Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “FILARIASIS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5Linked to original sources
PubMed2007

Qualitative analysis of the impact of a lymphatic filariasis elimination programme using mass drug administration on Misima Island, Papua New Guinea.

BACKGROUND: Papua New Guinea is the only endemic country in the Western Pacific Region that has not yet introduced a countrywide programme to eliminate lymphatic filariasis. However, on Misima Island in Milne Bay Province, government and private sectors have collaborated to implement a pilot elimination programme. Although interim evaluation indicated that the programme has been parasitologically successful, an appreciation that sustainable health gains depend on understanding and accommodating local beliefs prompted this qualitative study. METHODS: We investigated Misima community members knowledge and attitudes about lymphatic filariasis and the elimination programme. A combination of focus groups and key informant interviews were used to explore participants perceptions of health; knowledge of the aetiology and symptoms of filariasis, elephantiasis and hydrocele; attitudes towards the disease and mass drug distribution; and the social structure and decision-making protocols within the villages. RESULTS: Focus group discussions proved inferior to key informant interviews for gathering rich data. Study participants did not consider lymphatic filariasis ("pom") a major health problem but were generally positive about mass drug administration campaigns. A variety of conditions were frequently and incorrectly attributed to filariasis. Participants expressed the belief that individuals infected with filariasis always had visible manifestations of disease. A common misconception was that taking drugs during campaigns provided long-term immunity against disease. The role of mosquito vectors in transmission was not generally appreciated and certain clinical presentations, particularly hydrocele, were associated with supernatural forces. Multiple adverse events were associated with mass drug administration campaigns and most study participants mentioned community members who did not participate in campaigns. CONCLUSION: Important issues requiring educational intervention and elimination activity modification in the Misima region were identified during this study. Research outcomes should assist Papua New Guinea in developing and implementing a national elimination strategy and inform discussions regarding the appropriateness of current elimination strategies.

Journal Article↗
PubMed2001

Lymphatic filariasis in kenya since 1910, and the prospects for its elimination: a review.

OBJECTIVES: To provide an overview of lymphatic filiariasis in Kenya from the first time its prevalence was reported to the present day, with suggestions of issues that are yet to be resolved and to present the prospects for its elimination. DATA SOURCES: Published and unpublished reports on filariasis studies in Kenya. STUDY SELECTION: Field-based epidemiological studies covering aspects of clinical, parasitology, entomology, social, economic, diagnosis and control of filariasis. DATA EXTRACTION: Review of published articles in scientific journals and communications, retrieval and review of published scientific articles from the Internet and personal communications. DATA SYNTHESIS: Re-organisation and pooling retrieved published data. CONCLUSIONS: Almost one century after the first documented report of lymphatic filariasis in Kenya, no National Control Programme has been instituted. However, important findings that have implications on its control have been made and they should be utilised to implement a National Control Programme. On implementation of the National Control Programme, research should be focussed on the remaining unresolved issues and conducted within the framework of the Programme. The World Health Organisation has targeted lymphatic filariasis for global elimination by the year 2020. Kenya is well positioned to formulate her National Plan for Elimination of Lymphatic Filariasis (NPELF) and join other endemic countries worldwide, which have already launched their plans, in the global efforts to eliminate lymphatic filariasis as a public health problem.

Clinical Trials as Topic↗
PubMed1999

Biased TCR repertoire in infiltrating lesional T cells in human Bancroftian filariasis.

To investigate the hypothesis that T cells recognizing specific Ags localize to the site of disease activity in human bancroftian filariasis, we have compared the repertoire of TCR Vbeta gene segments in lesions vs blood in individual patients by RT-PCR ELISA. Vbeta14 and Vbeta24 were overrepresented (5% greater in tissue compared with PBMCs and/or tissue/PBMC ratios in the highest 5% of all tissue/PBMC ratios for all Vbetas for all subjects) in 50% and 40% of study subjects, respectively. Overrepresentation of these two Vbetas did not occur in any control subject. In comparing three patient groups, the proportion of individuals meeting at least one criterion for Vbeta14 overrepresentation was shown to increase in tandem with our current concepts of disease progression (asymptomatic filariasis = 25%; clinical filariasis with active infection = 60%; clinical filariasis without active infection = 71%). In 6 of the 10 individuals with Vbeta14 overrepresentation, Vbeta14 represented >20% of the entire lesional Vbeta repertoire. All but one of the 20 study subjects had at least one Vbeta gene segment that was overrepresented in tissue compared with PBMCs. Only a small number of Vbetas, usually three or less, were overrepresented in any single filariasis patient. However, in the same tissue, no differences between patient groups were found when IFN-gamma, TNF-alpha, IL-4, IL-5, and IL-12 mRNA expression were examined. Taken together, these findings suggest that, in principle, in essentially all patients, whether with subclinical or with clinical filariasis, distinct and limited T cell populations are concentrated in affected tissue.

Animals↗
PubMed2001

Human bancroftian filariasis - a role for antibodies to parasite carbohydrates.

Studies on immune responses to parasites have been undertaken in filariasis with a view to understand protective immunity, pathogenesis of the disease process and mechanisms of immune deviation. However none of the investigations conducted so far on antibody responses have addressed the issue of immunogenicity of filarial carbohydrate antigens in human lymphatic filariasis. In this communication we report details on relative protein and carbohydrate contents of various developmental stages of filarial parasites and antibody responses to filarial proteins (Fil.Pro) and carbohydrates (Fil.Cho) in different clinical spectrum of human bancroftian filariasis. As expected, antibodies of IgM and IgG2 subclass recognized primarily Fil.Cho while IgG4 filarial antibodies recognized exclusively Fil.Pro. Reactivity of IgG3 to Fil.Cho was similar to that of IgG2 while IgG1 more readily recognized Fil.Pro than Fil.Cho. The IgG2 and IgG3 antibodies to Fil.Cho were found to be significantly more in patients with chronic filarial disease and in endemic normals when compared with microfilariae (mf) carriers while IgG4 antibodies to Fil.Pro were significantly more in mf carriers. The dichotomy in reactivity of filarial IgG2, IgG3 and IgG4 was dependent on active filarial infection as indicated by presence of circulating filarial antigen (CFA). Individuals with CFA were found to possess significantly more IgG4 to Fil.Pro than those without CFA while IgG2 and IgG3 levels to Fil.Cho was significantly more in CFA negative subjects when compared to those with CFA. Although IgG1 reacted more readily with Fil.Pro, unlike IgG4, their levels were significantly more in CFA negative subjects when compared to those with active filarial infection. Absorption of sera with phosphorylcholine (PC) resulted in no significant loss of reactivity to Fil.Cho indicating that most of the anticarbohydrate antibodies were recognizing non-PC determinants in human filariasis. Elevated levels of IgG2 and IgG3 antibodies to Fil.Cho in individuals free of filarial infection indicate a possible role for carbohydrate antigens in induction of protective immunity in human filariasis.

Animals↗
PubMed1996

A survey of bancroftian filariasis among South-East Asian expatriate workers in Saudi Arabia.

In a survey of bancroftian filariasis among expatriate workers from five South-East Asian countries (India, Bangladesh, Sri Lanka, Thailand and the Philippines) where human filariasis is endemic, 762 individuals were examined in the Abha area (Asir) of south-western Saudi Arabia. A prevalence of microfilaraemia of 3.5% and a mean mf density of 6.0/20 mm3 of blood was found among 259 Indian males only. In three out of 9 microfilaraemic cases, clinical signs suggestive of filariasis were observed. The only species identified was Wuchereria bancrofti showing strict nocturnal periodicity. Preliminary laboratory studies on the susceptibility of local mosquitoes to infection with W. bancrofti in which laboratory-bred Culex (C.) pipiens was fed directly on a microfilaraemic volunteer from Madras, South India, revealed that this species was highly susceptible to the Madras strain of the parasite with an average infection rate of 57 (range 41-75)% and a worm burden of 3.5 L3/infective mosquito. This is the first report that local Cx. pipiens mosquitoes may act as a potential vector of introduced bancroftian filariasis in Saudi Arabia. The potential danger of bancroftian filariasis importation and, more importantly, the establishment of new self-sustained foci of the disease is likely to depend upon the abundance of mf carriers and density of vector mosquitoes feeding on carriers.

Adult↗
PubMed1982

Endemic filariasis on a Pacific island. I. Clinical, epidemiologic, and parasitologic aspects.

The clinical and parasitologic aspects of filariasis were investigated in 459 inhabitants of a South Pacific island endemic for subperiodic Wuchereria bancrofti filariasis. Episodes of filarial fevers, usually with concomitant lymphangitis and/or lymphadenitis, were experienced by 26%. Lymphobstructive lesions, manifest in the later decades of life, were present in 12 with elephantiasis and 24 with hydroceles. Microfilaremia was detectable by membrane filtration of 1 ml of blood in 33% of persons, with a quarter of these having less than 50 microfilariae/ml. Microfilaremia and filarial fevers were more frequent in males than females and in residents of the most inland villages. Neither presence nor magnitude of lymphadenopathy correlated with other manifestations of filariasis except that markedly enlarged inguinal-femoral nodes were more common in those with elephantiasis or hydroceles. A history of filarial fevers did not correlate with presence of microfilaremia. Over 70% of adults had microfilaremia and/or historical or physical manifestations of filariasis. The absence of detectable microfilaremia in many residents with clinical evidence of filariasis and the presence of asymptomatic microfilaremia emphasize the limitations in relying only on microfilaremia rates or clinical findings in the study of the prevalence or manifestations of filarial infection.

Adolescent↗
PubMed1999

Demographic and socio-economic factors with implications for the control of lymphatic filariasis in Kwale District, Kenya.

OBJECTIVE: To examine demographic and socio-economic factors with regard to control of lymphatic filariasis. DESIGN: A cross sectional data collection approach using a questionnaire. SETTING: Three adjacent villages, namely Lutsangani, Dzivani and Gandini in Kwale district. This was the study site for a larger KEMRI-JICA lymphatic filariasis control project. Findings from the larger project showed filariasis prevalence rates of 22.6%, 12.1% and 11.9% in the three villages respectively. SUBJECTS: All 891 household-heads in the three villages. MAIN OUTCOME MEASURES: Relationship between selected factors (age, sex, education, employment status, availability of latrine and permanent roofing for the main dwelling) and current use of protection against mosquito bites. RESULTS: Use of mosquito-bed nets, mosquito repellents and insecticides was found in 13.8% of the households. Education and employment status of the household-heads were positively associated with protection against man-vector contact (p < 0.001). Non-availability of latrines and lack of permanent roofing (tiles or corrugated iron sheets) for the main dwellings in 80% and 95% households, respectively, were additional clear indicators of low socio-economic development. CONCLUSION: Given the inter-village variations in the prevalence of the filariasis, wide scale diagnosis for treatment control approach could be prohibitively expensive. Effective control of filariasis in this and similar communities may be by mass treatment with either diethylcarbamazine (DEC) or ivermectin combined with albendazole.

Adolescent↗
PubMed1999

[Evaluation of DNA recombinant chitinase fusion protein antigens in serological diagnosis for filariasis].

OBJECTIVE: To evaluate DNA-recombinant chitinase fusion protein antigen in serodiagnosis for Bancroft's filariasis in jirds rats with microfilaremia and normal jirds rats with ELISA, and its prospect in the market to be spread. METHODS: Oligonucleotide was synthesized with filaria monoclonal antibody (Mf(1))-recognized microfilaria chitinase fusion protein and basic primer recognized by original clonal nucleosides, and amplified with polymerase chain reaction (PCR). PCR products were expressed in Pmal-c vector and purified by affinity chromatography. Experimental animals were inoculated with chitinase fusion protein antigen and infected with larval stage filaria Brugia malayi, respectively. Functional protein molecule of chitinase antigen was analyzed with SDS-PAGE and western blot. Serum level of specific antibody to chitinase antigen was determined by ELISA, and compared with that to microfilaria xt antigen (Mf-xt). RESULTS: Specific function protein molecule of the above-mentioned chitinase antigen has been identified as 69,000. Serum antibody against chitinase antigen was 100% positive for jirds and patients with microfilaremia, but, that against Mf-xt only 80% positive. Serum antibody against chitinase antigen was negative for all normal jirds and normal persons, but that against Mf-xt had 5% false positive in normal serum. For those with microfilaremia from non-filariasis-prevalent areas, false sero-positivity was 5% and 20% with chitinase antigen and Mf-xt, respectively. CONCLUSION: ELISA with DNA recombinant fusion protein antigen is a sensitive and specific method in serological diagnosis and surveillance for filariasis, with simple, easy and convenient manipulation. It can be used in field serologic surveillance and diagnosis for filariasis during the late phase in control of filariasis and can be spread in good prospects.

Animals↗
PubMed2001

Community perception of Malayan filariasis in the rural areas of Cherthala Taluk of Kerala State, south India.

Lymphatic filariasis, one of the major public health problems can be controlled with the active participation of the community. The human factors involved in the disease transmission are important. The knowledge on the community perception and practice is essential to develop community oriented control programmes. A descriptive study was conducted in the filariasis endemic area of Cherthala, Kerala State, India, to identify the level of people's perception on Malayan filariasis. Two methods namely, interviews and uncontrolled observation were used in the study. A total of 450 respondents (150 microfilaria carriers, 150 chronic patients and 150 normals) were interviewed. The study results showed that majority of the respondents (86.7%) were aware that the disease was caused by a parasite and 93.6% had awareness on transmission of the disease through mosquito bite. The knowledge on the preventive measures against filariasis was also high (78.2%) among the sampled respondents. The strategy for community mobilization in filariasis control programme is discussed in view of high awareness.

Animals↗
PubMed1992

[Serological epidemiologic surveillance on filariasis by ELISA].

In 1984-1990 longitudinal or sectional serological surveillance on filariasis by ELISA with Brugia malayi adult antigen was carried out in 6 villages, Yuhang County, Zhejiang Province, where malayan filariasis had been under control. During that period the microfilaraemia rate of inhabitants had been declining continuously till nil, the positive rate and mean optical density (OD) value in ELISA for positive inhabitants concurrently declined year by year, especially for children under age of 10. By the 5th year after control both the positive rate and mean OD value were close to those of healthy persons living in nonendemic areas of filariasis, no positivity was found in children. In the meantime, ELISA was used to detect serum antibodies in members of a family who were infected with bancroftian filariasis and inhabitants living around them in 1990. Positive rate of ELISA was higher in these inhabitants (8.33%) than in healthy persons (2.53%), and positive ones were detected from children under age of 10. The results suggest that the detection of antifilarial antibody by using ELISA is an effective method for the surveillance of filariasis.

Adolescent↗
PubMed2003

Comparative assessment of an Og4C3 ELISA and an ICT filariasis test: a study of Myanmar migrants in Thailand.

Detection of circulating filarial antigen has now emerged as an alternative method for the diagnosis of bancroftian filariasis. We compared two antigen detection assays, an Og4C3 ELISA and an ICT (immunochromatography) Filariasis test, for the diagnosis of Wuchereria bancrofti infections in migrant Myanmar workers in Tak province, Western Thailand. A total of 337 Myanmars participated in this study. The microfilarial rate was 3.3%. The Og4C3 ELISA could detect 19.1% of bancroftian filariasis while the ICT test detected 12.7%. Both antigen assays could detect all microfilaremics. The Og4C3 ELISA detected 14.8% of amicrofilaremics while the ICT test identified 8.1%. Those who were positive for the ICT test were also positive by the Og4C3 ELISA. Those Og4C3 positive cases, that were ICT negative (ICT-ve/Og4C3+ve) had statistically significant (p < 0.05, unpaired t-test) lower Og4C3 antigen levels (409.5 units, range 117-2,389) than those that were ICT positive (ICT+ve/Og4C3+ve) (5,252.0 units, range 130-28,062). Our results emphasize the problem of bancroftian filariasis in Myanmar migrants working in Thailand. Close monitoring and control of this disease in Myanmar migrants are of public health importance. Antigen detection systems are promising tools for the surveillance of bancroftian filariasis.

Adolescent↗
PubMed1983

Cultural factors in the epidemiology of filariasis due to Brugia malayi in an endemic community in Malaysia.

A study was carried out to identify some of the cultural factors in the epidemiology of filariasis in an endemic community in Malaysia. The viewpoint of the community, data an responses on knowledge of illness and filariasis, host related factors, health examination, vector study were analysed and discussed. The observations noted on cultural factors were: Occupational pattern: Different agricultural occupations seemed to related to transmission in terms of body exposure. Activities not related to production of crops: Play groups in late afternoon, bathing of household members near and after sunset, congregations at prayer houses very much exposed the population to mosquito bites in different degree in terms of length of time spent outside the house. Knowledge of filariasis: Filariasis was understood in terms of elephantiasis, the chronic stage of the disease. Other signs of disease-adenolymphangitis, red lines running down one or both legs and abscess were generally recognized but not often annonated with specific disease. Attitude toward disease: Filariasis was not seen as a health problem and the idea of filarial worms was still hard to believe. Knowledge on disease causation: Biological causes were generally recognized, though the idea of bacteria was not widespread.

Adolescent↗
PubMed1994

Epidemiological surveillance of filariasis after its control in Shandong Province, China.

Shandong Province used to be the highly endemic area of Wuchereria bancrofti. Culex pipiens pallens was the main mosquito vector. After about 30 years of large scale anti-filariasis control campaign, filariasis was controlled throughout the province in 1983. Since then, extensive cross-sectional and consecutive longtitudinal surveillances have been carried out. Parasitological and entomological data indicated that the microfilaremia rate of the human population, and the natural infection rate of mosquito vector kept declining, with many villages dropping to zero; no children under ten were infected. Serological surveillance showed that antifilarial antibody had fallen to the same level as that in non-endemic areas 10-15 years after control. In addition, patients with chronic manifestations were reduced in number. It is suggested that the achievement in filariasis control in Shandong Province is stable: the transmission of filariasis has been interrupted. However, there are still a few residual microfilaremia cases, which may bring about new infection under conditions favorable for transmission. Infectious sources may be introduced by population movements from a neighboring province where filariasis is still endemic at present. Moreover, new cases with chronic manifestations, especially chyluria, continually emerge. So systematic surveillance should be continued and proper control measures must be taken to eventually wipe the disease out of the province.

Adolescent↗
PubMed1996

Rapid community diagnosis of lymphatic filariasis.

We conducted a pilot study to test rapid assessment procedures for the community diagnosis of lymphatic filariasis in some rural communities in Ghana. The assessment criteria included direct key informant interviews, focus group discussions, routine reporting from health facilities, self-administered questionnaires, and a random examination of adult males for hydroceles. All the data collection methods were easy, convenient, non-invasive to use and acceptable to the community. The study provided reliable estimates of the burden of lymphatic filariasis in the community when compared with data from standard epidemiological surveys. The direct key informant interviews and focus group discussions gave a broad perspective of the burden of diseases in the community in general, and lymphatic filariasis in particular. The use of self-administered questionnaires provided data comparable with data on elephantiasis in the community from a case search. Examination of a random 30-40 adult males for hydroceles provided a good correlation with the community microfilaria prevalence, with a correlation coefficient of linear regression r = 0.79. These individual rapid assessment procedures of the burden of lymphatic filariasis, if further developed and tested could, be widely used in combination for the mapping of the distribution of lymphatic filariasis in Ghana and possibly, the African sub-region.

Adult↗
PubMedDate not supplied

Community diagnosis of Bancroftian filariasis.

The objective of this study was to find the best tests for efficiently estimating the true prevalence of Bancroftian filariasis in endemic areas. The study population comprised 427 people over 10 years of age in an endemic village in Egypt. Four tests were evaluated; a standardized clinical examination, night blood examinations for microfilariae (50 microL thick films and 1 mL membrane filtration), and a test for circulating filarial antigen. 191 subjects (44.75%) had at least one positive test and were considered to have filariasis. The sensitivities of clinical examination, thick films, membrane filtration and antigen testing for filariasis were 16%, 50%, 64%, and 88%, respectively. Relative to membrane filtration of night blood, the filarial antigen test had a sensitivity of 97.5%, a positive predictive power of 71%, and a negative predictive power of 99%. None of the blood tests was a sensitive indicator of clinical filariasis; 69% of clinical cases were negative in all 3 blood tests and would have been missed if clinical examinations had not been done. Therefore, we recommend a combination of clinical examination and the filarial antigen test (with optional examination for microfilariae of those with positive antigen tests) for community diagnosis of Bancroftian filariasis in endemic areas.

Adolescent↗
PubMedDate not supplied

Mapping and estimating the population at risk from lymphatic filariasis in Africa.

Lymphatic filariasis remains a major public health problem in Africa and is 1 of the World Health Organization's 6 diseases targeted for global eradication. However, no detailed maps of the geographical distribution of this disease exist, making it difficult to target control activities and quantify the population at risk. We hypothesized that the distribution lymphatic filariasis is governed by climate. The climate at sites in Africa where surveys for lymphatic filariasis had taken place was characterized using computerized climate surfaces. Logistic regression analysis of the climate variables predicted with 76% accuracy whether sites had microfilaraemic patients or not. We used the logistic equation in a geographical information system to map risk of lymphatic filariasis infection across Africa, which compared favourably with expert opinion. Further validation with a quasi-independent data set showed that the model predicted correctly 88% of infected sites. A similar procedure was used to map risk of microfilaraemia in Egypt, where the dominant vector species differs from those in sub-Saharan Africa. By overlaying risk maps on a 1990 population grid, and adjusting for recent population increases, we estimate that around 420 million people will be exposed to this infection in Africa in the year 2000. This approach could be used to produce a sampling frame, based on estimated risk of microfilaraemia, for conducting filariasis surveys in countries that lack accurate distribution maps and thus save on costs.

Africa↗
PubMedDate not supplied

Lymphatic filariasis in Lower Shire, southern Malawi.

Surveys for lymphatic filariasis were carried out for the first time in Lower Shire (Nsanje and Chikawawa Districts) of southern Malawi, in April-June 2000. There were 3 phases. In phase I, questionnaire surveys in 48 randomly selected villages indicated that chronic manifestations of lymphatic filariasis ('swollen scrotum' and 'swollen legs') were common and widespread in the area. In phase II, volunteers from 10 of the villages reporting frequent manifestations of filariasis in phase I were examined with the ICT whole-blood test for Wuchereria bancrofti-specific circulating filarial antigen (CFA). The observed prevalence of CFA positivity was very high (range, 38.8-79.1% for the villages). In phase III, a more detailed parasitological, CFA and clinical investigation was carried out in 2 of the high CFA prevalence villages identified in phase II (1 in each district). Overall, 18.1% and 22.2% were positive for microfilariae, and 62.3% and 64.6% were positive for CFA in the 2 villages. Among those aged > or = 15 years, 3.7% and 1.3% had leg elephantiasis, and 17.9% and 13.0% (of males only) had hydrocoele. In both phase II and III, CFA prevalences were unexpectedly high, especially in children. This was probably related to a recent increase in transmission of filariasis as a result of extensive flooding in the area prior to the study. The study indicated that lymphatic filariasis is highly endemic in the Lower Shire area of Malawi, and calls for action towards its control.

Adolescent↗
PubMedDate not supplied

Abnormalities of the leg lymphatics are not specific for bancroftian filariasis.

Studies using conventional angiography or non-invasive scintigraphy have revealed widespread abnormalities in the lymphatics of the legs of patients with bancroftian filariasis, regardless of whether clinical lymphoedema is present. To determine if the observed changes were specific for filarial infections, we imaged the lymphatics of both legs in native residents of an area in Brazil where filariasis is not endemic. Study participants were matched by age, socioeconomic status and physical activities to patients with filariasis in Recife, evaluated in parallel. Based on textbook criteria, only one of 15 study participants had a completely normal lymphoscintigram. Modest to severe pathology of the leg lymphatics was observed in the remaining 14 residents of the non-endemic area and in 49 of 50 patients with bancroftian filariasis. These results indicated that factors other than filarial worms are a common cause of subclinical pathology of the leg lymphatics in north-eastern Brazil, and that the latter is not specific for bancroftian filariasis.

Brazil↗