Filariasis Infection Research Articles

Bancroftian filariasis: circulating B‐1 cells decreased in microfilaria carriers and correlate with immunoglobulin M levels

B-1 cells play an important role in the outcome of infection in schistosomiasis, pneumonia and experimental filariasis. However, no information exists regarding status of B-1 cells in clinical manifestations of human filariasis. We investigated the levels of B-1 cells from the total B cells by flow cytometry. Significantly low levels of B-1 cells and IgM antibodies were detected against a wide variety of autoantigens in microfilariae carriers as compared to endemic controls and patients with chronic pathology. A positive correlation was found between IgM antibodies to actin and ss-DNA. Absorption of plasma with soluble actin, myosin and lipopolysaccharides (LPS) resulted in significant removal of antifilarial antibodies. Affinity-purified anti-ss-DNA antibodies were found to be reactive to filarial antigens and various autoantigens. Further, a positive correlation was found between polyreactive antibodies and B-1 cells in filarial-infected human subjects. After antifilarial treatment, levels of IgM antibodies to ss-DNA, actin, LPS and filarial antigen increased significantly indicating a role of polyreactive naturally occurring antibodies in filarial infection. Our findings add to the existing evidence that the B-cell defect in BALB.Xid mice account for susceptibility to murine filarial infection and indicate an important role for these antibodies in providing host protection against filarial infection.

Real-time PCR detection of the HhaI tandem DNA repeat in pre- and post-patent Brugia malayi Infections: a study in Indonesian transmigrants.

BackgroundLymphatic filariasis caused by Wuchereria bancrofti or Brugia spp. is a public health problem in developing countries. To monitor bancroftian filariasis infections, Circulating Filarial Antigen (CFA) test is commonly used, but for brugian infections only microfilariae (Mf) microscopy and indirect IgG4 antibody analyses are available. Improved diagnostics for detecting latent infections are required.MethodsAn optimized real-time PCR targeting the brugian HhaI repeat was validated with plasma from microfilariae negative Mongolian gerbils (jirds) infected with B. malayi. Plasma samples from microfilaremic patients infected with B. malayi or W. bancrofti were used as positive and negative controls, respectively. PCR results of plasma samples from a transmigrant population in a B. malayi endemic area were compared to those of life-long residents in the same endemic area; and to IgG4 serology results from the same population. To discriminate between active infections and larval exposure a threshold was determined by correlation and Receiver-Operating Characteristics (ROC) curve analyses.ResultsThe PCR detected HhaI in pre-patent (56 dpi) B. malayi infected jirds and B. malayi Mf-positive patients from Central Sulawesi, Indonesia. HhaI was also detected in 9/9 elephantiasis patients. In South Sulawesi 87.4% of the transmigrants and life-long residents (94% Mf-negative) were HhaI PCR positive. Based on ROC-curve analysis a threshold for active infections was set to >53 HhaI copies/μl (AUC: 0.854).ConclusionsThe results demonstrate that the HhaI PCR detects brugian infections with greater sensitivity than the IgG4 test, most notably in Mf-negative patients (i.e. pre-patent or latent infections).

Association of IL-10 & IL-10RA Polymorphisms with Lymphatic Filariasis in South Indian Population

Aim: The filariasis infection is initiated by mosquito derived third stage larva (L3), which establishes itself in different immunocompetent niches by adopting different evasion and immunomodulatory mechanisms. Immunological and clinical outcomes can vary considerably at the individual and population levels during lymphatic filariasis infection. The protein product coded by the interleukin-10 ( IL-10 ) gene has broad immunomodulatory function in filarial load and patency of the disease. The potential influence of altered IL-10 expression encoded by IL-10 promoter single nucleotide

Filariasis Presenting as Massive Diffuse Cervical Swelling in Child

Filariasis infection is common in India and causes a wide spectrum of clinical manifestations, namely, asymptomatic filariaemia, recurrent lymphadenitis, chronic lymphadenitis with swelling of the dependent limb, scrotal swelling, and tropical pulmonary eosinophilia. Waucheria bancrofti and Brugia malayi are the common species in India. Waucheria bancrofti is responsible for 90% of the cases. An unusual presentation of common disease is being communicated. An 8-year-old male child presented with a history of cervical swelling along with mild fever for the last 1 month. Examination revealed a large tender cervical swelling measuring 10 × 8 cm on the right side (Figure 1). The child was otherwise normal and did not show enlargement of any other lymph node. Imaging studies suggested the possibility of neoplastic growth (Non-Hodgkin lymphoma/sarcoma). No fluid collections were seen. Ultrasound-guided fine-needle aspiration cytology (FNAC) was performed from different areas of the mass. Smears were stained with papanicolaou's stain (PAP) stain. All of the smears showed numerous sheated microfilariae admixed with inflammatory cells (morphologically consistent with W. bancrofti) (Figure 2). No granulomas necrosis, fungal organisms, atypical or malignant cells were seen. The hematological investigations showed 10% eosinophils on differential leukocyte count. Peripheral blood smear examination was negative for microfilariae. Filarial antigen test was also done, which was negative. The child was given diethyl carbamazine for 1 month. The child showed improvement within 1 week and the swelling subsided completely within 1 month. Figure 1. Child with massive cervical swelling. Figure 2. H&E stained smears showing many microfilariae (20×10). Filariasis is endemic in India and a majority of the children are asymptomatic. Few may develop hydrocele, acute disease in the form of either acute adenolymphangitis or dermal adenolymphangitis. In our case, the child had massive cervical swelling and mild fever and was diagnosed accurately by FNAC. Common methods of diagnosis of filariasis are a demonstration of microfilariae in stained or unstained blood films, circulating filarial antigen detection, and a demonstration of organism in histopathological sections. Fluid cytology or FNAC are rarely applied for routine diagnosis of clinically suspected filariasis, however, various studies have shown the usefulness of FNAC in diagnosing filarial infection at various sites. Mitra and others1 studied 250 cases of superficial swellings at various sites and detected microfilariae in 24 cases. Varghese and others2 detected microfilariae in six cases by FNAC and showed that careful screening of FNAC smears might be helpful in the detection of microfilarie. In their study, cytology played a significant role in early detection of the disease and institution of specific therapy as in our case. Therefore, FNAC is a rapid and reliable diagnostic test for detection of filarial infection.

Correction: Sequential Modelling of the Effects of Mass Drug Treatments on Anopheline-Mediated Lymphatic Filariasis Infection in Papua New Guinea

Correction: Sequential Modelling of the Effects of Mass Drug Treatments on Anopheline-Mediated Lymphatic Filariasis Infection in Papua New Guinea

COMPARATIVE REPELLENCY DURATION OF CITRONELLA OIL LOTION (Cymbopogon nardus L.) BETWEEN Culex sp. WITH Aedes sp. AS LYMPHATIC FILARIASIS VECTOR

Lymphatic filariasis is a mosquito borne disease, transmitted by mosquitoes such as Culex , Anopheles , Aedes , Mansonia . Filariasis infection resulting in disability. The important method to avoid being bitten from mosquitoes is by using a repellent. The purpose of this study were to compare repellency duration of citronella oil lotion against Culex sp. to Aedes sp. and to compare its repellency duration to N,N-diethyl-m-toluamide (DEET). Laboratory experimental design was conducted at each of five men as subjects using five randomly treatments: 20%, 40% citronella oil lotion (COL), lotion base (negative control), 12.5% DEET lotion with one-day time lag. Repellency duration, since the forearm was inserted into the cage until first mosquito land, was assessed using female Culex sp. and Aedes sp, according to modification of Fradin and Day method. Repellency duration was analyzed using one-way ANOVA, Tukey HSD followed by paired t-test level of significance with a=0.05 level of significance at p<0.05. There were highly significant differences (p<0.01) between average repellency duration (minute) of 20%, 40%, 80% COL against Culex sp. and 40%, 80% against Aedes sp . compared to 12.5% DEET. It was concluded that citronella oil lotion was more effective to Culex sp. than that of Aedes sp. Nevertheless the potency of citronella oil lotion was weaker than 12.5% DEET. Key word : lotion citronelle oil, Culex sp., Aedes sp., Filariasis

Impact of Six Rounds of Mass Drug Administration on Brugian Filariasis and Soil-Transmitted Helminth Infections in Eastern Indonesia

BackgroundThe lymphatic filarial parasite Brugia timori occurs only in eastern Indonesia where it causes high morbidity. The absence of an animal reservoir, the inefficient transmission by Anopheles mosquitoes and the high sensitivity to DEC/albendazole treatment make this species a prime candidate for elimination by mass drug administration (MDA).Methodology/Principal FindingsWe evaluated the effect of MDA using DEC and albendazole on B. timori and soil transmitted helminths (STH) in a cross-sectional study of a sentinel village on Alor Island annually over a period of 10 years. Pre-MDA the microfilaria (MF) prevalence was 26% and 80% of the residents had filaria-specific IgG4 antibodies. In 2010, 34 months after the 6th round of MDA, MF and antibody rates were only 0.17% and 6.4%, respectively. The MDA campaign had also a beneficial effect on STH. Baseline prevalence rates for Ascaris, hookworm and Trichuris were 34%, 28%, and 11%, respectively; these rates were reduced to 27%, 4%, and 2% one year after the 5th round of MDA. Unfortunately, STH rates rebounded 34 months after cessation of MDA and approached pre-MDA rates. However, the intensity of STH infection in 2009 was still reduced, and no heavy infections were detected.Conclusions/SignificanceMDA with DEC/albendazole has had a major impact on B. timori MF and IgG4 antibody rates, providing a proof of principle that elimination is feasible. We also documented the value of annual DEC/albendazole as a mass de-worming intervention and the importance of continuing some form of STH control after cessation of MDA for filariasis.

Comparative Study of the Sensilla on Antenna and Maxillary Palps of Five Culicine Mosquitoes in Sohag Governorate

Mosquitoes are unquestionably the most medically important arthropod vectors of disease. The maintenance and transmission of the pathogens that cause malaria, lymphatic filariasis, and numerous viral infections are absolutely dependent on the availability of competent mosquito vectors. Although the medical community has known for over a century the role played by mosquitoes in the transmission of malaria and lymphatic filariasis, these diseases continue to have a devastating influence on less privileged populations throughout the tropical and subtropical regions of the world. The present study was done to identify the different culicine mosquitoes in four different districts in Sohag Governorate and to describe and compare the various types of sensilla located on their antenna and maxillary palps using scanning electron microscopy.

Sequential Modelling of the Effects of Mass Drug Treatments on Anopheline-Mediated Lymphatic Filariasis Infection in Papua New Guinea

BackgroundLymphatic filariasis (LF) has been targeted by the WHO for global eradication leading to the implementation of large scale intervention programs based on annual mass drug administrations (MDA) worldwide. Recent work has indicated that locality-specific bio-ecological complexities affecting parasite transmission may complicate the prediction of LF extinction endpoints, casting uncertainty on the achievement of this initiative. One source of difficulty is the limited quantity and quality of data used to parameterize models of parasite transmission, implying the important need to update initially-derived parameter values. Sequential analysis of longitudinal data following annual MDAs will also be important to gaining new understanding of the persistence dynamics of LF. Here, we apply a Bayesian statistical-dynamical modelling framework that enables assimilation of information in human infection data recorded from communities in Papua New Guinea that underwent annual MDAs, into our previously developed model of parasite transmission, in order to examine these questions in LF ecology and control.ResultsBiological parameters underlying transmission obtained by fitting the model to longitudinal data remained stable throughout the study period. This enabled us to reliably reconstruct the observed baseline data in each community. Endpoint estimates also showed little variation. However, the updating procedure showed a shift towards higher and less variable values for worm kill but not for any other drug-related parameters. An intriguing finding is that the stability in key biological parameters could be disrupted by a significant reduction in the vector biting rate prevailing in a locality.ConclusionsTemporal invariance of biological parameters in the face of intervention perturbations indicates a robust adaptation of LF transmission to local ecological conditions. The results imply that understanding the mechanisms that underlie locally adapted transmission dynamics will be integral to identifying points of system fragility, and thus countermeasures to reliably facilitate LF extinction both locally and globally.

Epidemiological assessment of neglected diseases in children: lymphatic filariasis and soil-transmitted helminthiasis

ObjectiveTo report the prevalence of lymphatic filariasis and intestinal parasitic infections in school-aged children living in a filariasis endemic area and discuss about the therapeutic regimen adopted in Brazil for the large-scale treatment of filariasis. MethodsA cross-sectional study including 508 students aged 5-18 years old, enrolled in public schools within the city of Olinda, Pernambuco. The presence of intestinal parasites was analyzed using the Hoffman, Pons and Janer method on 3 stool samples. The diagnosis of filarial infection was performed using the rapid immunochromatographic technique (ICT) for the antigen, and the polycarbonate membrane filtration for the presence of microfilariae. Descriptive statistics of the data was performed using EpiInfo version 7. ResultsThe prevalence of filariasis was 13.8% by ICT and 1.2% by microfilaraemia, while intestinal parasites were detected in 64.2% of cases. Concurrent diagnosis of filariasis and intestinal parasites was 9.4%, while 31.5% of students were parasite-free. Among individuals with intestinal parasites, 55% had one parasite and 45% had more than one parasite. Geohelminths occurred in 72.5% of the parasited individuals. In the group with filarial infection the prevalence of soil-transmitted helminthiasis was 54.5%. ConclusionsThe simultaneous diagnosis of filariasis and intestinal parasites as well as the high frequency of geohelminths justify the need to reevaluate the treatment strategy used in the Brazilian filariasis large-scale treatment program.

Survey of Bancroftian filariasis infection in humans and Culex mosquitoes in the western Brazilian Amazon region: implications for transmission and control

The aim of this work was to identify possible lymphatic filariasis foci in the western Brazilian Amazonian that could be established from the reports of Rachou in the 1950s. The study was conducted in three cities of the western Brazilian Amazon region - Porto Velho and Guajará-Mirim (State of Rondônia) and Humaitá (State of Amazonas). For human infection evaluation thick blood smear stained with Giemsa was used to analyze samples collected from 10pm to 1am. Polymerase chain reaction (PCR) was used to examine mosquito vectors for the presence of Wuchereria bancrofti DNA. Humans were randomly sampled from night schools students and from inhabitants in neighborhoods lacking sanitation. Mosquitoes were collected from residences only. A total 2,709 night students enrolled in the Program for Education of Young Adults (EJA), and 935 people registered in the residences near the schools were examined, being 641 from Porto Velho, 214 from Guajará-Mirim and 80 from Humaitá. No individual examined was positive for the presence of microfilariae in the blood stream. A total of 7,860 female Culex quinquefasciatus specimens examined were negative by PCR. This survey including human and mosquito examinations indicates that the western Amazon region of Brazil is not a focus of Bancroftian filariasis infection or transmission. Therefore, there is no need to be included in the Brazilian lymphatic filariasis control program.

Surveillance of lymphatic filariasis after stopping ten years of mass drug administration in rural communities in south India

While various studies provided insight into the impact of mass drug administration (MDA), information on the dynamics of the post-MDA threshold level lymphatic filariasis (LF) infection facilitates understanding its disappearance pattern and determining the duration of post-MDA monitoring and evaluation. The changes in microfilaraemia (Mf) prevalence and vector infection rates were monitored for four (2005-2008) and six years (2005-2010) respectively after stopping ten rounds of annual mass diethylcarbamazine (DEC) administration in a group of five villages located in South India. Four years after stopping MDA, circulating filarial antigenaemia (Ag) status among children and adults was also assessed in two villages. Overall Mf prevalence (n = 700) and vector infection rates (n=803-3520) showed a declining trend. Two villages maintained zero Mf status in each of the four years, vector infection rate was zero from the third year onwards and Ag prevalence in adults was 0.4% (n = 226). In two other villages despite persistence of Mf and vector infection there was zero vector infectivity rate during the third to sixth year and Ag prevalence among children (n = 50) was nil. In the fifth village Mf prevailed at <1.0% and Ag prevalence among 1-7 year old children was 4.6% (n = 44) and vector infectivity rate during the sixth year was 0.1% (n = 852). The incidence of sporadic new infections is evident in highly endemic communities such as the fifth village. However, there is uncertainty on the potential of the Ag positive children to reestablish infection. Six years of post-MDA monitoring and evaluation appears to be adequate to discern the status of transmission interruption and appropriate decision making.

Impact of insecticide treated mosquito nets and low dose monthly diethylcarbamazine on lymphatic filariasis infection between 1999 and 2004 in two endemic communities of north-eastern Tanzania.

Lymphatic filariasis (LF) is among the poverty related neglected tropical diseases earmarked for elimination using mass drug administration (MDA) strategy. Additional use of insecticide treated mosquito nets (ITNs) might enhance elimination of LF infection. Between August 1998 and July 1999, all individuals aged 8 months from Magoda and Mpapayu villages in north-eastern Tanzania, were administered with monthly low dose diethylcarbamazine (DEC) at a dosage of 50mg in children aged < 15 years and 100mg in adults aged ≥ 15 years. ITNs were also distributed to Magoda in December 1998 and to Mpapayu in March 2001. The main objective of our study was to assess the impact of ITNs and low dose DEC on microfilaria (mf) prevalence and intensity and incidence of new mf infections. Four annual cross-sectional surveys were conducted between 1999 and 2004 in the two villages to screen for Wuchereria bancrofti microfilariae in individuals aged ≥ 1 year. Overall, 80% of the population in Magoda and 66% in Mpapayu were covered during these surveys. Results revealed a significant decrease in both mf prevalence and intensity in both villages. Furthermore, there was a steady decrease in mf incidence in Magoda; with 36.7 cases per 1000 person years in 2000 and 7.4 in 2004. In Mpapayu, the incidence initially increased from 20.8 cases in 2000 to 24.3 in 2001 and then decreased to 7.2 cases in 2004. Individuals using ITNs in Magoda had significantly lower risk of mf (OR=0.681; 95%CI: 0.496-0.934); and the risk of new infections was reduced by 58.8% (95%CI: 30.3-75.4). These results suggest that when MDA is complemented with ITNs there is high likelihood to half filariasis transmission within a shorter period than using chemotherapy alone.

Multivalent fusion protein vaccine for lymphatic filariasis

Lymphatic filariasis affects approximately 3% of the whole world population. Mass drug administration is currently the major control strategy to eradicate this infection from endemic regions by year 2020. Combination drug treatments are highly efficient in controlling the infection. However, there are no effective vaccines available for human or animal lymphatic filariasis despite the identification of several subunit vaccines. Lymphatic filariasis parasites are multicellular organisms and potentially use multiple mechanisms to survive in the host. Therefore, there is a need to combine two or more vaccine candidate antigens to achieve the desired effect. In this study we combined three well characterized vaccine antigens of Brugia malayi, heat shock protein 12.6 (HSP12.6), Abundant Larval transcript-2 (ALT-2) and tetraspanin large extra cellular loop (TSP-LEL) as a multivalent fusion vaccine. Putative immune individuals carry circulating antibodies against all three antigens. Depletion of these antigen specific antibodies from the sera samples removed the ability of the sera to participate in the killing of B. malayi L3 in an antibody dependent cellular cytotoxicity (ADCC) mechanism. Vaccination trials in mice with a bivalent [HSP12.6+ALT-2 (HA), HSP12.6+TSP-LEL (HT) or TSP-LEL+ALT-2 (TA)] or trivalent [HSP12.6+ALT-2+TSP-LEL (HAT)] vaccines using DNA, protein or heterologous prime boost regimen showed that trivalent HAT vaccine either as protein alone or as heterologous prime boost vaccine could confer significant protection (95%) against B. malayi L3 challenge. Immune correlates of protection suggest a Th1/Th2 bias. These finding suggests that the trivalent HAT fusion protein is a promising prophylactic vaccine against lymphatic filariasis infection in human.

Bayesian geostatistical modelling of malaria and lymphatic filariasis infections in Uganda: predictors of risk and geographical patterns of co-endemicity

BackgroundIn Uganda, malaria and lymphatic filariasis (causative agent Wuchereria bancrofti) are transmitted by the same vector species of Anopheles mosquitoes, and thus are likely to share common environmental risk factors and overlap in geographical space. In a comprehensive nationwide survey in 2000-2003 the geographical distribution of W. bancrofti was assessed by screening school-aged children for circulating filarial antigens (CFA). Concurrently, blood smears were examined for malaria parasites. In this study, the resultant malariological data are analysed for the first time and the CFA data re-analysed in order to identify risk factors, produce age-stratified prevalence maps for each infection, and to define the geographical patterns of Plasmodium sp. and W. bancrofti co-endemicity.MethodsLogistic regression models were fitted separately for Plasmodium sp. and W. bancrofti within a Bayesian framework. Models contained covariates representing individual-level demographic effects, school-level environmental effects and location-based random effects. Several models were fitted assuming different random effects to allow for spatial structuring and to capture potential non-linearity in the malaria- and filariasis-environment relation. Model-based risk predictions at unobserved locations were obtained via Bayesian predictive distributions for the best fitting models. Maps of predicted hyper-endemic malaria and filariasis were furthermore overlaid in order to define areas of co-endemicity.ResultsPlasmodium sp. parasitaemia was found to be highly endemic in most of Uganda, with an overall population adjusted parasitaemia risk of 47.2% in the highest risk age-sex group (boys 5-9 years). High W. bancrofti prevalence was predicted for a much more confined area in northern Uganda, with an overall population adjusted infection risk of 7.2% in the highest risk age-group (14-19 year olds). Observed overall prevalence of individual co-infection was 1.1%, and the two infections overlap geographically with an estimated number of 212,975 children aged 5 - 9 years living in hyper-co-endemic transmission areas.ConclusionsThe empirical map of malaria parasitaemia risk for Uganda presented in this paper is the first based on coherent, national survey data, and can serve as a baseline to guide and evaluate the continuous implementation of control activities. Furthermore, geographical areas of overlap with hyper-endemic W. bancrofti transmission have been identified to help provide a better informed platform for integrated control.

Sustained reduction in prevalence of lymphatic filariasis infection in spite of missed rounds of mass drug administration in an area under mosquito nets for malaria control

BackgroundThe Global Programme to Eliminate Lymphatic Filariasis (GPELF) was established by the World Health Organisation (WHO) in 2000 with the goal of eliminating lymphatic filariasis (LF) as a public health problem globally by 2020. Mass drug administration (MDA) of antifilarial drugs is the principal strategy recommended for global elimination. Kenya launched a National Programme for Elimination of Lymphatic Filariasis (NPELF) in Coast Region in 2002. During the same year a longitudinal research project to monitor trends of LF infection during MDA started in a highly endemic area in Malindi District. High coverage of insecticide treated nets (ITNs) in the coastal region has been associated with dramatic decline in hospital admissions due to malaria; high usage of ITNs is also expected to have an impact on LF infection, also transmitted by mosquitoes.ResultsFour rounds of MDA with diethylcarbamazine citrate (DEC) and albendazole were given to 8 study villages over an 8-year period. Although annual MDA was not administered for several years the overall prevalence of microfilariae declined significantly from 20.9% in 2002 to 0.9% in 2009. Similarly, the prevalence of filarial antigenaemia declined from 34.6% in 2002 to 10.8% in 2009. All the examined children born since the start of the programme were negative for filarial antigen in 2009.ConclusionsDespite the fact that the study villages missed MDA in some of the years, significant reductions in infection prevalence and intensity were observed at each survey. More importantly, there were no rebounds in infection prevalence between treatment rounds. However, because of confounding variables such as insecticide-treated bed nets (ITNs), it is difficult to attribute the reduction to MDA alone as ITNs can lead to a significant reduction in exposure to filariasis vectors. The results indicate that national LF elimination programmes should be encouraged to continue provision of MDA albeit constraints that may lead to missing of MDA in some years.

Particularités anatomopathologiques de la maladie rénale du sujet de l’Afrique sub-Saharienne : revue synthétique des données de la République démocratique du Congo

Chronic kidney disease (CKD) is a major global public health problem. But kidney involvement is more common and appears more severe in Africa than in developed countries. The likely causes of end stage renal disease (ESRD) or CKD stage 3 and above in developed countries are diabetes, hypertension and less frequently glomerular diseases. In contrast, in decreasing order in Africa are glomerulopathies, hypertension and diabetes. The reasons for this preponderance of glomerular diseases are not fully known but may be linked to the persistence or reemergence of tropical diseases. This study reviews the kidney involvements more associated with common tropical diseases including HIV/AIDS. The most common HIV/AIDS lesion is a specific focal and segmental glomerulosclerosis (FSGS) termed HIV-associated nephropathy (HIV-AN). Renal complications of tropical parasites are heterogenous. Various glomerulopathies like FSGS occur during various filariasis infections. Schistosoma mansoni is responsible for membranoproliferative glomerulonephritis and amyloidosis. Human African trypanosomiasis is associated with cryoglobulinemic membranoproliferative glomerulonephritis. The Plasmodium malariae is mainly responsible for membranoproliferative glomerulonephritis. Acute patterns (acute tubular necrosis or acute postinfectious glomerulonephritis) are observed during Plasmodium falciparum infection. Several other viral, bacterial or mycobacterial infections like leprosy and tuberculosis still prevalent in Africa can also affect the kidney. Sickle cell disease is responsible for a variety of renal injuries. In conclusion, kidney lesions linked to tropical diseases partly explain the peculiar pattern of CKD of the black race and play a significant role in the current outbreak of the CKD in Subsaharan Africa.

Molecular differentiation of nocturnally periodic and diurnally sub-periodic Wuchereria bancrofti by Randomly Amplified Polymorphic DNA (RAPD).

Wuchereria bancrofti, a nematode parasite, is responsible for causing 90% of lymphatic filariasis infection in the world. In India, W. bancrofti exists in two physiological forms, nocturnally periodic in the main land and diurnally sub-periodic in Car Nicobar group of islands. Differentiation of these two parasitic forms by conventional microscopic methods difficult requiring good skill and hence tedious. Therefore, we developed a simple and rapid Random Amplified Polymorphic DNA (RAPD) assay to differentiate these parasitic forms. Also, the phylogenetic relationship between periodic and sub-periodic W. bancrofti and also Brugia malayi populations was analyzed using RAPD profile generated. Distinct RAPD profiles were observed among the three parasites with the formation of three distinct clusters in the phylogenetic tree. Substantial genetic diversity (Nei's genetic diversity H) was observed among periodic (H=0.0577) and sub-periodic (H=0.1415) W. bancrofti populations.

Plant Products in the Treatment and Control of Filariasis and Other Helminth Infections and Assay Systems for Antifilarial/Anthelmintic Activity

Lymphatic filariasis, onchocerciasis, loaisis, and other helminth infections cause serious health problems especially in resource-limited tropical and subtropical developing countries of the world, and more than 2 billion people are infected with at least one helminth species. From times immemorial, man looked up to the plant kingdom in search of anthelmintics, antifilarials, and remedies for parasite-induced health problems. Although more than 50 % of drugs in modern medicine are derived from plants or leads from plants, a success story of plant-based anthelminthics or antifilarials is yet to be told. In the last 5 decades, more than 100 plant products were reported to be beneficial in the treatment or control of these parasitic infections but they could not be developed into viable drugs for a variety of reasons. This review focuses on the plant products reported to be useful in the control and treatment of human helminth infections with the main emphasis on filariasis and the in vitro and in vivo systems available for assaying anthelmintic activity.

Absence of lymphatic filariasis infection among secondary-school children in Oman

The endemicity status of lymphatic filariasis in Oman is uncertain, with only sporadic cases reported, mostly imported. Immunochromatographic card test surveys were carried out to assess the presence of circulating Wuchereria bancrofti antigenaemia as a marker for active infection in children from suspected high-risk areas of Oman (South Batinah and Dhofar). Lot quality assurance sampling surveys were carried out on a minimum of 250 secondary-school children aged 17-18 years in each of 8 districts from February 2004 to March 2004. All tested students were negative for circulating W. bancrofti antigen. Based on these findings as well as previous data, Oman may possibly be classified as a nonendemic country, with no evidence of indigenous lymphatic filariasis transmission.