 59-month-old children. Fifty percent of all invasive Hib disease that occurred during the study period was attributable to exposure to day-care; the attributable risk for household crowding was 18%. Dose-response effects were observed for hours per week of day-care attendance and extent of household crowding. Breast-feeding was protective for infants less than 6 months of age (OR 0.08, 95% CL 0.01 to 0.59). After controlling for socioeconomic and other confounding factors, we could demonstrate no effect of black race on cumulative risk of invasive Hib disease. Our study defines high-risk groups and provides a population-based model of the interrelationship between risk factors associated with invasive Hib disease.
Assuntos
Infecções por Haemophilus/epidemiologia , Fatores Etários , Creches , Pré-Escolar , Aglomeração , Exposição Ambiental , Feminino , Georgia , Infecções por Haemophilus/transmissão , Humanos , Lactente , Masculino , Risco , Fatores Socioeconômicos , Estatística como AssuntoRESUMO
In the period 1971-1981, 1,835 cases of leprosy were reported in the United States; only 10% of these cases were indigenous. Since 1977, the number of new cases reported each year has risen because of an increase in imported cases of disease, a situation reflecting the increased number of refugees and immigrants who have entered the United States from areas endemic for leprosy. Forty-five of the 50 states reported cases. In only 25% of the imported cases were the patients known to have had leprosy at the time of immigration; the remaining 75% were diagnosed in this country. The highest rate of disease onset for this latter group occurred within 12 months after entry into the United States, but cases continued to be reported 10 years after entry. Active refugee resettlement programs have widely distributed persons with leprosy, contacts of diseased persons, and persons from endemic areas throughout the 50 states, a situation necessitating the development of expertise by medical professionals and public health officials in the diagnosis, treatment, and long-term follow-up of patients with leprosy.
Assuntos
Hanseníase/epidemiologia , Adolescente , Adulto , Idoso , Animais , Tatus , Ásia/etnologia , Criança , Pré-Escolar , Emigração e Imigração , Feminino , Humanos , Lactente , Hanseníase/diagnóstico , Hanseníase/tratamento farmacológico , Masculino , México/etnologia , Pessoa de Meia-Idade , Ilhas do Pacífico/etnologia , Refugiados , Risco , Fatores de Tempo , Estados UnidosRESUMO
From November 1, 1981, through April 30, 1982, we performed a case-control study of primary invasive Haemophilus influenzae infections in children in Colorado. Information was collected for 121 (83%) of 146 children with positive cultures and for 196 (67%) of 292 age-matched controls selected at random from birth certificates. Infected children were more likely to have attended a day care center or nursery (DCC/N) and to have an elementary school-aged household member. For attendance at DCC/N, the relative risk was significantly increased only for children 12 months of age or older, and increased with the size of the DCC/N. After controlling for DCC/N attendance and school-aged siblings, children younger than 6 months of age with infection were significantly less likely to have been breast-fed, suggesting a protective effect of breast-feeding. We identified DCC/N attendees, especially those older than 1 year of age, to be at increased risk of primary H. influenzae disease. They could benefit from immunization.