Parasite prevalence in a village in Burkina Faso: the contribution of new techniques.

Parasites are a major public health problem in developing countries. A coproparasitological and immunoparasitological study was conducted in Burkina Faso, in the rural village of Touguri, in November and December 2011. The coproparasitologic analysis was conducted in the pediatric population and seroprevalence surveys were conducted in the adult population to research intestinal, blood, and helminth parasites.Methodology: The coproparasitologic study was performed on stool samples using two diagnostic methods –standard microscopy and the FLOTAC technique. The total of 49 stool samples analyzed were obtained from children between two months and eleven years of age. The serology study was carried out to evaluate the prevalence of P. falciparum, Echinococcusspp., Tenia solium, and A. lumbricoidesusing different immunological techniques such as ELISA and Western Blot techniques. The study population included 85 adult patientsbetween 15 and 70 years of age.Results: Results of coproparasitological analyses showed Hymenolepis nanaas the only helminth found, in 28.6% of the total number of patients. Results of serological evaluation revealed a practically null prevalence of Echinococcus, Taenia solium,andAscaris lumbricoides, and a 77.64% prevalence of Plasmodium falciparum.Conclusions: Despite the small number (especially in terms of coprological samples) of individuals examined, this study showed that theparasite prevalence in a rural area of Burkina Faso has a significant impact in the general population, particularly in children. Another finding was that FLOTAC had a higher sensitivity than the widely used ethyl ether-based concentration technique for coprological sample analysis

Distribution of helminths in buffalo farms from central Italy

The aim of the present study was to obtain up-to-date information on the distribution of helminths in buffalo farms of central Italy. The survey was carried out on a sample of 127 farms (epidemiological units), selected using a grid approach within a Geographical Information System, followed by proportional allocation. In each farm the number of buffaloes tested (adults, heifer/steers and calves) ranged from 9 to 21 based on the number of animals on the farm. The total number of faecal samples collected from the 127 farms was 1883. Copromicroscopic examinations were performed using the FLOTAC technique. The following helminths were detected in the examined farms: gastrointestinal strongyles (33.1%), Strongyloides spp. (3.1%), Fasciola hepatica (7.1%), Dicrocoelium dendriticum (2.4%), Paramphistomidae (7.1%), and Moniezia spp. (2.4%)

Mini-FLOTAC as an alternative, non-invasive diagnostic tool for Schistosoma mansoni and other trematode infections in wildlife reservoirs

Schistosomiasis and food-borne trematodiases are not only of major public health concern, but can also have profound implications for livestock production and wildlife conservation. The zoonotic, multi-host nature of many digenean trematodes is a significant challenge for disease control programmes in endemic areas. However, our understanding of the epidemiological role that animal reservoirs, particularly wild hosts, may play in the transmission of zoonotic trematodiases suffers a dearth of information, with few, if any, standardised, reliable diagnostic tests available. We combined qualitative and quantitative data derived from post-mortem examinations, coprological analyses using the Mini-FLOTAC technique, and molecular tools to assess parasite community composition and the validity of non-invasive methods to detect trematode infections in 89 wild Hubert’s multimammate mice (Mastomys huberti) from northern Senegal

Seasonal variations of EPG levels in gastro-intestinal parasitic infection in a southeast asian controlled locale:a statistical analysis

We present a data based statistical study on the effects of seasonal variations in the growth rates of the gastro-intestinal (GI) parasitic infection in livestock. The alluded growth rate is estimated through the variation in the number of eggs per gram (EPG) of faeces in animals. In accordance with earlier studies, our analysis too shows that rainfall is the dominant variable in determining EPG infection rates compared to other macro-parameters like temperature and humidity. Our statistical analysis clearly indicates an oscillatory dependence of EPG levels on rainfall fluctuations. Monsoon recorded the highest infection with a comparative increase of at least 2.5 times compared to the next most infected period (summer). A least square fit of the EPG versus rainfall data indicates an approach towards a super diffusive (i. e. root mean square displacement growing faster than the square root of the elapsed time as obtained for simple diffusion) infection growth pattern regime for low rainfall regimes (technically defined as zeroth level dependence) that gets remarkably augmented for large rainfall zones. Our analysis further indicates that for low fluctuations in temperature (true on the bulk data), EPG level saturates beyond a critical value of the rainfall, a threshold that is expected to indicate the onset of the nonlinear regime. The probability density functions (PDFs) of the EPG data show oscillatory behavior in the large rainfall regime (greater than 500 mm), the frequency of oscillation, once again, being determined by the ambient wetness (rainfall, and humidity). Data recorded over three pilot projects spanning three measures of rainfall and humidity bear testimony to the universality of this statistical argument. © 2013 Chattopadhyay and Bandyopadhyay

A general framework to support cost-efficient fecal egg count methods and study design choices for large-scale STH deworming programs-monitoring of therapeutic drug efficacy as a case study

BACKGROUND: Soil-transmitted helminth (STH) control programs currently lack evidence-based recommendations for cost-efficient survey designs for monitoring and evaluation. Here, we present a framework to provide evidence-based recommendations, using a case study of therapeutic drug efficacy monitoring based on the examination of helminth eggs in stool. METHODS: We performed an in-depth analysis of the operational costs to process one stool sample for three diagnostic methods (Kato-Katz, Mini-FLOTAC and FECPAKG2). Next, we performed simulations to determine the probability of detecting a truly reduced therapeutic efficacy for different scenarios of STH species (Ascaris lumbricoides, Trichuris trichiura and hookworms), pre-treatment infection levels, survey design (screen and select (SS); screen, select and retest (SSR) and no selection (NS)) and number of subjects enrolled (100-5,000). Finally, we integrated the outcome of the cost assessment into the simulation study to estimate the total survey costs and determined the most cost-efficient survey design. PRINCIPAL FINDINGS: Kato-Katz allowed for both the highest sample throughput and the lowest cost per test, while FECPAKG2 required both the most laboratory time and was the most expensive. Counting of eggs accounted for 23% (FECPAKG2) or >/=80% (Kato-Katz and Mini-FLOTAC) of the total time-to-result. NS survey designs in combination with Kato-Katz were the most cost-efficient to assess therapeutic drug efficacy in all scenarios of STH species and endemicity. CONCLUSIONS/SIGNIFICANCE: We confirm that Kato-Katz is the fecal egg counting method of choice for monitoring therapeutic drug efficacy, but that the survey design currently recommended by WHO (SS) should be updated. Our generic framework, which captures laboratory time and material costs, can be used to further support cost-efficient choices for other important surveys informing STH control programs. In addition, it can be used to explore the value of alternative diagnostic techniques, like automated egg counting, which may further reduce operational costs. TRIAL REGISTRATION: ClinicalTrials.gov NCT03465488

DETECTION OF STREPTOCOCCUS EQUI DNA IN RHIPICEPHALUS BURSA TICKS FROM SOUTHERN ITALY

Ticks are obligated ecto-parasites of wild and domestic animals and occasionally humans. They have veterinary interest because vectors of different viruses, bacteria and protozoa. Among the most common species in Italy and Europe there are Ixodes ricinus and Rhipicephalus spp. The tick-borne diseases epidemiologically relevant in our country are: Lyme disease, rickettsiosis, relapsing fever, tularemia, meningoencephalitis and ehrlichiosis. Recently, the extensive characterization of the tick-associated microbiome faces the possible role of ticks in the transmission of additional pathogens, which are known to be transmitted by other arthropod vectors. Through the Denaturing Gradient Gel Electrophoresis (DGGE), we analysed the bacterial community of seven ticks belonging to three species from different areas of Italy: no. 2 Rhipicephalus sanguineus (Lombardia), no. 2 Rhipicephalus bursa (Campania) and no. 3 Ixodes ricinus (Marche). The samples were analysed selecting the highly variable V3 region of the bacterial 16S rRNA gene as target. The dominant DGGE bands were purified and sequenced allowing the identification of the bacteria present in each samples. Burkholderia sp., Coxiella-like endosymbiont, unc. Clostridium, Rickettsia peacockii, unc. Staphylococcus and Xanthomonas sp. were detected, as already described in ticks. Moreover, Streptococcus equi subsp. zooepidemicus/ruminatorum was identified in R. bursa collected from buffalos living in rural areas of Southern Italy (the high genetic identity does not allow the distinction of these subspecies, that is usually achieved by biochemical tests on cultured bacteria). The DGGE outcome was confirmed by multiplex-PCR in other R. bursa samples collected from buffalos, ponies and goats from the same area. In particular, no. 6 positive samples over no. 15 analyzed were detected (no. 2 from buffalos and no. 4 from ponies). S. equi is a complex-species including S. e. equi, S. e. zooepidemicus and S. e. ruminatorum: S. e. equi is the ethological agent of strangles, a highly contagious and serious infection of horses, whereas S. e. zooepidemicus and S. e. ruminatorum can cause several infections in both animals and humans. All these pathogens are known to be transmitted through direct contact. The DNA detection of S. e. zooepidemicus/ruminatorum in R. bursa is particularly interesting since to our knowledge this pathogen was not previously detected in any tick species. Thus, in-depth studies are worthy to assess an effective competence of ticks as vectors of S. equi subspecies, since if a potential role of R. bursa in their transmission will be confirmed, new perspectives in the control of these zoonoses will be opened

Field Validity and Feasibility of Four Techniques for the Detection of Trichuris in Simians: A Model for Monitoring Drug Efficacy in Public Health?

Worldwide, millions of people are infected with soil-transmitted helminths, particularly in developing countries. Efforts to control these infections involve periodic mass drug treatment in endemic areas. Since these large-scale interventions are likely to intensify, monitoring of drug efficacy has become a key issue in order to detect the emergence of resistance. At present, the drop in infection intensity is under examination for monitoring the drug efficacy. However, studies comparing detection techniques based on infection intensities are scarce. Moreover, little attention has been addressed to their feasibility and their ability to estimate drug efficacies. We have compared different techniques for the detection of whipworm (Trichuris) in simian stool samples based on prevalence, infection intensities, feasibility and ability to estimate the ‘true’ drug efficacy. We have found that techniques often fail to detect low infection intensities and that not all techniques are appropriate for estimating infection intensities. The time needed to obtain a test result varied from 3.9 to 17.7 min/sample. Finally, accurate estimates of drug efficacy were only obtained in high pre-drug administration infection intensities. To conclude, along with accurate estimates of infection intensities, feasibility is a considerable criterion for the detection techniques used in drug efficacy monitoring programs

Dog filariosis in the Lazio region (Central Italy): first report on the presence of Dirofilaria repens

BACKGROUND: Epidemiological investigations were carried out in the Lazio Region to assess the status of canine filariosis and to evaluate the actual risk for veterinary and medical public health. METHODS: Since August 2001 to June 2003, a total of 972 canine blood samples, collected in public kennels and from private owners animals of the 5 Provinces of the Region, were tested. The presence of filarial parasites was evaluated by microscopy and bio-molecular techniques; the species identification was performed by means of the same diagnostic tools. RESULTS: A total of 17/972 (1.75%; 95%CI 1.06%–2.85%) blood samples were parasitized by D. repens,13 out them drawn by dogs resident in the Province of Roma, and 4 in the other provinces. Multivariate analysis was performed in order to evaluate the association between filariosis and risk factors. The origin from coastal territories seems to be a significant risk factor to acquire the infection. CONCLUSION: This is the first report of canine filariosis in the Lazio Region, where D. repens was before reported only in foxes. The risk of human zoonotic infection is stressed, and the absence of other filarial species is discusse

Prevalence of anthelmintic resistance in gastrointestinal nematodes of sheep and goats in Norway

In the period of 2008–2009, the efficacies of the benzimidazole (BZ) albendazole and the macrocyclic lactone (ML) ivermectin against gastrointestinal nematodes (GIN) of small ruminants were evaluated by means of the fecal egg count reduction (FECR) test and by post-treatment identification of surviving third stage (L3) larvae after coproculture. Sheep (n = 28) and goat (n = 28) flocks from three areas of Norway were randomly selected to assess the prevalence of anthelmintic resistance (AR), whereas only lambs from non-randomly selected sheep flocks (n = 32) with a farm management that could select for AR were investigated the second year. Only flocks with a mean excretion of nematode eggs per gram feces (EPG) ≥150 at time of treatment were included in the survey. In total, 48 (80%) and 13 (46.4%) of the selected sheep and goat flocks, respectively, fulfilled the inclusion criteria. The proportions of flocks classified as resistant (i.e., FECR <95% and with a lower 95% confidence interval of <90%) for the BZ drug albendazole were 10.5% and 31.0% in the randomly and non-randomly selected sheep flocks, respectively. When restricting the area to Rogaland County, eight flocks out of ten (80%) non-randomly selected sheep flocks showed BZ resistance. The efficacy of ML was 100% in all surveyed sheep and goat flocks. In post-treatment coprocultures from the non-randomly selected flocks, the main nematode genera were Teladorsagia/Trichostrongylus in five flocks, Haemonchus in two flocks, and a mixture of these genera in the remaining two flocks. In the goat flocks, the pre-treatment infection levels of GIN were low compared to what was found in the sheep flocks. Still, in one flock, AR against BZ in Teladorsagia/Trichostrongylus was found. New strategies and recommendations to face the emerging AR situation in Rogaland County in order to limit the spread of resistant nematodes within and into other areas are urgently needed