The animal reservoir of cutaneous leishmaniasis on Mount Elgon, Kenya.
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Animals↗
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[Chagasic cardiopathy in Tehuantepec. Preliminary report].
UNLABELLED: American trypanosomosis was described in the state of Oaxaca, Mexico in 1936, and is probably endemic in rural areas. However, there is no information regarding chronic disease in the Isthmus of Tehuantepec, previous to this report. OBJECTIVE: To identify the prevalence of American trypanosomosis and its consequences, such as the chronic chagas cardiomyopathy (CCC) among patients who were evaluated by the cardiology service in two general hospitals in Salina Cruz in the state of Oaxaca which is the main city of the Tehuantepec Region. MATERIAL AND METHODS: Consecutive patients referred to the two cardiology services were identified as primary dilated myocardiopathy after a complete clinical and epidemiological history, chest roengentgram, EKG and echocardiogram. Blood was obtained through venipuncture and samples were studied for anti-Trypanosoma cruzi antibodies using validated indirect immunofluorescence, ELISA and Western blot assays. RESULTS: Over a two period in which 540 cardiologic patients were examined, 16 (2.4% cases) of primary dilated cardiomyopathy were diagnosed and 13 (81%) of these were seropositive for anti-T. cruzi and therefore, fulfilled epidemiological and clinical criteria for chronic chagasic cardiomyopathy (CCC). CONCLUSIONS: American trypanosomosis and CCC were diagnosed in cases of dilated cardiomyopathy within a geographical area where, there is an important distribution of triatomine bugs infected and Trypanosoma cruzi. Infection caused a progressive heart disease in this population exposed to insect vectors due to poor housing and sanitary conditions. The present study points out the need for further epidemiological studies in the Tehuantepec region.
Aged↗
Control of Musca domestica third instar larvae by the latex of Calotropis procera (Family: Asclepiadaceae).
Calotropis procera (Family: Asclepiadaceae) is known to contain alkaloids, steroids and resinous substance. Different concentrations of its latex were topically applied to the 3rd stage larvae of Musca domestica. A dose of 3 ul (5% of the latex) killed and partially digested the larvae in three hours. The effect of this latex is most probably enzymatic in nature. No doubt, the shift to plant extracts in controlling insect-vectors or pests in general, pave the way to a health environment.
Animals↗
[Hemoparasites in wild birds in Madagascar].
This study aims to evaluate the prevalence and density of haemoparasites in native Malagasy birds. Among the 387 birds, belonging to 43 species sampled at six localities in different bio-climatic zones of the island, 139 (35.9%) showed at least 1 hemoparasite with, by order of frequency, Plasmodium and/or Haemoproteus (19.9%), microfilariae (13.7% of 387 birds), Leucocytozoon (11.1%) and Trypanosoma (1.0%). An analysis to further elucidate these observations took into account the interaction of different environmental variables (altitude, season, site of collection) or aspects of the birds (age, weight, sex). There is evidence that some parasites preferentially infect some bird species or families. The largest male birds harboured the highest prevalences and densities of haemoparasite, regardless of species. These findings extend knowledge of bird/blood parasite relationships of Malagasy birds and provide interesting insights, especially concerning the pathogenicity of this type of parasitism and the parasite transmission by insect vectors.
Age Distribution↗
The potential of pathogens as biological control of parthenium weed (Parthenium hysterophorus L.) in Ethiopia.
P. hsyterophorus is an exotic invasive annual weed now causing severe infestation in Ethiopia. Studies on diagnosis, incidence and distribution of pathogens associated with parthenium weed in Ethiopia were carried out from 1998-2002. Several fungal isolates were obtained from seed and other parts of parthenium plants. Among them were putative pathogenic fungal species of the genus Helminthosporium, Phoma, Curvularia, Chaetomium, Alternaria, and Fusarium. However, pathogenecity test of the isolates obtained showed no or non-specific symptoms. It was concluded that these pathogens could be opportunistic with insignificant potential for biological control of parthenium. Two most important diseases associated with parthenium were a rust disease, caused by Puccinia abrupta var. partheniicola, and a phyllody disease, caused by a phytoplasma of fababean phyllody (PBP) phytoplasma group. The rust was commonly found in cool mid altitude (1500-2500 m) areas while phyllody was observed in low to mid altitude regions (900-2500 m) of Ethiopia, with a disease incidence up to 100% and 75%, respectively, in some locations. Study of the individual effects of the rust and phyllody diseases under field conditions showed a reduction on weed morphological parameters (plant height, leaf area, and dry matter yield). Parthenium seed production was reduced by 42% and 85% due to rust and phyllody, respectively. Phyllody and rust diseases of parthenium showed significant potential for classical biological control of parthenium after further confirmation of insect vectors that transmit phyllody and host range of phyllody disease to the related economic plants in Ethiopia.
Alternaria↗
[Detection of Leishmania (Viannia) braziliensis in vascular endothelium lesions of patients with localized cutaneous leishmaniasis].
In the present study, we examined the cutaneous lesions of 8 patients with cutaneous leishmaniasis, from regions situated near the rivers Chama-Mocoties, in Merida state, Venezuela. The lesions of the patients were diagnosed on the basis of clinical, parasitological and immmunological examinations. The Polymerase Chain Reaction (PCR) assay showed infection by Leishmania (Viannia) braziliensis in cutaneous lesions samples. Histopathology of skin biopsy specimens showed inflammatory infiltrates of mononuclear and polymorphonuclear leukocytes. Granulomatous reactions and amastigotes were observed in the dermis. The histological sections of the cutaneous lesions in one patient (No. 5), showed alterations in the integrity of dermal blood vessels, leishmanial antigens on the superficial endothelium and free parasites in the capillary lumen and inside mononuclear cells. The Leishmania amastigotes also were detected in the cytoplasm of neutrophils in Giemsa-stained imprints. The skin biopsies examined using immunofluorescence (IFI) and immunoperoxidase assay (PAP), show amastigotes and antigenic material adsorbed on the vecinity of the walls of dermal microvessels. Based on these results, we concluded that in the cutaneous lesions it is possible to show the presence of intra and extracellular parasites, attached to wall of the dermal blood vessels and free, in the capillary lumen. The circulating parasites in peripheral blood may allow the possibility of developing secondary infections as well as the propagation of the infection in endemic areas of leishmaniasis, where the parasite circulates between domestic and wild reservoirs, vector insects and humans living in those areas.
Adolescent↗
Introduction and spread of thermophilic campylobacters in broiler flocks.
Campylobacteriosis is the most commonly reported infectious cause of human gastroenteritis in developed countries and broiler chickens are considered to be the major food-borne source of the infection. The control of the infection in man depends upon its control in broiler flocks but the epidemiology in poultry is poorly understood. Up to 50 per cent of broiler flocks may be infected and most of the birds in an infected flock carry the organisms until slaughter. Vertical transmission through the egg appears unlikely but there are many other potential sources of the infection for the chicks; direct contact with infected animals or birds has been proposed and there is also evidence for indirect transmission through drinking water or insect vectors. It is suggested that the cross-sectional studies discussed in this review should be followed by well designed case-control studies to test the aetiological hypotheses put forward.
Animals↗
Control of gene expression and genetic manipulation in the Trypanosomatidae.
Mechanisms controlling gene expression in trypanosomatids depend on several layers of regulation, with most regulatory pathways acting at a post-transcriptional level. Consequently, these parasites can follow the rapid changes associated with transitions between the insect vector and the mammalian host, with instant reprogramming of genetic expression. Using primarily Trypanosoma brucei as a model, the basic controlling mechanisms have been elucidated and now researchers are beginning to define the cellular factors involved in the transcription, processing and translation of the mRNAs in these parasites. We describe some of the studies made on a subset of genes that are differentially expressed during the life cycles of T. brucei and T. cruzi. It is becoming evident that the regulatory strategies chosen by different species of trypanosomatids are not the same, and therefore, the lessons learned from one species do not necessarily apply to the others. Some of the tools available for genetic manipulation that have been developed along with these studies are also described. Two of them are of particular interest in this postgenomic period: inducible systems to express foreign genes and specific inhibition of gene expression by RNA interference.
Animals↗
Vector problems-past and present.
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Animals↗
First record of Aedes albopictus from Trinidad, West Indies.
This is the 1st report of the occurrence of Aedes albopictus in Trinidad, West Indies. Eggs collected in 2 ovitraps, 1 in November and 1 in December 2002, were hatched and reared to adults at the Insect Vector Control Division laboratory. Three female Ae. albopictus emerged, whereas 6 females were collected by human-bait collections. The implications of these findings are discussed.
Aedes↗
[Sanitary control of communicable diseases in Hispanic America in the XVI, XVII, and XVIII centuries].
In each time and each place, man has avoided diseases, has tried to limit diffusion of diseases. The purpose of this article was to present in a general manure the measures taken in Hispano America during colonial times to control communicable diseases. The main problems of health during the XVI, XVII, and XVIII centuries, in Hispano American region were communicable diseases. Practices to avoid them derived from observation, control measures referred to stay away from the contagious places, and to isolate sick persons by means of quarantine, and implied some epidemiologic surveillance. The supply of safe drinking water, sewage disposal systems and sanitary control of food were not habitual practices; garbage, residuals, and waste collection were not opportune, This favored the existence of vectors-insects and animals. Domestic waste did not go away in a timely fashion, it allowed to accumulate excreta and waste near houses. In some places, the were measures related to water supply, excreta disposal, handling of dead bodies, and environmental sanitation. It was believed that with prayers and processions, prevalent diseases could be avoided. Demographic information, data on mortality, births, and morbidity, were irregular and incompletes, some data were compiled in parishes: physicians should inform and notify the governmental medical board, which regulated medicine and public heath who the cared for an action carried out only as and exception. Compiled data had no clear medical or sanitary use.
Communicable Diseases↗
[Contributing factors and control strategies of pine wilt disease].
There are several types of pine wilt diseases with inherent inter-relations. The diseases are closely related with the complex ecological system composed of local environment, pine trees, insect vectors, and pathogenic nematodes and some other microorganisms. Sustainable pest management based on ecology is a potential approach for pine wilt disease control.
Animals↗
[Bartonelloses].
Bartonellae belong to less known causal agents of many human diseases. They are gram-negative bacteria growing slowly on culture media enriched with hemin or bovine serum. The genus Bartonella, which currently involves more than 15 species, is present worldwide. Bartonellae live in natural foci in dependence on the occurrence of natural host (rodents, felines, canidae, human) and insect vector (flea, tick, louse). By reservoir animals they usually cause permanent intraerythrocytic bacteraemia without system inflammation symptoms. A classical example of a human disease is cat scratch disease (CSD) caused by Bartonella henselae and characterised by regional lymphagoitis and lymphadenitis. Increasing interest is being devoted to the ability of Bartonella sp. (e.i. B. quintana) to cause the opportune infections with diverse clinical manifestation: bacillary angiomatosis, specific liver and spleen vasculitis (peliosis hepatis, splenis), endocarditis and others. The issue of Bartonella infections is relatively new and its importance is still growing with increasing knowledge in this field.
Animals↗
Purification and characterization of an extracellular phosphoglycan from Leishmania donovani.
An extracellular phosphoglycan (exPG), present in the culture medium of the promastigote form of Leishmania donovani, was purified and structurally characterized. The purification scheme included ethanol precipitation of the culture medium, anion exchange chromatography, hydrophobic chromatography on phenyl-Sepharose, and preparative polyacrylamide gel electrophoresis. Structural analysis by 1H-1H NMR, methylation linkage analysis, and glycosidase digestion revealed that the exPG consisted of the following structure: (CAP)----[PO4-6Galp beta 1-4Manp alpha 1]10-11-PO4-6Galp beta 1-4Man. The cap was found to be one of several small, neutral oligosaccharides, the most abundant of which was the trisaccharide Galp beta 1-4(Manp alpha 1-2)Man. The results indicated structural analogy to the cellular-derived lipophosphoglycan (LPG) from L. donovani. The important exceptions are a lack of the lipid anchor, the entire phosphosaccharide core, and several of the repeating disaccharide units. Although the function of exPG is presently unknown, it may play a protective role for the promastigote in the insect vector or during infection of a mammalian host.
Animals↗
Influence of chemotherapy on the Plasmodium gametocyte sex ratio of mice and humans.
Plasmodium species, the etiologic agents of malaria, are obligatory sexual organisms. Gametocytes, the precursors of gametes, are responsible for parasite transmission from human to mosquito. The sex ratio of gametocytes has been shown to have consequences for the success of this shift from vertebrate host to insect vector. We attempted to document the effect of chemotherapy on the sex ratio of two different Plasmodium species: Plasmodium falciparum in children from endemic area with uncomplicated malaria treated with chloroquine (CQ) or sulfadoxine-pyrimethamine (SP), and P. vinckei petteri in mice treated with CQ or untreated. The studies involved 53 patients without gametocytes at day 0 (13 CQ and 40 SP) followed for 14 days, and 15 mice (10 CQ and 5 controls) followed for five days. During the course of infection, a positive correlation was observed between the time of the length of infection and the proportion of male gametocytes in both Plasmodium species. No effects of treatment (CQ versus SP for P. falciparum or CQ versus controls for P. vinckei petteri) on the gametocyte sex ratio were found for either Plasmodium species. This indicates that parasites do not respond to chemotherapy by altering their sex allocation strategy, even though, in the case of P. falciparum, they apparently increase their overall investment in sexual stages. This suggests that malaria parasite species respond to different environmental cues for their sex differentiation and sex determination.
Animals↗
[Control of Trypanosoma cruzi infection in blood donors in Colombia, 2003].
INTRODUCTION: Chagas disease is a public health problem in Latin America. Whereas the primary source of transmission is the insect vector, the second is by blood transfusion. Consequently, in Colombia, screening for trypanosomiasis has been obligatory for blood donors since 1995. OBJECTIVE: The effectiveness ot current strategies for infection control in donors was evaluated in order to estimate the risk of blood stock contamination with Chagas disease. The screening data came from the blood banks in the Program of External Evaluation in the Performance of Serology and the reports of the Laboratories of Public Health on confirming donor serology tests. RESULTS: In 2003, 482,371 units of blood were collected in all of Colombia. Of these, 99.9% were analyzed for anti-T. cruzi reactivity, with a positives of 0.42% detected. The Casanare Province presented the biggest number of reactive donors 107/1487 (7.2%), with 75 confirmed positive. In the Program of External Evaluation in the Performance of Serology, 45.5% of all banks participated-all used ELISA for screening of anti-T. cruzi. 1.1% false positives and nofalse negatives were indicated in 12 provinces, where 338,563 units were analyzed for anti- T.cruzi, 1298 units were reactive and 1108 (85.4%) were confirmed by the IFI test. This indicated a rate of Chagas positives of 0.33%. CONCLUSIONS: Although the analysis covered arrived at 99.9% of the blood units, a small degree of infection risk for T. cruzi still remains. The cases of T. cruzi in donors oscillate between 0 and 50 per thousand. This rate is highest in Casanare with a concomitantly high risk for acquisition of transfusional Chagas. ot show negative false results.
Animals↗
Studies on rodents role as reservoir hosts of leishmaniasis with specical reference to their ectoparasites in Suez Governorate.
The distribution of rodents was studied in three different habitats. Seven rodent species were identified: Rattus norvegicus, R. alexandrinus, R. frugivorous, Mus musculus, Acomys russatus, Meriones sacramenti and Gerbillus pyramidum. The species distribution varied with the habitat type. The highest density of rodents was in July and August and the lowest one was in January. However, some species were collected all the year round. The rodents were investigated for the endo- and ecto-parasites. No Leishmania parasites were found. The ectoparasites were: Xenopsylla cheopis, Leptopsylla segnis and Ctenocephalides felis, Polyplax spinulos, Hyalomma dromedarii (nymph) and Echinolaelaps echidninus and Hemolaelaps glassgowi. Ecto-parasites were on rodents all year-round in domestic habitat and peridomestic habitats. In wild one, ecto-parasites activity was from March to December. The rodents' role as reservoir for L. major was experimentally studied. Rodents inoculated with L. major together with hamster and BALB-c mice developed cutaneous lesions. The active lesions, the rodents' ecological habitats and the presence of insect-vector may pave the way to an epidemic zoonotic leishmaniasis role.
Animals↗
[Tularaemia as a differential diagnosis in tumour colli].
BACKGROUND: Tularaemia is a bacterial zoonosis caused by the bacterium Francisella tularensis. Different species of rodents and small mammals are the main reservoir; the transmission of disease is caused by direct contact with diseased animals, via insect vectors, or by ingestion of contaminated food and water. The disease is known to cause a complex clinical presentation in which head and neck manifestations are common. It occurs at a low annual rate in the northern and middle regions of Norway, but in recent years there have been several reported cases also in the southern parts of the country. The incidence of tularaemia is much higher in Sweden compared to Norway; the reason remains obscure. MATERIAL AND METHODS: In this paper we report two admitted cases in which fever and a solitary neck mass were the predominant clinical findings. We review the number of cases reported to the Norwegian Institute of Public Health from 1976 to 2002, with particular emphasis on the role of tularaemia in the context of a neck tumour and oropharyngeal symptoms. RESULTS AND INTERPRETATION: The suspicion of tularaemia should be raised in patients with a solitary neck mass of presumed infectious aetiology, in particular when administration of beta-lactam antibiotics has failed. The diagnosis is usually dependent on serological evidence of F. tularensis infection. Recently, PCR techniques have been developed that facilitate rapid detection of F. tularensis in clinical specimens.
Adult↗