Evaluation of the impact of chemical control measures and entomological surveillance on Chagas' disease in the counties of Mambaí and Buritinópolis, Goiás State, Brazil

Epidemiological surveillance activities were implemented in 1980 in Mambaí and Buritinópolis counties, Goiás State. Twenty years later the authors evaluated the impact of these vector control measures on Chagas' disease transmission, based on entomological indicators. Entomological investigation was conducted using the man-hour technique and covering all domiciles. In order to study vector food sources the stomach contents of triatomines were analyzed using the modified precipitins technique. Triatomines were shown to be present in 48 (71.6%) of the 67 locations. Peridomiciliary infestation rates in Mambaí and Buritinópolis were 8.7% and 12.1%, respectively, while intradomiciliary rates were 0.7% and 1.2%. Triatoma sordida was the species identified in 97.3% of all captured specimens. It was also the only species found to be naturally infected with Trypanosoma cruzi. Birds were the most frequent food source (45%) for Triatoma sordida. The most significant result was the complete absence of Triatoma infestans in the two counties.

Education in primary school as a strategy to control dengue

The proliferation of Aedes aegypti, a species of mosquito that is the vector of the dengue pathogen, is being augmented by the population's lack of care in allowing the formation of larval habitats. One form of controlling dengue is the distribution of information on the mosquito to improve awareness and to provide the means necessary for the elimination of its reproductive habitats. To evaluate a teaching method concerning the vector and dengue, students from the 5th and 6th years of primary education were compared before and after didactic intervention with a group of control students. The students who received intervention were more successful in identifying the stages of the cycle, biological and morphological characteristics of the adult insect and the importance of the mosquito in health issues. The didactic intervention was successful in developing knowledge leading to increased awareness of the importance of preventative measures that should be taken against the vector and the disease.

Environmental sanitation conditions and health impact: a case-control study

This epidemiological investigation examines the impact of several environmental sanitation conditions and hygiene practices on diarrhea occurrence among children under five years of age living in an urban area. The case-control design was employed; 997 cases and 999 controls were included in the investigation. Cases were defined as children with diarrhea and controls were randomly selected among children under five years of age. After logistic regression adjustment, the following variables were found to be significantly associated with diarrhea: washing and purifying fruit and vegetables; presence of wastewater in the street; refuse storage, collection and disposal; domestic water reservoir conditions; feces disposal from swaddles; presence of vectors in the house and flooding in the lot. The estimates of the relative risks reached values up to 2.87. The present study revealed the feasibility of developing and implementing an adequate model to establish intervention priorities in the field of environmental sanitation.

Problems and perspectives for Chagas disease control: in search of a realistic analysis

Chagas disease was an important medical and social problem in almost all of Latin America throughout the twentieth century. It has been combated over a broad swath of this continent over recent decades, with very satisfactory results in terms of vector and transfusional transmission. Today, a surveillance stage still remains to be consolidated, in parallel with appropriate care required for some millions of infected individuals who are today living in endemic and non-endemic areas. Contradictorily, the good results attained have generated excessive optimism and even disregard among health authorities, in relation to this disease and its control. The loss of visibility and priority may be a logical consequence, particularly in Latin American healthcare systems that are still disorganized and overburdened due to insufficiencies of financial and human resources. Consolidation of the victories against Chagas disease is attainable but depends on political will and continual attention from the most consequential protagonists in this struggle, especially the Latin American scientific community.

Tityus stigmurus (Thorell, 1876) (Scorpiones; Buthidae): response to chemical control and understanding of scorpionism among the population

In this study, the events following application of the insecticideDemand 2.5 concentrated solution (CS) in the field, to control Tityus stigmurus, were investigated. Data on attitudes and practices relating to scorpionism were collected using a questionnaire. During the months of May to July 2005, 69 premises were monitored on different days following insecticide treatment, focusing on scorpion frequency and mortality. According to the results, 42% of the premises showed scorpion incidence, with an average of three specimens per house. The highest incidence was recorded during the first week following the treatment. Only 7% of the specimens were found dead. Most (72%) of the population showed knowledge about prevention and control measures. Despite this, 100% of the premises presented breeding sites, mainly in debris (79.7%). These results indicate that the scorpion control method used by health agents during this investigation was not efficient, and the results suggest that the method may have had a dispersive effect on these animals.

Visceral leishmaniasis in Rio de Janeiro, Brazil: eco-epidemiological aspects and control

From 1977 (index case) to 2006, 87 cases of visceral leishmaniasis were confirmed in the municipality of Rio de Janeiro, Brazil, in periurban areas on the continental and coastal slopes of the Pedra Branca massif and the continental slopes of the Gericinó massif. The majority (65.5%) of the patients were more than five years old, predominantly males (61.5%), but without any difference between the sexes below the age of 14 years. The overall fatality rate was 10.4%. Two cases of visceral leishmaniasis/human immunodeficiency virus coinfection were detected. Leishmania chagasi was isolated from human and canine cases. The associations between the presence of phlebotomines and human and canine migrations, disorderly occupation involving degradation of environmental preservation areas and poor socioeconomic conditions may have created a favorable setting for the establishment and propagation of the disease. Close epidemiological surveillance associated with traditional control measures and others (active case researches, land clearing and health education), reduced the incidence of human cases from 2.8 per 100,000 inhabitants in 1981 to less than 0.01 per 100,000 since 1997. The canine infection rates decreased from 4.6% in 1984 to 1.6% in 2008. Lutzomyia longipalpis was not detected in some locations where human and canine cases occurred. In the years 2007 and 2008, no new human cases were reported, but there is a persistent and worrisome residual canine seroprevalence.

Is severe visceral leishmaniasis a systemic inflammatory response syndrome? A case control study

INTRODUCTION: The objective of the study is to identify the main risk factors for death by New World visceral leishmaniasis and establish a coherent pathogenic substrate of severe disease based on clinical findings. METHODS: Seventy-six deceased inpatients and 320 successfully treated inpatients with VL were studied in a case control study. RESULTS: Bacterial infection and bleeding were mutually exclusive events leading to death. Five risk factors were unique for death by bacterial infection (malnutrition, pulmonary rales, severe anemia, severe absolute neutropenia and higher neutrophil count), while another six were unique for death by bleeding (jaundice, severe relative neutropenia, severe thrombocytopenia, liver injury, kidney failure, higher bone marrow parasite load). Bacterial infection, bleeding, severe anemia, diarrhea, dyspnea, edema, jaundice and bone marrow parasite load were the main syndromes of visceral leishmaniasis among successfully treated patients. CONCLUSIONS: The data support the idea that bacterial infections are due to immune paralysis. Broad organ and system involvement is plausibly due to the high production of proinflammatory cytokines, whose actions fit well with visceral leishmaniasis. The syndromes and causative mediators are typical of a slowly developing systemic inflammatory response syndrome.

Predictors of adherence to influenza vaccination for healthcare workers from a teaching hospital: a study in the prepandemic era

INTRODUCTION: Even before the 2009 pandemics, influenza in healthcare workers (HCW) was a known threat to patient safety, while Influenza vaccine coverage in the same group was generally low. Identification of predictors for HCW adherence to Influenza vaccination has challenged infection control committees. METHODS: Our group conducted a cross-sectional survey in December 2007, interviewing 125 HCWs from a teaching hospital to identify adherence predictors for Influenza vaccination. The outcomes of interest were: A - adherence to the 2007 vaccination campaign; B - adherence to at least three yearly campaigns in the past five years. Demographic and professional data were assessed through univariate and multivariate analysis. RESULTS: Of the HCWs interviewed, 43.2% were vaccinated against Influenza in 2007. However, only 34.3% of HCWs working in healthcare for more than five years had adhered to at least three of the last five vaccination campaigns. Multivariate analysis showed that working in a pediatric unit (OR = 7.35, 95%CI = 1.90-28.44, p = 0.004) and number of years in the job (OR = 1.32, 95%CI = 1.00-1.74, p = 0.049) were significant predictors of adherence to the 2007 campaign. Physicians returned the worst outcome performances in A (OR = 0.40, 95%CI = 0.16-0.97, p = 0.04) and B (OR = 0.17, 95%CI = 0.05-0.60, p = 0.006). CONCLUSIONS: Strategies to improve adherence to Influenza vaccination should focus on physicians and newly-recruited HCWs. New studies are required to assess the impact of the recent Influenza A pandemics on HCW-directed immunization policies.

Hepatitis B marker seroprevalence and vaccination coverage in adolescents in the City of Itajaí, State of Santa Catarina, Southern Brazil, in 2008

INTRODUCTION: Hepatitis B infection constitutes an important cause of morbidity and mortality worldwide. In Brazil, however, the current epidemiological situation is not clear. Considering the importance of establishing this prevalence, the aim of this study was to determine the prevalence of HBV markers in voluntary adolescents, junior high (secondary school) students, in the City of Itajaí, State of Santa Catarina, Brazil. METHODS: A seroepidemiological, transverse study was conducted with 353 randomly chosen adolescents from elementary school in 2008. Blood samples were analyzed for HBsAg, anti-HBc and anti-HBs. All analyses were conducted by automated microparticle enzyme immunosorbent assay (Abbott®, AxSYM system, Deerfield, IL, USA), according to the manufacturer's instructions. RESULTS: The prevalence of HBsAg was 0.6% (CI 95% 0.1 - 2.0), that of anti-HBc was 1.1% (CI 95% 0.3 - 2.9) and that of detectable anti-HBs was 83.6% (CI 95% 79.3 - 87.3). Hepatitis B vaccination coverage was 97.5% (CI 95% 95.2 - 98.8). CONCLUSIONS: These results demonstrate the success of the vaccination program against hepatitis B in the region studied and indicate that prevention strategies must be maintained and, if possible, expanded to contribute to the establishment of positive prevalence rates in all age groups.

Improving tuberculosis control through the partnership between university and the health system

INTRODUCTION: Tuberculosis (TB) control is linked to the availability of qualified methods for microbiological diagnostics; however, microscopy with limited sensitivity is the only method available in many locations. The objective of this study was to evaluate the introduction of culture, drug susceptibility testing (DST), and genotyping in the routine of a Municipal Program of Tuberculosis Control. METHODS: Direct microscopy of sputum and culture in Ogawa-Kudoh were performed on 1,636 samples from 787 patients. DST of positive cultures was performed by resazurin microtiter assay and genotyping by mycobacterial interspersed repetitive units-variable number tandem repeat. RESULTS: A total 91 patients with TB were identified. The culture increased case detection by 32% compared with the microscopy; acquired resistance was 3.3% and the genotyping showed high genetic diversity. CONCLUSIONS: Ogawa-Kudoh contributed significantly to the increase in case detection and is suitable for implementation in poor-resource locations. The acquired resistance rate was lower than that reported in a recent Brazilian survey. The high genetic diversity is possibly related to the high TB prevalence in the population, as well as to early detection and suitable treatment of patients. The interaction between research and health care is important for reorienting the practice, transferring technology, and improving TB control.

Epidemiology of malaria in the municipality of Cruzeiro do Sul, State of Acre, Brazil, in 2010: uses of a control chart at the local level

INTRODUCTION: This study describes the uses of a control chart in the malaria surveillance at the local level, signaling whether there is a need to intensify or adapt control measures. METHODS: The districts of Cruzeiro do Sul (n=14), State of Acre, Brazil, were classified into three groups: I) those with an incidence lower than expected; II) those with an incidence within the expected range; and III) those with an epidemic. RESULTS: Thirteen of the fourteen districts had outbreaks of malaria at some point in 2010, and six districts showed persistent malaria epidemic throughout the year. CONCLUSIONS: The control chart may help the malaria control at the local level.

Primary multidrug-resistant tuberculosis and its control implications in the State of Amazonas, Brazil: report of 3 cases

The occurrence of tuberculosis with first-line multidrug resistance leads to the use of alternative medications, often at higher costs, longer treatment periods, and greater clinical complexity. Here, we report 3 patients with multidrug-resistant tuberculosis. One patient with human immunodeficiency virus died before the sensitivity test was performed. The early diagnosis of multidrug-resistant tuberculosis and appropriate treatment should be priorities of the National Tuberculosis Control Program in order to break the chain of transmission. In addition, the possibility of substituting the proportion method with more modern and faster techniques should be urgently evaluated.

Perceptions of the usefulness of external support to immunization coverage in Guinea-Bissau: a Delphi analysis of the GAVI-Alliance cash-based support

INTRODUCTION: Although many countries have improved vaccination coverage in recent years, some, including Guinea-Bissau, failed to meet expected targets. This paper tries to understand the main barriers to better vaccination coverage in the context of the GAVI-Alliance (The Global Alliance for Vaccines and Immunisation) cash-based support provided to Guinea-Bissau. METHODS: The analysis is based on a document analysis and a three round Delphi study with a final consensus meeting. RESULTS: Consensus attributed about 25% of the failure to perform better to implementation problems; and about 10% to governance and also 10% to scarce resources. The qualitative analysis validates the importance of implementation issues and upgraded the relevance of the human resources crisis as an important drawback. The recommendations were balanced in their upstream-downstream focus but were blind to health information issues and logistical difficulties. CONCLUSIONS: It is commendable that such a fragile state, with all sorts of barriers, manages to sustain a slow steady growth of its vaccination coverage. Not reaching the targets set reflects the inappropriateness of those targets rather than a lack of commitment of the health workforce. In the unstable context of countries such as Guinea-Bissau, the predictability of the funds from global health initiatives like the GAVI-Alliance seem to make all the difference in achieving small consistent health gains even in the presence of other major bottlenecks.