Annals of Tropical Medicine & Parasitology最新文献

{"title":"Snail-parasite compatibility and prevalence of Schistosoma haematobium on the shores of Lake Kariba, Zambia","authors":"L. Mubila, D. Rollinson","doi":"10.1179/000349802125000592","DOIUrl":"https://doi.org/10.1179/000349802125000592","url":null,"abstract":"Abstract Reduced snail-parasite compatibility might be at least partially responsible for the decrease observed, over the last three decades, in the prevalence of urinary schistosomiasis on the shores of Lake Kariba, Zambia. To explore this possibility, the prevalences of urinary schistosomiasis in schoolchildren were investigated in three disparate areas of Zambia (Lake Kariba, Lake Bangweulu and Lusaka), and attempts were made to infect the snails that developed from the eggs of snails collected from each of these sites with Schistosoma haematobium from each of the sites. The prevalence of S. haematobium infection in schoolchildren ranged from 0% around Lake Bangweulu to 76% around Lake Kariba. The F1 progeny of Siavonga (Lake Kariba) snails showed good compatibility with the local parasite but were also susceptible to all of the geographical strains of S. haematobium tested. The interaction between the S. haematobium and S. mansoni found along the shores of Lake Kariba may favour S. mansoni, since prevalences of urinary schistosomiasis tend to be relatively high where S. mansoni is absent. Although Lake Bangweulu was confirmed to be an area of very low endemicity for urinary schistosomiasis, the snails bred from snails collected in this area were compatible with isolates of S. haematobium from the same region and also those from the other regions. In general, sympatric snail-parasite combinations were the most successful. All the snails were identified as Bulinus globosus, on the basis of common enzyme profiles, although polymorphism was evident for malate dehydrogenase (MDH): two samples had type-1 MDH and the rest were of type 3. Isoenzyme patterns for both acid phosphatase (AcP) and MDH could be used to distinguish between infected and uninfected snails.","PeriodicalId":8038,"journal":{"name":"Annals of Tropical Medicine & Parasitology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83770227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rapid epidemiological mapping of onchocerciasis (REMO): its application by the African Programme for Onchocerciasis Control (APOC)","authors":"M. Noma, B. Nwoke, I. Nutall, P. Tambala, P. Enyong, A. Namsenmo, J. H. Remme, U. Amazigo, Oladele O. Kale, A. Sékétéli","doi":"10.1179/000349802125000637","DOIUrl":"https://doi.org/10.1179/000349802125000637","url":null,"abstract":"Abstract One of the fundamental challenges that the African Programme for Onchocerciasis Control (APOC) has had to face is how to identify the endemic communities where its mass ivermectin-treatment operations are to be carried out in conformity with its stated objective of targetting the most highly endemic, aVected and at-risk populations. This it has done by adopting a technique, known as the rapid epidemiological mapping of onchocerciasis (REMO), that provides data on the distribution and prevalence of onchocerciasis. Integration of the REMO data into a geographical information system (GIS) enables delineation of zones of various levels of endemicity, and this is an important step in the planning process for onchocerciasis control. Zones are included in (or excluded from) the APOC-funded programme of community-directed treatment with ivermectin (CDTI), depending on whether or not their levels of onchocercal endemicity reach the threshold set by APOC. This review describes the application of the REMO/GIS technique by APOC in its operations, and identifies the remaining related challenges.","PeriodicalId":8038,"journal":{"name":"Annals of Tropical Medicine & Parasitology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77436749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Monitoring community-directed treatment programmes for sustainability: lessons from the African Programme for Onchocerciasis Control (APOC)","authors":"U. Amazigo, Oka Obono, K. Dadzie, J. H. Remme, J. Jiya, R. Ndyomugyenyi, J. Roungou, M. Noma, A. Sékétéli","doi":"10.1179/000349802125000664","DOIUrl":"https://doi.org/10.1179/000349802125000664","url":null,"abstract":"Abstract Community-directed treatment is a relatively new strategy that was adopted in 1997 by the African Programme for Onchocerciasis Control (APOC), for large-scale distribution of ivermectin (Mectizan®). Participatory monitoring of 39 of the control projects based on community-directed treatment with ivermectin (CDTI) was undertaken from 1998–2000, with a focus on process implementation of the strategy and the predictors of sustainability. Data from 14,925 household interviews in 2314 villages, 183 complete treatment records, 382 focus-group discussions, and the results of interviews with 669 community leaders, 757 trained communitydirected drug distributors (CDD) and 146 health personnel (in 26 projects in four countries) were analysed. The data show that CDD dispensed ivermectin to 65.4% of the total population (71.2% of the eligible population), with no significant gender differences in coverage (P > 0.05). Treatment coverage ranged from 60.2% of the eligible subjects in Cameroon to 76.9% in Uganda. There was no significant relationship between the provision of incentives to CDD and treatment coverage (P > 0.05). The frequency of treatment refusal was highest in Cameroon (29.2%). Although most (72.1%) of the communities investigated selected their CDD on the basis of a community decision at a village meeting, only 37.9% chose their distribution period in the same way. There is clearly a need to improve communication strategies, to address the issues of absentees and refusals, to emphasise community ownership and to de-emphasise incentives for CDD. The investigation of the ‘predictor indicators’ of sustainability should enable APOC to understand the determinants of project performance and to initiate any appropriate changes in the programme.","PeriodicalId":8038,"journal":{"name":"Annals of Tropical Medicine & Parasitology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89235613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The achievements and challenges of the African Programme for Onchocerciasis Control (APOC)","authors":"A. Sékétéli, G. Adeoye, A. Eyamba, E. Nnoruka, P. Drameh, U. Amazigo, M. Noma, F. Agboton, Y. Aholou, O. Kale, K. Dadzie","doi":"10.1179/000349802125000628","DOIUrl":"https://doi.org/10.1179/000349802125000628","url":null,"abstract":"Abstract The main strategy of APOC, of community-directed treatment with ivermectin (CDTI), has enabled the programme to reach, empower and bring relief to remote and under-served, onchocerciasis-endemic communities. With CDTI, geographical and therapeutic coverages have increased substantially, in most areas, to the levels required to eliminate onchocerciasis as a public-health problem. Over 20 million people received treatment in 2000. APOC has also made eVective use of the combination of the rapid epidemiological mapping of onchocerciasis (REMO) and geographical information systems (GIS), to provide information on the geographical distribution and prevalence of the disease. This has led to improvements in the identification of CDTI-priority areas, and in the estimates of the numbers of people to be treated. A unique public–private-sector partnership has been at the heart of APOC’s relative success. Through efficient capacity-building, the programme’s operations have positively influenced and strengthened the health services of participating countries. These laudable achievements notwithstanding, APOC faces many challenges during the second phase of its operations, when the full impact of the programme is expected to be felt. Notable among these challenges are the sustainability of CDTI, the strategy’s effective integration into the healthcare system, and the full exploitation of its potential as an entry point for other health programmes. The channels created for CDTI, could, for example, help efforts to eliminate lymphatic filariasis (which will feature on the agenda of many participating countries during APOC’s Phase 2). However, these other programmes need to be executed without compromising the onchocerciasis-control programme itself. Success in meeting these challenges will depend on the continued, wholehearted commitment of all the partners involved, particularly that of the governments of the participating countries.","PeriodicalId":8038,"journal":{"name":"Annals of Tropical Medicine & Parasitology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84484152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cystic echinococcosis in a rural Peruvian family","authors":"P. Moro, R. Moro, L. Poggi, Robert H. Gilman","doi":"10.1179/000349802125000709","DOIUrl":"https://doi.org/10.1179/000349802125000709","url":null,"abstract":"The prevalence of human infection with was not painful, surgery was recommended and a subcutaneous cyst, measuring 5 cm Echinococcus granulosus, the cause of cystic echinococcosis (CE), is particularly high in diameter, was subsequently removed. As CE was conŽ rmed when this neck cyst where the Andes pass through central and southern Peru (Otarola, 1966). That infection was examined, the girl’s abdomen was then checked with ultrasound (US) and three is common in this area is largely the result of high levels of human–dog contact (dogs further cysts — two (measuring 10 and 4 cm in diameter) in the right lobe of the liver being the parasite’s main deŽ nitive host) and inadequate disposal of the viscera of infected and another (5 cm) in the left lobe — were revealed. A chest X-ray appeared normal. livestock (Moro et al., 1994, 1997). Given the epidemiology of the disease, it is perhaps Like the neck cyst, all the liver cysts were surgically removed and pathological examnot surprising that clusters of human infection are sometimes observed in areas where CE ination conŽ rmed them to be of Echinococcus. The girl’s post-operative recovery was is common. One such cluster, in a Peruvian family of seven members, six of whom uneventful. In April 1989, one of the boy’s in the underwent surgical treatment for CE over a 6-year period (1986–1992), is described family, then 16 years old, was admitted to hospital complaining that he had had a cough below. All members of this family (a man and woman and their Ž ve children) were and mild haemoptysis since August 1987 (he had been previously diagnosed, at another born in Huarochiri, a small rural town, 3000 m above sea level, in the department medical centre, as a case of pulmonary tuberculosis but had shown no improvement of Lima. The family raised sheep and cattle and usually kept three sheep dogs to help on treatment for this condition). A chest X-ray then showed a small round shadow manage the farm animals. The children, both boys and girls, were allowed to have (2×2 cm) on the upper lobe of the right lung, and an abdominal scan with US revealed close contact with the dogs. The livestock were slaughtered, when necessary, by the cysts in both lobes of the boy’s liver. The lung infection was checked Ž rst, by surgery; adults, close to their house, and the adults reported feeding raw viscera, from livestock multiple small cysts were found in the upper lobe of the right lung and a lobectomy was known to have the cysts of CE, to their dogs on several occasions. performed. At a subsequent laparotomy, three cysts (measuring 12, 12 and 4 cm in In August 1986, one of the girls, then aged 5 years, complained of a swelling on diameter) were found in the right lobe of the liver and another 12-cm cyst, with a Ž stula the back of her neck. This swelling gradually increased in size until, 9 months after the into the biliary tract, was found in the left lobe. Crystal-clear  uid was aspirated from swelling had Ž rst been noti","PeriodicalId":8038,"journal":{"name":"Annals of Tropical Medicine & Parasitology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80092090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Revisiting the question of limited genetic variation within Schistosoma japonicum","authors":"T. Le, D. Blair, D. McManus","doi":"10.1179/000349802125000268","DOIUrl":"https://doi.org/10.1179/000349802125000268","url":null,"abstract":"Abstract Recent electrophoretic data have indicated that Schistosoma japonicum in mainland China may be a species complex, with the existence of a cryptic species being predicted from the analysis of schistosome populations from Sichuan province. To investigate the Sichuan form of S. japonicum, 4.9 kbp of mitochondrial DNA from each of three samples of the parasite from China (two from Sichuan and one from Hunan) and one from Sorsogon in the Philippines were amplified, sequenced and characterized. The sequence data were compared with those from the related South-east Asian species of S. mekongi (Khong Island, Laos) and S. malayensis (Baling, Malaysia) and that from S. japonicum from Anhui (China). At both the nucleotide and amino-acid levels, the variation among the five S. japonicum samples was limited (<1%). This was consistent with the conclusions drawn from previous molecular studies, in which minimal variation among S. japonicum populations was also detected. In contrast, S. mekongi and S. malayensis, species recognized as separate but closely related, differ from each other by about 10%, and each differs by 25%-26% from S. japonicum. Phylogenetic trees provided a graphic representation of these differences, showing all S. japonicum sequences to be very tightly clustered and distant from S. mekongi and S. malayensis, the last two being clearly distinct from each other. The results thus indicate no significant intraspecific genetic variation among S. japonicum samples collected from different geographical areas and do not support the idea of a distinct form in Sichuan.","PeriodicalId":8038,"journal":{"name":"Annals of Tropical Medicine & Parasitology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84943569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The rarity of infection with Leishmania (Viannia) braziliensis among patients from the Manaus region of Amazonas state, Brazil, who have cutaneous leishmaniasis","authors":"G. Romero, E. Ishikawa, E. Cupolillo, C. B. Toaldo, M. V. Guerra, M. G. Paes, V. Macêdo, J. Shaw","doi":"10.1179/000349802125000745","DOIUrl":"https://doi.org/10.1179/000349802125000745","url":null,"abstract":"Abstract The frequency of Leishmania (Viannia) braziliensis infection was assessed in 79 of the 138 patients with cutaneous leishmaniasis who attended a reference outpatient unit in Manaus, Amazonas state, between the August and December of 1997. The disease was characterized by one or more cutaneous ulcers, the skin lesions being frequently associated with satellite lymph-node enlargement. All parasite isolates were identified using monoclonal antibodies and enzyme electrophoresis. Only two (2.8%) of the 71 patients from whom parasites were successfully isolated were found to be infected with L. (V.) braziliensis, the other 69 isolates being identified, from their isoenzyme profiles, as L. (V.) guyanensis. In the Manaus region, therefore, almost all human cutaneous leishmaniasis is the result of infection with L. (V.) guyanensis, and L. (V.) braziliensis is a relatively rare cause of the disease.","PeriodicalId":8038,"journal":{"name":"Annals of Tropical Medicine & Parasitology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74661176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Are intestinal helminths a risk factor for non-typhoidal Salmonella bacteraemia in adults in Africa who are seropositive for HIV? A case-control study","authors":"J. J. Dowling, C. Whitty, M. Chaponda, C. Munthali, E. Zijlstra, C. Gilks, S. Squire, M. Gordon","doi":"10.1179/000349802125000277","DOIUrl":"https://doi.org/10.1179/000349802125000277","url":null,"abstract":"Abstract In Africa, invasive, non-typhoidal Salmonella (NTS) infections are a common but life-threatening complication in adults who are seropositive for HIV. The high prevalence of human infection with intestinal helminths which penetrate the gut could explain the greater importance of NTS bacteraemia in Africa compared with that in industrialized countries. If helminth infection is a major risk factor for NTS it would provide a locally relevant, public-health target. Intestinal helminth carriage in 57 HIV-positive patients with NTS bacteraemia (the cases) was compared with that in 162 HIV-positive controls who were similar to the cases in terms of age, sex, urban dwelling and socio-economic factors. The prevalence of helminth infection, 29% overall, was lower among the cases (18%) than among the controls (33%), giving a crude odds ratio of 0.40 [with a 95% confidence interval (CI) of 0.21-0.9] and an adjusted odds ratio (aOR) of 0.79 (CI=0.4-1.8). Five (9%) of the cases and 12 (7%) of the controls were infected with nematodes which penetrate the gut (Ascaris lumbricoides and/or Strongyloides stercoralis). The aOR for infection with these penetrating worms, corrected for age, sex, urban dwelling and phase of study, was 1.40 (CI=0.4-4.5). The present results do not exclude the possibility that helminths play a role in invasive NTS infections, but are not consistent with helminths being a sufficient risk factor in this population to be a public-health target. Anthelmintics are unlikely to have a major impact on preventing NTS bacteraemia in patients diagnosed HIV-positive in Africa.","PeriodicalId":8038,"journal":{"name":"Annals of Tropical Medicine & Parasitology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74405945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The immunodiagnostic potential of protoscolex antigens in human cystic echinococcosis and the possible influence of parasite strain","authors":"A. Rafiei, P. Craig","doi":"10.1179/000349802125001195","DOIUrl":"https://doi.org/10.1179/000349802125001195","url":null,"abstract":"Abstract The results of ELISA, SDS-PAGE and western blotting indicated that the protoscolex antigens of Echinococcus granulosus (of 10-125 kDa) included antigens recognized by sera from human cases of cystic echinococcosis (CE). Some of the latter antigens (of approximately 79, 59, 45, 38, 31 and 29 kDa) exhibited cross-reactivity with sera from humans with other parasitic infections, including alveolar echinococcosis, cysticercosis and African trypanosomiasis. The 31-kDa antigen recognized by IgG antibodies in human CE sera only appeared to be present in the extracts of protoscoleces from sheep, and not in the corresponding extracts from horse or camel cysts. In contrast, the human CE sera recognized a 45-kDa protoscolex antigen only present in the horse cysts and a 125-kDa antigen present in the camel and horse (but not sheep) cysts. Extracts of protoscoleces from different species of hosts might therefore provide a source of strain-specific diagnostic antigens for human CE.","PeriodicalId":8038,"journal":{"name":"Annals of Tropical Medicine & Parasitology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85068617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The identification, cloning and functional expression of the gene encoding orotidine 5'-monophosphate (OMP) decarboxylase from Plasmodium falciparum","authors":"R. Menz, O. Cinquin, R. Christopherson","doi":"10.1179/000349802125001230","DOIUrl":"https://doi.org/10.1179/000349802125001230","url":null,"abstract":"Abstract The coding region of a putative orotidine 5'-monophosphate decarboxylase gene from Plasmodium falciparum was identified in genomic data from the Malarial Genome Sequencing Project. The gene encodes a protein of 323 amino acids with a predicted molecular weight of 37.8 kDa. The gene was cloned into a bacterial expression vector and over-expressed in Escherichia coli. The recombinant protein was purified and shown to have orotidine 5'-monophosphate decarboxylase activity, confirming the identity of the gene.","PeriodicalId":8038,"journal":{"name":"Annals of Tropical Medicine & Parasitology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91383821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}