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On the association between high temperature and mortality in warm climates.
We conducted a time-series analysis of 1997-1999 data records of air temperature and all-cause mortality in Greater Beirut, using bi-linear Poisson auto-regressive models, and published our findings in the Science of the Total Environment [El-Zein, A., Tewtel-Salem, M., Nehme, G., 2004. A time-series analysis of mortality and air temperature in Greater Beirut. Sci. Total Environ. 330, 71-80]. We compared our results to those of Curriero et al. [Curriero, F.C., Heiner, K.S., Samet, J.M., Zeger, S.L., Strug, L., Patz, J.A., 2002. Temperature and mortality in 11 cities of the Eastern United States. Am. J. Epidemiol. 155(1) 80-87.], who subsequently reported that their original results were inaccurate and published new results [Curriero, F.C., Heiner, K.S., Samet, J.M., Zeger, S.L., Strug, L., Patz, J.A., 2002. Temperature and mortality in 11 cities of the Eastern United States. Am. J. Epidemiol. 155(1) 80-87; Curriero, F.C., Samet, J.M., Zeger, S.L., 2003. Letter to the Editor re. On the Use of Generalized Additive Models in Time-Series Studies of Air Pollution and Health" and "Temperature and Mortality in 11 Cities of the Eastern United States". Am. J. Epidemiol. 158(1) 93-94.]. In this letter, we report two changes in the interpretation of our findings as a result of the change in the results of Curriero et al. [Curriero, F.C., Heiner, K.S., Samet, J.M., Zeger, S.L., Strug, L., Patz, J.A., 2002. Temperature and mortality in 11 cities of the Eastern United States. Am. J. Epidemiol. 155(1) 80-87]. Their newly-reported results reinforce our conclusion that heat-related mortality can be a significant public health issue even in temperate to warm climates. However, our findings raise a question concerning the ability of socioeconomic indicators to explain differences in vulnerability to heat between high-income and low-income countries.
The Simulium damnosum complex in western Uganda and its role as a vector of Onchocerca volvulus.
The status of onchocerciasis vectors in the former Ruwenzori focus in western Uganda was re-examined some 15 years after control measures against Simulium damnosum s.l. were suspended. The four cytoforms S. kilibanum, 'Sebwe', 'Nkusi' and S. pandanophilum were found. While the nonanthropophilic 'Sebwe' was still widely distributed in rivers north, east and south of the Ruwenzori, the only anthropophilic species and vector, S. kilibanum, had disappeared from most of its former habitats and was now restricted to two limited foci, where high biting densities were encountered. It was still a vector south of the Ruwenzori (Kasese focus), where 15.4% of the parous flies were infected with larval stages of Onchocerca volvulus and 34 infective larvae were found in the heads of 1000 parous flies. In the second focus along the Mahoma and Nsonge rivers, a chromosomally highly polymorphic population of S. kilibanum had replaced the former vector S. neavei, but does not act as a vector. Only 2.3% of the parous females were infected and just 1 infective larva was found in the heads of 1000 parous flies.
Pollinarium morphology and floral rewards in Brazilian Maxillariinae (Orchidaceae).
BACKGROUND AND AIMS: There is strong support for the monophyly of the orchid subtribe Maxillariinae s.l., yet generic boundaries within it are unsatisfactory and need re-evaluation. In an effort to assemble sets of morphological characters to distinguish major clades within this subtribe, the pollinarium morphology and floral rewards of representative Brazilian species of this subtribe were studied. METHODS: The study was based on fresh material from 60 species and seven genera obtained from cultivated specimens. Variation of pollinarium structure and floral rewards was assessed using a stereomicroscope and by SEM analysis. KEY RESULTS: Four morphological types of pollinaria are described. Type 1 appears to be the most widespread and is characterized by a well-developed tegula. Type 2 lacks a stipe and the pollinia are attached directly to the viscidium. Type 3 also lacks a stipe, and the viscidium is rigid and dark. In Type 4, the stipe consists of the whole median rostelar portion and, so far, is known only from Maxillaria uncata. Nectar, trichomes, wax-like and resin-like secretions are described as flower rewards for different groups of species within the genus Maxillaria. Data on the biomechanics and pollination biology are also discussed and illustrated. In Maxillariinae flowers with arcuate viscidia, the pollinaria are deposited on the scuttellum of their Hymenopteran pollinators. In contrast, some flowers with rounded to rectangular, pad-like viscidia fix their pollinaria on the face of their pollinators. CONCLUSIONS: Pollinarium morphology and floral features related to pollination in Brazilian Maxillariinae are more diverse than previously suggested. It is hoped that the data presented herein, together with other data sources such as vegetative traits and molecular tools, will be helpful in redefining and diagnosing clades within the subtribe Maxillariinae.
Resolving evolutionary relationships in the lichen-forming genus Porpidia and related allies (Porpidiaceae, Ascomycota).
The lichen-forming genus Porpidia (Porpidiaceae, Ascomycota) provides excellent opportunities for evolutionary, reproductive, and ecological studies of crustose epilithic lichen symbioses. However, despite the fact that the genus itself seemed to be clearly delimited, the group was thought to be a hopeless case with regard to intrageneric relationships and species delimitations due to apparently rampant homoplasy throughout most character systems. Contrary to the situation for non-molecular data, a robust and generally well-resolved phylogeny was recovered based on DNA-sequence data. Separate and combined analyses of nuclear ribosomal RNA large subunit and nuclear beta-tubulin gene fragments were performed using maximum parsimony, maximum likelihood, and Bayesian approaches. Branch support was estimated using non-parametic bootstrapping and posterior probabilities, while monophyly of a priori defined groups was tested using posterior probabilities. The results reveal a highly supported "Porpidia sensu lato," however, Porpidia itself is not monophyletic. Several smaller genera of the Porpidiaceae and probably the large genus Lecidea (Lecideaceae) are nested within the group. Most taxa analyzed fall into one of four major subgroups within Porpidia s.l., though the basal relationships among these subgroups could not be supported. This phylogeny will make it possible to re-evaluate morphological and chemical characters in the group, and to conduct detailed studies of species delimitations within the monophyletic subgroups.
[Control of malaria re-emergence in Reunion].
Réunion is currently posed with the operational problem of the last phase of the struggle against malaria, that is the consolidation and the maintenance of the state of cradication. The native parasite was eliminated, but the risk of resurgence of malaria remains on the island. This risk is even increasing from year to year because of the following: 1) the regular increase of the number of travellers originating from countries with malaria and consequently, the increase in the number of imported malaria cases; 2) the appearance of malaria strains resistant to amino-4-quinoleines, in the south-western regions of the Indian Ocean; 3) the persistence of the vector which cannot be eliminated because of its rapid evolutionary cycle and the multiplicity of its larval habitats. Furthermore, the reintroduction of malaria on the island would present serious consequences considering the disappearance of immunity in the population of Réunion. Thus it is necessary to maintain the struggle at a high level of intervention following a strategy based on: 1) the detection and the control of the malaria cases; 2) a targeted anti-vectorial activity based on a systematic anti-larval fight, eventually completed by the eradication of the adapted adult vectors. The reduction of personnel and the difficulties encountered in establishing a mechanization of the adapted tasks lead to a reduction of activities of insect eradication and endanger the existing strategy of the struggle. This strategy has been redefined during these last several years. The malaria situation in Réunion, satisfactory until today, rests on a careful epidemiological surveillance and on an optimized entomological surveillance. Currently, the treatments are abandoned in the least sensitive zones to the benefit of a better surveillance of priority zones (prospecting, entomological studies and treatments). Anopheles gambiae s.l. is present on the island and each year some parasites are imported to the Réunion territory. The requisite conditions for an eventual re-emergence of transmission of the native parasite would seem to be combined. However, this transmission is not observed. The role of the Applied Entomology Group is to evaluate the risk of malaria and to reorient, if necessary, the strategy of the antimalaria struggle in Réunion.
[The maintenance of malaria eradication in Reunion island (1979-1990)].
Malaria, which first occurred in Reunion in 1868, was eradicated from the island in 1979, as a result of eradication campaigns conducted since 1949. Reunion is now in a state of "anophelism without malaria". However, relations with nearby countries with a high malaria potential (Madagascar, Comoros) are responsible for a regular increase in the number of annual cases of imported malaria. This increase, associated with the appearance of chloroquine-resistance in the Indian Ocean area, illustrates the persisting risk of malaria re-appearance in La Réunion, and the need for maintaining a control programme. After describing the epidemiological situation and the ecology of Anopheles gambiae s.l. on the island, the authors give detail on the organisation of malaria control as adopted by the health services. Continuing eradication, which puts emphasis on antivector measures as Reunion is considered as an area with "unstable" malaria, implies an annual invest of US $3,350,000, of which 77% is exclusively used for vector control.
Impact of permethrin-treated bed nets on entomologic indices in an area of intense year-round malaria transmission.
The effect of permethrin-treated bed nets (ITNs) on malaria vectors was studied as part of a large-scale, randomized, controlled trial in western Kenya. Indoor resting densities of fed Anopheles gambiae s.l. and An. funestus in intervention houses were 58.5% (P = 0.010) and 94.5% (P = 0.001) lower, respectively, compared with control houses. The sporozoite infection rate in An. gambiae s.l. was 0.8% in intervention areas compared with 3.4% (P = 0.026) in control areas, while the sporozoite infection rates in An. funestus were not significantly different between the two areas. We estimated the overall transmission of Plasmodium falciparum in intervention areas to be 90% lower than in control areas. Permethrin resistance was not detected during the study period. As measured by densities of An. gambiae s.l., the efficacy of bed nets decreased if one or more residents did not sleep under a net or if bed nets had not been re-treated within six months. These results indicate that ITNs are optimally effective if used every night and if permethrin is reapplied at least biannually.
Natural interspecific hybridisation of simulium sanctipauli s.l. with Simulium squamosum and Simulium yahense (Diptera: Simuliidae).
Natural hybridisation between Simulium sanctipauli (sensu Quillevéré et al. 1981) and Simulium squamosum/yahense occurs at a rate of around 0.001. A single larva has been found which is unambiguously a backcross between S. sanctipauli s.l. and a S. sanctipauli s.l. X squamosum/yahense hybrid. This discovery indicates the possibility of genetic introgression between these species. Examination of the polytene chromosomes of this backcross progeny and subsequent re-examination of the type specimens has led to the remapping of fixed interspecific inversions in chromosome arm 1L.
[The use of screens in the anti-tsetse campaign in the forest zone].
After preliminary studies on the ecodistribution of Glossina palpalis s.l. in the sleeping sickness focus of Vavoua (Ivory Coast) trials with screens impregnated with decamethrine were carried out. Artificial supports for insecticide present several advantages: less pollution, less costly, simplicity, facility of use by local personnel, possibility of re-use, integration with other methods. On the other hand, its action based on the attraction of flies which come into contact with the screen is relatively slow, particularly in obtaining a complete interruption of reproduction. The technique is compared with other control methods as the use of biconical traps and selective spraying along borders. Its action can be improved by the addition of attractive host odours or sex pheromones.
Lyme borreliosis in rheumatological practice: identification of Lyme arthritis and diagnostic aspects in a Swedish county with high endemicity.
To prospectively study the prevalence of Lyme arthritis, 100 consecutive patients referred to a rheumatology out-patient clinic and 115 patients with a classified rheumatological disease were included. Individuals seropositive for antibody against the Borrelia burgdorferi sensu lato complex were examined for clinical signs or a history of Lyme borreliosis. Positive titres against B. burgdorferi s.l. were found in 7/100 and 15/115, respectively. Among the 100 referred patients. Lyme arthritis was diagnosed in five cases. Carpal tunnel syndrome was the presenting clinical feature in two of them. One of the 115 individuals with a previously classified rheumatological disease was re-classified as Lyme arthritis. All cases of Lyme arthritis improved after oral antibiotic treatment. This study revealed Lyme arthritis to be a common disorder in this part of Sweden and the diagnosis should be considered in patients with acute or recurrent episodes of mono- or oligoarthritis.
The relative efficacy of repellents against mosquito vectors of disease.
Laboratory tests of insect repellents by various different methods showed that An.stephensi Liston was consistently more susceptible than An.gambiae Giles, An.albimanus Wiedemann or An.pulcherrimus Theobald. The six repellents tested were di-ethyl toluamide (deet), di-methyl phthalate (DMP), ethyl-hexanediol, permethrin, citronella and cedarwood oil. Testing systems in which the mosquitoes were presented with a choice gave consistently lower ED50 values than when there was no choice, i.e. the standards of tolerance are not absolute but depend on the options available. In field tests in an experimental hut a curtain with a high dose of di-ethyl toluamide (deet) reduced biting in the hut but had to be re-impregnated frequently. Deet-impregnated anklets gave about 84% protection against Culex quinquefasciatus Say for 80 days after one impregnation, in a trial in which the anklets were brought out of sealed storage and tested for 2 h nightly. Similar protection was found against An.funestus Giles but the protection against An.gambiae s.l., An. coustani Laveran and Mansonia spp. was not as good. There were highly significant differences between the four collectors' mosquito attractiveness but this varied highly significantly between the mosquito species.
Reduced prevalence of onchocerciasis in Uganda following either deforestation or vector control with DDT.
To determine the prevalence of onchocerciasis in western Uganda following deforestation and vector control, three foci were re-examined 20 years after previous surveys. In the Ruteete focus Simulium neavei had apparently disappeared and the prevalence of onchocerciasis declined in adults from about 70% in 1971 to a standardised prevalence of 12% in 1992. An increase of population density together with extended deforestation was assumed as cause of this strong reduction. In Bugoye, a S. damnosum s.l. focus, the standardised prevalence of microfilaria carriers declined from 62% in 1972 to 4.7% in 1992. Entomological data indicated the absence of man biting blackflies in the nineties. It can be suggested that the vector control using DDT performed during the seventies had lead to a change of the species composition from anthropophilic to non-anthropophilic S. damnosum s.l. In the focus Kicheche environmental changes were insignificant, deforestation was not progressive and S. neavei was abundant. Here the standardised prevalence of microfilaria carriers was still high (61%).
Re-assessment of monophyly, evolution of myrmecophytism, and rapid radiation in Neonauclea s.s. (Rubiaceae).
The biologically interesting ant-plant association, myrmecophytism, occurs in ca. 140 of the 11,000 species and 22 of the 630 genera of the coffee family (Rubiaceae). These myrmecophytic Rubiaceae species are predominantly distributed in Southeast Asia, especially the Malesian region, with comparatively few species in mainland Africa and the Neotropics. The mostly Southeast Asian genus Neonauclea s.s is one of the three Rubiaceae genera with extensive radiation of myrmecophytes and also the most speciose genus of the tribe Naucleeae s.l. We perform parsimony phylogenetic analyses of Neonauclea s.s., previously resolved as paraphyletic, and its allied genera using both ETS and ITS sequencing data to test: (1) the paraphyly of Neonauclea s.s.; (2) the phylogenetic relationships within the Ludekia-Myrmeconauclea-Neonauclea complex; and (3) the evolution of myrmecophytism within the complex. The earlier proposed paraphyly of Neonauclea s.s. appears to be the result of the combined effects of parallel substitutions in Metadina trichotoma and the sampled ITS putative pseudogenes of Neonauclea longipedunculata and losses of some synapomorphies of Neonauclea s.s. in the latter. The analyses present strong support for the monophyly of Myrmeconauclea and Neonauclea s.s. and their sister-group relationships. Our findings additionally favor the hypothesis of multiple origins of myrmecophytism in the Bornean Neonauclea, which have independently been exploited by at least three Cladomyrma ant species. Furthermore, we interpret the low levels of variation in both the ETS and ITS sequences as indication of a recent and rapid radiation for Neonauclea s.s. (with 65 species) and a recent and slow radiation for Myrmeconauclea (with three species). We argue that the rapid diversification of Neonauclea s.s. is partly associated with the nature of its fruits and its ability to colonize a wide range of habitats. We postulate that both ecological and geographical events may have been responsible for the radiation of the non-myrmecophytic Neonauclea species. Finally, we argue that the acquisition of the pseudo-multiple fruits and long-tailed seeds has allowed Myrmeconauclea to specialize on rheophytic habitats but its narrow ecological tolerance may have hindered its speciation.
Village-scale evaluation of mosquito nets treated with a tablet formulation of deltamethrin against malaria vectors.
A field trial was carried out in the Sundargarh district of Orissa, India on the efficacy of mosquito nets treated with a tablet formulation of deltamethrin (K-O TAB) against malaria vectors. Treated nets were used in one village, and in the two control villages, one used untreated nets and the other used indoor spraying with DDT, without nets. In this area the primary malaria vectors are Anopheles culicifacies Giles sensu lato (Diptera: Culicidae) and An. fluviatilis James s.l., which are both endophagic and endophilic, and fully susceptible to deltamethrin. Treatment of a 10-m(2) mosquito net with one of the tablets gave a deltamethrin deposit of 25 mg/m(2). Bioassays repeated on domestically used nets over 7 months showed persistence of almost 100% mortality of An. fluviatilis, whereas An. culicifacies showed a decline from 100% to 71% mortality over this period, after which the nets were re-treated and bioassays were not continued. The sum of collections of mosquitoes resting in village houses and those in exit traps and dead on floor sheets showed a reduction in the numbers of the two vector species due to the treated nets, compared with untreated or no nets, but no reduction in other anophelines or Culex species. Large proportions of the collections of the vector and non-vector anophelines were dead on the floor sheets, but among Culex, mortality was delayed. Treated and untreated nets reduced the proportion of anophelines that had blood-fed; the treated nets did so more effectively than the untreated in the case of An. culicifacies and of Culex mosquitoes. In rooms with treated nets a larger proportion of the total collections [dead + live] were in the exit traps, which can be attributed to the excito-repellent effect of deltamethrin. It is easier to pack and handle tablets of insecticide than liquid concentrate and the use of one tablet per net may be preferable to making up a large volume of diluted insecticide and dipping many nets at a time.
Relationship between malaria and filariasis transmission indices in an endemic area along the Kenyan Coast.
BACKGROUND AND OBJECTIVES: An entomological survey was conducted to determine the relationship between malaria and lymphatic filariasis transmission by Anopheles gambiae s.l. and An. funestus in two inland villages along the Kenyan coast. METHODS: Mosquitoes were sampled inside houses by pyrethrum spray sheet collection (PSC). In the laboratory, the mosquitoes were sorted to species, dissected for examination of filarial infection and the anophelines later tested for Plasmodium falciparum circumsporozoite proteins by an enzyme-linked immunosorbent assay (ELISA). RESULTS: From a total of 2,032 female mosquitoes collected indoors, An. gambiae s.l constituted 94.4% while the remaining 5.6% comprised of An. funestus and Culex quinquefasciatus. None of the Cx. quinquefasciatus was positive for filarial worms. P. falciparum sporozoite rate for An. gambiae s.l. from both villages was significantly higher than Wuchereria bancrofti infectivity rate. Similarly, the entomological inoculation rate for An. gambiae s.l. was significantly higher than the corresponding W. bancrofti infective biting rate and transmission potential for both the villages. Mass treatment of people with filaricidal drugs in Shakahola in the ongoing global elimination of lymphatic filariasis campaign seemed to have reduced the indices of filariasis transmission but had no effect on malaria transmission. INTERPRETATION AND CONCLUSION: These results indicate the intensity of malaria transmission by anophelines to be much higher than that of lymphatic filariasis in areas where both diseases co-exist and re-emphasise the need to integrate the control of the two diseases in such areas.
Diagnosis of human trypanosomiasis, due to Trypanosoma brucei gambiense in central Africa, by the polymerase chain reaction.
During a mass screening of sleeping sickness conducted in 1998 and 1999, and involving 27,932 persons in Cameroon and the Central African Republic, we tested the polymerase chain reaction (PCR) on whole blood for the diagnosis of human African trypanosomiasis due to Trypanosoma brucei gambiense. The 1858 samples obtained were from 4 groups: 155 infected patients, 1432 serological suspects detected by the card agglutination test for trypanosomiasis (CATT), 222 negative controls living in the prospected area (negative with the CATT and parasitological methods), and 49 negative controls (CATT and parasitological methods) and unexposed to the disease (Europeans). The technique of DNA extraction used made it possible to preserve the blood samples in the field. The primers used were specific for T. brucei s.l. Only 1 patient was PCR negative, and 3 of the negative controls, exposed to the disease, were PCR positive. Among the 1432 serological suspects, only 50 were PCR positive. During the 6-month follow-up after the surveys, the 3 negative controls, who were initially positive by PCR, were found to be negative. These initial positive PCR results are unlikely to have been due to a cross-reaction with T. brucei brucei, which is non-pathogenic for man, but are more likely to have resulted from a mislabelling of sample tubes. All control individuals, exposed or not to the disease, were negative by PCR. The PCR-negative patient was possibly a registration error. Among 50 PCR positive serological suspects, 39 of them were re-examined. Five were found to be positive by the kit for in-vitro isolation of trypanosomes, representing an increase in patients of almost 13%. At the end of the study, 160 patients were diagnosed, and the PCR was positive for 159 of them (99.4%). Moreover, the PCR made it possible to reduce the number of suspects to be re-examined (50 instead of 1432; a reduction of 96.5%).
Studies on biting Simulium damnosum s.l. at a breeding site in the Onchocerciasis Control Programme area during and after an interruption of insecticidal treatments.
The increase of population of biting S. damnosum s.l. at a breeding site situated within the Onchocerciasis Control Programme area of West Africa following a temporary cessation of insecticidal treatments was studied by making every day collections on human bait at five catching sites and for 2--3 days per week at seven others, between 17 January and 9 April 1977. Observations on pupal and larval densities, water and air temperatures, relative humidity and water level were also made. The results showed that there was an interval of 23 days between the last application of insecticide and the appearance of the first nulliparous biting flies. This coincided with the finding of the first S. damnosum larvae. Subsequently, the biting densities increased following a geometric progression from about 10 flies per day to a maximum of 188 per day, giving a daily rate of increase of 1.07. Ten days after the re-application of insecticide, biting densities had fallen to about 5% of the pre-control level giving a daily rate of decrease of 0.74. Very little dispersion was observed with biting rates falling to 5% at 3000 m. perpendicular to the river. At these sites nullipars predominated. Conversely along the axis of the river densities at 1000 m away had to only 68% and were composed mainly of parous flies. Studies on diel activity showed the greatest biting activity between 15.00 h and 18.00 h with a lesser period of activity between 07.00 and 10.00 h. The significance of these observations in future planning of control strategy is discussed.