A field trial of a PCR-based Mansonella ozzardi diagnosis assay detects high-levels of submicroscopic M. ozzardi infections in both venous blood samples and FTA® card dried blood spots

BACKGROUND: Mansonella ozzardi is a poorly understood human filarial parasite with a broad distribution throughout Latin America. Most of what is known about its parasitism has come from epidemiological studies that have estimated parasite incidence using light microscopy. Light microscopy can, however, miss lighter, submicroscopic, infections. In this study we have compared M. ozzardi incidence estimates made using light microscopy, with estimates made using PCR. METHODS: 214 DNA extracts made from Large Volume Venous Blood Samples (LVVBS) were taken from volunteers from two study sites in the Rio Solimões region: Codajás [n = 109] and Tefé [n = 105] and were subsequently assayed for M. ozzardi parasitism using a diagnostic PCR (Mo-dPCR). Peripheral finger-prick blood samples were taken from the same individuals and used for microscopic examination. Finger-prick blood, taken from individuals from Tefé, was also used for the creation of FTAcard dried blood spots (DBS) that were subsequently subjected to Mo-dPCR. RESULTS: Overall M. ozzardi incidence estimates made with LVVBS PCRs were 1.8 times higher than those made using microscopy (44.9% [96/214] compared with 24.3% [52/214]) and 1.5 times higher than the PCR estimates made from FTAcard DBS (48/105 versus 31/105). PCR-based detection of FTAcard DBS proved 1.3 times more sensitive at diagnosing infections from peripheral blood samples than light microscopy did: detecting 24/105 compared with 31/105. PCR of LVVBS reported the fewest number of false negatives, detecting: 44 of 52 (84.6%) individuals diagnosed by microscopy; 27 of 31 (87.1%) of those diagnosed positive from DBSs and 17 out of 18 (94.4%) of those diagnosed as positive by both alternative methodologies. CONCLUSIONS: In this study, Mo-dPCR of LVVBS was by far the most sensitive method of detecting M. ozzardi infections and detected submicroscopic infections. Mo-dPCR FTAcard DBS also provided a more sensitive test for M. ozzardi diagnosis than light microscopy based diagnosis did and thus in settings where only finger-prick assays can be carried-out, it may be a more reliable method of detection. Most existing M. ozzardi incidence estimates, which are often based on light microscope diagnosis, are likely to dramatically underestimate true M. ozzardi parasitism incidence levels.Jansen Fernandes de Medeiros had financial support from edital PPSUS FAPEAM/SUSAM/MS/CNPq 007/2009. FAPEAM also provided finical support for the work of: Tatiana Amaral Pires de Almeida; Lucyane Bastos Tavares da Silva and J. Lee Crainey. The authors would like to thank Ricardo Mota and personal at Tefé for their technical assistance and two referees for their useful comments, which have helped to improve the manuscript. This paper is contribution number 23 of the Research Programme on Infectious Disease Ecology in the Amazon (RP-IDEA) of the Instituto Leônidas and Maria Deane—Fiocruz Amazônia.S

Ecological niche modelling for predicting the risk of cutaneous leishmaniasis in the Neotropical moist forest biome

A major challenge of eco-epidemiology is to determine which factors promote the transmission of infectious diseases and to establish risk maps that can be used by public health authorities. The geographic predictions resulting from ecological niche modelling have been widely used for modelling the future dispersion of vectors based on the occurrence records and the potential prevalence of the disease. The establishment of risk maps for disease systems with complex cycles such as cutaneous leishmaniasis (CL) can be very challenging due to the many inference networks between large sets of host and vector species, with considerable heterogeneity in disease patterns in space and time. One novelty in the present study is the use of human CL cases to predict the risk of leishmaniasis occurrence in response to anthropogenic, climatic and environmental factors at two different scales, in the Neotropical moist forest biome (Amazonian basin and surrounding forest ecosystems) and in the surrounding region of French Guiana. With a consistent data set never used before and a conceptual and methodological framework for interpreting data cases, we obtained risk maps with high statistical support. The predominantly identified human CL risk areas are those where the human impact on the environment is significant, associated with less contributory climatic and ecological factors. For both models this study highlights the importance of considering the anthropogenic drivers for disease risk assessment in human, although CL is mainly linked to the sylvatic and peri-urban cycle in Meso and South America. © 2019 Chavy et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Detection of DENV-4 genotype I from mosquitoes collected in the city of Manaus, Brazil

Background\ud Dengue epidemics have been reported in Brazil since 1981. In Manaus, a large city in the Amazon region, dengue is endemic with all four-virus serotypes (DENV-1, -2, -3, and -4) simultaneously causing human disease. In 2008, during a surveillance of dengue virus in mosquitoes in the district of Tancredo Neves in Manaus, 260 mosquitoes of Aedes genus were captured, identified and grouped into pools of 10 mosquitoes.\ud \ud Findings\ud RNA extracts of mosquito pools were tested by a RT-Hemi-Nested-PCR for detection of flaviviruses. One amplicon of 222 bp, compatible with dengue virus serotype 4, was obtained from a pool of Aedes aegypti. The nucleotide sequence of the amplicon indicated that the mosquitoes were infected with DENV-4 of genotype I. This virus of Asian origin has been described in Manaus in 2008 infecting acute febrile illness patients.\ud \ud Conclusion\ud This is the first report of dengue virus serotype 4 genotype I infecting Aedes aegypti in the Americas.This work was supported by Conselho Nacional de Desenvolvimento Científico e Tecnológico - CNPq

SARS-CoV-2 in the Amazon region

A medida que la pandemia del Síndrome Respiratorio Agudo Severo Coronavirus 2 (SARS-CoV-2) continúa expandiéndose, los recursos de atención médica a nivel mundial se han reducido. Ahora, la enfermedad es extendiéndose rápidamente por América del Sur, con consecuencias mortales en áreas con ya sistemas de salud pública debilitados. La región amazónica es particularmente susceptible a la devastación generalizada de la enfermedad por coronavirus 2019 (COVID-19) debido a sus habitantes amerindios nativos inmunológicamente frágiles y vulnerabilidades epidemiológicas. Aquí, nosotros discutir la situación actual y el impacto potencial de COVID-19 en la región amazónica y cómo una mayor propagación de la ola epidémica podría resultar devastadora para muchas personas amerindias que viven en la selva amazónicaAs the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) pandemic continues to expand, healthcare resources globally have been spread thin. Now, the disease is rapidly spreading across South America, with deadly consequences in areas with already weakened public health systems. The Amazon region is particularly susceptible to the widespread devastation from Coronavirus disease 2019 (COVID-19) because of its immunologically fragile native Amerindian inhabitants and epidemiologic vulnerabilities. Herein, we discuss the current situation and potential impact of COVID-19 in the Amazon region and how further spread of the epidemic wave could prove devastating for many Amerindian people living in the Amazon rainfores

Simulium

<i>Simulium</i> (<i>Psaroniocomps</i> a) <i>guaporense</i> Py­Daniel <p>(Figs. 1–33)</p> <p> <i>Simulium guaporense</i> Py­Daniel, 1989: 502 ­508. HOLOTYPE pupa (on slide, INPA 5849­1), BRAZIL: Rondônia State, Igarapé Ponte de Pedra, km 27 da rodovia RO­399, Fazenda Régis; 14.vi.1981 (V. Py­Daniel) (INPA) [Examined]</p> <p> <i>Simulium</i> (<i>Psaroniocompsa</i>) <i>siolii</i> Py­Daniel, 1988: 294 –300. [In part]</p> <p> <b>Female.</b> General body color black. Body mean length (specimens pinned) 1.67 mm (SD = 0.05, <i>n</i> = 5), wing mean length 1.7 mm (SD = 0.09, <i>n</i> = 5), wing mean width 0.7 mm (SD = 0.03, <i>n</i> = 5).</p> <p>Head dichoptic with dark eyes and nudiocular area small (Fig. 3). Frons, clypeus, and occiput pollinose with metallic reflections; clypeus, frons, and occiput bare in all specimens examined. Antenna length 0.25 mm; scape and pedicel yellowish brown, flagellum dark brown (Fig. 1). Palpus brown (Fig. 2); sensory vesicle occupying less than half length of third palpomere, with short neck; palpomere V approximately 2.5 times as long as palpomere III and 1.9 times as long as palpomere IV. Mandible with 6­8 external serrations and 28­30 internal teeth. Lacinia with 21–23 retrorse teeth. Cibarium with sclerotised cornuae and prominent teeth in central trough [triangular small teeth are in membrane of pharynx and in anterolateral margin of cornuae] (Fig. 4).</p> <p>Thorax with scutum black covered by recumbent, brass­colored scale­like setae, with greenish and bluish reflections with some light. Scutum, independent of light incidence, black without pattern, covered with evenly arranged scale­like setae forming 5 longitudinal lines, 1 median and 2 + 2 submedian, on central region of scutum extending from anterior to near posterior margin of scutum, and groups of setae in clumps that form broken lines diverging from anterior to lateral margins; posterior margin with single, recumbent, unevenly arranged whitish hairs (Figs. 9, 10); humeri silver pruinose [best seen in specimens devoid of setae]; lateral and posterior margins silver pruinose [best seen with light incidence posterior and specimens tilted laterally]. Scutellum dark brown, devoid of hairs in few specimens examined. Postnotum dark brown to black with distinct silver pruinosity. Pleura and sterna black with silver pruinosity. Costa of wing with sparse distribution of spines and setae (Fig. 20); subcosta without hairs or spines (Fig. 20); radius with single row of spines toward apex, basal section of radius bare (Fig. 20); basal tuft of long, dark setae. Coloration and proportions of legs as in Figs. 5–7. Foreleg (Fig. 5) with coxa, trochanter, femur, and dorsal margin of tibia yellowish brown; ventral margin of tibia whitish; basitarsus and tarsomeres I–IV black. Middle leg (Fig. 6) with coxa, apical one­third of basitarsus and tarsomeres I–IV dark brown; trochanter, femur and tibia yellow; two­thirds of basitarsus whitish. Hind leg (Fig. 7) with coxa, two­thirds of femur and tibia, apical one­third of basitarsus and tarsomeres I–IV dark brown; trochanter, basal one­third of femur and tibia yellow; basal two­thirds of basitarsus whitish [silver pruinose in pinned specimens]. Femur and tibia of hind legs covered with lanceolate scale­like setae interspersed with erect black hairs. Calcipala as broad as long, reaching pedisulcus. Tarsal claws curved with basal tooth (Fig. 8). Halters lemon yellow with dark brown base.</p> <p>Abdomen (Fig. 15) with tergites I, III–V velvet dark brown, VI–IX shiny black; tergite II brown on median region with silver pruinosity on lateral margin; basal fringe with long, brown hairs. Tergal plates developed. Sternites greyish; genitalia dark brown to black. Hypogynial lobes (= gonapophyses) subtriangular, covered by small microtrichia, mainly membranous but sclerotised on inner margins (Fig. 13). Cercus suboval, covered with long, brown setae; anal lobe (= paraproct) about 1.5 times longer than wide at mid point, covered with long hairs (Fig. 11). Genital fork with slender, weakly sclerotised stem; termination of lateral arms with anterior margin nearly straight and well developed; anterior processes well developed and rounded apically; posterior processes poorly developed (Fig. 12). Spermatheca (Fig. 14) oval without external sculpturing; internal spicules arranged in groups of 2 or 3; area of insertion of spermathecal duct membranous, nearly one­third maximum width of spermatheca.</p> <p> <b>Male.</b> General body color black. Body mean length (specimens pinned) 1.61 mm (SD = 0.03, <i>n</i> = 3), wing mean length 1.5 mm (SD = 0.02, <i>n</i> = 3), wing mean width 0.7 mm (SD = 0.03, <i>n</i> = 3).</p> <p>Head holoptic with dark red eyes. Antenna mean length 0.25 mm, scape and pedicel yellowish brown, flagellum dark brown (Fig. 16). Palpus (Fig. 17) brown, palpomere V approximately 2.3 times as long as palpomere III and 2.1 times as long as palpomere IV; sensory vesicle small, subspherical. Rest of head and scutum coloration (Figs 18, 19) as in female; humeri weakly pruinose; lateral margins black. With light source posterior to specimen, humeri and lateral margin silver pruinose. Scutellum dark brown with long, brown, erect setae on posterior margin. Postnotum dark brown with silvery grey pruinosity. Wing setation as in female (Fig. 20). Leg coloration and setation as in female (Figs 5–7), but tarsal claw without basal tooth.</p> <p>Abdominal tergites dark brown, basal fringe with thin, long, brown hairs and golden highlights; tergite II with silver pruinosity; tergites III–VIII with silver pruinosity on lateral margin, extent of pruinosity on tergites VI and VII being larger. Gonocoxite subquadrangular nearly as long as wide; gonostyle subtriangular, 1.5 times shorter than gonocoxite, terminating in 1 distinct apical spine and bearing 1 longitudinal ridge (Fig. 23); gonocoxite and gonostyle covered with long setae (Figs. 23, 24). Ventral plate (Fig. 22) subrectangular, weakly sclerotised, with well­developed body, distinctly raised at its center; lateral arms developed and wide apically; main body of ventral plate covered by numerous setae. Median sclerite (Fig. 21) suboval. Paramere (Fig. 21) with welldeveloped and sclerotised basal process and numerous long spines.</p> <p> <b>Pupa.</b> Cocoon length dorsally 2.1–2.4 mm (<i>n</i> = 2), ventrally 2.4­2.6 mm (<i>n</i> = 2); pupa length 1.3–1.8 mm (<i>n</i> = 2); gill length 2.1–2.4 mm (mean = 2.3 mm, SD = 0.10, <i>n</i> = 10). Cocoon slipper shaped, pale brown, composed of thick coalesced fibers, without anterior projection; anterior margin reinforced (Fig. 27).</p> <p>Gill configuration with short petiole and (2 + 2) + 2 filaments (Figs. 28, 29). The dorsal branch divides into 2 secondary branches on basal one­third, 1 anterior and 1 posterior, each bifurcating at different heights at some distance from gill base. The ventral primary branch bifurcates into 2 secondary branches nearly at midpoint of gill length, often nearly at same level as anterior secondary branch. Variation in this pattern occurs with ventral primary branch bifurcating more apically than anterior and posterior secondary branches, and anterior and secondary branches bifurcating at same level. Filaments slender, with rounded ends, edges crenate, covered by small, dark, spicules; all filaments approximately of same length.</p> <p>Head with 2 + 2 long, quadrifid frontal and 1 + 1 long, quadrifid, dorsal (= facial) trichomes; frontoclypeus with faint group of platelets mesally and 1 + 1 dorsolaterally in frontal region, respectively; rounded and pointed tubercles sparsely to densely distributed over entire surface (Fig. 25).</p> <p>Thorax with 5 + 5 dorsal bifid and quadrifid trichomes located near dorsal cleft and 1 + 1 bifid trichome on central region; tubercles rounded (some pointed), densely distributed anteriorly and scarce on posterior region of thorax (Fig. 26).</p> <p>Abdominal tergite I with 1 + 1 lateral, long, simple or bifid trichomes; tergite II with 3 + 3 median, simple, small trichomes in longitudinal row, 3 + 3 simple, small, trichomes to outmost trichomes unevenly arranged and 1 + 1 sublateral, small, simple trichomes; tergites III and IV with 4 + 4 submedian, simple hooks in longitudinal row, 1 + 1 small, simple trichomes anterior to outer hooks, and 2 + 2 submedian and 1 + 1 sublateral, simple or bifid trichomes on posterior margin; tergites V, VI, and VII with spine combs on anterior margin, sometimes developed into sclerotised spines centrally and with 1 + 1 or 2 + 2 small, simple, trichomes on posterior margin; sternite VIII with small spine combs; sternite IX weakly sclerotised and 1 + 1 small terminal spine. Abdominal sternite III with 2 + 2 sublateral, simple trichomes; sternite IV with 2 + 2 submedian, simple or bifid, and 2 + 2 lateral, single trichomes; sternite V with 2 + 2 median, close, bifid or quadrifid hooks in longitudinal row, 2 + 2 simple, small trichomes anterior to outer hooks; sternite VI and VII with 4 + 4 well­separated hooks, innermost trifid and outermost on right side bifid and on left side simple; sternite VIII with single, small, simple trichomes on posterior margin; sternite IX weakly sclerotised. Spine combs distributed on anterior margin of abdominal sternites III–VIII.</p> <p> <b>Larva.</b> In general, as in original description (Py­Daniel, 1989), but first pair of dorsal tubercles located on third thoracic segment, not on first abdominal segment (Fig. 30); abdominal segments I–IV with 2 pairs of tubercles, 1 dorsal and 1 lateral; abdominal segment V with 1 pair of dorsal tubercles. Subesophageal ganglion not pigmented. Anal papillae with 3 branches, each with 14–16 digitiform lobes.</p> <p> <b>Taxonomic Discussion.</b> <i>Simulium guaporense</i> was described by Py­Daniel (1989) from larvae and pupae collected in the state of Rondônia, Brazil. In his 1989 paper, Py­ Daniel mentioned that in the original description of <i>S. siolii</i> (Py­Daniel 1988), one larva he collected in Rondônia State, Igarapé da Cachoeira, Bacia do rio Guaporé matched the morphology of <i>S. guaporense</i>. The second author (LMH) of the present paper examined the holotype of <i>S. guaporense</i>, which is housed in INPA.</p> <p> <i>Simulium guaporense</i> was placed in the <i>siolii</i> species group of the subgenus <i>Psaroniocompsa</i> by Py­Daniel (1989), based on the presence of dorsal and lateral tubercles and multiple branched scale­like setae on the larval body. However, the presence of these tubercles (or protuberances) is apparently not restricted to this species group in the Neotropical Region. Shelley <i>et al.</i> (2002) described similar tubercles in two populations of the relatively well­studied species <i>Simulium guianense</i> Wise (species complex) collected in Rio Verdão and Rio Doce, Goiás State, Brazil. Similar variation in tubercles is also seen in larvae of the <i>S. damnosum</i> complex in Africa, in which variation in tubercle size ranges from absent to well developed. In some cases, these tubercles may be associated with cytotype or occur in populations of a single cytotype (Shelley <i>et al.</i> 2002).</p> <p> Adults reared from pupae collected near the type locality of <i>S. guaporense</i> do not resemble those of the <i>siolii</i> group. The females in the <i>siolii</i> group are distinguished by having the thorax black with a pattern consisting of 1 + 1 silver pruinose bands that extend from the anterior to the posterior margins [light source anterior]. In males, the thorax is also black with a pattern consisting of 1 + 1 sublateral, silver pruinose cunae [light source anterior] [BMNH Digital Images Archive; Hamada 2000]. The adults of <i>S. guaporense</i> externally resemble species in the <i>auristriatum</i> species group by having the thorax covered with brass­colored, scale­like, recumbent setae arranged in lines in the central region of the scutum and grouped in clumps forming broken lines from the anterior to lateral margins (Figs. 9, 10, 18, 19). The morphology of the female and male genitalia of <i>S. guaporense</i> agrees with the characters given by Coscarón & Wygodzinsky (1984) and Coscarón (1987, 1991) for species in the subgenus <i>Psaroniocompsa</i>. At this stage, we prefer to regard <i>S. guaporense</i> as a “species unplaced to group”, but near the <i>auristriatum</i> species group in <i>Psaroniocompsa.</i></p> <p> The thoracic pattern of females and males of <i>S. guaporense</i> resembles that of other species in the <i>auristriatum</i> species group (<i>S. auristriatum</i> Lutz; <i>S. anamariae</i> Vulcano; <i>S. brevifurcatum</i> Lutz; <i>S. schmidtmummi</i> Wygodzinsky; and <i>S. stellatum</i> Gil­Azevedo, Figueiró & Maia­Herzog), from which the species can be separated by the number and configuration of gill filaments and the cocoon shape. The pupa of <i>S. guaporense</i> has six filaments, which separate it from <i>S. auristriatum</i> (two filaments), <i>S. schmidtmummi</i>, and <i>S. stellatum</i> (both with four filaments). <i>Simulium anamariae</i> and <i>S. brevifurcatum</i> also have six filaments; however, <i>S. brevifurcatum</i> can be identified by having all filaments originating from a small stem and bifurcating basally, whereas <i>S. anamariae</i> has a distinct bifid protuberance on the anterolateral margin of the cocoon. In <i>S. guaporense</i>, all filaments bifurcate at some distance from the gill base and the cocoon lacks the distinct bifid protuberance on the anterolateral margin.</p> <p> The females of <i>S. guaporense</i> might also be confused with females of <i>S. incrustatum</i> by the thorax having numerous hairs forming a longitudinal line running the length of the scutum. However, <i>S. incrustatum</i> can be identified by the scutum having only one median longitudinal line of hairs and 1 + 1 silver pruinose cunae on the anterior one­third [light incidence posterior] (Shelley <i>et al.</i> 2000: 192, Figs. 42–43). The males of <i>S. guaporense</i> have an arrangement of hairs similar to that of the females. The males are reliably separated from those of <i>S. incrustatum</i> by the structure of the ventral plate and the gonostyle. The ventral plate in <i>S. guaporense</i> is subrectangular and weakly developed centrally. The gonostyle is triangular, terminating in a well­developed spine and bearing one longitudinal ridge. In <i>S. incrustatum</i>, the ventral plate is subtriangular, with the main body not developed centrally, and the gonostyle is rectangular, terminating in a poorly developed spine (Shelley <i>et al.</i> 2000: 200–201, Figs. 103, 113). Both species cannot be reliably identified based on the pupal gill configuration. Another species with similar branching pattern is <i>S. angrense</i> Pinto. However, <i>S. angrense</i> can be recognized by the considerably longer gill filaments (length 4.3 mm). In <i>S. guaporense</i>, the gill length ranges from 2.1 to 2.4 mm.</p> <p> Variation in the pupal gill configuration and the setation on abdominal sternites V, VI, and VII was seen in specimens of <i>S. guaporense</i> we examined. The filaments of the primary and dorsal branches can bifurcate at the same level or at different heights (Figs. 28, 29), whereas the hooks on abdominal sternites V–VII can be simple to trifid.</p> <p> In the original description of <i>S. siolii</i>, <i>S. damascenoi</i>, and <i>S. lourencoi</i>, Py­Daniel (1988) reported the presence of one pair of tubercles, on the dorsal region of the first larval abdominal segment. However, when he described <i>S. guaporense</i> (Py­Daniel 1989), he changed his description of the location of these paired dorsal tubercles in <i>S. siolii</i>, <i>S. damascenoi</i>, and <i>S. lourencoi</i> to the second larval abdominal segment. He believed that <i>S. guaporense</i> larvae had their first paired dorsal tubercles on the first abdominal segment. Hamada (2000) also placed the first pair of dorsal tubercles on the second abdominal segment in her description of <i>S. tergospinosum</i>. After close examination of larvae of <i>S. guaporense</i>, <i>S. siolii</i>, <i>S. damascenoi</i>, and <i>S. tergospinosum</i>, we realized that the location of the first pair of dorsal tubercles of these species needs to be reassigned. We did not examine larvae of <i>S. lourencoi</i>. In the larvae of <i>S. guaporense</i>, the first pair of dorsal tubercles is located on the third thoracic segment (Fig. 30). Figure 30 also shows the first dorsal tubercles on the same segment as the hind leg histoblast. Figures 31­33 show the location of the first pair of dorsal tubercles on the first abdominal segment of the larvae of <i>S. damascenoi</i>, <i>S. siolii</i>, and <i>S. tergospinosum</i>, respectively.</p> <p> <b>Distribution.</b> <i>S. guaporense</i> has been recorded only from Brazil in the state of Rondônia (Crosskey & Howard, 1997, 2004). In this paper, we report this species for the first time in Mato Grosso State.</p> <p> <b>Biology.</b> The immature stages of <i>S. guaporense</i> are found in sandy­bottomed streams in forest or open areas that were formerly forested, with mean width of 2.1 m (SD = 0.63, <i>n</i> = 4), mean water temperature of 22.5 oC (SD = 1, <i>n</i> = 4), mean pH of 5.1 (SD = 0.24, <i>n</i> = 4), and electrical conductivity of less than 10 S/cm. Larvae and pupae were collected from deciduous leaves and trailing vegetation. More than one hundred females were collected biting humans in Igarapé da Roda d’Agua, Mato Grosso State, during early morning (about 8:00–9:00 AM).</p>Published as part of <i>Hamada, Neusa, Hernandez, Luis M. & Luz, Sergio Luiz Bessa, 2006, Taxonomy of Simulium guaporense Py­Daniel (Diptera: Simuliidae) from Brazil, with the first description of males and females, pp. 23-34 in Zootaxa 1104</i> on pages 24-32, DOI: <a href="http://zenodo.org/record/171413">10.5281/zenodo.171413</a&gt

Avaliação de cloradores simplificados por difusão para descontaminação de água de poços em assentamento rural na Amazônia, Brasil

Resumo Apesar da região amazônica abrigar a maior reserva de água doce do planeta, a falta de saneamento e de tratamento de água, sobretudo na zona rural, causa problemas ambientais e de saúde. Em assentamentos rurais isolados, o abastecimento geralmente é feito por poços rasos (cacimbões) e a qualidade da água é uma preocupação dos moradores. Nestes casos, as opções de tratamento de água são restritas. O objetivo deste estudo foi avaliar o uso de cloradores simplificados por difusão como método alternativo de tratamento de água. Foram realizadas análises bacteriológicas de 100 amostras de água dos poços, antes e após a aplicação dos cloradores, no Assentamento Rural do Rio Pardo, Presidente Figueiredo (AM). As fontes analisadas foram consideradas inadequadas para consumo sem tratamento prévio, e o uso dos cloradores zerou a contaminação por coliformes termotolerantes, na grande maioria dos casos. Além disso, o método teve boa receptividade pelos moradores por não conferir sabor à água de consumo, por ter relativo baixo custo e ser de fácil manuseio. Discutimos as vantagens e as limitações do uso deste método de tratamento para esse contexto socioambiental e apresentamos sugestões de melhoria e adaptação para a aplicação desta metodologia em outros assentamentos

Simulium (Chirostilbia) jefersoni Hamada & Hernandez & Luz & Pepinelli 2006, New Species

Simulium (Chirostilbia) jefersoni Hamada, Hernández, Luz & Pepinelli New Species (Figs. 1–45) Female (Figs. 1–17). General body color dark brown to black (specimens recovered from alcohol) (Figs. 1–4). Body length (specimens in alcohol) 2.6 –3.0 mm (n = 3); thorax lateral length 0.9 mm (n = 3). Wing length 1.3–1.8 mm (n = 3); wing width 0.7–0.8 mm (n = 3). Head dichoptic with dark red eyes and fronto­ocular triangle well developed (Fig. 8). Frons, clypeus, and occiput black, with silver pruinosity; clypeus and frons covered with dark, erect setae. Antennae with silver pubescence, 0.40–0.44 mm in length; scape and pedicel pale brown, remaining segments dark brown (Fig. 6). Maxillary palpus dark brown; sensory vesicle elongated occupying more than 1 / 3 length of palpomere III; palpomere V twice length of palpomere III and IV (Fig. 5). Mandible with 12 external serrations and 34–38 internal teeth. Lacinia with 25 or 26 retrorse teeth. Cibarium with well­developed, sclerotized cornuae, without teeth (Fig. 7). Thorax with scutum black covered by evenly arranged, recumbent, whitish setae; posterior margin with short, recumbent, whitish setae. Scutal pattern varying with illumination. With anterior illumination, thorax black with 1 + 1 median and 1 + 1 sublateral, silver pruinose vittae extending from anterior to posterior margin of thorax and black lyre­shaped pattern; humeri pale brown with faint gray pruinosity; lateral and posterior margins black (Fig. 1). With posterior illumination, lyre­shaped pattern silver pruinose on black scutum; humeri weakly pale brown and lateral margins weakly silver pruinose; posterior margin black (Fig. 2). Anepisternum dark brown; katepisternum light brown. Scutellum dark brown with recumbent whitish setae interspersed with long, black bristles. Postnotum dark brown with silver pruinosity. Pleura dark brown with silver pruinosity. Costa of wing with sparse distribution of spines and setae. Subcosta with line of few setae up to half length of vein (Fig. 9). Radius with line of setae intermixed with spines apically; basal section bare. Basal tuft of long, dark setae (Fig. 9). Leg coloration and proportions as in Figs. 10–12. Fore leg with coxa, trochanter, femur, and tibiae yellow; apex of tibia weakly pale brown; basitarsus and tarsomeres I–IV dark brown (Fig. 10). Middle leg pale yellow except apical two­thirds of basitarsus and tarsomeres I–IV dark brown to black and one­third of basitarsus whitish (Fig. 11). Hind leg with coxa, apex of femur, half of tibiae, apical onethird of basitarsus, and tarsomeres I–IV dark brown, remainder of hind leg pale yellow (Fig. 12). Claws curved with basal tooth (Fig. 13). Halteres cream with brown base. Abdomen with tergites I–IX dark brown to black (Figs. 3, 4); tergite II silver pruinose on anterolateral margins. Basal fringe with thin, long, golden hairs. Tergal plates developed; sternal plates undeveloped. Sternites grayish black; genitalia dark brown. Eighth sternite weakly sclerotized with irregularly distributed setae on posterior margin; hypogynial valves (= gonapophyses) nearly same length as eighth sternite at its midpoint, subtriangular, membranous except weakly sclerotized on internal margins (Fig. 14). Cercus subquadrangular, covered with long, brown setae; anal lobe (= paraproct) subtriangular, nearly one and one­half times longer than cercus, sclerotized and covered by long setae basally and small hairs on distal region of posterior margin (Fig. 15). Genital fork stout, sclerotized with apical termination of stem expanded; termination of lateral arm almost straight; anterior process developed, rounded apically; posterior processes poorly developed (Fig. 16). Spermatheca globular, with internal spicules in groups of 2–4 (Fig. 17); spermathecal duct and area of attachment unpigmented. Male (Figs. 18–28). General body color dark brown (specimen recovered from alcohol) (Figs. 18, 19, 23, 24). Body length (specimens in alcohol) 2.2 –3.0 mm (n = 3); thorax lateral length 0.72–0.78 mm (n = 3). Wing length 1.6–2.5 mm (n = 3); wing width 0.9 mm (n = 3). Head holoptic with dark red eyes. Antenna with whitish pubescense, 0.50 mm in length; scape, pedicel, and first flagellomere light brown, remaining flagellomeres dark brown (Fig. 20). Palpus dark brown, sensory vesicle small, occupying less than 1 / 5 of palpomere III; palpomere V about 1.6 times as long as palpomeres III and IV (Fig. 21). Thorax with scutum black covered with recumbent golden hairs. Scutal pattern varies slightly with light incidence: with anterior light source thorax black with 1 + 1 submedian, silver pruinose cunae on anterior one­third (Fig. 18). With light source posterior to specimen, thorax black (Fig. 19). Humeri pale brown; lateral and posterior margins of scutum pruinose [best seen when specimen viewed laterally]. Scutellum dark brown with recumbent whitish hairs interspersed with long, erect black hairs on posterior margin. Postnotum dark brown to black with silvery gray pruinosity. Anepisternum and katepisternum dark brown. Wing setation and leg coloration as in female, except claws without basal tooth (Fig. 22). Abdomen (Figs. 23, 24) with tergite I black with posterior margin silver pruinose; basal fringe with long, thin, golden hairs; tergite II black in median region and pale brown laterally; tergites III–IV black; tergites V–IX black mesally and grayish in lateral margins; tergites II (anteriorly), IV–VII with silver pruinosity on ventrolateral margin; in some specimens, silver pruinosity also on tergites VIII and IX [best seen on specimens in lateral view]. Sternal plates undeveloped. Genitalia black; gonocoxite subquadrangular (Fig. 28); gonostyle conical (finger­like) (Fig. 28), nearly as long as gonocoxite at midpoint, with ridge in median region and 2 spiniform setae apically [visible only at high magnification]; gonocoxite and gonostyle covered with long setae. Ventral plate sclerotized, with ventral margin almost straight, without keel and covered by small hairs; basal arms short and deeply sclerotized (Fig. 27). Median sclerite Y shaped with distinct incision in apical one­third (Fig. 26). Paramere with developed and sclerotized basal process and numerous stout teeth centrally (Fig. 25). Pupa (Figs. 29–38). Cocoon length dorsally 2.8–3.8 mm (mean = 3.2 mm, SD = 0.28, n = 10), ventrally 3.8–5.4 mm (mean = 4.5 mm, SD = 0.39, n = 10); pupa length 2.6–3.9 mm (mean = 3.1 mm; SD = 0.43, n = 10); gill length 1.5–2.5 mm (mean = 1.9 mm, SD = 0.38, n = 8). Cocoon shoe shaped, dark brown composed of thick coalesced fibres posteriorly and distinct, loop­like fenestrations anteriorly (Figs. 29, 30). Frontoclypeus with 3 + 3 long, multiramous frontal and 1 + 1 long, multiramous, dorsal trichomes (Fig. 34); frontoclypeus with distinct groups of platelets mesally, 1 + 1 dorsolaterally and 2 or 3 platelets in 2 groups laterally in frontal region, respectively (Fig. 33); tubercles rounded, densely distributed (Fig. 36) over entire frontal and dorsal region. Thorax with 5 pairs of long, multiramous (Fig. 32) trichomes near margin of dorsal cleft, 2 + 2 multiramous and 1 simple trichomes at gill base, one small, bifid or simple trichome on ventral margin, and 1 bifid or trifid trichome in median region of thorax; tubercles rounded, densely distributed over entire surface. Antennal sheath with transversal punctuations (Fig. 35). Gill filaments pale yellowish with 8 forwardly directed filaments, arranged in 3 dimensions, curving at midpoint and directed inward apically. Gill configuration with main trunk short, giving rise to 3 sets of primary branches, dorsal and ventral (internal) primary branches each consisting of 3 secondary branches; external set consists of 2 secondary branches; all filaments bifurcate at different heights near base of gill. Filaments stout basally and becoming narrower toward apex, rounded distally, without spicules on surface; edges weakly crenate. All gill filaments approximately same length (Fig. 31). Abdominal tergite I (Figs. 37 a–e) with 1 + 1 submedian, simple trichomes. Tergite II with 4 + 4 submedian, spiniform setae in longitudinal row, 2 + 2 small, simple trichomes anterior to most external spiniform setae and 1 + 1 simple trichome on lateral margin (Fig. 37 a). Tergites III and IV with 4 + 4 submedian, simple hooks in longitudinal row (Figs. 37 b, 37 c), 1 + 1 small, simple trichomes anterior to most lateral hooks, and 1 + 1 small, simple trichomes on lateral margin. Tergite V with 1 + 1 sublateral, small, simple trichomes, and 1 + 1 small, simple trichomes on anterior margin; tergite VI with 1 + 1 submedian and 1 + 1 sublateral, small trichomes. Tergite VII with 1 + 1 sub­median and 1 + 1 sublateral, small, simple trichomes. Tergite VIII with 1 + 1 submedian, simple or bifid, and 1 + 1 sublateral, simple trichomes, and spine combs distinctly resembling teeth on anterior margin (Fig. 37 e). Tergite IX weakly sclerotized, with 1 + 1 small spines. Spine combs on anterior margin of tergites II, VI–IX (Fig. 37 d). Abdominal sternite III (Figs. 38 a–d) with 1 + 1 submedian and 2 + 2 sublateral, small, simple trichomes; sternite IV with 1 + 1 submedian and 2 + 2 sublateral, small, simple trichomes; sternite V with 2 + 2 close, bifid or trifid hooks in row and 2 + 2 simple trichomes anterior to most lateral hooks (Fig. 38 b); sternites VI and VII with 2 + 2 well separated, simple, bifid or trifid hooks (Figs. 38 c, 38 d), sternite VII with 1 + 1 simple trichomes on lateral margin; sternite VIII without hooks; sternite IX weakly sclerotized. Abdominal sternites III–IX with spine combs on anteromedian margin (Fig. 38 a). Larva (last instar) (Figs. 39–45). Body length: 5.8–6.6 mm (mean = 6.2 mm, SD = 0.2, n = 10); head capsule lateral length: 0.6–0.8 mm (mean = 0.7 mm, SD = 0.06, n = 10); dorsal width of head capsule: 0.5–0.7 mm (mean = 0.6 mm, SD = 0.05, n = 10). General body coloration pale gray (in Carnoy’s solution); form as in Fig. 39. Head mainly pale brown, numerous small setae present on all surfaces and head capsule slightly wrinkled. Head pattern positive (Fig. 43). Cervical sclerites small, elliptical, free in membrane. Postgenal cleft subtriangular, wider basally (Figs. 41, 44). Postgenal bridge 0.7 times as long as hypostoma (Fig. 41). Hypostoma with strongly pigmented anterior margin and 9 apical teeth (Fig. 40): median tooth simple and more prominent than sublateral teeth, 3 + 3 rows of sublateral teeth, middle tooth smaller than remaining teeth, 1 + 1 lateral teeth nearly same height as median tooth, 2 poorly developed paralateral teeth, and 3 small lateral serrations; hypostoma with 1 + 1 line of 6 or 7 lateral setae parallel to lateral margin and 1 + 1 long and 1 + 1 or 2 + 2 short setae in posterior region of hypostoma near hypostomal groove. Subesophageal ganglion not pigmented. Antennae (Fig. 42) as long as labral fan stalk; antennal segments brown, except whitish apical one­third of median and basal region of distal segment; segments proportions (proximal, medial and distal) approximately 0.7–0.9: 0.4–0.6: 1.2–1.3 (n = 3). Mandible with 3 apical teeth, basal tooth more prominent than remaining teeth, second comblike teeth with first tooth longer than second and third, mandible with 9 internal teeth, and mandibular serration with anterior teeth longer than posterior; mandibular brushes well developed; mandible with small, simple setae near external margin and 2 prominent, simple trichomes at base of apical mandibular brush. Lateral mandibular process simple and thick. Maxillary palp heavily pigmented, nearly 3 times as long as wide at base. Cephalic fan with 43–47 rays. Thorax pale dorsally and grey ventrally. Proleg with plate heavily sclerotized with band of more than 40 processes of nearly 13 hooks (n = 1). Pupal gill histoblast dark brown with 8 filaments. Abdomen usually completely gray dorsally, progressively paler ventrally, last segments white; faint segmental banding visible dorsally (Fig. 39). Cuticle mainly lacking setae. Ventral nerve cord pale gray. Ventral posterior tubercles absent. Anterodorsal arms of anal sclerite shorter in length than posteroventral arms (Fig. 45). Posterior proleg bearing approximately 100 rows of up to 13 or 14 hooks (n = 2). Anal papillae with 3 branches, each with approximately 7 or 8 finger­shaped lobes of same length (n = 1). Type Material Holotype (INPA): Brazil, Bahia State, Palmeiras County. Parque Nacional Chapada Diamantina: Cachoeira da Fumaça stream (# 32), 12 o 36 ’S 41 o 27 ’W, 31.vii. 2005 (N. Hamada, M. Pepinelli and V.L. Landeiro) ­ female (pinned), with pupal exuviae in glycerine. Paratypes: Brazil, Bahia State, Palmeiras County. Parque Nacional Chapada Diamantina: Cachoeira da Fumaça stream (# 32), 12 o 36 ’S 41 o 27 ’W, 31.vii. 2005 (N. Hamada, M. Pepinelli & V.L. Landeiro) ­ 2 pupae (P), 2 larvae (L) in ethanol, 1 male (M) pinned, with pupal exuviae in glycerine (INPA); small tributary of Mucujezinho stream (# 26), 12 o 28 ’S 41 o 27 ’W, 07.vii. 2003 (N. Hamada & J. Silva) ­ 2 P, 2 L in ethanol (INPA); Galinha stream (# 29), Bomba village (Vale do Capão), Gerais do Vieira, 12 o 40 ’S 41 o 29 ’W, 08.vii. 2003 (N. Hamada & J. Silva) ­ 3 L in ethanol (INPA); Batista River (# 30), Pousada do Capão, 12 o 37 ’S 41 o 29 ’W, 08.vii. 2003 (N. Hamada & J. Silva) ­ 2 L in ethanol (INPA); Sobradinho stream (# 34), Lençóis­Capão trail, Gerais do Morrão, 12 o 32 ’S 41 o 28 ’W, 10.vii. 2003 (N. Hamada & J. Silva) ­ 1 L, 1 P in ethanol, 1 F pinned with pupal exuviae in glycerine (INPA); Águas Claras stream, Gerais do Morrão, Lençóis­Capão trail, 12 o 31 ’S 41 o 28 ’W, 10.vii. 2003 (# 35) (N. Hamada & J. Silva) ­ 1 L, 2 P in ethanol (INPA), 26.vii. 2005 (# 14) (N. Hamada & M. Pepinelli) ­ 2 P ethanol (INPA); Morrão stream (# 13), Morrão trail, 12 o 31 ’S 41 o 28 ’W, 26.vii. 2005 (N. Hamada & M. Pepinelli) ­ 1 L, 2 P in ethanol (INPA); headwater of Conceição dos Gatos stream (# 15), Morrão trail, 12 o 32 ’S 41 o 28 ’W, 26.vii. 2005 (N. Hamada & M. Pepinelli) ­ 1 P in ethanol (INPA); Mucujezinho stream (# 17), 12 o 28 ’S 41 o 27 ’W, 27.vii. 2005 (N. Hamada & M. Pepinelli) ­ 2 L, 3 P in ethanol (INPA). Lençóis County, Parque Nacional Chapada Diamantina: Cachoeirinha stream (# 32), 12 o 33 ’S 41 o 24 ’W, 09.vii. 2003 (N. Hamada & J. Silva) ­ 2 P in ethanol (INPA), 25.vii. 2005 (N. Hamada & M. Pepinelli) ­ 1 P in ethanol (INPA). Andaraí County, Parque Nacional Chapada Diamantina: Piabas River (below erosion area) (# 39), 12 o 51 ’S 41 o 18 ’W, 11.vii. 2003 (N. Hamada & J. Silva) ­ 1 L, 2 P in ethanol (INPA); Piabas River (# 43), 12 o 57 ’S 41 o 16 ’W, 04.viii. 2005 (N. Hamada, M. Pepinelli & V.L. Landeiro) ­ 2 L, 2 P in ethanol (INPA); Coisa Boa River (# 40), 12 o 51 ’S 41 o 18 ’W, 11.vii. 2003 (N. Hamada & J. Silva) ­ 1 P in ethanol (INPA); Roncador River (# 41), “off road” track between Andaraí and Lençóis, 12 o 41 ’S 41 o 21 ’W, 11.vii. 2003 (N. Hamada & J. Silva) ­ 2 L, 3 P in ethanol, 1 F pinned (INPA); Serrano River (# 9), 12 o 33 ’S 41 o 23 ’W, 25.vii. 2005 (N. Hamada, M. Pepinelli) ­ 2 L, 1 P in ethanol (INPA); Pombos waterfall (# 38), Igatu, 12 o 54 ’S 41 o 19 ’W, 03.viii. 2005 (N. Hamada, M. Pepinelli & V.L. Landeiro) ­ 2 P in ethanol (INPA). Mucugê County, Parque Nacional Chapada Diamantina: Cumbuca River (# 42), 12 o 59 ’S 41 o 21 ’W, 12.vii. 2003 (N. Hamada & J. Silva) ­ 3 P in ethanol, 1 M pinned (INPA); 1 F, 1 M pinned (genitalia on slide), 2 F, 2 M, 7 P, 4 L in slides, several P in ethanol, several L in Carnoys (BMNH); stream in the access road to Sibéria waterfall (# 45), 12 o 56 ’S 41 o 21 ’W, 15.vii. 2003 (N. Hamada & J. Silva) ­ 3 P in ethanol (INPA); Pimenteiras stream (# 46), in the access road to Sibéria waterfall, 12 o 57 ’S 41 o 21 ’W, 15.vii. 2003 (N. Hamada & J. Silva) ­ 1 L, 4 P in ethanol (INPA); first stream on the access road to Sibéria waterfall (# 41), 12 o 58 ’S 41 o 21 ’W, 04.viii. 2005 (N. Hamada, M. Pepinelli & V.L. Landeiro) ­ 2 L, 2 P in ethanol (INPA). Itaitê County, Urubu River (# 24), Chapadinha, Rumo village, 13 o 11 ’S 41 o 10 ’W, 29.vii. 2005 (N. Hamada, M. Pepinelli) ­ 2 P in ethanol, 1 F pinned (INPA); Barrigudinha River (# 26), Rumo village, 13 o 13 ’S 41 o08’W, 29.vii. 2005 (N. Hamada, M. Pepinelli) ­ 2 L, 2 P in ethanol, 2 F, 2 M pinned (INPA). Ibicoara County, Parque Muncipal Natural do Espalhado, Espalhado River (# 52), 13 o 19 ’S 41 o09’W, 08.viii. 2005 (N. Hamada, M. Pepinelli & V.L. Landeiro) ­ 4 P in ethanol, 1 F, 1 M pinned (INPA). Rio de Contas County, Mocotó River (# 57), Mato Grosso village, 13 o 25 ’S 41 o 50 ’W, 10.viii. 2005 (N. Hamada, M. Pepinelli & V.L. Landeiro) ­ 2 L, 3 P in ethanol (INPA). Etymology: This species is named in honor of Jeferson Oliveira da Silva (INPA / CPEN), an ethical and dedicated professional and a good friend, who has been working tirelessly with N. Hamada in the field and laboratory. Taxonomic discussion and diagnosis: Simulium jefersoni n. sp. is placed in the subgenus Chirostilbia based on the combination of characters given by Coscarón (1987, 1991). Within Chirostilbia, this species might be included in the S. pertinax species group by having females with a black thorax and tarsal claws with a basal tooth (Coscarón 1987). However, the males have a ridge on the median region of the gonostyle, as in the species of the S. subpallidum group. The adults in the subgenus Chirostilbia are difficult to separate, especially those species in the S. pertinax group, without examination of the pupal gill configuration. Comparisons, especially with species in image archives in the BMNH, identified black fly specimens at INPA and BMNH, and published illustrations of known species of Chirostilbia, indicate that S. jefersoni n. sp. is morphologically similar to several species. The females are externally similar to females of S. acarayense Coscarón & Wygodzinsky, S. laneportoi Varg a s, S. papaveroi Coscarón, S. serranum Coscarón, S. spinibranchium Lutz, the black form of S. subpallidum Lutz, and S. striginotum Enderlein by having the scutum black with 1 + 1 median and 1 + 1 sublateral silver pruinose vittae and a black lyre­shaped pattern. However, the new species can be distinguished by the structure of the anal lobe (Fig. 15) and its length, which is nearly 1.5 times longer than the cercus. In the other species, the anal lobe is approximately 2.5 to 3 times longer than the cercus. The male thoracic pattern of S. jefersoni n. sp. is also similar to that of species in the S. pertinax species group, from which this species can be distinguished by the structure of the gonostyle and the ventral plate. In S. jefersoni n. sp., the gonostyle is conical and finger­like with a ridge (Fig. 28), and the ventral plate is distinctly rectangular, with the ventral margin nearly straight (Fig. 27), similar to that of S. acarayense (Coscarón 1991). The most reliable character for identifying S. jefersoni n. sp. is the structure of the cocoon and the number and configuration of the pupal gill filaments. The pupa of the new species has eight gill filaments (Fig. 31), which group this species with S. acarayense, S. empascae, S. laneportoi, S. papaveroi, S. pertinax, S. serranum, S. spinibranchium and S. subpallidum. However, S. jefersoni n. sp. can be separated by the shoe­shaped cocoon with prominent anterior fenestrations (Figs. 29, 30). In this respect, S. jefersoni n. sp. is similar to S. distinctum, S. friedlanderi, S. obesum Vulcano and S. riograndense, but the number of its gill filaments distinguishes it from these species, which have 10, 11,> 100, and 10 filaments, respectively. The cocoon in S. empascae is also shoe­shaped, but the pupal gill filaments and the cocoon have different configurations. The pupa of S. jefersoni n. sp. also can be recognized by the set of three primary branches giving rise to three sets of secondary branches that curve at their midpoints and diverge inward apically (Fig. 31), and the thorax and frontoclypeus with prominent, multiramous trichomes (Figs. 32, 34). The pupae of the known eight­filamented species of Chirostilbia in the Neotropical Region have a different gill and trichome configuration pattern. The postgenal cleft of the lastinstar larva of S. jefersoni n. sp. is similar to that of S. serranum (Coscarón 1981), but both species can be distinguished by the different structure of the filaments of the gill histoblast. Bionomics: Simulium jefersoni n. sp. has been collected only in the state of Bahia, Brazil, in Chapada Diamantina National Park and the surrounding area. The immature stages were collected from trailing vegetation, deciduous leaves, and rocks in areas with faster flow in 30 rock­bottomed streams, with width varying from 1 to 50 m. The streams had black water, mean water temperature of 21 o C (SD = 2.0), median electrical conductivity below 20 µS/cm, and mean pH of 4.5 (SD = 0.45). These streams were located at altitudes of 468 to 1345 m. Females were not collected biting humans.Published as part of Hamada, Neusa, Hernandez, Luis M., Luz, Sergio Luiz Bessa & Pepinelli, Mateus, 2006, Simulium (Chirostilbia) jefersoni, a new species of black fly (Diptera: Simuliidae) from the state of Bahia, Brazil, pp. 21-37 in Zootaxa 1123 on pages 23-32, DOI: 10.5281/zenodo.17176

Ecological niche modelling for predicting the risk of cutaneous leishmaniasis in the Neotropical moist forest biome.

A major challenge of eco-epidemiology is to determine which factors promote the transmission of infectious diseases and to establish risk maps that can be used by public health authorities. The geographic predictions resulting from ecological niche modelling have been widely used for modelling the future dispersion of vectors based on the occurrence records and the potential prevalence of the disease. The establishment of risk maps for disease systems with complex cycles such as cutaneous leishmaniasis (CL) can be very challenging due to the many inference networks between large sets of host and vector species, with considerable heterogeneity in disease patterns in space and time. One novelty in the present study is the use of human CL cases to predict the risk of leishmaniasis occurrence in response to anthropogenic, climatic and environmental factors at two different scales, in the Neotropical moist forest biome (Amazonian basin and surrounding forest ecosystems) and in the surrounding region of French Guiana. With a consistent data set never used before and a conceptual and methodological framework for interpreting data cases, we obtained risk maps with high statistical support. The predominantly identified human CL risk areas are those where the human impact on the environment is significant, associated with less contributory climatic and ecological factors. For both models this study highlights the importance of considering the anthropogenic drivers for disease risk assessment in human, although CL is mainly linked to the sylvatic and peri-urban cycle in Meso and South America