A sero-epidemiological study of onchocerciasis with the indirect hemagglutination test.

A sero-epidemiological study of onchocerciasis was carried out with the IHA test in Guatemala. In the endemic area, 94.8% of 191 subjects with microfilariae, 82.1% of 172 cases with onchocercal nodules, and 22.5% of 236 cases without either microfilariae or nodules gave positive reactions in the IHA test. On the other hand, the positive rate was 3.4% and 2.0% in each of 2 nonendemic populations. A follow-up study of reactors in the IHA with neither microfilariae nor nodules showed that 11 (42%) of 26 cases were microfilaria positive 6--7 mo after the first examination. A clear correlation was found between the results of the IHA test and skin biopsy in surveyed communities. The age distribution curve of the IHA test was closely associated with skin biopsy although the former was higher. IHA titers rose in proportion to microfilarial density. A sex-related difference was evident in the IHA positive rate in the subjects from medium and low endemic areas, but little difference was shown in individuals from a higher endemic area.

Anopheles neomaculipalpus, first record for Guatemala.

Anopheles neomaculipalpus is being confirmed in Guatemala for the first time, based on adult females and larvae collected in distinctly different parts of the country. Habitat data are also given.

Chemical control of Simulium ochraceum Walker (Diptera: Simuliidae) larvae in an onchocerciasis endemic area of Guatemala.

Chemical control against larvae of Simulium ochraceum, the principal vector of onchocerciasis, was carried out from 1979 to 1984 in a 91.3 km2 area of Guatemala where onchocerciasis is endemic. The control operation was divided chronologically into three phases according to the different tactics employed. Phase 1 (1979-1981), using briquettes of fat and detergent containing 10% temephos, was effective only in perennial streams. Phase 2 (1981-1982), which limited the application target to small streams with discharges of 0.1-1 litre/sec, was not effective. Successful control was achieved by Phase 3 (1982-1984), which consisted of fort-nightly applications of 5% temephos water dispersable powder in fixed doses of 24 g (1.2 g active ingredient) to every 50-100 m stretch of all streams with discharge rates of 0.1-50 l/sec. Vector biting rates were reduced by 97.8% in 1982 to 1983 and 97.6% in 1983-1984. The biting density of S. ochraceum at all five stations was reduced to less than 1.9/man/hour, the proposed critical level for long term transmission of onchocerciasis. The biting density of the S. metallicum/horacioi complex was not apparently affected by this operation. Through analysis of the density of S. ochraceum at various distances from the untreated areas, infiltration of the flies was found to be rare, if the distance was beyond 2 km. Fly-round surveys proved to be practical as a surveillance method for detecting larval breeding in untreated or improperly treated streams. The cost for a nation-wide vector control operation was presented.

Incremento de volumen de cavidades clase I en molares humanos durante el reemplazo de restauraciones de resina compuesta y amalgama por diferentes grupos de operadores y su relación con el conocimiento en MIO / Increased volume of class I cavities in human molars during replacement of composite restorations and amalgam of different groups of operators and their relationship to knowledge in MID

La remoción y reemplazo de las restauraciones durante la vida del paciente puede resultar en anchas y profundas cavidades, por lo que es necesario ser conservador cuando se requiere un reemplazo. Evaluar el incremento de volumen en cavidades clase I en molares humanos, posterior a la remoción de restauraciones de resina compuesta y amalgama dental por diferentes grupos de operadores. Se seleccionaron 60 individuos pertenecientes a 4 grupos: Estudiantes de pregrado G1, estudiantes de postgrado G2, Profesores del Departamento de Odontología Restauradora G3 y Odontólogos Generales de Servicios Públicos G4. Cada operador respondió el Test de Conocimientos de Mínima Intervención en Odontología (MIO), y luego removió dos restauraciones; una de resina (RC) y otra de amalgama (AD). Para la preparación de las muestras se realizó una copia de la cara oclusal de los dientes con acrílico y se obtuvo un molde del diente sano. Posteriormente, se hizo la preparación Oclusal (Clase I Black), se tomó el registro del volumen inicial con material de impresión polivinil siloxano aplicando la ecuación v = m/d; se obturaron las cavidades y luego de la remoción se hizo un segundo registro para evaluar el incremento de volumen. Para el análisis se usaron modelos estadísticos descriptivos y modelos estadísticos inferenciales (ANOVA Bifactorial Univariante, MANOVA Bifactorial y relación lineal). Al comparar conocimientos de MIO y grupos de operadores (ANOVA) no encontró diferencia estadísticamente significativa. El diferencial de volumen (MANOVA) no encontró diferencia significativa entre grupos de operadores y materiales. En el estudio de relación lineal no existe relación predictiva entre Puntaje del Test de MIO e incremento de volumen de las cavidades. En las condiciones que se realizo esta investigación el incremento de volumen de las cavidades posterior al recambio no dependen de la experiencia individual de los diferentes grupos de operadores

The removal and substitution of restorations during the patient's life can result in wide and deep cavities. Hence, it is necessary to be conservative when a substitution is required. The purpose of this research was to evaluate the increment of volume in class I cavities after removing composite and amalgam restorations by different groups of operators. 60 people belonging to one of these groups were selected: undergraduate students G1, graduate students G2, professors of the department of restorative dentistry G3, and general dentist working in public services G4. Each operator answered the test of knowledge on Minimal Invasive Dentistry (MID), and the he/she removed two restorations: one of composite (C) and other of amalgam (DA). For the reparation of the sample teeth a copy of the occlusal surface with acrylic and a mold of the healthy tooth were obtained. Later, occlusal preparation was performed (Class I Black). Initial volume was registered with polivinil siloxane material and using the equation v=m/d. then, cavities were filled and a second register or volume was performed after remotion to evaluate volume increment. Inferential statistical tests were performed to analyze the data (1-way ANOVA, MANOVA and lineal regression). When comparing knowledge about MID and groups of operators, the ANOVA did not show statistically significant differences. The MANOVA analysis indicated that differential volume was not statistically significantly different among the groups of operators and materials. The lineal regression analysis indicated that there is not predictive relationship between the test of MIO's scores and increment of volume in cavities. Under the conditions of the present study, cavities volume increment does not depend on operator's experience