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ObjectivesTo estimate the protection against laboratory-confirmed SARS-CoV-2 infection, hospitalisations, and death after homologous or heterologous third-dose (booster) in individuals with primary vaccination schemes with rAd26-rAd5, ChAdOx1nCoV-19, BBIBP-CorV or heterologous combinations, during the period of Omicron BA.1 predominance.DesignRetrospective, test-negative, case-control study, with matched analysis.SettingProvince of Buenos Aires, Argentina, between 12/1/21-4/1/21.Participants422,144 individuals ≥50 years who had received two or three doses of COVID-19 vaccines and were tested for SARS-CoV-2.Main outcome measures: Odds ratios of confirmed SARS-CoV-2 infection, hospitalisations and death after administering different boosters, compared to a two-dose primary scheme.ResultsOf 221,933(52.5%) individuals with a positive test, 190,884(45.2%) had received a two-dose vaccination scheme and 231,260(54.8%) a three-dose scheme. The matched analysis included 127,014 cases and 180,714 controls.The three-dose scheme reduced infections (OR 0.81[0.80-0.83]) but after 60 days protection dropped (OR 1.04[1.01-1.06]). The booster dose decreased the risk of hospitalisations and deaths after 15-59 days (ORs 0.28[0.25-0.32] and 0.25[0.22-0.28] respectively), which persisted after administration for 75[66-89] days.Administration of a homologous booster after a primary scheme with vectored-vaccines provided low protection against infections (OR 0.94[0.92-0.97] and 1.05[1.01-1.09] before and after 60 days). Protection against hospitalisations and death was significant (OR 0.30[0.26-0.35] and 0.29[0.25-0.33] respectively) but decreased after 60 days (OR 0.59[0.47-0.74] and 0.51[0.41- 0.64] respectively).The inoculation of a heterologous booster after a primary course with ChAdOx1 nCoV-19, rAd26-rAd5, BBIBP-CorV, or heterologous schemes, offered some protection against infection (OR 0.70[0.68-0.71]), which decreased after 60 days (OR 1.01[0.98-1.04]). The protective effect against hospitalisations and deaths (OR 0.26[0.22-0.31] and 0.22[0.18-0.25] respectively) was clear and persisted after 60 days (OR 0.43[0.35-0.53] and 0.33[0.26-0.41]).ConclusionsThis study shows that, during Omicron predominance, heterologous boosters provide an enhanced protection and longer effect duration against COVID-19-related hospitalisations and death in individuals older than 50, compared to homologous boosters.

BackgroundAlthough paediatric clinical presentations of COVID-19 are usually less severe than in adults, serious illness and death have occurred. Many countries started the vaccination rollout of children in 2021; still, information about effectiveness in the real-world setting is scarce. The aim of our study was to evaluate vaccine effectiveness (VE) against COVID-19-associated-hospitalisations in the 3-17-year population during the Omicron outbreak.MethodsWe conducted a retrospective cohort study including individuals aged 3-17 registered in the online vaccination system of the Buenos Aires Province, Argentina. mRNA-1273 and BNT162b2 were administered to 12-17-year subjects; and BBIBP-CorV to 3-11- year subjects. Vaccinated group had received a two-dose scheme by 12/1/2021. Unvaccinated group did not receive any COVID-19 vaccine between 12/14/2021-3/9/2022, which was the entire monitoring period. Vaccine effectiveness (VE) against COVID-19-associated hospitalisations was calculated as (1-OR) x100.FindingsBy 12/1/2021, 1,536,435 individuals aged 3-17 who had received zero or two doses of SARS-CoV-2 vaccines were included in this study. Of the latter, 1,440,389 were vaccinated and 96,046 not vaccinated. VE were 78·0% [68·7-84·2], 76·4%[62·9-84·5] and 80·0%[64·3-88·0] for the entire cohort, 3-11 subgroup and 12-17 subgroup, respectively. VE for the entire population was 82·7% during the period of Delta and Omicron overlapping circulation and decreased to 67·7% when Omicron was the only variant present.InterpretationThis report provides evidence of high vaccine protection against associated-hospitalisations in the paediatric population during the Omicron outbreak but suggests a decrease of protection when Omicron became predominant. Application of a booster dose in children aged 3-11 warrants further consideration.Research in contextEvidence before this studyThere is limited evidence on the effectiveness of vaccines in the pediatric population, particularly in children aged 3-11 years after the SARS-CoV-2 B.1.1.529 (Omicron) variant’s emergence.We searched preprint and peer-reviewed published articles in PubMed, medRxiv, and SSRN for observational studies, with no language restrictions, using the term “COVID-19 OR SARS-CoV-2” AND “vaccine effectiveness” OR “vaccine impact” AND “children” OR “pediatric” AND “Omicron” published between December 1, 2021, and April 1, 2022. We found 4 studies that included subjects in the 3-17-year population who received a two-dose-scheme of any of the available vaccines-according to each country’s authorisation. Three studies were from the US; two were test-negative-case-control studies and one was a retrospective non-peer-reviewed cohort study. The reported vaccine effectiveness (VE) for 2-doses of BNT162b2-mRNA (Pfizer-BioNTech) in preventing hospitalisations during Omicron predominance was 48-78%; and it was 40-92% for 5-11 and 12-17-year subgroups, respectively. The fourth was a cohort study still in preprint form conducted in Chile and utilized an inactivated vaccine, CoronaVac (SinoVac), widely used in Latin-America. VE for two doses of CoronaVac in the 3-5-year subgroup against hospitalisations was 64% and 69% against ICU admissions.Added value of this studyUp to date, there are no published studies about the effectiveness of the BBIBP-CorV vaccine against hospitalisation in the pediatric population. Additionally, there are no real-world studies from low and middle-income countries about VE in the 12-17 aged population during the Omicron outbreak.This study shows that VE after 14 days or more from two-dose-scheme was 78·0% [68·7-84·2], 76·4% [62·9-84·5] and 80·0% [64·3-88·0] for the 3-17-year entire group, and for 3-11-year (BBIBP-CorV) and 12-17-year (mRNA vaccines) subgroups, respectively. VE for the 3-17-year entire group was 82·7% during the period of Delta and Omicron overlapping circulation and decreased to 67·7% when Omicron was the only variant present. These effects were consistent across all subgroups.Implications of all the available evidenceOur results provide evidence of high vaccine protection against COVID-19 associated-hospitalisations in the pediatric population during the Omicron outbreak, but suggest a decrease of protection when Omicron became predominant. Application of a booster dose in children aged 3-11 warrants further consideration.

Although paediatric clinical presentations of COVID-19 are usually less severe than in adults, serious illness and death have occurred. Many countries started the vaccination rollout of children in 2021; still, information about effectiveness in the real-world setting is scarce. The aim of our study was to evaluate vaccine effectiveness (VE) against COVID-19-associated-hospitalisations in the 3-17-year population during the Omicron outbreak.We conducted a retrospective cohort study including individuals aged 3-17 registered in the online vaccination system of the Buenos Aires Province, Argentina. mRNA-1273 and BNT162b2 were administered to 12-17-year subjects; and BBIBP-CorV to 3-11-year subjects. Vaccinated group had received a two-dose scheme by 12/1/2021. Unvaccinated group did not receive any COVID-19 vaccine between 12/14/2021 and 3/9/2022, which was the entire monitoring period. Vaccine effectiveness (VE) against COVID-19-associated hospitalisations was calculated as (1-OR)x100.By 12/1/2021, 1,536,435 individuals aged 3-17 who had received zero or two doses of SARS-CoV-2 vaccines were included in this study. Of the latter, 1,440,389 were vaccinated and 96,046 not vaccinated. VE were 78.0%[68.7-84.2], 76.4%[62.9-84.5] and 80.0%[64.3-88.0] for the entire cohort, 3-11-year (BBIBP-CorV) subgroup and 12-17 (mRNA vaccines) subgroup, respectively. VE for the entire population was 82.7% during the period of Delta and Omicron overlapping circulation and decreased to 67.7% when Omicron was the only variant present.This report provides evidence of high vaccine protection against associated hospitalisations in the paediatric population during the Omicron outbreak but suggests a decrease of protection when Omicron became predominant. Application of a booster dose in children aged 3-11-year warrants further consideration.None.

Introducción. El plan de vacunación de la provincia de Buenos Aires ha priorizado los grupos de mayor riesgo epidemiológico, iniciando el proceso de inmunización sobre el Personal de Salud (PS).El presente trabajo tiene por objetivo evaluar el impacto de la vacunación sobre la evolución media de nuevos casos SARS-Cov-2 en PS comparada con la de la población general. Metodología. La información de los casos confirmados se obtuvo del Sistema Nacional de Vigilancia de la Salud, período abril/2020 a marzo/2021. La cantidad de vacunados utilizó la base del sistema VacunatePBA. Resultados. A partir de septiembre, el número de casos comienza a disminuir más pronunciadamente en PS que en la población general. Esta tendencia se consolida con el comienzo del plan de vacunación. Para febrero de 2021 se han inmunizado con la primera dosis el 42% del PS y con la segunda dosis el 24%. Se observa que, en marzo, mientras la cantidad de casos de la Población General aumenta un 10% respecto a febrero, PS disminuye un 35%. Esto indica un descenso significativamente más pronunciado en PS (p-valor < 0.00001). Discusión. A partir de la introducción de la vacuna contra COVID-19 a finales de diciembre en distintos países, se ha comenzado a reportar una baja de la incidencia de nuevos casos de infección por SARS-CoV-2 en PS, coincidente con los hallazgos del presente estudio. Nuestro estudio aporta los primeros datos del país sobre el impacto de las vacunas COVID-19 en PS.

Objetivo: evaluar la persistencia de los anticuerpos IgG contra SARS-CoV2, en trabajadores de salud del subsector público de la Provincia de Buenos Aires, y correlacionarla con variables demográficas (sexo, edad) y otros indicadores de salud (diagnóstico de COVID-19, comorbilidades y embarazo). Metodología: Estudio descriptivo, observacional, de corte transversal. Al personal de salud con un resultado positivo en una primera muestra (N=388) se les realizó una segunda prueba para evaluar la persistencia de anticuerpos mediante ELISA. Resultados: De las 386 personas evaluadas con resultado concluyente, 296 contaban con un primer resultado positivo entre los 30 y los 90 días anteriores a la segunda prueba, el 90% presentó anticuerpos detectables. En aquellas personas con un resultado positivo hacía más de 90 días (45) se observó una caída significativa en la persistencia del 26,7%. No hubo asociaciones significativas entre las variables demográficas y de salud y el resultado de la segunda prueba. Conclusión: Los anticuerpos se mantienen detectables por al menos 90 días en el 90% de los casos analizados. Resulta fundamental continuar este estudio en el tiempo para contar con un período de tiempo mayor entre pruebas. La información aquí mostrada arroja datos interesantes y prometedores en cuanto a la posible protección de nuevos contagios de COVID-19 en personal con alta exposición de riesgo. Estas evidencias podrían contribuir a la toma de decisiones, tanto a nivel local como regional, para la adecuada planificación de la vacunación, así como también, para el manejo de la pandemia ante una posible segunda ola de casos en América Latina.

BackgroundTherapies to interrupt progression of early COVID-19 remain elusive. Among them, convalescent plasma in hospitalized patients was unsuccessful, perhaps because antibody should be administered earlier. We advanced plasma infusions to the first 72 hours of symptoms to arrest COVID-19 progression.MethodsA randomized, double-blind, placebo-controlled trial of convalescent plasma with high IgG titers against SARS-CoV2 in elderly subjects within 72 hours of mild COVID-19 symptoms. The primary endpoint was severe respiratory disease defined as a respiratory rate ≥30 and/or an O2satResults160 patients underwent randomization. In the intention-to-treat analysis (ITT), 13/80(16.2%) patients receiving plasma vs. 25/80(31.2%) receiving placebo experienced severe respiratory disease [RR(95%CI)= 0.52(0.29,0.94); p=0.026)] with an RRR=48%.A modified ITT analysis, excluding six subjects who experienced the primary endpoint before infusion, showed a larger effect size [RR(95%CI) = 0.40(0.20, 0.81), p=0.007]. High- and low-titer donor analyses, based on a median IgG titer=1:3,200, evidenced a dose-dependent response with an RRR=73.3% for recipients of high-titer plasma (p=0.016) and a number needed to treat (NNT)=4.4. All secondary endpoints exhibited trends towards protection. No solicited adverse events were observed.ConclusionsEarly administration of high-titer convalescent plasma against SARS-CoV2 to mildly ill infected seniors reduced COVID-19 progression. This safe, inexpensive, outpatient intervention facilitates access to treatment from industrialized to LMIC, can decompress demands on hospitals, and may contribute to save lives.Funded by The Bill & Melinda Gates Foundation and The Fundación INFANT Pandemic Fund. Registered in the Dirección de Sangre y Medicina Transfusional del Ministerio de Salud (PAEPCC19), Plataforma PRIISA (1421), and clinicaltrials.gov (NCT04479163).All authors have completed the ICMJE uniform disclosure form atwww.icmje.org/coi_disclosure.pdfand declare: no support from any organization for the submitted work; RL, GPM, DW and FPP are investigators in a phase 3 SARS CoV2 trial from Pfizer; no other relationships or activities that could appear to have influenced the submitted work.

Introducción: frente a la identificación de la ocurrencia de un brote de COVID19 en el Barrio de Villa Azul y dadas las características de vulnerabilidad del barrio que dificultarían cumplir con el aislamiento domiciliario y las medidas de prevención se implementó una estrategia de aislamiento comunitario como respuesta sanitaria al brote. Objetivo: describir la estrategia de aislamiento comunitario utilizada en el Barrio de Villa Azul para contener y mitigar un brote de COVID19. Métodos: Se identificaron los límites del barrio y se procedió al cierre del mismo con fuerzas de seguridad. Quedó permitida la circulación por dentro del barrio asumiendo que todos los habitantes eran casos sospechosos de COVID19 o bien eran contactos estrechos de algún caso. En los días subsiguientes se continuó con la búsqueda activa de casos sospechosos de COVID19, se realizaron los hisopados en el barrio y se obtuvieron los resultados a las 24 horas. Todos los días, luego de la recepción de los casos se les informaba el resultado a los casos negativos y se iba a las casas de los casos positivos para notificarlos del resultado y sugerirles el aislamiento fuera del barrio para cortar la cadena de contagios. Resultados: En el barrio Villa Azul entre el 22 de mayo y el 20 de junio se registraron 731 casos sospechosos de los cuales 379 fueron casos confirmados para COVID19 (tasa de positividad acumulada del 52,1%). La primera semana hubo entre 20 y 40 casos confirmados diarios con un índice de positividad entre el 66 y 81% pero con el correr del tiempo como consecuencia de la estrategia descripta fueron bajando el número de casos por día y también la positividad. Se trasladaron 193 traslados de pacientes confirmados para aislarse afuera del barrio. Fallecieron 3 personas, todas con comorbilidades (tasa de letalidad 0,8%). Discusión: La estrategia de aislamiento comunitario resultó efectiva para contener el brote de COVID19 en el Barrio de Villa Azul. La posibilidad de garantizar de forma diaria la búsqueda activa de casos, sumado a la posibilidad de hisoparlos en el barrio y a las 24 horas tener el resultado, sugiriendo luego el traslado fuera del mismo de los confirmados para COVID19 fueron algunas de las claves.

IntroductionThe aim of this study was to estimate the seroprevalence of the SARS-CoV-2 infection in health workers of the Sanitary Region VIII, at province of Buenos Aires during June 2020.MethodsA cross-sectional design was used. A probabilistic sampling by two-stage conglomerates was carried out. Data were collected from a self-administered questionnaire and a blood sample for antibody identification. The COVIDAR IgG and IgM test were used. RESULTS: 738 health workers were included; the overall response rate was 73.80%. 71.83% of that were women; age showed a normal distribution. Nurses and doctors accounted for more than half of the staff. 75.86% of people claimed to always use Personal Protective Equipment. 5.61% of people had close contact with a confirmed case of COVID-19. 4.60% of people had previously had a nasopharyngeal swab with a negative result. Five workers had positive IgG for SARS-CoV-2 (four women and one man) with negative IgM. The mean age of the cases was 35 years old; two of them were asymptomatic; neither of them had a swab sample taken. The overall seroprevalence was 0.75%, with no significant differences between strata.DiscussionThe seroprevalence found was low; indicating a large proportion of workers was susceptible to infection. We stress the need to complement passive epidemiological surveillance strategies with serological monitoring in health workers.

Introducción: La morbi-mortalidad por COVID-19 constituye un problema de salud pública en Argentina y la Provincia de Buenos Aires. Las poblaciones con vulnerabilidad social poseen una fragilidad que las expone a riesgos de manera potenciada. Objetivo: Caracterizar la vulnerabilidad social de una serie de casos confirmados con residencia en el Área Metropolitana Buenos Aires. Métodos: Estudio descriptivo de corte transversal. Fueron analizadas variables de sexo, edad, evolución y domicilio categorizadas por medio del Índice de Vulnerabilidad Socio Territorial. Resultados: la edad de los casos fue entre 20 y 59 años, el sexo fue un 48% mujeres y el restante varones. De zonas vulnerables hubo un 47% de casos. Las internaciones fueron el 28% de los casos, la mayoría de zonas no vulnerables. Llegaron a cuidados intensivos el 3,8% de los casos. Los casos con vulnerabilidad tuvieron mayor requerimiento de cuidados intensivos. La letalidad fue de 2,4% y fue mayor en varones. A partir de los 60 años el exceso de letalidad en zonas vulnerables fue estadísticamente significativo. Discusión: Entre los casos no hubo diferencias importantes entre los residentes de zonas vulnerables y no vulnerables. Las diferencias estuvieron marcadas en la gravedad (medido por internación en UCI) y letalidad de los mayores de 60 años que fue mayor en zonas vulnerables. La vulnerabilidad se expresó en la evolución de la enfermedad de los mayores de 60 años.

A identificação humana post mortem é uma área de estudo e pesquisa de extensa atuação da Odontologia Legal. Nessa área do conhecimento, a forma mais utilizada é a da comparação dos registros ante mortem (AM) com os achados post mortem (PM). Em casos de cadáveres carbonizados, geralmente os elementos dentários são capazes de resistir à ação térmica. Dessa forma, os exames de imagens que integram os prontuários odontológicos, quando em boa qualidade, possibilitam sua comparação com os mesmos exames realizados no cadáver. O propósito desse artigo foi o de relatar um caso em que a comparação de tomografias computadorizadas AM e PM permitiu a identificação positiva de um cadáver carbonizado. A comparação das imagens tomográficas AM, utilizadas para um planejamento reabilitador com implantes, com as imagens PM, realizadas no Instituto Médico Legal da Polícia Civil do Distrito Federal, permitiu, de forma rápida, eficaz e econômica, a identificação positiva do cadáver devido à quantidade e à qualidade dos pontos semelhantes encontrados nas imagens, associados à ausência de divergências inexplicáveis

Objetivo: Evaluar la prevalencia de anticuerpos para SARS Cov-2 en el Barrio Villa Azul, del partido de Quilmes, junto con otras variables demográficas y de movilidad. Métodos: Estudio descriptivo de corte transversal realizado a través de una muestra probabilística sistemática. El tamaño de la muestra fue de 311 casos y consintieron la aplicación del test 284 casos. Fue aplicada una encuesta al 100% de los casos testeados. La información fue procesada con software SPSS 23 y los análisis consideraron la ponderación de la muestra de acuerdo al diseño equiprobabilístico establecido. Resultados: El 61% eran mujeres. La media de edad era de 40 años, la estructura poblacional era similar a la del universo. La presencia de anticuerpos fue del 14,8% de los casos, la mayoría en mujeres y de 40 años que no salieron a trabajar y no utilizaron transporte público. El ser trabajador de la salud no representó un riesgo acrecentado para el contagio. Se observa que de cada un caso sintomático existirían 1,2 asintomáticos. Conclusiones: Hubo una prevalencia mayor de personas con anticuerpos que en otros estudios, aunque comparando territorios similares la prevalencia de anticuerpos fue menor y esto pude ser una consecuencia de un abordaje territorial oportuno. La seroprevalencia fue predominantemente en mujeres y esto no indicaría mayor contagio en este sexo ya que existe incertidumbre en la relación entre infección y anticuerpos. Se observó que los contagios podrían haber sido dentro del hogar o el entorno comunitario ya que afectó a personas que no salían a trabajar.

One of the main problems in controlling COVID-19 epidemic spread is the delay in confirming cases. Having information on changes in the epidemic evolution or outbreaks rise before lab-confirmation is crucial in decision making for Public Health policies. We present an algorithm to estimate on-stream the number of COVID-19 cases using the data from telephone calls to a COVID-line. By modeling the calls as background (proportional to population) plus signal (proportional to infected), we fit the calls in Province of Buenos Aires (Argentina) with coefficient of determination $R^2 > 0.85$. This result allows us to estimate the number of cases given the number of calls from a specific district, days before the lab results are available. We validate the algorithm with real data. We show how to use the algorithm to track on-stream the epidemic, and present the Early Outbreak Alarm to detect outbreaks in advance to lab results. One key point in the developed algorithm is a detailed track of the uncertainties in the estimations, since the alarm uses the significance of the observables as a main indicator to detect an anomaly. We present the details of the explicit example in Villa Azul (Quilmes) where this tool resulted crucial to control an outbreak on time. The presented tools have been designed in urgency with the available data at the time of the development, and therefore have their limitations which we describe and discuss. We consider possible improvements on the tools, many of which are currently under development., 16 pages, 8 figs. Includes details on the Villa Azul outbreak in Argentina

Background We estimated rates of influenza-associated deaths and hospitalizations in Argentina, a country that recommends annual influenza vaccination for persons at high risk of complications from influenza illness. Methods We identified hospitalized persons and deaths in persons diagnosed with pneumonia and influenza (P&I, ICD-10 codes J10-J18) and respiratory and circulatory illness (R&C, codes I00-I99 and J00-J99). We defined the influenza season as the months when the proportion of samples that tested positive for influenza exceeded the annual median. We used hospitalizations and deaths during the influenza off-season to estimate, using linear regression, the number of excess deaths that occurred during the influenza season. To explore whether excess mortality varied by sex and whether people were age

This study was designed to evaluate the accuracy and safety of electromagnetic needle tracking for sonographically guided percutaneous liver biopsies. We performed 23 consecutive ultrasound-guided liver biopsies for liver nodules with an electromagnetic tracking of the needle. A sensor placed at the tip of a sterile stylet (18G) inserted in a coaxial guiding trocar (16G) used for biopsy was localized in real time relative to the ultrasound imaging plane, thanks to an electromagnetic transmitter and two sensors on the ultrasound probe. This allows for electronic display of the needle tip location and the future needle path overlaid on the real-time ultrasound image. Distance between needle tip position and its electronic display, number of needle punctures, number of needle pull backs for redirection, technical success (needle positioned in the target), diagnostic success (correct histopathology result), procedure time, and complication were evaluated according to lesion sizes, depth and location, operator experience, and “in-plane” or “out-of-plane” needle approach. Electronic display was always within 2 mm from the real position of the needle tip. The technical success rate was 100%. A single needle puncture without repuncture was used in all patients. Pull backs were necessary in six patients (26%) to obtain correct needle placement. The overall diagnostic success rate was 91%. The overall true-positive, true-negative, false-negative, and failure rates of the biopsy were 100% (19/19) 100% (2/2), 0% (0/23), and 9% (2/23). The median total procedure time from the skin puncture to the needle in the target was 30 sec (from 5–60 s). Lesion depth and localizations, operator experience, in-plane or out-of-plane approach did not affect significantly the technical, diagnostic success, or procedure time. Even when the tumor size decreased, the procedure time did not increase. Electromagnetic-tracked biopsy is accurate to determine needle tip position and allows fast and accurate needle placement in targeted liver nodules.

Os Autores, após terem demonstrado no laboratório a atividade "in vitro" de 119 produtos naturais de origem vegetal no bloqueio da evolução externa de Ancilostomídeos e S. stercoralis, pesquisaram a aplicação prática da Profilaxia ecológica fitoquímica das respectivas endemias parasitárias. A investigação foi realizada em dois grupos populacionais de favelados da Ilha do Governador (Rio de Janeiro, Brasil), ao longo de 26 meses de intenso trabalho que compreendeu: 1) seleção e levantamento demográfico das áreas; 2) inquérito geral para determinação da incidência parasitária; 3) introdução dos vegetais ativos em uma das áreas, ficando a outra como controle; 4) tratamento em massa de ambas as populações, repetido 10 meses depois; 5) três controles epidemiológicos, após cada tratamento e a intervalos constantes de 60 a 70 dias, para verificação das reinfestações e do confronto final da prevalência das helmintoses nas duas áreas. Das plantas introduzidas somente se adaptou o C. citratus que atingiu uma concentração média de uma touceira por 10 m². Os níveis de ancilostomose cairam na área plantada de 23,2% para 2,2% e na área controle de 14,5% para 5,8%, durante o período de 21 meses da investigação. A estrongiloidose desceu de 17,1% para 0,6% na área tratada fitoecologicamente e de 13,0% para 2,9% na área controle. Da população inicialmente examinada, 46% foram acompanhados até o término da experiência. A redução da prevalência de ancilostomídeos, 30,5% superior na área plantada, é considerada estatisticamente significativa e, portanto, o novo método profilático válido e viável. Para conclusão definitiva, já teve início uma pesquisa comparada, sob rigorosas condições de controle. Tudo indica que o método ora instituído, pioneiro na literatura mundial, seja de grande valor profilático reduzindo sensivelmente a prevalência, após tratamento em massa das populações, nas áreas endêmicas. Pelas suas características, tais como aceitação popular, pequeno custo operacional e, sobretudo, obtenção de resultados a curto prazo, será altamente oportuno, considerando-se que os recursos convencionais são baseados na educação e engenharia sanitárias, cujos resultados são obtidos a médio e longo prazos e sempre dependentes de cada indivíduo. Além da aplicação médico-sanitária, a presente pesquisa poderá estabelecer possibilidades na profilaxia de certas fitonoses e zoonoses de grande importância econômica na agropecuária.The previously reported activity of natural products of plant origin which inhibit the external larval evolution of Ancylostomidae and of Strongyloides stercoralis, has now been applied in the pratical ecological prophylaxis of human parasitic disease. The study was made in two populations of low economic level inhabiting shanty towns on the Ilha do Governador, Rio de Janeiro, Brasil. During 26 months the following phases were completed: 1 - selection and census ofeach area; 2 - parasitological survey; 3 - mass treatment of both populations with the anthelminthics pyrantel pamoate and thiabendazole, this treatment repeated 10 months later; 4 - introduction of plants with parasitic inhibitory activity in one area, leaving the other as control; 5 - three epidemiological Controls, one after each treatment and then at intervals of 60 to 70 days to determine the prevalence and reinfection leveis of the two parasites in each area. Of the plants introduced only lemon-grass, Cymbopogon citratus, survived and attained an average density of one dump per 10 m². Ancylostomiasis levels fell in the plantedarea from 23.2% to 2.2% and in the control are from 14.5% to 5.8% during the twenty-one month study. Strongyloidiasis fell from 17.1% to 0.6% in the planted area, and from 13% to 2.9% in the control area. 46% of the initially examined populations were followed through to the end. The reduction in prevalence of hookworms, 30.5% higher in the planted area, is considered statistically significant, and the method therefore valid and viable. Supporting evidence is being sought in a parallel experiment with animais where complete control is possible. The method, apparently novel, seems of value in the reduction of reinfection after mass treatment in endemic areas. It is popularly acceptable, cheap and produces quick results and may bridge the gap until definitive measures such as sanitary education and engineering produce their longer term solution. In addition to the medicai and sanitary application, the results presented suggest applications in the veterinary and phytosanitary fields.

An extract of Calea lantanoides which inhibits larval development of Strongyloides stercoralis and three species of hookworms gave the heliangolide 15-deoxybudlein A.