Fernando José da Silva

Natural Leishmania infantum infection in Migonemyia migonei (França, 1920) (Diptera:Psychodidae:Phlebotominae) the putative vector of visceral leishmaniasis in Pernambuco State, Brazil

A study of the natural infection of phlebotomine sand flies by Leishmania (Leishmania) infantum was conducted in an area of visceral leishmaniasis in São Vicente Férrer, located in the northern part of the Atlantic rain forest region in the State of Pernambuco, Brazil. In a previous study, Migonemyia migonei have been found predominantly in peridomiciles and houses in this endemic area. The analysis of M. migonei, collected by CDC light trap, by multiplex PCR assay coupled to non-isotopic hybridization showed that 2 females out of 50 were infected by L. infantum. This is the first finding of natural infection of M. migonei by L. infantum suggesting that M. migonei may be the vector of L. infantum in areas of visceral leishmaniasis where Lutzomyia longipalpis, the usual vector, is absent.

Ecology of Lutzomyia longipalpis in an area of visceral leishmaniasis transmission in north-eastern Brazil

Visceral leishmaniasis is a major public health issue in South America, where the disease is rapidly spreading. Changes in ecology and distribution of the principal vector, Lutzomyia longipalpis are among the factors accounting for the increasing incidence of the disease in this region. However, information about the ecology of L. longipalpis is still incipient, which may directly impair the implementation of effective control programs. Herein, the ecology of L. longipalpis was studied in a focus of visceral leishmaniasis in north-eastern Brazil. From August 2009 to August 2010, phlebotomine sand flies were monthly collected in four localities using CDC light traps (~37 per month) and a lantern-baited Shannon trap with mouth aspirators. A total of 24,226 phlebotomine sand flies were collected with light traps and 375 with mouth aspirators. The most abundant species was L. longipalpis, representing 97.9% of the specimens collected with light traps and 91.5% with the mouth aspirator. Other species (Lutzomyia evandroi, Lutzomyia lenti and Lutzomyia sallesi) were found in low numbers. Most phlebotomine sand flies (94.6%) were collected at chicken coops and corrals. No significant correlation was found between the monthly abundance of phlebotomine sand flies and the monthly averages of temperature, relative humidity or rainfall. However, interestingly enough, 82.4% of L. longipalpis specimens were collected in months when relative humidity surpassed 75%. This study points out that this vector is well adapted to live in different habitats and to different climate conditions. It also suggests that some north-eastern populations of L. longipalpis may be more xerotolerant than southern populations. Further studies to assess the relationship between microclimate and L. longipalpis density in different Brazilian regions are advised.

Cutaneous and visceral leishmaniosis in dogs from a rural community in northeastern Brazil.

A community-based epidemiological study was carried out in a rural area in northeastern Brazil, where visceral leishmaniasis is endemic, but the primary vector Lutzomyia longipalpis has never been found. Forty-one dogs were screened by an indirect immunofluorescence antibody test (IFAT) for the presence of anti-Leishmania antibodies and 12 (29.3%) of them were positive. One of the IFAT-positive dogs was also positive for Leishmania amastigotes in bone marrow cytology and for Leishmania infantum by real-time polymerase chain reaction (PCR) on blood. One IFAT-negative dog was positive for L. infantum by PCR on bone marrow and other for Leishmania amastigotes in skin stained-smears. When tested for L. braziliensis by PCR, 20 dogs were positive. Considering all diagnostic tests, the estimated prevalence of Leishmania spp. infection in the studied rural dog population was 58.5%. There was no significant difference in IFAT-positivity in relation to age, gender, and clinical status of the dogs. When tested for L. infantum by real-time PCR, 20 ticks collected from IFAT-positive dogs were all negative. This study shows a high level of exposure to Leishmania spp. infection in dogs from a rural community in northeastern Brazil. In general, the results do not support the participation of ticks as vectors of L. infantum in this area, which is likely to be transmitted by Lutzomyia spp. other than L. longipalpis. Finally, this study highlights that the use of IFAT in areas where both L. infantum and L. braziliensis are present should be withdraw in order to avoid the unnecessary culling of dogs that are actually infected only by L. braziliensis.

Phlebotomine sandfly species from an American visceral leishmaniasis area in the Northern Rainforest region of Pernambuco State, Brazil

The aim of this study was to identify the fauna of phlebotomine sandflies in an area with incidence of American visceral leishmaniasis (AVL) in São Vicente Férrer, a municipality (county) located in the northern Zona da Mata in Pernambuco State, Brazil. Sandfly captures were conducted monthly for four nights/month from December 2002 to November 2003, by means of manual captures (with a Shannon trap) and by CDC light traps. A total of 23,156 specimens of phlebotomines sandflies were collected in a remnant of the Atlantic rainforest, houses, and animal shelters. Lutzomyia complexa was the most prevalent species, with a frequency of 62.5% (14,445/23,156), followed by Lutzomyia migonei, with 33.2% (7,677/23,156). No Lutzomyia longipalpis (the main vector of Leishmania chagasi in Brazil and the Americas) was found in the target area. Some specimens were dissected, but no Leishmania parasites were found.

Antemortem diagnosis of human rabies in a veterinarian infected when handling a herbivore in Minas Gerais, Brazil

The Ministry of Healths National Human Rabies Control Program advocates pre-exposure prophylaxis (PEP) for professionals involved with animals that are at risk of contracting rabies. We report an antemortem and postmortem diagnosis of rabies in a veterinarian who became infected when handling herbivores with rabies. The antemortem diagnosis was carried out with a saliva sample and a biopsy of hair follicles using molecular biology techniques, while the postmortem diagnosis used a brain sample and conventional techniques. The veterinarian had collected samples to diagnose rabies in suspect herbivores (bovines and caprines) that were subsequently confirmed to be positive in laboratory tests. After onset of classic rabies symptoms, saliva and hair follicles were collected and used for antemortem diagnostic tests and found to be positive by RT-PCR. Genetic sequencing showed that the infection was caused by variant 3 (Desmodus rotundus), a finding confirmed by tests on the brain sample. It is essential that professionals who are at risk of infection by the rabies virus undergo pre-exposure prophylaxis. This study also confirms that molecular biology techniques were used successfully for antemortem diagnosis and therefore not only allow therapeutic methods to be developed, but also enable the source of infection in human rabies cases to be identified accurately and quickly.

Phlebotomine sandflies (Diptera: Psychodidae) in São Vicente Férrer, a sympatric area to cutaneous and visceral leishmaniasis in the state of Pernambuco, Brazil.

INTRODUCTION In the last decades, a considerable geographic expansion of the leishmaniases in all regions of Brazil has been observed. The present study was carried out to identify the composition of the phlebotomine sandfly fauna and verify the seasonal variation of the main species after environmental changes occurred in São Vicente Férrer Municipality, State of Pernambuco, Brazil. METHODS Captures were carried out during four consecutive nights of each month using Centers for Disease Control and Prevention light traps from September 2009 to September 2010. The correlation between the number of phlebotomine sandflies captured and climatic factors (temperature and rainfall) was evaluated. RESULTS A total of 13,872 specimens belonging to 20 species were captured, of which, 6,247 (45%) were females, and 7,625 (55%) were males. Lutzomyia migonei was the most abundant species with 9,964 (71.8%) specimens, being predominant in the intradomicile and peridomicile areas with 108 (86.4%) and 9,746 (97%), respectively. In the forest remnants, Lutzomyia complexa 2,395 (65%) and Lutzomyia sordellii 770 (20.8%) predominated. The correlation analysis between the total number of sandflies captured and climatic factors did not show a significant influence on population density. CONCLUSIONS The high abundance of Lutzomyia migonei and Lutzomyia complexa indicates the possibility of new cases of cutaneous leishmaniasis (CL).

Spatial and temporal patterns of occurrence of Lutzomyia sand fly species in an endemic area for cutaneous leishmaniasis in the Atlantic Forest region of northeast Brazil

ABSTRACT: Sand fly populations of different ecological niches in the Amaraji endemic American Cutaneous Leishmaniasis (ACL) focus of the Pernambuco Atlantic Forest region of northeastern Brazil were monitored spatiotemporally. Lutzomyia whitmani was dominant in all niches but occurred in smaller numbers in forested locations. L. whitmani was significantly less seasonal than the other species, being present throughout the year while other species were more abundant between February and April. These results suggest that L. whitmani may potentially be the principal vector of ACL in the region, even though the sand fly fauna was diverse: 88% were L.whitmani and 12% belonged to 11 other species. Two other species, L. complexa (1.3%) and L. migonei (0.8%), considered to be ACL vectors in other regions, were also present. This detailed picture of the sand fly populations abundance and spatiotemporal distribution provides a basis for future modeling studies of forecasting sand fly activity patterns and ACL occurence.

Molecular detection of Leishmania in phlebotomine sand flies in a cutaneous and visceral leishmaniasis endemic area in northeastern Brazil

Several phlebotomine sand fly species have been regarded as putative or proven vectors of parasites of the genus Leishmania in Brazil, but data for the northeastern region remains incipient. In this study, a total of 600 phlebotomine sand flies were grouped in pools of 10 specimens each and tested by a Leishmania genus-specific PCR and by a PCR targeting Leishmania (Leishmania) infantum. Fourteen out of 60 pools were positive by the genus-specific PCR, being five pools of L. migonei, seven of L. complexa, one of L. sordellii and one of L. naftalekatzi, which correspond to a minimal infection rate of 2.3% (14/600). Our results, associated with their known anthropophily and their abundance, suggest the participation of L. migonei and L. complexa as vectors of Leishmania in northeastern Brazil. Remarkably, this is the first time in this country that the detection of Leishmania DNA in L. sordellii and L. naftalekatzi has been reported, but future studies are necessary to better understand the significance of these findings.

Bilateral anomaly in Evandromyia evandroi (Diptera: Psychodidae: Phlebotominae) captured in Vicência municipality, Northern Rainforest region of Pernambuco State, Brazil.

Abstract Approximately 800 species of phlebotomine sand flies, many of which are vectors of Leishmania, have been described. Besides morphological similarities within groups, the occurrence of anomalies within a species may lead to an erroneous description of new species. This paper describes one phlebotomine sand fly, Evandromyia evandroi, with a symmetrical bilateral anomaly in the number of spines on the gonostyle. In this specimen, the anomalous spine is located in the external region of gonostyle, inserted between the upper external and the lower external spines. It is important to document morphological anomalies, so as to avoid erroneous sand fly identifications.

Sand fly population dynamics and cutaneous leishmaniasis among soldiers in an Atlantic forest remnant in northeastern Brazil

Outbreaks of cutaneous leishmaniasis are relatively common among soldiers involved in nocturnal activities in tropical forests. We investigated the population dynamics of sand flies in a military training camp located in a remnant of Atlantic rainforest in northeastern Brazil, where outbreaks of cutaneous leishmaniasis have sporadically been described. From July 2012 to July 2014, light traps were monthly placed in 10 collection sites, being nine sites located near the forest edge and one near a sheep and goat stable. Light traps operated from 5:00 pm to 6:00 am, during four consecutive nights. Leishmania infection in sand flies was assessed using a fast real-time PCR assay. Cases of cutaneous leishmaniasis among soldiers were also investigated. In total, 24,606 sand flies belonging to 25 species were identified. Males (n = 12,683) predominated over females (n = 11,923). Sand flies were present during all months, being more numerous in March (n = 1,691) and April 2013 (n = 3,324). Lutzomyia choti (72.9%) was the most abundant species, followed by Lutzomyia longispina (13.8%), Lutzomyia complexa (5.3%), representing together >90% of the sand flies collected. Forty cases of cutaneous leishmaniasis were recorded among soldiers from January 2012 to December 2014. Leishmania isolates were obtained from eight patients and were all characterized as Leishmania braziliensis. Soldiers and anyone overnighting in Atlantic rainforest remnants should adopt preventative measures such as the use of repellents on bare skin or clothes and insecticide-treated tents.