Biological control program against simuliids in the State of São Paulo, Brazil

In Brazil, the use of biological vector-control methods has been largely confined to experimental research, with little or no application of such techniques by public institutions responsible for implementing control programs. The notable exceptions have been the black fly control program carried out by the Health Secretariat in the State of São Paulo. Since the 1980s, São Paulo's "Superintendência de Controle de Endemias" has been conducting studies on the viability of using Bacillus thuringiensis (H-14) for simuliid control, and the results have been so encouraging that the agency has now incorporated this method into its Simuliid Control Program.

Update of the Gene Discovery Program in Schistosoma mansoni with the Expressed Sequence Tag Approach

Continuing the Schistosoma mansoni Genome Project 363 new templates were sequenced generating 205 more ESTs corresponding to 91 genes. Seventy four of these genes (81%) had not previously been described in S. mansoni. Among the newly discovered genes there are several of significant biological interest such as synaptophysin, NIFs-like and rho-GDP dissociation inhibitor

Genetic Structure of Triatoma sordida (Hemiptera: Reduviidae) Domestic Populations from Bolivia: Application on Control Interventions

The genetic population of Triatoma sordida group 1, a secondary vector of Chagas disease in Bolivia, was studied by multi-locus enzyme electrophoresis. A total of 253 nymphal and adult specimens collected from seven neighbouring localities in the Velasco Province, Department of Santa Cruz, were processed. The relatively low genetic variability was confirmed for this species (rate of polymorphism: 0.20). The absence of genetic disequilibrium detected within the seven localities was demonstrated. A geographical structuration appears between localities with distances greater than 20 km apart. Although T. sordida presents a relatively reduced dispersive capacity, its panmictic unit is wider than compared with T. infestans. Genetic distances between T. sordida populations were correlated with geographic distance. Gene flow between geographic populations of T. sordida provides an efficient framework for effective vigilance and control protocols.

Simulium spp. control program in Rio Grande do Sul, Brazil

Insects of the Simuliidae family have been the object of control in Rio Grande do Sul since the 70s. Their constant attacks became a social-economical problem as well as a problem of Public Health, with serious consequences to men and to the economy of the areas in which the insects develop. At first, the control was done with a chemical larvicide Themephos ABATE 500 E, but an imperfect measuring of outflow to determine the quantity of the product made Simulium spp. resistant to it. From 1983 on, following a study of a new method for the outflow measuring, we started to use a biological larvicide Bacillus thuringiensis serovar israelensis based. The biological control uses the new method in 36.4% of the state area, assisting about 3,500,000 inhabitants.

Triatoma rubrovaria (Blanchard, 1843) (Hemiptera-Reduviidae-Triatominae) III: patterns of feeding, defecation and resistance to starvation

Data from the Chagas Disease Control Program indicate a growing domiciliary and peridomiciliary invasion of Triatoma rubrovaria in the State of Rio Grande do Sul, where it has become the most frequent triatomine species captured there since the control of T. infestans. Bionomic characteristics that could influence the vectorial capacity of T. rubrovaria as vector of Trypanosoma cruzi were evaluated: patterns of (i) feeding, (ii) defecation, and (iii) resistance to starvation, using insects fed on mice. Fifty three percent of the females showed a defecation pattern conducive to chagasic transmission, defecating either on or near the bite site. The averages of the resistance to starvation varied from 48.1 to 179 days, for the first and fifth nymphal stages, respectively. Our study shows that with respect to the patterns of feeding, defecation and resistance to fasting, T. rubrovaria presented similar rates to the ones observed for other effective vector species, such as T. infestans. Thus, based on our studies we conclude that T. rubrovaria has biological characteristics that can positively influence its capacity to become infected and transmit T. cruzi, and also to keep residual populations after chemical control interventions.

Schistosomiasis mansoni: follow-up of control program based on parasitologic and serologic methods in a Brazilian community of low endemicity

A field survey on schistosomiais was carried out in 1998, in the municipality of Pedro de Toledo, a low endemic area in the state of São Paulo, Brazil. According to the parasitologic Kato-Katz method, the prevalence rate was 1.6%, with an infection intensity of 40.9 eggs per gram of stool. By the immunofluorescence test (IFT) for detection of IgG and IgM antibodies in the serum, IgG-IFT and IgM-IFT, respectively, prevalence indices of 33.2% and 33.5% were observed. To assess the impact of the schistosomiasis control program in the area, parasitologic and serologic data obtained in 1998, analyzed according to the age, sex, and residence zone, were compared to previous data obtained in a epidemiologic study carried out in 1980, when prevalence indices were of 22.8% and 55.5%, respectively by Kato-Katz and IgG-IFT. A significant fall of the prevalence was observed, indicating that the control measures were effective. Nonetheless, residual transmission was observed, demonstrating the need for a joint effort to include new approaches for better understanding the real situation and improving the control of the disease in low endemic areas.

Insecticide and community interventions to control Triatoma dimidiata in localities of the State of Veracruz, Mexico

Three different interventions to control Triatoma dimidiata in the State of Veracruz were implemented: X-1 = whole dwelling spraying, X-2 = middle wall spraying, X-3 = household cleaning. Cyfluthrin was sprayed 3 times with 8 month intervals. After each spraying, insects were collected and sent to the laboratory to be recorded and to determine genus and species of the adult triatomine bugs, and nymphs were counted. Trypanosoma cruzi presence was determined. With X-1, the infestation, colonization, and natural infection indexes were reduced to 0% in the 3 localities, with respect to t0. With X-2, the infestation index was reduced to 10% at t3 in 3 localities; the colonization index was reduced to 0% in only 1 locality at t3, and the natural infection index was reduced to 0% at t3. With X-3 the 3 indexes were not effectively reduced but they decreased with respect to the baseline study. Insecticide application to the whole dwelling is a more efficient intervention than its application to only the lower half of the walls and to the cleaning of houses.

Antimicrobial susceptibility patterns of unusual nonfermentative gram-negative bacilli isolated from Latin America: report from the SENTRY Antimicrobial Surveillance Program (1997-2002)

The antimicrobial susceptibility of 176 unusual non-fermentative gram-negative bacilli (NF-GNB) collected from Latin America region through the SENTRY Program between 1997 and 2002 was evaluated by broth microdilution according to the National Committee for Clinical Laboratory Standards (NCCLS) recommendations. Nearly 74% of the NF-BGN belonged to the following genera/species: Burkholderia spp. (83), Achromobacter spp. (25), Ralstonia pickettii (16), Alcaligenes spp. (12), and Cryseobacterium spp. (12). Generally, trimethoprim/sulfamethoxazole (MIC50, < 0.5 µg/ml) was the most potent drug followed by levofloxacin (MIC50, 0.5 µg/ml), and gatifloxacin (MIC50, 1 µg/ml). The highest susceptibility rates were observed for levofloxacin (78.3%), gatifloxacin (75.6%), and meropenem (72.6%). Ceftazidime (MIC50, 4 µg/ml; 83.1% susceptible) was the most active beta-lactam against B. cepacia. Against Achromobacter spp. isolates, meropenem (MIC50, 0.25 µg/ml; 88% susceptible) was more active than imipenem (MIC50, 2 µg/ml). Cefepime (MIC50, 2 µg/ml; 81.3% susceptible), and imipenem (MIC50, 2 µg/ml; 81.3% susceptible) were more active than ceftazidime (MIC50, >16 µg/ml; 18.8% susceptible) and meropenem (MIC50, 8 µg/ml; 50% susceptible) against Ralstonia pickettii. Since selection of the most appropriate antimicrobial agents for testing and reporting has not been established by the NCCLS for many of NF-GNB species, results from large multicenter studies may help to guide the best empiric therapy.

Chronic Trypanosoma cruzi-elicited cardiomyopathy: from the discovery to the proposal of rational therapeutic interventions targeting cell adhesion molecules and chemokine receptors - how to make a dream come true

One hundred years ago, Carlos Chagas discovered a new disease, the American trypanosomiasis. Chagas and co-workers later characterised the disease's common manifestation, chronic cardiomyopathy, and suggested that parasitic persistence coupled with inflammation was the key underlying pathogenic mechanism. Better comprehension of the molecular mechanisms leading to clinical heart afflictions is a prerequisite to developing new therapies that ameliorate inflammation and improve heart function without hampering parasite control. Here, we review recent data showing that distinct cell adhesion molecules, chemokines and chemokine receptors participate in anti-parasite immunity and/or detrimental leukocyte trafficking to the heart. Moreover, we offer evidence that CC-chemokine receptors may be attractive therapeutic targets aiming to regain homeostatic balance in parasite/host interaction thereby improving prognosis, supporting that it is becoming a non-phantasious proposal.

Schistosomiasis control program in the state of Minas Gerais in Brazil

The Schistosomiasis Control Program (PCE) was implemented in Minas Gerais (MG) in 1984. In 1999, the state started the investigation and control of schistosomiasis in 470 municipalities. The aim of the present paper is to report the evolution of this Program from 1984-2007. The program included a coproscopic survey carried out in the municipalities of known endemic areas using a quantitative method. Positives were treated with praziquantel and given a program of health education. The information for this study was obtained from data collected and stored by the Health State Department. From 2003-2007, 2,643,564 stool examinations resulted in 141,284 positive tests for Schistosoma mansoni (5.3%). In the first evaluation after treatment, a decrease in the number of municipalities with prevalence over 10% was documented. In one village, selected for a more detailed evaluation, the percentage of positive tests decreased from 14.9% in the baseline survey to 5.3% after treatment. A reference centre for patients with severe schistosomiasis was created in Belo Horizonte, MG. Based on our findings, we believe that the implementation of PCE in MG is on the right path and in due time these new initiatives will provide desirable results.

The potential for vaccination in leprosy elimination: new tools for targeted interventions

Despite the huge effort and massive advances toward the elimination of leprosy over the last two decades, the disease has proven stubborn; new case detection rates have stabilised over the last few years and leprosy remains endemic in a number of localised regions. The American Leprosy Missions and Infectious Disease Research Institute have undertaken a large research effort aimed at developing new tools and a vaccine to continue the push for leprosy elimination. In this paper, we outline our strategy for the integration of rapid diagnostic tests and lab-based assays to facilitate the detection of early or asymptomatic leprosy cases, as well as the efficient and focused implementation of chemoprophylaxis and immunisation to intervene in leprosy development and transmission.

Immune response to the mumps component of the MMR vaccine in the routine of immunisation services in the Brazilian National Immunisation Program

A non-controlled longitudinal study was conducted to evaluate the combined vaccine against measles, mumps and rubella (MMR) immunogenicity in 150 children vaccinated in the routine of three health units in the city of Rio de Janeiro, Brazil, 2008-2009, without other vaccines administered during the period from 30 days before to 30 days after vaccination. A previous study conducted in Brazil in 2007, in 1,769 children ranging from 12-15 months of age vaccinated against yellow fever and MMR simultaneously or at intervals of 30 days or more between doses, had shown low seroconversion for mumps regardless of the interval between administration of the two vaccines. The current study showed 89.5% (95% confidence interval: 83.3; 94.0) seroconversion rate for mumps. All children seroconverted for measles and rubella. After revaccination, high antibody titres and seroconversion rates were achieved against mumps. The results of this study and others suggest that two MMR doses confer optimal immunoresponses for all three antigens and the possible need for additional doses should be studied taking into account not only serological, but also epidemiological data, as there is no serological correlate of protection for mumps.

A four-year surveillance program for detection of Plasmodium falciparum chloroquine resistance in Honduras

Countries could use the monitoring of drug resistance in malaria parasites as an effective early warning system to develop the timely response mechanisms that are required to avert the further spread of malaria. Drug resistance surveillance is essential in areas where no drug resistance has been reported, especially if neighbouring countries have previously reported resistance. Here, we present the results of a four-year surveillance program based on the sequencing of the pfcrt gene of Plasmodium falciparum populations from endemic areas of Honduras. All isolates were susceptible to chloroquine, as revealed by the pfcrt “CVMNK” genotype in codons 72-76.

Where do these bugs come from? Phenotypic structure ofTriatoma infestans populations after control interventions in the Argentine Chaco

House re-invasion by native triatomines after insecticide-based control campaigns represents a major threat for Chagas disease vector control. We conducted a longitudinal intervention study in a rural section (Area III, 407 houses) of Pampa del Indio, northeastern Argentina, and used wing geometric morphometry to compare pre-spray and post-spray (re-infestant bugs) Triatoma infestanspopulations. The community-wide spraying with pyrethroids reduced the prevalence of house infestation by T. infestans from 31.9% to < 1% during a four-year follow-up, unlike our previous studies in the neighbouring Area I. Two groups of bug collection sites differing in wing shape variables before interventions (including 221 adults from 11 domiciles) were used as a reference for assigning 44 post-spray adults. Wing shape variables from post-spray, high-density bug colonies and pre-spray groups were significantly different, suggesting that re-infestant insects had an external origin. Insects from one house differed strongly in wing shape variables from all other specimens. A further comparison between insects from both areas supported the existence of independent re-infestation processes within the same district. These results point to local heterogeneities in house re-infestation dynamics and emphasise the need to expand the geographic coverage of vector surveillance and control operations to the affected region.

The 15-minute family interview: a family health strategy tool

The 15-minute family interview is a condensed form of the Calgary Family Assessment and Intervention Models (CFAM and CFIM) that aims to contribute to the establishment of a therapeutic relationship between nurses and family and to implement interventions to promote health and suffering relief, even during brief interactions. This study investigated the experience of nurses from the Family Health Strategy (FHS) who used the 15-minute interview on postpartum home. The qualitative research was conducted in three stages: participants' training program, utilization of the 15-minute family interview by participants, and interviews with nurses. The data were collected through semi-structured interviews with eight nurses. The thematic analysis revealed two main themes: dealing with the challenge of a new practice and evaluating the assignment. This work shows that this tool can be used to deepen relationships between nurses and families in the Family Health Strategy.