Filaria journal最新文献

{"title":"Lymphadenovarix in the axilla--an unusual presentation of filariasis.","authors":"Adhish Basu,&nbsp;Sarath Chandra Sistla,&nbsp;Surendra Kumar Verma,&nbsp;S Jagdish","doi":"10.1186/1475-2883-5-9","DOIUrl":"https://doi.org/10.1186/1475-2883-5-9","url":null,"abstract":"<p><p>Clinical manifestations of lymphatic filariasis depend on the area of lymphatic involvement and the duration of infection. A 21 year old man, resident in a filariasis endemic region, presented with multiple matted lymph nodes with cystic areas forming a large mass in his left axilla. An ultrasound scan of the axilla using a 7.5 MHz transducer revealed grossly dilated lymphatics but no filarial dance sign. Fine needle (21 G) aspiration cytology (FNAC) from the dilated lymphatics and solid areas in the lymph node mass revealed multiple microfilariae in a background of reactive lymphoid cells. Peripheral blood smears revealed microfilaremia with significant eosinophilia. Diagnosis of left axillary Bancroftian lymphadenovarix was made. On the administration of oral diethylcarbamazine, the diameter of the lymphatic vessels in the lymphadenovarix reduced considerably in size and microfilaremia disappeared. We report this case because axillary lymphadenovarix is a rare presentation of filariasis. This case is also unique since microfilariae were demonstrated in the fluid aspirated from the dilated lymphatics of the lymphadenovarix in the absence of live adult worms.</p>","PeriodicalId":84756,"journal":{"name":"Filaria journal","volume":"5 ","pages":"9"},"PeriodicalIF":0.0,"publicationDate":"2006-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/1475-2883-5-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"26169884","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Concomitant infections of Plasmodium falciparum and Wuchereria bancrofti on the Kenyan coast.","authors":"Ephantus J Muturi,&nbsp;Charles M Mbogo,&nbsp;Joseph M Mwangangi,&nbsp;Zipporah W Ng'ang'a,&nbsp;Ephantus W Kabiru,&nbsp;Charles Mwandawiro,&nbsp;John C Beier","doi":"10.1186/1475-2883-5-8","DOIUrl":"10.1186/1475-2883-5-8","url":null,"abstract":"<p><strong>Background: </strong>Anopheles gambiae s.l. and An. funestus are important vectors of malaria and bancroftian filariasis, which occur as co-endemic infections along the Kenyan Coast. However, little is known about the occurrence and prevalence of concomitant infections of the two diseases in mosquito and human populations in these areas. This study reports the prevalence of concomitant infections of Plasmodium falciparum and Wuchereria bancrofti in mosquito and human populations in Jilore and Shakahola villages in Malindi, Kenya.</p><p><strong>Methods: </strong>Mosquitoes were sampled inside houses by pyrethrum spray sheet collection (PSC) while blood samples were collected by finger prick technique at the end of entomological survey.</p><p><strong>Results: </strong>A total of 1,979 female Anopheles mosquitoes comprising of 1,919 Anopheles gambiae s.l and 60 An. funestus were collected. Concomitant infections of P. falciparum sporozoites and filarial worms occurred in 1.1% and 1.6% of An. gambiae s.l collected in Jilore and Shakahola villages respectively. Wuchereria-infected mosquitoes had higher sporozoite rates compared to non-infected mosquitoes, but multiple infections appeared to reduce mosquito survivorship making transmission of such infections rare. None of the persons examined in Shakahola (n = 107) had coinfections of the two parasites, whereas in Jilore (n = 94), out of the 4.3% of individuals harbouring both parasites, 1.2% had P. falciparum gametocytes and microfilariae and could potentially infect the mosquito with both parasites simultaneously.</p><p><strong>Conclusion: </strong>Concerted efforts should be made to integrate the control of malaria and bancroftian filariasis in areas where they co-exist.</p>","PeriodicalId":84756,"journal":{"name":"Filaria journal","volume":"5 ","pages":"8"},"PeriodicalIF":0.0,"publicationDate":"2006-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/1475-2883-5-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"26042150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tissue localization of collagenase and leucine aminopeptidase in the bovine filarial parasite Setaria cervi.","authors":"Daya R Pokharel,&nbsp;Reeta Rai,&nbsp;Pankaj Kumar,&nbsp;C M Chaturvedi,&nbsp;Sushma Rathaur","doi":"10.1186/1475-2883-5-7","DOIUrl":"https://doi.org/10.1186/1475-2883-5-7","url":null,"abstract":"<p><strong>Background: </strong>Like other helminth proteases, filarial proteases have also been shown to require for parasite survival inside the host and mediate various physiologic processes such as tissue invasion, feeding, embryogenesis and host immune evasion. Many of these proteases have shown potential for vaccines and chemotherapeutic agents against active filarial infections. Setaria cervi is a bovine filarial parasite and serves as a good parasite model for the studies in lymphatic filariasis. Recently, a 175 kDa collagenase and leucine aminopeptidase (LAP) have been purified and characterized from the bovine filarial parasite S. cervi and shown to be potential vaccine candidate and diagnostic marker, respectively for human lymphatic filariasis. However, their tissue localizations and putative roles in the parasite biology have not yet been examined and thus remain unclear. Therefore, the current study attempts to localize and explore the putative roles of these two enzymes in S. cervi.</p><p><strong>Methods: </strong>The tissue distributions of 175 kDa collagenase and leucine aminopeptidase in S. cervi were examined by immunohistochemical and histochemical methods, respectively. Immune sera obtained from the jirds immunized with collagenase served as primary antibody, rabbit anti-mouse IgG-HRP conjugate as secondary antibody and DAB as the substrate for the immunostaining of collagenase. Leu-betaNA was used as the substrate for the histochemical staining of LAP.</p><p><strong>Results: </strong>Both the collagenase and LAP were present in the body wall; however, they differ in their distribution pattern in different layers of body wall. Collagenase was mainly localized in epicuticle, cuticle, syncytial hypodermis and the nerve cord region whereas LAP was more concentrated in epicuticle, longitudinal muscle layers and almost absent or very faintly stained in syncytial hypodermis and nerve cord region. Both collagenase and LAP showed their common distributions in intestine, uterus and mature eggs, growing embryos and mf. Very strong immunostaining of collagenase in the outer body surface of the parasite indicates its major role in host-parasite relationship whereas the presence of LAP in muscular region suggests its role in tissue remodeling. The common presences of collagenase and LAP in the S. cervi intestine, ovary, uterus, eggs and mf suggest that they also have collaborative roles in molting, nutrition and embryogenesis. The data obtained on their immunological characterizations and their presence in important parasite organs give strong indication that they are critical for the survival of filarial parasite and thus can be good vaccine candidates and/or diagnostic markers for human lymphatic filariasis.</p><p><strong>Conclusion: </strong>The manuscript reports for the first time the tissue distribution of collagenase and LAP in the bovine filarial parasite S. cervi and discuss their putative roles in vivo. Our findings also open th","PeriodicalId":84756,"journal":{"name":"Filaria journal","volume":"5 ","pages":"7"},"PeriodicalIF":0.0,"publicationDate":"2006-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/1475-2883-5-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"26039145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A possible case of spontaneous Loa loa encephalopathy associated with a glomerulopathy.","authors":"Tuna Lukiana, Madone Mandina, Nanituma H Situakibanza, Marcel M Mbula, Bompeka F Lepira, Wobin T Odio, Joseph Kamgno, Michel Boussinesq","doi":"10.1186/1475-2883-5-6","DOIUrl":"10.1186/1475-2883-5-6","url":null,"abstract":"<p><p>It is well known that renal and neurological complications may occur after antifilarial treatment of patients infected with Loa loa. Conversely, spontaneous cases of visceral complications of loiasis have been rarely reported. A 31-year-old Congolese male patient who had not received any antifilarial drug developed oedema of the lower limbs, and then transient swellings of upper limbs. Two months after, he developed troubles of consciousness within several hours. At hospital, the patient was comatose with mild signs of localization. Laboratory tests and an abdominal echography revealed a chronic renal failure due to a glomerulopathy. Three weeks after admission, Loa microfilariae were found in the cerebrospinal fluid, and a calibrated blood smear revealed a Loa microfilaraemia of 74,200 microfilariae per ml. The level of consciousness of the patient improved spontaneously, without any specific treatment, but several days after becoming completely lucid, the patient died suddenly, from an undetermined cause. Unfortunately, no biopsy or autopsy could be performed. The role of Loa loa in the development of the renal and neurological troubles of this patient is questionable. But the fact that such troubles, which are known complications of Loa infection, were found concomitantly in a person harbouring a very high microfilarial load suggests that they might have been caused by the filarial parasite. In areas endemic for loiasis, examinations for a Loa infection should be systematically performed in patients presenting an encephalopathy or a glomerulopathy.</p>","PeriodicalId":84756,"journal":{"name":"Filaria journal","volume":"5 ","pages":"6"},"PeriodicalIF":0.0,"publicationDate":"2006-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1471781/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"26011072","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advances and challenges in predicting the impact of lymphatic filariasis elimination programmes by mathematical modelling.","authors":"Wilma A Stolk,&nbsp;Sake J de Vlas,&nbsp;J Dik F Habbema","doi":"10.1186/1475-2883-5-5","DOIUrl":"https://doi.org/10.1186/1475-2883-5-5","url":null,"abstract":"<p><p>Mathematical simulation models for transmission and control of lymphatic filariasis are useful tools for studying the prospects of lymphatic filariasis elimination. Two simulation models are currently being used. The first, EPIFIL, is a population-based, deterministic model that simulates average trends in infection intensity over time. The second, LYMFASIM, is an individual-based, stochastic model that simulates acquisition and loss of infection for each individual in the simulated population, taking account of individual characteristics. For settings like Pondicherry (India), where Wuchereria bancrofti infection is transmitted by Culex quinquefasciatus, the models give similar predictions of the coverage and number of treatment rounds required to bring microfilaraemia prevalence below a level of 0.5%. Nevertheless, published estimates of the duration of mass treatment required for elimination differed, due to the use of different indicators for elimination (EPIFIL: microfilaraemia prevalence < 0.5% after the last treatment; LYMFASIM: reduction of microfilaraemia prevalence to zero, within 40 years after the start of mass treatment). The two main challenges for future modelling work are: 1) quantification and validation of the models for other regions, for investigation of elimination prospects in situations with other vector-parasite combinations and endemicity levels than in Pondicherry; 2) application of the models to address a range of programmatic issues related to the monitoring and evaluation of ongoing control programmes. The models' usefulness could be enhanced by several extensions; inclusion of different diagnostic tests and natural history of disease in the models is of particular relevance.</p>","PeriodicalId":84756,"journal":{"name":"Filaria journal","volume":"5 ","pages":"5"},"PeriodicalIF":0.0,"publicationDate":"2006-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/1475-2883-5-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25932632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Onchocerca parasites and Wolbachia endosymbionts: evaluation of a spectrum of antibiotic types for activity against Onchocerca gutturosa in vitro.","authors":"Simon Townson,&nbsp;Senyo Tagboto,&nbsp;Helen F McGarry,&nbsp;Gillian L Egerton,&nbsp;Mark J Taylor","doi":"10.1186/1475-2883-5-4","DOIUrl":"https://doi.org/10.1186/1475-2883-5-4","url":null,"abstract":"<p><strong>Background: </strong>The filarial parasites of major importance in humans contain the symbiotic bacterium Wolbachia and recent studies have shown that targeting of these bacteria with antibiotics results in a reduction in worm viability, development, embryogenesis, and survival. Doxycycline has been effective in human trials, but there is a need to develop drugs that can be given for shorter periods and to pregnant women and children. The World Health Organisation-approved assay to screen for anti-filarial activity in vitro uses male Onchocerca gutturosa, with effects being determined by worm motility and viability as measured by reduction of MTT to MTT formazan. Here we have used this system to screen antibiotics for anti-filarial activity. In addition we have determined the contribution of Wolbachia depletion to the MTT reduction assay.</p><p><strong>Methods: </strong>Adult male O. gutturosa were cultured on a monkey kidney cell (LLCMK 2) feeder layer in 24-well plates with antibiotics and antibiotic combinations (6 to 10 worms per group). The macrofilaricide CGP 6140 (Amocarzine) was used as a positive control. Worm viability was assessed by two methods, (i) motility levels and (ii) MTT/formazan colorimetry. Worm motility was scored on a scale of 0 (immotile) to 10 (maximum) every 5 days up to 40 days. On day 40 worm viability was evaluated by MTT/formazan colorimetry, and results were expressed as a mean percentage reduction compared with untreated control values at day 40. To determine the contribution of Wolbachia to the MTT assay, the MTT formazan formation of an insect cell-line (C6/36) with or without insect Wolbachia infection and treated or untreated with tetracycline was compared.</p><p><strong>Results: </strong>Antibiotics with known anti-Wolbachia activity were efficacious in this system. Rifampicin (5 x 10(-5) M) was the most effective anti-mycobacterial agent; clofazimine (1.25 x 10(-5) M and 3.13 x 10(-6) M) produced a gradual reduction in motility and by 40 days had reduced worm viability. The other anti-mycobacterial drugs tested had limited or no activity. Doxycycline (5 x 10(-5) M) was filaricidal, but minocycline was more effective and at a lower concentration (5 x 10(-5) M and 1.25 x 10(-5) M). Inactive compounds included erythromycin, oxytetracycline, trimethoprim and sulphamethoxazole. The MTT assay on the insect cell-line showed that Wolbachia made a significant contribution to the metabolic activity within the cells, which could be reduced when they were exposed to tetracycline.</p><p><strong>Conclusion: </strong>The O. gutturosa adult male screen for anti-filarial drug activity is also valid for the screening of antibiotics for anti-Wolbachia activity. In agreement with previous findings, rifampicin and doxycycline were effective; however, the most active antibiotic was minocycline. Wolbachia contributed to the formation of MTT formazan in the MTT assay of viability and is therefore not exclusively a measure","PeriodicalId":84756,"journal":{"name":"Filaria journal","volume":"5 ","pages":"4"},"PeriodicalIF":0.0,"publicationDate":"2006-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/1475-2883-5-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25928969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cytokine profiles of filarial granulomas in jirds infected with Brugia pahangi.","authors":"Ramakrishna U Rao,&nbsp;Thomas R Klei","doi":"10.1186/1475-2883-5-3","DOIUrl":"https://doi.org/10.1186/1475-2883-5-3","url":null,"abstract":"<p><strong>Background: </strong>A granulomatous inflammatory response develops in jirds infected subcutaneously or intraperitoneally with filarial nematodes namely Brugia pahangi and B. malayi. Previous studies by light and electron microscopy have shown cellular inflammatory responses in and around these granulomas. Furthermore, the cellular inflammatory responses of granulomas found in the lymphatics and peritoneal cavity appear to be similar. The purpose of this study was to determine the cytokine profiles of granulomas in the peritoneal cavity of B. pahangi-infected jirds and to determine whether the granulomas release any proinflammatory cytokines ex vivo.</p><p><strong>Methods: </strong>A semiautomated quantitative polymerase chain reaction (Q-PCR) was performed on cDNA prepared from the granulomas of infected jirds to study the species-specific mRNA expression of IL-2, IL-4, IFN-gamma, IL-5, and IL-10. Genomic DNA was extracted from the granulomas, and parasite DNA was detected by Q-PCR by amplifying the HhaI repeat sequence. The levels of the inflammation-causing cytokines IL-6 and TNFalpha that were secreted by the granulomas were measured by cell-based assays.</p><p><strong>Results: </strong>Florid granulomas showed higher levels of IFN-gamma than other cytokines, linking this Th1 cytokine to the granulomatous inflammation that develops in jirds and humans. IL-4 expression was much lower than that of IFN-gamma but higher than that of IL-10. A low level of IL-5 mRNA expression was detectable in all granulomas as was the level of IL-2 expression. The levels of the inflammatory cytokines IL-6 and TNFalpha, secreted by intact granulomas, spontaneously increased by 48 h after culture. Parasite antigen stimulation and subsequent release of IL-6 and TNFalpha by the granulomas indicated a moderate increase in the levels of these two cytokines. The amplification of the Brugia HhaI repeat DNA and Wolbachia 16S rDNA indicated worm components and bacterial components in the granulomatous tissue.</p><p><strong>Conclusion: </strong>Granuloma development in filarial infections is a complex process involving cellular reactions responding to parasite/bacteria and their components. The interactions between worm-derived granulomas and their hosts are dynamic and multifaceted. The data collected thus far suggest that the expression profiles of many of the measured cytokines in the lymphoid tissues of Brugia-infected jirds are different from those of the cytokines in granulomas. Moreover, granulomas have the ability to secrete the inflammatory cytokines IL-6 and TNFalpha.</p>","PeriodicalId":84756,"journal":{"name":"Filaria journal","volume":"5 ","pages":"3"},"PeriodicalIF":0.0,"publicationDate":"2006-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/1475-2883-5-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25910839","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PCR and dissection as tools to monitor filarial infection of Aedes polynesiensis mosquitoes in French Polynesia.","authors":"Catherine Plichart,&nbsp;Yves Sechan,&nbsp;Neil Davies,&nbsp;Anne-Marie Legrand","doi":"10.1186/1475-2883-5-2","DOIUrl":"https://doi.org/10.1186/1475-2883-5-2","url":null,"abstract":"<p><strong>Background: </strong>Entomological methods may provide important tools for monitoring the transmission of filariasis in French Polynesia. In order to standardize our PCR method and refine our protocol to assess filarial infection levels in mosquitoes, we compared dissection of the vector, Aedes polynesiensis, with the poolscreening polymerase chain reaction (PS-PCR) assay.</p><p><strong>Methods: </strong>(1) Mosquitoes were collected in human landing catches in five areas in Moorea island, French Polynesia. (2) A fraction of the captured mosquitoes was dissected for Wuchereria bancrofti larvae. (3) Laboratory-reared mosquitoes (uninfected as well as experimentally infected ones) were repeatedly tested to optimize a PS-PCR protocol (DNA extracts from 1-50 pooled mosquitoes were tested with an internal standardized system and primers specific for the Ssp1 repeat sequence. PCR products were analysed by gel electrophoresis). (4) Another fraction of the captured mosquitoes was assayed by PS-PCR according the optimized protocol.</p><p><strong>Results: </strong>The prevalence of field-mosquito infection with W. bancrofti ranged from 1 to 8 % by dissection (L1-L3) and point estimates of infection prevalence, as assayed by PS-PCR, ranged from 0.4 to 3.7 %. There was a moderately strong correlation between larval infection rates as determined by dissection and PCR.</p><p><strong>Discussion: </strong>Our results suggest that the PS-PCR assay is specific and highly sensitive for detecting parasite DNA. We obtained similar although not identical results with dissections of mosquitoes. PS-PCR appears to be adequate for testing large numbers of mosquitoes in the context of filariasis elimination programs. The role and advantages of using entomologic methods to monitor filariasis programs are discussed.</p>","PeriodicalId":84756,"journal":{"name":"Filaria journal","volume":"5 ","pages":"2"},"PeriodicalIF":0.0,"publicationDate":"2006-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/1475-2883-5-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25877862","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of microfilarial loads in the skin of onchocerciasis patients after treatment with different regimens of doxycycline plus ivermectin.","authors":"Alexander Yaw Debrah,&nbsp;Sabine Mand,&nbsp;Yeboah Marfo-Debrekyei,&nbsp;John Larbi,&nbsp;Ohene Adjei,&nbsp;Achim Hoerauf","doi":"10.1186/1475-2883-5-1","DOIUrl":"https://doi.org/10.1186/1475-2883-5-1","url":null,"abstract":"<p><strong>Background: </strong>Infection with the filarial nematode Onchocerca volvulus can lead to severe dermatitis, visual impairment, and ultimately blindness. Since the currently used drug, ivermectin does not have macrofilaricidal or strong permanent sterilising effects on the adult worm, more effective drugs are needed to complement the use of ivermectin alone. Wolbachia endosymbiotic bacteria in filariae have emerged as a new target for treatment with antibiotics which can lead to long -term sterilization of the adult female filariae.</p><p><strong>Methods: </strong>In the Central Region of Ghana, 60 patients were recruited, allocated into four groups and treated with 200 mg doxycycline per day for 2 weeks, 4 weeks, 6 weeks respectively. Untreated patients served as controls. Some of the treated patients and the untreated controls were given 150 microg/kg ivermectin 8 months after the start of doxycycline treatment.</p><p><strong>Results: </strong>A follow up study 18 months post treatment showed that when using doxycycline alone there was a significant reduction of microfilarial (mf) loads in patients treated for either 4 or 6 weeks. However, there was no significant difference between the untreated controls and those given the 2 weeks regimen. Although no significant difference was demonstrated between the 4 and 6 weeks regimens, there was a trend observed, in that, microfilarial reduction appeared to have been greater following the 6 weeks regimen. Twelve months after ivermectin (i.e. 20 months after doxycycline) treatment, 8 out of 11 ivermectin-alone treated patients were mf-positive. In contrast, 1 out of the 7 patients treated for 4 weeks with doxycycline and none of the 4 patients treated for 6 weeks doxycycline (who were available for re-examination) were mf-positive after the combined treatment of doxycycline plus ivermectin treatment.</p><p><strong>Conclusion: </strong>Treatment of onchocerciasis with doxycycline for 4 weeks is effective. Nonetheless, mf reduction appeared to be greater in the 6 weeks regimen. It is recommended that until further studies are carried out i.e. 4 weeks treatment with doxycycline is proven equivalent to the 6 weeks, selected groups of onchocerciasis patients should be treated for 6 weeks with doxycycline. As discussed earlier, this treatment should be accompanied by two doses of ivermectin.</p>","PeriodicalId":84756,"journal":{"name":"Filaria journal","volume":"5 ","pages":"1"},"PeriodicalIF":0.0,"publicationDate":"2006-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/1475-2883-5-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25839339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A flow cytometry based method for studying embryogenesis and immune reactivity to embryogenic stages in filarial parasites.","authors":"Bikash Ranjan Sahu,&nbsp;Alok Das Mohapatra,&nbsp;Arindam Majumder,&nbsp;Pradip K Das,&nbsp;Balachandran Ravindran","doi":"10.1186/1475-2883-4-11","DOIUrl":"https://doi.org/10.1186/1475-2883-4-11","url":null,"abstract":"<p><strong>Background: </strong>In the absence of intermediate animal hosts, the process of embryogenesis leading to fecundity of adult female filarial worms is very critical for persistence of these obligate parasites in human communities. Embryogenesis in adult female filarial parasites involves fertilization of eggs or oocytes by sperms and their subsequent development into motile microfilariae inside the uterine cavity of worms. Development of assays for monitoring embryogenesis in adult female worms is a critical requirement in filariasis research--filarial worms are known to harbour endosymbionts such as Wolbachia which play a significant role in fecundity. Tetracycline or doxycycline treatment of the infected hosts effectively eliminates the endosymbionts resulting in inhibition of embryogenesis in female worms. Currently, inhibition of embryogenesis in adult filarial worms can be monitored only by microscopic examination of in vitro harvested intrauterine stages.</p><p><strong>Methods: </strong>Adult female filarial worms of bovine filarial parasites, Setaria digitata were collected from the peritoneum of infected animals and intrauterine stages were harvested in culture medium and were analyzed for forward and side scatter by flowcytometry using a BD FACS Calibur. Different populations were gated, sorted and identified by phase microscopy. Binding of biotinylated lectins to intra uterine stages was monitored using FITC labeled Avidin and monitored by flow cytometry of gated populations. Similarly, binding of antibodies in human filarial sera to intrauterine stages was monitored using FITC labeled anti-human immunoglobulins.</p><p><strong>Results: </strong>The forward and side scatter for intrauterine stages delineated 3 distinct populations labeled as R1, R2 and R3. The three populations were sorted and identified to be a) fully stretched microfilariae, b) early and c) late developmental stages of eggs respectively. Lectins such as Wheat Germ agglutinin or Concanavalin-A were found to bind strongly to egg stages and less prominently to intra-uterine microfilariae. Similarly the binding of antibodies in filarial sera to the three intra-uterine stages could also be precisely quantified.</p><p><strong>Conclusion: </strong>The manuscript reports a novel flow cytometry based method to monitor progression of embryogenesis in adult filarial worms. Apart from relative quantification of different intra uterine developmental stages, the assay allows quantitative binding of lectins and antibodies to each of the intrauterine stages. It may now be possible to quantify levels of antibodies in infected and immune hosts to monitor anti-fecundity immunity in filariasis--the assay can thus be used as a powerful tool for drug development and in immunological studies in human and experimental filariasis.</p>","PeriodicalId":84756,"journal":{"name":"Filaria journal","volume":"4 1","pages":"11"},"PeriodicalIF":0.0,"publicationDate":"2005-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/1475-2883-4-11","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25676700","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}