Climate change: effects on animal disease systems and implications for surveillance and control.

Climate driven and other changes in landscape structure and texture, plus more general factors, may create favourable ecological niches for emerging diseases. Abiotic factors impact on vectors, reservoirs and pathogen bionomics and their ability to establish in new ecosystems. Changes in climatic patterns and in seasonal conditions may affect disease behaviour in terms of spread pattern, diffusion range, amplification and persistence in novel habitats. Pathogen invasion may result in the emergence of novel disease complexes, presenting major challenges for the sustainability of future animal agriculture at the global level. In this paper, some of the ecological mechanisms underlying the impact of climatic change on disease transmission and disease spread are further described. Potential effects of different climatic variables on pathogens and host population dynamics and distribution are complex to assess, and different approaches are used to describe the underlying epidemiological processes and the availability of ecological niches for pathogens and vectors. The invasion process can disrupt the long-term co-evolution of species. Pathogens adhering to an r-type strategy (e.g. RNA viruses) may be more inclined to encroach on a novel niche resulting from climate change. However, even when linkage between disease dynamics and climate change are relatively strong, there are other factors changing disease behaviour, and these should be accounted for as well. Overall vulnerability of a given ecosystem is a key variable in this regard. The impact of climate-driven changes varies in different parts of the world and in the different agro-climatic zones. Perhaps priority should go to those geographical areas where the integrity of the ecosystem is most severely affected and the adaptability, in terms of robustness and sustainability of response, relatively low.

[Impact of climatic change on the epidemiology of diseases]. / Influence des changements climatiques sur l'epidémiologie des maladies transmissibles.

Potential climate driven changes in the epidemiology of human and animal disease are widely discussed and complex to assess. Recent spreads of exotic pathogens or vectors feed speculations; although most of these introductions are mainly linked to the increased worldwide traffic, trade of goods and transportation of animal and human, abiotic factors are known to impact on vectors and pathogens bionomics and their ability to establish in new ecosystems; altogether changes in climatic patterns and in seasonal conditions may affect disease behaviour in term of spread pattern, diffusion range, amplification and persistence in novel habitats. Invasion may result in the emergence of novel disease processes, presenting major challenges for the epidemiologists. In this paper, some of the ecological mechanisms underlying the impact of climatic change on disease transmission and disease spread are further described. Potential effects of different climatic variables on pathogens and hosts population dynamics and distributions are complex to assess and different approaches are used to describe the dynamics in ecological range and the availability of ecological niches for pathogens and vectors. However even when linkage between disease dynamics and climate change are relatively strong, there are always other factors also changing disease behaviour and these should be accounted for as well.

Leishmaniasis in Portugal: enzyme polymorphism of Leishmania infantum based on the identification of 213 strains.

This study reports isoenzyme polymorphism of Leishmania strains isolated in different regions of Portugal between 1982 and 2005. A total of 213 strains were obtained from cases of visceral and cutaneous leishmaniasis isolated from immunocompetent patients (adults and children) and immunocompromised adults, as well as from dogs and sandflies. Four zymodemes were identified: MON-1, MON-24, MON-29 and MON-80. Zymodeme MON-1 was identified in 96.7% of the strains, predominating in both immunocompetent and immunocompromised human patients, and it was the only zymodeme isolated from dogs. Isoenzyme diversity in HIV-infected patients was higher than in the immunocompetent group, in which all the strains from visceral leishmaniasis were MON-1. The domestic dog was confirmed as the reservoir host of zoonotic leishmaniasis in Portugal and Phlebotomus perniciosus and Phlebotomus ariasi as vectors. The overall low enzyme polymorphism observed in the Portuguese foci contrasts with the neighbouring foci in Spain.

Mark-release-recapture of sand flies fed on leishmanial dogs: the natural life-cycle of Leishmania infantum in Phlebotomus ariasi.

Wild-caught Phlebotomus ariasi Tonnoir permitted to feed on dogs infected with Leishmania infantum Nicolle were marked with fluorescent powder and released into their natural habitat in an uninhabited area of the Cévennes in southern France. Over a period of 29 days after release, 253 females were recaptured with CDC miniature light traps or by active search at night with portable UV lamps. The ovaries and infections in the alimentary tract were then examined. The females oviposited 6 nights after in infecting blood meal. Second blood meals were never taken during the maturation of eggs. During the first ovarian cycle, midgut infections with promastigotes were only moderately heavy. The intensity of infection increased markedly during the second ovarian cycle and, in the third ovarian cycle, the first pharynx infected with paramastigotes was seen (on day 19). From day 19 to day 29, 76% of the flies had pharyngeal infections. Three out of 19 sand flies with pharyngeal infections recaptured during this period had metacyclic promastigotes in their mouthparts. The long time required for parasites to reach the proboscis in completely natural conditions suggests that their presence in the mouthparts is not a prerequisite for transmission by bite. It is more likely that transmission is most commonly by the regurgitation of metacyclic promastigotes from the thoracic midgut following damage to the stomodaeal valve by chitinase produced by the parasite during its development in the gut of the fly. Nevertheless, it is reasonable to assume that the bite of a fly with metacyclic promastigotes in the proboscis (or salivary glands) would also be infective.

Isoenzymatic identification of Leishmania isolates from repeated clinical human leishmaniasis episodes in Catalonia (Spain).

Forty human strains of Leishmania infantum isolated in 1985-99 from 17 patients with repeated cutaneous, mucosal or visceral leishmaniasis episodes in Catalonia (Spain) were examined by isoenzyme electrophoresis. Six zymodemes were revealed: MON-1, MON-24, MON-28, MON-29, MON-33 and MON-34. In 2 patients 2 different zymodemes were identified in consecutive episodes.

[Phlebotomines of the Isle of Cyprus. III. Species inventory ]. / Les phlébotomes de l'Ile de Chypre. III--Inventaire faunistique.

Three surveys on canine leishmaniasis were carried out in Cyprus (1993, 1998 and 1999) emphasise the presence of eleven species of phlebotomine sandflies: Phlebotomus (Phlebotomus) papatasi, P. (Paraphlebotomus) alexandri, P. (Pa.) jacusieli (first mention in Cyprus), P. (Pa.) sergenti, P. (Larroussius) galilaeus, P. (L.) tobbi, P. (Transphlebotomus) economidesi, P. (T.) mascittii, Sergentomyia (Sergentomyia) azizi (its specific statute is validated by the authors), S. (S.) fallax et S. (S.) minuta. P. (Adlerius) kyreniae was not caught during the surveys. The authors propose hypothesis of settlement of the island by phlebotomine sandflies according this species inventory. A first migration period took probably place during the Miocene time and a second one during the Pleistocene time.

Molecular systematics of the phlebotomine sandflies of the subgenus Paraphlebotomus (diptera, psychodidae, phlebotomus) based on ITS2 rDNA sequences. Hypotheses Of dispersion and speciation.

Phylogenetic Paraphlebotomus relationships are inferred by a study based on the sequences of ITS2, which has been sequenced in nine Paraphlebotomus species: P. alexandri, P. andrejevi, P. jacusieli, P. kazeruni, P. mireillae, P. mongolensis, P. saevus, P. sergenti and P. similis and in two out-groups species of the subgenus Phlebotomus: P. papatasi and P. duboscqi. Paraphlebotomus alexandri appears as the sister group of all other Paraphlebotomus sandflies. Among the other species, three groupings are clearly highlighted: andrejevi and mongolensis; mireillae and saevus; jacusieli, kazeruni, sergenti and similis. These groupings are related to speculations about the migration of Paraphlebotomus from a centre of dispersion located in the Middle East sometime from the early Eocene to the late Miocene.

[Phlebotomine sandflies (Diptera-Psychodidae) of the isle of Cyprus. II--Isolation and typing of Leishmania (Leishmania infantum Nicolle, 1908 (zymodeme MON 1) from Phlebotomus (Larroussius) tobbi Adler and Theodor, 1930]. / Les phlébotomes (Diptera-Psychodidae) de l'île de Chypre. II--Présence de Leishmania (Leishmania) infantum Nicolle, 1908 (zymodeme MON1) chez Phlebotomus (Larroussius) tobbi Adler et Theodor, 1930.

During two surveys conducted in Cyprus (August 1998 and September 1999), 2,910 phlebotomine sandflies females were caught by CDC miniature light traps then dissected under binocular and examined on microscope. Eleven species were identified: Phlebotomus papatasi, P. sergenti, P. jacusieli, P. alexandri, P. tobbi, P. galilaeus, P. mascittii, P. economidesi, Sergentomyia fallax, S. minuta et S. azizi. The Larroussius species (P. galilaeus and P. tobbi) are the most abundant (more than 60% of our captures). Promastigotes were isolated from one specimen identified as P. tobbi. A Leishmania stock was successfully cultured and identified by isoenzyme characterisation as belonging to L. infantum zymodeme MON 1. The same zymodeme was isolated and identified from four dogs too. Because of the absence of usual vectors of L. infantum in the eastern part of the Mediterranean basin (P. neglectus and P. syriacus), and according to its distribution in Cyprus, P. tobbi constitute certainly a good local vector. It seems to be not very anthropophilic, that could explain the very few human cases.

Enzymatic polymorphism and phylogenetic relationships in Leishmania Ross, 1903 (Sarcomastigophora: Kinetoplastida): a case study in Colombia.

Leishmaniasis is widespread in Colombia and is found in 30 of 32 Departments. More than 200 infection zones have been reported from different regions, which vary from sea-level to an altitude of 2,300 m along the Atlantic Coast, Pacific coast, Amazon basin, Cauca and Magdalena valleys. We report 76 Leishmania stocks isolated from humans, dogs and phlebotomine hosts. Isoenzyme electrophoresis revealed 16 zymodemes, which could be divided into four phylogenetic complexes, i.e., L. braziliensis, L. amazonensis, L. guyanensis/panamensis and L. infantum. Three zymodemes became integrated into the subgenus Leishmania and the other zymodemes into the subgenus Viannia. Cutaneous infections were due to the L. braziliensis (9.2%) and L. guyanensis/panamensis (85.54%) complexes. Mucous secondary involvement was due to the L. braziliensis and L. guyanensis/panamensis complexes. In this work the specific status of L. (V.) guyanensis and L. (V.) panamensis is discussed.

[Canine leishmaniasis from Leishmania infantum: value and production of the latex test. Ecoepidemiologic applications]. / Leishmaniose canine à Leishmania infantum: intérêt et réalisation du test au latex. Applications en éco-épidémiologie.

The authors relate the realization, evaluation and eco-epidemiological applications of a "field-test": the agglutination of latex particles coated with a soluble antigen of Leishmania infantum in the presence of homologous antibodies. Evaluated on 1,035 canine sera, the sensitivity of the latex agglutination test (LAT) was 93.4% compared to the indirect fluorescent antibody test (IFAT). 90 node cultures were carried out on dogs with positive or negative LAT and/or positive or negative IFAT. The frequency of positive node cultures (70%) as versus positive LAT came between the results obtained for an IFAT > 1/40 (64%) and IFAT > 1/80 (73%). 32/33 (97%) dogs had positive node culture, LAT and IFIAT(> 1/80). 6 dogs had negative LAT but positive node culture: 5 of these had also an IFAT < 1/160. This test was used in the field on several eco-epidemiological surveys in leishmanian enzootic areas. Node cultures were made on the dogs with positive TL. 39 strains were isolated: 18 in Algeria, 15 in Morocco, 2 in Syria and 4 in Yemen. 13/39 strains were obtained from dogs with IFI < 1/160: 2 at 1/20, 8 at 1/40 and 3 at 1/80. In Algeria this test was also used for the diagnosis of human visceral leishmaniasis in a child. This quick, simple, sensitive and specific test could be usefully carried out on "field" surveys for the diagnosis of visceral-leishmaniasis in animals and human beings.

[Description of Aedes (Ochlerotatus) coluzzii n. sp. (Diptera, Culicidae), twin A species of the detritus complex]. / Description d'Aedes (Ochlerotatus) coluzzii n. sp. (Diptera, Culicidae), espèce jumelle A du complexe detritus.

Reports of a wide variation in space and time of the frequency of autogeny in Aedes (Ochlerotatus) detritus (Haliday, 1833) of the Camargue (Delta of the Rhône, Bouches-du-Rhône, Gard, France) led us to make an enzymatic analysis of male and female adults from different larval biotopes. The study showed the existence of two genetically distinct, sympatric populations which are morphologically indistinguishable. By diagnostic enzymes monomorph Got-2, Gpd, the grouping of the individual into two subgroups satisfies a Hardy-Weinberg equilibrium for the polymorphic enzymes. It is concluded that Ae. detritus is composed of a complex of two sibling species provisionally designated by the letters A (Got-2RR, GpdCC) and B (Got-2LL, GpdBB). In the present article, we retrace the history of the binomen Ae. detritus since the original description (sub nom. Culex detritus) to the split into the detritus complex. Certain ecophysiological (steno-eurygamy) and chorological (bioclimatic gradients N-S) criteria show that the sibling species B should be assigned to the taxon described in UK (Holywood, County Down, Ireland) by A.H. Haliday. Species A is here named Aedes (Ochlerotatus) Coluzzii n. sp.

Leishmania infantum and L. major in Algeria.

Since 1980, the development of leishmaniasis in Algeria has been marked by a considerable increase in the number of cases of both visceral leishmaniasis (1121 cases recorded) and cutaneous leishmaniasis (more than 2000 cases per year). New Leishmania infantum and L. major foci have appeared in the north and south of the country. During this period, 100 strains of Leishmania isolated from humans, other mammals and sandflies have been identified. The presence of L. major MON-25 in Psammomys obesus and Phlebotomus papatasi had identified these species as the main reservoir and vector, respectively, of zoonotic cutaneous leishmaniasis. Similarly, the presence of L. infantum MON-1 in Ph. perniciosus and dogs has implicated them as the vector and reservoir of visceral leishmaniasis. The isolation of the dermotropic zymodeme MON-24 of L. infantum from Ph. perfiliewi suggested that it was one of the main vectors of cutaneous leishmaniasis in the north of the country; the reservoir has not been identified. In addition, other zymodemes of Leishmania have been identified in visceral leishmaniasis patients, frequently associated with human immunodeficiency virus (MON-24, MON-33, MON-34 and MON-78), in patients with cutaneous leishmaniasis (MON-80), and in dogs with leishmaniasis (MON-34 and MON-77).

Visceral leishmaniasis in HIV-infected patients in the south of France.

Between 1989 and 1993, investigations by classical parasitological procedures of 139 HIV-infected adults living in visceral leishmaniasis (VL) endemic areas showed that 10 of them (7.2%) were positive for Leishmania (by stained smears and culture). In the same period we identified 15 VL cases in patients not infected with HIV. Thus, 40% (10/25) of our VL cases were associated with HIV infection.

The use of isoelectric focusing on polyacrylamide gel for the enzymatic analysis of 'Old World' Leishmania species.

Using isoelectric focusing (IEF), a high resolution electrophoresis technique, we analysed 6 enzymes of 24 cloned strains representing all major taxa of 'Old World' Leishmania. The comparison of enzymatic patterns obtained with IEF and starch gel electrophoresis showed that IEF is a more discriminatory and more informative technique for the enzymatic analysis of Leishmania strains; it can detect very slight differences between 2 electromorphs not revealed with starch gel electrophoresis. Moreover, IEF detected several multi-banded patterns which appeared as single bands with starch gel electrophoresis. These multi-banded patterns could not be the result of strain heterogeneity since all the strains had been cloned. Their significance in the biology of Leishmania is discussed.

Resistance monitoring in Culex pipiens (Diptera: Culicidae) from central-eastern France.

Insensitive acetylcholinesterase (AceR) and five over-produced esterases (A1, A2 and B2, and A4 and B4) involved in detoxification are responsible for resistance to organophosphorous insecticides (OPs) in Culex pipiens L. from the Rhône-Alpes region, where C. pipiens control is mainly accomplished with the OPs temephos and chlorpyrifos using 0.15 mg/liter doses. The strong linkage disequilibria observed between esterases A1 and Est-20(0.64), esterases A4 and B4, and esterases A2 and B2 indicate that these genes were introduced in the Rhône-Alpes region. AceR and esterase A1, which appeared in the south of France 3 yr before the start of mosquito control in Rhône-Alpes, had the highest frequencies. All resistant genotypes were shown to be killed by 0.15 mg/liter temephos in natural breeding sites, but not by 0.15 mg/liter chlorpyrifos. These results are discussed in relation with mosquito control strategies.

[New localities for Phlebotomus mariae Rioux, Croset, Léger et Bailly-Choumara, 1974, in Morocco]. / Nouvelles stations de Phlebotomus mariae Rioux, Croset, Léger et Bailly-Choumara, 1974, au Maroc.

Phlebotomus mariae was first described in the South of Morocco in 1974. More specimens were found again recently in the High Atlas, showing that this species can be considered as a valid one, placed in the sub-genus Larroussius. The female remains to be found.