Echinococcosis in southern Brazil: efforts toward implementation of a control program in Santana do Livramento, Rio Grande do Sul

This investigation aimed to design a strategy for echinococcosis control in Santana do Livramento county, an endemic area in state of Rio Grande do Sul (Brazil). Fecal samples from 65 dogs were obtained from urban, suburban and rural areas. Purging with Arecoline Bromhidrate (AB) was done to visualize Echinococcus granulosus, and Enzyme Linked Immunosorbent Assay (ELISA) was performed to detect parasite coproantigen. Samples were obtained at the beginning and at the end of treatment with Praziquantel. A third fecal sampling was also done in rural areas four months after the end of treatment. Each dog was treated immediately after the first purging and every 30 days for eight months. In urban and suburban areas no infected dogs were found. In rural areas, first evaluation showed 11.36% and 27.69% of infected dogs by AB and ELISA, respectively. No infected dogs were diagnosed in the second evaluation and in the third evaluation 36.84% and 47.37% infected dogs were identified by AB and ELISA, respectively. Medication program to combat dog infection resulted in successful interruption of parasite transmission, but the project failed to create awareness of the need for dog prophylaxis among rural populations as well as to establish a permanent control program in this municipality.

Visceral leishmaniasis in Brazil: revisiting paradigms of epidemiology and control

In the last 20 years, despite the known underestimation of cases, Brazil registered a marked increase in the incidence of visceral leishmaniasis. The main goal of this review is to reflect on some aspects of this zoonosis in Brazil and also to encourage the discussion in order to find more viable, effective and affordable strategies to be implemented by the Brazilian Leishmaniasis Control Program. The current situation of visceral leishmaniasis in Brazil might be seen as a paradox: the most important aspects of the disease are known, but so far the control of this disease has not yet been achieved. The current control strategies have not been able to prevent the geographical expansion, and even a rise in the incidence and lethality of visceral leishmaniasis. There is a need not only for a better definition of priority areas, but also for the implementation of a fieldwork monitoring system to the disease surveillance that could permit a further evaluation of the control program in areas where visceral leishmaniasis is endemic.

Mass treatment for intestinal helminthisis control in an Amazonian endemic area in Brazil

The objective of the present study was to estimate the prevalence of soil-transmitted helminthiasis and evaluate the sanitary conditions and the role of a mass treatment campaign for control of these infections in Santa Isabel do Rio Negro. A cross-sectional survey was carried out in 2002, to obtain data related to the sanitary conditions of the population and fecal samples for parasitological examination in 308 individuals, followed by a mass treatment with albendazole or mebendazole with coverage of 83% of the city population in 2003. A new survey was carried out in 2004, involving 214 individuals, for comparison of the prevalences of intestinal parasitosis before and after the mass treatment. The prevalences of ascariasis, trichuriasis and hookworm infection were 48%; 27% and 21% respectively in 2002. There was a significant decrease for the frequency of infections by Ascaris lumbricoides (p < 0.05; OR / 95% CI = 0.44 / 0.30 - 0.65), Trichuris trichiura (p < 0.05; OR / 95% CI = 0.37 / 0.22 - 0.62), hookworm (p < 0.05; OR / 95% CI = 0.03 / 0.01 - 0.15) and helminth poliparasitism (p < 0.05; OR / 95% CI = 0.16 / 0.08 - 0.32). It was also noticed a decrease of prevalence of infection by Entamoeba histolytica / dispar (p < 0.05; OR / 95% CI = 0.30 / 0.19 - 0.49) and non-pathogenic amoebas. It was inferred that a mass treatment can contribute to the control of soil-transmitted helminthiasis as a practicable short-dated measure. However, governmental plans for public health, education and urban infrastructure are essential for the sustained reduction of prevalences of those infections.

Successful control program to implement the appropriate antibiotic prophylaxis for cesarean section

OBJECTIVE: Describe implementation of a successful program to reduce doses (cefazolin 2 to 1 g) used for antimicrobial prophylaxis. METHODS: Evaluation of an intervention program to reduce prophylactic antimicrobial doses. The intervention included weekly staff discussions, automatic dispensation of 1g-vial of cefazolin by the pharmacy unless expressly requested by surgeon and increase in post-discharge surveillance as a strategy to reassure surgeons of the safety of the reduction. In the pre and post intervention periods, a prospective study of antimicrobial consumption and surgical site infections were measured. RESULTS: There were 5,164 and 5,204 deliveries in 2001-2002 and 2003-2004, respectively; 1,524 (29.5%) and 1,363 (26%) were cesarean sections. There was a 45% decrease in cefazolin vials used on average per cesarean section (2.29 to 1.25). Patients evaluated increased from 16% to 67% and the SSI rates in both periods were 3.34% to 2.42%, respectively. CONCLUSION: An ample intervention, including administrative and educational measures, led to high compliance with dose reduction and saved more than US$4,000 in cefazolin, considered important because government reimbursement in Brazil for cesarean section is $80.

Potential of biologically active plant oils to control mosquito larvae (Culex pipiens, Diptera: Culicidae) from an egyptian locality

The insecticidal effect of six commercially available plant oils was tested against 4th larval instars of Culex pipiens. Larvae were originally collected from Meit El-Attar, Qalyubia Governorate, Egypt, and then reared in the laboratory until F1 generation. The LC50 values were 32.42, 47.17, 71.37, 83.36, 86.06, and 152.94 ppm for fenugreek (Trigonella foenum-grecum), earth almond (Cyperus esculentus), mustard (Brassica compestris), olibanum (Boswellia serrata), rocket (Eruca sativa), and parsley (Carum ptroselinum), respectively. The tested oils altered some biological aspects of C. pipiens, for instance, developmental periods, pupation rates, and adult emergences. The lowest concentrations of olibanum and fenugreek oils caused remarkable prolongation of larval and pupal durations. Data also showed that the increase of concentrations was directly proportional to reduction in pupation rates and adult emergences. Remarkable decrease in pupation rate was achieved by mustard oil at 1000 ppm. Adult emergence was suppressed by earth almond and fenugreek oils at 25 ppm. In addition, the tested plant oils exhibited various morphological abnormalities on larvae, pupae, and adult stages. Consequently, fenugreek was the most potent oil and the major cause of malformation of both larval and pupal stages. Potency of the applied plant oils provided an excellent potential for controlling C. pipiens.

On an acute case of Chagas disease in a region under vector control in the state of São Paulo, Brazil

No vector transmitted cases of Chagas disease had been notified in the state of São Paulo since the 1970s. However, in March, 2006, the death of a six-year-old boy from the municipality of Itaporanga was notified to the Center for Epidemiological Survey of the São Paulo State Health Secretariat: an autochthonous case of acute Chagas disease. The postmortem histopathological examination performed in the Hospital das Clínicas of the Botucatu School of Medicine confirmed the diagnosis. Reference to hospital records, consultation with the health professionals involved in the case and interviews with members of the patient's family supplied the basis for this study. We investigated parasite route of transmission, probable local reservoirs and vectors. No further human cases of acute Chagas disease were diagnosed. No locally captured vectors or reservoirs were found infected with Trypanosoma cruzi. Alternative transmission hypotheses - such as the possible ingestion of foods contaminated with vector excreta - are discussed, as well as the need to keep previously endemic regions and infested houses under close surveillance. Clinicians should give due attention to such signs as uni- or bilateral palpebral edema, cardiac failure, myocarditis, pericarditis, anasarca and atypical signs of nephrotic syndrome or nephritis and consider the diagnostic hypothesis of Chagas disease.

Lutzomyia longipalpis behavior and control at an urban visceral leishmaniasis focus in Argentina

During the earlier stages of visceral leishmaniasis transmission in Posadas City, Misiones, both the night activity and attraction to humans of Lutzomyia longipalpis were assessed, in order to provide preliminary recommendations. The impact of peridomestic deltamethrin spraying performed by local officials was also evaluated. Although Lu. longipalpis were found in traps located over a dog the entire night, 90% of the females were captured from 20.30h to 1.30h, and only landed on a human when he was at a distance of 1.5 m from the dog. Peridomestic spraying of deltamethrin (25 mg/m²) reduced the sand fly capture up to seven days post-intervention without dispersion in the border of the sprayed areas. These results support the recommendations about time-space focus of the protection measures: first half of the night, in the backyard, with pets and domestic animals kept at least 5 m from humans. The deltamethrin as it was used did not seem very effective in this scenario; neither did the eventual use of bed nets, at least in adults, due to the place/hour of sand fly higher activity. This study strengthens the need for a multidisciplinary approach to develop prevention strategies based both on biological and anthropological studies.

Leprosy control: perspectives & epidemiological and operational aspects

OBJECTIVES: As a starting point, a vast variety of 200 technical papers and documents published during the ten years 1999-2008, from Brazilian and international organizations dedicated to the control of leprosy, was taken. A study was then undertaken to investigate its future evolutive possibilities by employing resources obtained from scenario analyses. DESIGN: The methodological reconstruction in use was of a qualitative nature, based on a bibliographic review and content analysis techniques. The latter were employed in a documental, categorical, contingent, frequency-based format, in compliance with appropriate and pertinent conditions. RESULTS: Nowadays, important elements on epidemiological and operational aspects have been regained, as well as respective perspectives. CONCLUSIONS: A projection is made towards the fact that the maintenance of the disease's present incidence levels constitute economic and sanitary challenges that confront issues ranging from the neoliberal model of global societal organization to specific competences of actions taken by health teams in the field.

Case-control study of an outbreak of acute toxoplasmosis in an industrial plant in the state of São Paulo, Brazil

Foodborne diseases represent operational risks in industrial restaurants. We described an outbreak of nine clustered cases of acute illness resembling acute toxoplasmosis in an industrial plant with 2300 employees. These patients and another 36 similar asymptomatic employees were diagnosed with anti-T. gondii IgG titer and avidity by ELISA. We excluded 14 patients based on high IgG avidity and chronic toxoplasmosis: 13 from controls and one from acute disease other than T. gondii infection. We also identified another three asymptomatic employees with T.gondii acute infection and also anti-T. gondii IgM positive as remaining acute cases. Case control study was conducted by interview in 11 acute infections and 20 negative controls. The ingestion of green vegetables, but not meat or water, was observed to be associated with the incidence of acute disease. These data reinforce the importance of sanitation control in industrial restaurants and also demonstrate the need for improvement in quality control regarding vegetables at risk for T. gondii oocyst contamination. We emphasized the accurate diagnosis of indexed cases and the detection of asymptomatic infections to determine the extent of the toxoplasmosis outbreak.

Genetic Control of Mosquitoes: population suppression strategies

Over the last two decades, morbidity and mortality from malaria and dengue fever among other pathogens are an increasing Public Health problem. The increase in the geographic distribution of vectors is accompanied by the emergence of viruses and diseases in new areas. There are insufficient specific therapeutic drugs available and there are no reliable vaccines for malaria or dengue, although some progress has been achieved, there is still a long way between its development and actual field use. Most mosquito control measures have failed to achieve their goals, mostly because of the mosquito's great reproductive capacity and genomic flexibility. Chemical control is increasingly restricted due to potential human toxicity, mortality in no target organisms, insecticide resistance, and other environmental impacts. Other strategies for mosquito control are desperately needed. The Sterile Insect Technique (SIT) is a species-specific and environmentally benign method for insect population suppression, it is based on mass rearing, radiation mediated sterilization, and release of a large number of male insects. Releasing of Insects carrying a dominant lethal gene (RIDL) offers a solution to many of the drawbacks of traditional SIT that have limited its application in mosquitoes while maintaining its environmentally friendly and species-specific utility. The self-limiting nature of sterile mosquitoes tends to make the issues related to field use of these somewhat less challenging than for self-spreading systems characteristic of population replacement strategies. They also are closer to field use, so might be appropriate to consider first. The prospect of genetic control methods against mosquito vectored human diseases is rapidly becoming a reality, many decisions will need to be made on a national, regional and international level regarding the biosafety, social, cultural and ethical aspects of the use and deployment of these vector control methods.