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 235 records · Page 13Linked to original sources
PubMed1983

An epidemiological study of filariasis in Sorsogon province, Republic of the Philippines, with notes on experimental mosquito infection.

An epidemiological survey was conducted on Bancroftian filariasis in Sorsogon province, the Philippines, with special regard to low density microfilaremia (LDF). Filtration technique using nuclepore membrane examining 1 ml blood revealed 31% positive rate for microfilaria out of 262 volunteers. Out of 82 positives 21 (25.6%) had LDF (less than 10 in 1 ml blood). No conspicuous grouping of LDF was noted in younger age groups or sexes. In three out of 12 clinical filariasis, microfilaria was detected but none of them were LDF. Among 22 cases treated with diethylcarbamazine, nine subsequently had LDF suggesting necessity of improvement of drug administration regimen to avoid incomplete treatment. A series of feeding experiments using two mosquito species, Aedes poicilius and Culex quinquefasciatus, on volunteers showed that both species could act as vectors in the region. No larva was detected in either species fed on LDF carriers. It was concluded that there is little possibility that LDF plays an important role in the transmission of Bancroftian filariasis in the region.

Adolescent↗
PubMedDate not supplied

[Prevalence of human filariasis with microfilaremia in Gabon].

Direct examinations of blood and serologic tests were used to assess the intensity of the filarial endemicity in Gabon. Both methods revealed that the prevalence of filariasis with microfilaremia (Loa loa and Dipetalonema perstans) is presently very elevated. The areas that are more involved are the forest regions as well as the highest ones (ogoue, Lolo, Ngounie). Women appeared to be suffering from loasis to a lesser extent than men. On the other hand, the prevalence was identical for Dipetalonema perstans. For the gabonese population one can approximately say that 3 out of 5 adults patients have filariasis, two being D. perstans and one L. loa. Consequently these affections represent a major public health problem. Finally one must note that no case of lymphatic filariasis has been identified.

Adult↗
PubMed1995

Differential recognition of microfilarial chitinase, a transmission-blocking vaccine candidate antigen, by sera from patients with Brugian and Bancroftian filariasis.

We examined the reactivity of human sera with recombinant microfilarial chitinase and with the antigenic determinant on the native parasite molecule identified by monoclonal antibody (MAb) MF1. In Brugian filariasis, the MF1 epitope is preferentially recognized by residents of endemic areas who remain amicrofilaremic and asymptomatic despite lifelong exposure to filarial worms. Reactivity with filarial chitinase and its MF1 epitope inversely correlates with microfilaremia levels in Bancroftian filariasis and is associated with a prolonged amicrofilaremic state following a single course of treatment with diethylcarbamazine. Chitinase does not appear to be a target of human antibodies that promote the adherence of cells to microfilariae, even though MAb MF1 itself promotes antibody-dependent, cell-mediated cytotoxic (ADCC) reactions that kill microfilariae in vitro. Such ADCC reactions are most often mediated by sera from amicrofilaremic patients with chronic elephantiasis that contain low or undetectable levels of IgG antibodies to chitinase. In contrast, antibodies to the MF1 epitope on this microfilarial stage-specific antigen are mostly present in amicrofilaremic donors without clinical lymphatic disease. These observations indicate that antibodies to the MF1 epitope of microfilarial chitinase reflect some degree of immune resistance to microfilaremia in a subgroup of patients with asymptomatic lymphatic filariasis. The amicrofilaremic state of individuals with chronic lymphatic disease appears to be mediated by reactivity to a different parasite antigen(s).

Adult↗
PubMed1995

Facilitation in Anopheles and spontaneous disappearance of filariasis: has the concept been verified with sufficient evidence?

The validity of recently much argued phenomenon of facilitation in the transmission of filariasis was considered by examining previously published papers. It was concluded that there was no clear evidence to support the existence of facilitation and facilitation-based unstable equilibrium in relation to microfilaria prevalence and density in human population below which filariasis would spontaneously disappear, even when the vector was Anopheles mosquitoes. Instead, the existence of a critical level of man/mosquito contacts for the disappearance of filariasis was suggested.

Animals↗
PubMed1994

Prevalence of Bancroftian filariasis in Burdwan District, west Bengal: a comparative study between colliery and non-colliery areas.

The present study reports results of a survey of bancroftian filariasis in Burdwan district West Bengal. 85,974 persons were examined of which 46,221 were inhabitants of the colliery areas of the district and rest 39,753 were from non-Colliery areas, including urban and rural areas of the district. The clinicopositivity, endemicity, microfilaria(mf)-positivity, mf-clinicopositivity, and mf-density were determined. It was found that all these epidemiological and parasitological parameters were significantly higher in the colliery area as compared to non-colliery area. The high vector density in the colliery area may account for such significantly higher prevalence of filariasis in this area. From a differential count of neutrophils, eosinophils and lymphocytes in the mf-positive cases, it was revealed that neutrophil percentage was significantly (P < 0.01) decreased while eosinophils and Lymphocytes increased. The decrease of neutrophils was correlated ((Correlation co-efficient, r = -0.78) with the increase of lymphocytes, indicating an imbalance in the immune-system of the infected persons. The geographical and geological factors resulting in high vector density are considered responsible for the significantly higher rate of bancroftian filariasis in the Colliery area.

Adolescent↗
PubMed1993

Current status of filariasis in Indonesia.

Filariasis in Indonesia is widely distributed. Three species consisting of 5 ecologically different types have been identified infecting man. Compared to older data, infection rates are much lower, partly due to environmental change and partly as a result of control programs. Various dosage treatments have given good results. The higher dosage treatment gave severe reactions especially in brugian filariasis. Pockets of high endemicity can still be found in remote rural areas. Therefore a weekly low dosage treatment of 40 weeks through the Primary Health Care approach has been adopted. Filariasis research in Indonesia at present is concentrating on the use of biotechnological tools, especially for diagnostic and vector identification purposes, and to understand better the pathophysiology. Treatment trials with new drugs such as Ivermectin and DEC are being conducted both in man and experimental animals.

Animals↗
PubMed1993

Prevalence of filariasis in rural areas of Shahjahanpur district (Uttar Pradesh).

Night blood survey was carried out during May, 1990 to December, 1991 in 18 villages of 5 Primary Health Centres of district Shahjahanpur (UP), to find out the prevalence of filariasis in the area. Out of 2141 individuals surveyed randomly, 217 were found positive for microfilariae of Wuchereria bancrofti. The microfilaria rate, filarial disease rate and filarial endemicity rates were 10.1, 11.4 and 18.8 per cent respectively. An entomological survey revealed Culex quinquefasciatus as the vector. The average man hour density was 25.8. It is clear from the results that filariasis is more endemic in rural areas than urban area of Shahjahanpur as observed by local filariasis control unit.

Animals↗
PubMed1995

Identification of endemic foci of filariasis by examination of mosquitoes for microfilariae.

Studies were conducted in the Nile Delta of Egypt to determine the feasibility of detecting Wuchereria bancrofti microfilariae (Mf) in mosquitoes as a primary surveillance method for the identification of filariasis-endemic villages. Initial experimental studies evaluated the ingestion, survival, and migration rates of W. bancrofti Mf in Culex pipiens and Culex antennatus after mosquitoes were fed on infected volunteers. In 2 villages, 1,684 bloodfed mosquitoes were dissected during the night immediately after collections inside houses. In the village of Kafr Tahoria, Mf were found in 27 of 519 Cx. pipiens and in one of 8 Anopheles pharoensis. In Tahoria, Mf were detected in 7 of 799 Cx. pipiens and in one of 302 Cx. antennatus. Identifying filariasis-endemic villages based on the detection of Mf in mosquitoes may be a useful strategy for epidemiologic studies or for filariasis control programs.

Animals↗
PubMed1997

Prevalence of intestinal parasites in filariasis endemic areas in Egypt.

Stool and blood specimens were collected from 230 individuals of both sexes at 2 villages (Qualyubia Governorate) where filariasis is endemic. The overall prevalence of parasites was 81%, while it was higher (92.4%) among filariasis patients than non infected individuals (50%). On the other hand, the level of microfilaria (MF) in the blood apparently showed an influence on the prevalence of parasitic infection in the infected individuals. However, in all groups, E. histolytica was the commonest protozoal parasite followed by G. lamblia. As regard helminthic infections, S. mansoni was the commonest followed by E. vermicularis. These data suggest that filariasis as an endemic disease may suppress the immune response of the host and under such circumstances, the susceptibility for other infections become higher.

Adolescent↗
PubMed1987

Immunodiagnosis of bancroftian filariasis.

The development of immunodiagnostic tests (IDTs) for bancroftian filariasis must be aimed at defined objectives, such as the determination of exposure rates, the detection of microfilaraemia and the diagnosis of clinical filariasis. Assays for both antibody and antigen detection are necessary. Antigen determination may be more appropriate in the detection of microfilaraemia, but for clinical filariasis, antibody determination may prove more useful. The microfilarial surface antigens are very good candidates for this purpose. Determination of antibody to larval antigens may be the best way of establishing exposure rates for epidemiological purposes. An important prerequisite for IDT development is the characterization of antigens at epitope level. Sharing of antigen epitopes with host antigens could be a major limitation in IDT development. An understanding of the parasitological and immunological background of the endemic locality is also necessary. It is recommended that all IDTs are evaluated in follow-up case studies.

Animals↗
PubMed1993

Quinone analogues: a drug of choice for the control of filariasis.

Human filariasis is caused by Wuchereria bancrofti, Brugia malayi and B. timori. Of the several recommended model filarial parasites by WHO, Setaria digitata a bovine one has characteristics such as cyanide insensitivity, lack of detectable cytochromes, presence of two quinones Q8 and Q6. Of the two quinones Q8 seems to have a predominant role in energy production. In vitro inhibitory studies using quinone analogues, coenzyme Q0 and menadione have shown that these compounds paralyse the worms in very low concentrations compared to diethyl carbamazine, the drug of choice for filariasis. The mitochondrial energy production associated with electron transfer is intercepted by quinone analogues. Hence for the treatment of filariasis, this study paves a chemotherapeutic target for the design of drugs which can control the parasites by interacting at the subcellular level by energy depletion.

Animals↗
PubMed2002

Protective immunity in human lymphatic filariasis: problems and prospects.

Human filariasis caused by lymphatic dwelling nematodes, affecting 120 million persons worldwide, is a major public health problem. Efforts towards development of vaccines for such large tissue-dwelling nematodes depends significantly on identification and demonstration of protective immunity in the exposed population. Immunological studies conducted in human filariasis so far are essentially attempts to establish a correlation of the immune response phenotypes with presence or absence of filarial infections/disease in the host, and the cause-effect relationship between the observed immune responses in the host and protective immunity continues to be conjectural. This short review attempts to clarify the functional definition of protective immunity, problems associated with identification of putatively immune subjects in endemic areas, role of antibodies reactive to surface of microfilariae and larvae stages of filarial parasites and importance of undertaking immunological investigations on a longitudinal basis in different cohorts of subjects presenting with one or the features of infection and/or disease for more accurate delineation of protective immunity in human filariasis.

Animals↗
PubMed1993

Social and economic factors and the control of lymphatic filariasis: a review.

Formal control programmes do not exist for lymphatic filariasis in much of the endemic world. The literature on the social, economic and clinical impacts of the disease is so sparse as to provide virtually no guidance on whether the disease should be accorded more importance in national or local public health programmes. This type of research is a major priority. Putting together what little is known about the socioeconomic determinants of filariasis with the fairly extensive experience in control leads to a finding that control programmes must be undertaken at the community level to be effective. Diethylcarbamazine (DEC) is a readily available and apparently safe drug that can be deployed successfully for community control. While research currently is exploring the potential for individuals to protect themselves with DEC or a newer drug, ivermectin, community-wide control is unlikely to be achieved in that way. Under some special circumstances, controlling the mosquito vectors may be sufficient to control the disease, and in other cases, it may complement chemotherapy, but in general, it cannot be relied upon as a primary measure. DEC may be used in a variety of regimens which vary in their cost, duration, incidence of side effects and degree of community participation. Some, including DEC-medicated salt, are particularly attractive alternatives for many filariasis-endemic areas. The search for less expensive, yet effective, control options must continue, and this requires research not only into the costs of the various options, but also into the determinants of community acceptance, compliance and participation.

Animals↗
PubMed1994

Estimation of permissible levels of transmission of bancroftian filariasis based on some entomological and parasitological results of a 5-year vector control programme.

The impact of a 5-year vector control programme on transmission of bancroftian filariasis and microfilaraemia levels in the human population was examined in Pondicherry, South India. The programme reduced and maintained the transmission of Wuchereria bancrofti at appreciably low levels in many localities of Pondicherry town, but its impact on overall microfilaraemia prevalence was only limited. However, prevalence of infection was reduced drastically in children born after establishment of the programme and only 18% of the number expected without vector control were found infected. No new infections were found in localities with less transmission intensity. It is proposed that a Transmission Intensity Index of 0.50 and Annual Transmission Potential of less than the 96-105 range are permissible levels of transmission, and below these levels no new infections may occur. The required duration of vector control to eliminate Culex-borne filariasis foci is estimated to be 11-12 years, slightly longer than that required to eradicate anopheline-borne filariasis.

Animals↗
PubMedDate not supplied

Efficient assessment of filariasis endemicity by screening for filarial antigenaemia in a sentinel population.

We have previously reported that a monoclonal antibody-based antigen detection assay (AD12) is sensitive and specific for Bancroftian filariasis in Egypt. The purpose of the present study was to demonstrate the use of this assay in a sentinel population as a means of efficiently screening for filariasis endemicity. Antigen testing was performed with finger-prick blood collected during the day from 743 schoolchildren (ages 11-16 years). The school draws students from 5 villages in Qalubia Governorate, 35 km north-east of Cairo, Egypt. The prevalence of filarial antigenaemia in the school was 17.2%. Antigenaemia rates in children from the 5 villages were 29, 20, 18, 17, and 10% (non-uniformity significant by chi 2 analysis, P = 0.02). These data agree with Ministry of Health rankings of relative endemicity for these villages based on prior night blood surveys. The village with the highest antigen prevalence in children was surveyed one year before the present study. Prevalence rates of antigenaemia and microfilaraemia at that time for a different sample of children aged 11-16 years were 33% and 22%, respectively. We conclude that antigen detection in schoolchildren of this age group is an efficient means of assessing filariasis endemicity in Egypt.

Adolescent↗
PubMed1986

Genital filariasis in Minnesota.

Genitourinary filariasis is a well-known entity in most tropical areas. However, filariasis cannot be eliminated from the differential diagnosis of testicular, epididymal, or spermatic cord masses in nontropical climes. We report a case of filariasis of the spermatic cord that manifested as an unexplained scrotal mass in a patient in Rochester, Minnesota.

Adult↗
PubMed1990

Elevated levels of soluble CD8 molecule in patients with lymphatic filariasis.

The serum levels of soluble forms of suppressor/cytotoxic cells (sCD8) and interleukin-2 receptor (sCD25) were analyzed in 67 patients with lymphatic filariasis and 28 normal controls. Our results show that patients with lymphatic filariasis have significantly higher levels of sCD8 (p less than 0.05) than the control groups, whereas no such difference was observed for sCD25. Within the patient group, however, those in the chronic lymphatic obstruction (CP) had significantly higher levels of both sCD8 (491 +/- 52 U/ml, p less than 0.001) and sCD25 (293 +/- 36 U/ml; p less than 0.02) than those with asymptomatic microfilaremia (sCD8 344 +/- 32 U/ml; sCD25 190 +/- 10 U/ml, respectively). No statistically significant correlation was observed between the serological levels of sCD8 and the percentage of CD8 on peripheral blood T lymphocytes in any of the patient groups. Evaluation of the activation state of B lymphocyte did not reveal any difference in the cellular expression of B7, or serum levels of soluble CD23 in any of the groups studied. Thus the selective increase of sCD8 in patients with filariasis suggests a possible pathogenic role of the cells involved in the release of this molecule.

Antibodies, Monoclonal↗
PubMed1994

Molecular cloning of Brugia malayi antigens for diagnosis of lymphatic filariasis.

Immunological crossreactivity among nematodes has hampered development of specific serodiagnostic assays for lymphatic filariasis. In the present study, we report the molecular cloning and characterization of two filaria-specific recombinant clones (BmM5 and BmM14) with immunodiagnostic potential. BmM5 is a 505-bp cDNA which codes for a protein of 130 residues that ends with an endoplasmic reticulum targeting sequence. BmM14 is closely related to a recently reported clone (SXP-1), and it has 62% homology (deduced amino acid sequence) with a previously described Onchocerca volvulus clone, lambda RAL-2. Glutathione S-transferase fusion proteins of BmM5 and BmM14 were tested in various ELISA formats. The best results were obtained by measuring IgG4 antibodies to the fusion proteins. ELISA studies showed that approximately 90% of 111 sera from Indian and Egyptian patients with brugian and bancroftian filariasis were reactive with both antigens. Nonendemic sera as well as sera from patients with schistosomiasis or intestinal helminths were uniformly nonreactive. Assays based on BmM5 and BmM14 may be useful for large scale screening as an alternative to microfilaria or filarial antigen detection as a means of obtaining a rough index of filariasis endemicity in previously unstudied areas.

Amino Acid Sequence↗