FIRST REPORT OF ACUTE CHAGAS DISEASE BY VECTOR TRANSMISSION IN RIO DE JANEIRO STATE, BRAZIL

SUMMARY Chagas disease (CD) is an endemic anthropozoonosis from Latin America of which the main means of transmission is the contact of skin lesions or mucosa with the feces of triatomine bugs infected by Trypanosoma cruzi. In this article, we describe the first acute CD case acquired by vector transmission in the Rio de Janeiro State and confirmed by parasitological, serological and PCR tests. The patient presented acute cardiomyopathy and pericardial effusion without cardiac tamponade. Together with fever and malaise, a 3 cm wide erythematous, non-pruritic, papule compatible with a "chagoma" was found on his left wrist. This case report draws attention to the possible transmission of CD by non-domiciled native vectors in non-endemic areas. Therefore, acute CD should be included in the diagnostic workout of febrile diseases and acute myopericarditis in Rio de Janeiro.

Spontaneous morphogenetic juvenilization observed in laboratory populations of vector species of Chagas disease (Triatominae)

Reported are observations on spontaneous occurring morphogenetic juvenilization in laboratory populations of vector species of Chagas disease. Two general effects have been observed: arrested development and uncoordinated development. These are manifested by supernumerary nymphs (6th stage), intermediate nymphal-adult stages, badly deformed adults developed from 5th instar nymphs, uncoordinated development manifested by grotesque forms of adults, supernumerary adults unable to complete metamorphosis and complete supernumerary adults produced by 6th stage nymphs. The reoccurrence of insects with identical grades of juvenilization in the population is an indication that this is a genetic trait that might be inherited. The factors responsible for morphogenetic juvenilization cannot be transmitted through the juvenilized insects because they are sterile, than they were transmitted through normal insects probably as a recessive or a group recessive factors. The spontaneous morphogenetic juvenilization observed in laboratory populations has a striking similarity to juvenilizing effects induced by application of juvenile hormone analogues, described in the literature and also obtained in our laboratory in a study to be published. Thus it is suggested that both; the altered phenotypes occurring in wild populations and their "phenocopies" induced by the application of juvenile hormone analogues are products of gene controlled identical reactions.

Induction of male sterility through manipulation of genetic mechanisms present in vector species of Triatominae. II. Partial restoration of male fertility

The development of integrated measures which involve sterile mate release to supplement the conventional insecticidal techniques used in controlagainst insects of medical importance, raised the question, whether the vectors of Chagas'disease possess the natural mechanisms by manipulation of which they may be controlled. Results of earlier expenments, that had been published previously, were restricted to fragmentary information that raised various questions, the answer to which became available in the study herein described. Interspecific hybrids were produced from reciprocal crosses between T. pseudomaculata and T. sórdida and from unilateral crosses between female T. pseudomaculata and male. T. infestans. These females mated with males, laid less than the normal complement of eggs, but offspring was relatively abundant. When T. pseudomaculata females were paired with T. brasiliensis males, hybridization was more difficult because few of the females mated and those that did had a strongly reduced fertility. Adults emerged from ali crosses but exhibited sex disproportion, females predominating in all populations but one. The two Rhodnius species tested were also found to cross, but only when female R. prolixus were paired with male R. neglectus. These females laid a relatively high complement o f eggs, had a strongly reduced fertility, but 50% of the fertile eggs developed into vigorous adults, males predominating females. Neither type of hybrid male elicited fertilized eggs from either parental type of female, through their vesicula seminal is were found to be packed with spermatozoa, some normal looking and moving, others underdeveloped and motionless. Although, no artificial insemination was performed, the sperm in itself did not appear to be the prime inducer of sterility. Females paired with these hybrids did mate, sperm was transfered, as evidenced by the discharged spermatophores smeared with sperm, but did notcontain spermatozoa in their spermatecae. The failure of the sperm to migrate to the spermatecae indicate prezygotic pos-copulation incompatibility, thus the hybrid male can't be used to suppress populations. The female hybrids mated with parent males of either species had reduced fertility and ther sons were sterile as were those of their fertile daughters. However, continous backcrossing of the hybrid females and their female progeny to parental males partially restored fertility of the males and increased fertility of females, as scored by egg hatchability. Fertility of hybrid females, measured by the yield of adults capable to reproduce, indicated that the reproductive perfomance decreased when hybrid females and their daughters were backcrossed additional generations to parental males. It is tentatively suggested that hybrid females could be used for suppression if they compete efficiently with wild females.

The presence of Lutzomyia longipalpis in a focus of American visceral leishmaniasis where the only proven vector is Lutzomyia cruzi. Corumbá, Mato Grosso do Sul State

The present communication reports the presence of Lutzomyia longipalpis in Corumbá, Mato Grosso do Sul, where the principal vector is Lutzomyia cruzi.

Using epidemiological survey data to infer geographic distributions of leishmaniasis vector species

An important aspect of tropical medicine is analysis of geographic aspects of risk of disease transmission, which for lack of detailed public health data must often be reduced to an understanding of the distributions of critical species such as vectors and reservoirs. We examine the applicability of a new technique, ecological niche modeling, to the challenge of understanding distributions of such species based on municipalities in the state of São Paulo in which a group of 5 Lutzomyia sandfly species have been recorded. The technique, when tested based on independent occurrence data, yielded highly significant predictions of species' distributions; minimum sample sizes for effective predictions were around 40 municipalities.

A list of mosquito species of the Brazilian State of Pernambuco, including the first report of Haemagogus janthinomys (Diptera: Culicidae), yellow fever vector and 14 other species (Diptera: Culicidae)

INTRODUCTION: Besides mosquito species adapted to urban environments (Culex quinquefasciatus, Aedes aegypti and Aedes albopictus), only 15 species of Anopheles had been recorded in the State of Pernambuco. METHODS: Human-landing mosquitoes were collected in Dois Irmãos Park, in Recife. RESULTS: The first report for the state of Haemagogus janthinomys, an important vector of yellow fever virus, and 14 other species, including Trichoprosopon lampropus, a first reported for Brazil. CONCLUSIONS: The mosquito fauna in the area is diversified and has potential medical and veterinary importance.

Advanced megaesophagus (Group III) secondary to vector-borne Chagas disease in a 20-month-old infant

The authors report the case of a female infant with Group III (or Grade III) megaesophagus secondary to vector-borne Chagas disease, resulting in severe malnutrition that reversed after surgery (Heller technique). The infant was then treated with the antiparasitic drug benznidazole, and the infection was cured, as demonstrated serologically and parasitologically. After follow-up of several years without evidence of disease, with satisfactory weight and height development, the patient had her first child at age 23, in whom serological tests for Chagas disease yielded negative results. Thirty years after the initial examination, the patient's electrocardiogram, echocardiogram, and chest radiography remained normal.

Analysis of sandflies (Diptera: Psychodidae) in Barra do Garças, State of Mato Grosso, Brazil, and the influence of environmental variables on the vector density of Lutzomyia longipalpis (Lutz & Neiva, 1912)

INTRODUCTION: Leishmaniasis is an infectious and parasitic zoonotic, non-contagious, vector-borne disease caused by protozoa of the genus Leishmania. In Brazil, the major vector of Leishmania (Leishmania) infantum chagasi (Cunha & Chagas, 1934) is Lutzomyia longipalpis. Barra do Garças, State of Mato Grosso, was designated as a priority area by the Brazilian Ministry of Health for american visceral leishmaniasis, and it is important to identify the vector species present in this municipality. Our objective was to raise sandflies and study the influence of environmental variables on the vector density of Lutzomyia longipalpis. METHODS: We performed entomological monitoring in 3 districts using Centers for Disease Control and Prevention (CDC) light traps and recorded human cases of american visceral leishmaniasis in the city. We calculated the relative frequency and richness of sandflies and applied a transfer function model to the vector density correlate with relative humidity. RESULTS: The sandfly population was composed of 2 genera and 27 species, totaling 8,097 individuals. Monitoring identified Lutzomyia longipalpis (44%), followed by Lutzomyia lenti (18.9%), Lutzomyia whitmani (13.9%), Lutzomyia carmelinoi (9.1%), Lutzomyia evandroi (5.1%), Lutzomyia termitophila (3.3%), Lutzomyia sordellii (1.9%), and 20 other species (<4%). The male:female ratio was 3.5:1. We observed high species diversity (Dα = 6.65). Lutzomyia longipalpis showed occurrence peaks during the rainy season; there was a temporal correlation with humidity, but not with frequency or temperature. CONCLUSIONS: The presence of Lutzomyia longipalpis in the urban area of Barra do Garças underscores the changing disease profile, which was previously restricted to the wild environment.

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.

Larvicidal activity of crude extracts from Larrea cuneifolia (Zygophyllaceae) and of its metabolite nordihydroguaiaretic acid against the vector Culex quinquefasciatus (Diptera: Culicidae)

INTRODUCTION: The aim of the present study was to analyze the larvicidal activity of different crude extracts of Larrea cuneifolia and its most abundant lignan, nordihydroguaiaretic acid (NDGA), against Culex quinquefasciatus. METHODS: Chloroform, methanol, and aqueous extracts from L. cuneifolia and NDGA were tested against larvae of Cx. quinquefasciatus under laboratory conditions. RESULTS: The chloroform extract showed the highest larvicidal effect, with an estimated LC50 of 0.062 mg/ml. NDGA also demonstrated significant larvicidal activity with an estimated LC50 of 0.092 mg/ml. CONCLUSIONS: These results indicate that the chloroform extract of L. cuneifolia and NDGA are promising insecticides of botanical origin that could be useful for controlling Cx. quinquefasciatus.

Eclectic feeding behavior of Lutzomyia (Nyssomyia) intermedia (Diptera, Psychodidae, Phlebotominae) in the transmission area of American cutaneous leishmaniasis, state of Paraná, Brazil

Introduction The blood meal source of sandflies provides valuable information about the vector/host interaction and allows for an understanding of American cutaneous leishmaniasis (ACL) transmission mechanisms. The aim of this study was to identify the blood meal sources of Lutzomyia (Nyssomyia) intermedia in an endemic area of leishmaniasis in Brazil's State of Paraná using a precipitin test. Methods Sandflies were collected in the rural locality of Epitácio Pessoa within the City of Adrianópolis, State of Paraná, in southern Brazil. A total of 864 female sandflies were captured, and 862 (99.8%) were identified as L. intermedia species. However, two unidentified specimens were considered to be part of the genus Lutzomyia. Results Among the females examined, 396 specimens presented reactions to a certain type of tested antiserum, and most (67.9%) reacted to the simple type. These sandflies fed mainly on the blood of birds, opossums, and rodents, but specimens that fed on the blood of humans, dogs, horses, cattle, and cats were also found. Among the cross-reactions found (32.1%), bird/rodent, bird/opossum, bird/dog, bird/human, and horse/dog cross-reactions were the most common. Conclusions These results demonstrate a tendency in the eclectic feeding behavior of L. intermedia and support its potential role as a vector for ACL in the study area.

Profile of the Trypanosoma cruzi vector infestation in Jaboticatubas, State of Minas Gerais, Brazil

Introduction This work aimed to analyze the triatomine infestation scenario in Jaboticatubas after 30 years of the uninterrupted actions of the Program of Chagas Disease Control. Methods From 2007 to 2010, household unit infestation was researched, and an exploratory analysis of the localities infested with Panstrongylus megistus was performed. Results In total, 613 triatomines were captured in 78 households, the majority of which were Panstrongylus megistus and were captured mainly in chicken houses, but they were also found to be colonizing human houses. Conclusions The epidemiological importance of Panstrongylus megistus was confirmed in Jaboticatubas, and capability to colonize indoors has been demonstrated, as has its proximity to humans. Its distribution is aggregated in the northern and in central-eastern regions of the municipality.

Stomoxys calcitrans as possible vector of Trypanosoma evansi among camels in an affected area of the Canary Islands, Spain

Introduction Trypanosoma evansi was first identified in the Canary Islands in 1997, and is still present in a small area of the Archipelago. To date, the disease has exclusively affected camel herds, and has not been detected in any other animal hosts. However potential vectors of Trypanosoma evansi must be identified. Methods One Nzi trap was placed on a camel farm located in the infected area for a period of one year. Results Two thousand five hundred and five insects were trapped, of which Stomoxys calcitrans was the sole hematophagous vector captured. Conclusions Stomoxys calcitrans could be exclusively responsible for the transmission of Trypanosoma evansi among camels in the surveyed area, as other species do not seem to be infected by S. calcitrans in the presence of camels.