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P L Chiodini

Publications and source records attributed to P L Chiodini.

At least 19 recordsLinked to original sources
PubMed2006

Use of rapid diagnostic tests for diagnosis of malaria in the UK.

BACKGROUND: Malaria is currently diagnosed almost exclusively by microscopy in clinical laboratories. The introduction of rapid diagnostic tests (RDTs) may be useful in achieving rapid detection of malaria parasites, especially in situations where malaria is not often seen or where staff are inexperienced. AIM: To explore the use of RDT in UK laboratories. METHODS: The current use of RDTs was surveyed in UK laboratories subscribing to the United Kingdom National External Quality Assessment Scheme blood parasitology and haematology schemes. RESULTS: An overall survey response rate of 60.3% was seen. RDTs were found to be the preferred choice, either alone or in conjunction with microscopy in 31.2% of the samples examined during normal working hours and in 44.3% of the specimens examined on call. CONCLUSIONS: During on-call hours, the use of RDTs was observed to increase and RDTs changed the diagnosis in 12% of laboratories. No established protocol for RDT use was, however, observed in the UK. A protocol that needs to be validated in the laboratory setting is suggested.

After-Hours Care↗
PubMed2006

IPSE/alpha-1: a major immunogenic component secreted from Schistosoma mansoni eggs.

During infection with Schistosoma mansoni the egg stage of this parasite modulates the initial T helper (Th1) response into a Th2 response. This suggests that schistosome eggs contain factors responsible for that effect. We have recently described a glycoprotein (IPSE) from S. mansoni eggs that has a potent IL-4-inducing effect on human basophils. Here we demonstrate that IPSE is identical to a previously described molecule, the S. mansoni egg antigen alpha-1. We furthermore show that the expression of IPSE/alpha-1 at the level of both mRNA and protein is restricted to the egg stage. IPSE/alpha-1 is produced in and released from the subshell area of the egg and comes into close contact with inflammatory cells recruited to the vicinity of the egg surface. In line with this IPSE/alpha-1 is one of three major S. mansoni egg glycoproteins that induce pronounced antibody responses. Its IL-4-inducing capacity, moreover, suggests that IPSE/alpha-1 plays a role in initiating the Th2 response induced by patent S. mansoni infections.

Animals↗
PubMed2006

Malaria and blood transfusion.

The transmission of malaria by blood transfusion was one of the first recorded incidents of transfusion-transmitted infection. Although a number of different infections have been reported to be transmitted by transfusion since then, on a global scale malaria remains one of the most common transfusion-transmitted infections. Transfusion-transmitted malaria can have serious consequences, as infection with Plasmodium falciparum may prove rapidly fatal. Ensuring that, in non-endemic countries, the blood supply is free from malaria is problematical, especially as travel to malarious areas is increasing and there is some spread of the disease into new areas, as well as a resurgence of malaria in areas where previously it had been eradicated. In non-endemic countries, donor deferral can be effective, but clear guidelines are needed. In endemic countries the problem is far greater as the majority of donors may be potentially infected with malaria parasites. In both situations, the simple deferral of donors may be wasteful and can eventually erode the donor base. Thus, other strategies are needed to ensure safety with sufficiency. However, the screening of donations for evidence of malaria is not without its problems. Although the examination of blood films is still the basis for diagnosing acute malaria, in most situations it is not sufficiently sensitive for blood bank screening. In non-endemic countries, donor deferral in combination with screening for specific antimalarial immunoglobulin provides an effective means of minimizing the risk of transmission. In endemic countries, more specific donor questioning, consideration of seasonal variation and geographical distribution may help to identify the population of donors who are most likely to be infected. In addition, the administration of antimalarials to transfusion recipients may help to prevent transmission. Nonetheless, no matter what strategy is adopted, it is likely that cases of transfusion-transmitted malaria may still occur, so malaria must always be considered in any patient with a febrile illness post-transfusion.

Animals↗
PubMed2005

Clinical features and diagnosis of 42 travellers with cutaneous leishmaniasis.

BACKGROUND: Leishmania species that occur within different geographical areas may cause different clinical manifestations, virulence and drug sensitivity. Patients/Methods. All patients with a clinical diagnosis of cutaneous leishmaniasis seen at the Hospital for Tropical Diseases from 1997 to 2000 were identified and clinical details recorded onto a database, with emphasis on clinical presentation, risk factors, travel history and laboratory diagnosis. RESULTS: Forty-two patients were identified, 23 of whom had travelled to New World and 19 to Old World countries. Clinical presentation typically consisted of a single nodule with ulceration. In 50% infection was caused by L. (Viannia) braziliensis. PCR was performed in specimens from 34 patients and species identification was possible in 32 cases (sensitivity 94%), the two PCR negative patients had amastigotes demonstrated by histology and culture. Patients were treated with established therapies. Seventy one percent were cured by treatment, 12% had a spontaneous cure, 7% were lost to follow-up and the remaining 10% required a second-line therapy. No relapses were reported during a mean follow-up period of 27 months. CONCLUSIONS: Our study highlights the need for comprehensive investigations and the advantages of PCR in the diagnosis of patients with suspected leishmaniasis in non-endemic regions of the world.

Adolescent↗
PubMed2005

Fatal outcome of a hyperinfection syndrome despite successful eradication of Strongyloides with subcutaneous ivermectin.

We report the case of a 77-year-old man who developed a Strongyloides hyperinfection syndrome following immunosuppressive therapy more than 60 years after he moved away from an area endemic for Strongyloides stercoralis. Successful eradication of the nematode was achieved with an off label subcutaneous formulation of ivermectin. However, the patient subsequently died from acute respiratory distress syndrome (ARDS). Despite a high wormload in the stool and sputum of the patient and delayed infection control measures in the hospital, testing of the medical staff revealed a very low risk of Strongyloides transmission among healthcare workers.

Aged↗
PubMed2004

New world mucosal and cutaneous leishmaniasis: an emerging health problem among British travellers.

BACKGROUND: Mucosal leishmaniasis (ML) is an important complication of new world cutaneous leishmaniasis (CL) caused by species of the Leishmania Viannia subgenus. Previous reports of ML among travellers to Latin America are few. AIMS: To determine the annual number of cases of CL due to L. Viannia species diagnosed at this institution and to correlate this with changing patterns of travel. Secondly, to document the clinical presentation, diagnosis, treatment and outcome of ML at this institution. DESIGN: Retrospective observational study. METHODS: Data were collected from a clinical database, laboratory records, patient case notes and an international passenger survey. RESULTS: Between 1995 and 2003, the annual number of cases of CL (total 79) steadily increased from 4 per year to 18 per year; the estimated number of travellers from the UK to Latin America increased 3.5-fold. Six cases of ML were diagnosed among British travellers in 1995 (1), 1997 (1) and 2002 (4). These infections were acquired in Bolivia (3), Colombia (2) and Belize (1). Nasopharyngeal symptoms developed 0-15 months after returning to the UK. Four patients had concurrent CL at diagnosis. Diagnosis of ML was delayed up to 6 months from the onset of symptoms. Mucosal biopsies from all 6 patients were PCR-positive for L. (Viannia) DNA; microscopy and culture were less sensitive. ML relapsed in one patient following treatment. DISCUSSION: Increasing travel to Latin America from the UK was associated with an increasing number of diagnoses of L. Viannia CL. ML is likely to emerge as a more frequently imported infection among such travellers. Familiarity with these diseases is important for prompt diagnosis and optimal management.

Adolescent↗
PubMed2004

Evaluation of a malarial antibody assay for use in the screening of blood and tissue products for clinical use.

BACKGROUND AND OBJECTIVES: A new recombinant Plasmodium antigen enzyme immunoassay (EIA) for the detection of malarial antibodies was evaluated for the screening of 'malaria-risk' blood and tissue donations. MATERIALS AND METHODS: A total of 13,269 donor and patient samples were tested by both the EIA and the standard diagnostic antibody immunofluorescence test (IFAT). RESULTS: A total of 114/138 (82.6%) samples from patients with P. falciparum and 11/13 (84.6%) samples from patients with P. vivax tested positive. A total of 714/13,053 (5.47%) samples from donors identified as 'malaria risk', owing to residency or travel, were reactive in the EIA. CONCLUSIONS: The assay is more sensitive than a previously implemented malarial antibody EIA (73% in acute P. falciparum and 56% in acute P. vivax infections). The sensitivity of this new EIA is comparable to that of the IFAT, and the specificity is sufficient to screen 'malaria-risk' donors.

Animals↗
PubMed2004

Serological speciation of human schistosome infections by ELISA with a panel of three antigens.

AIMS: To find out whether serology can reliably speciate human schistosomiasis using a simple enzyme linked immunosorbent assay (ELISA) technique. METHODS: Stored sera from 66 patients with microscopically confirmed schistosomiasis were subjected to ELISA using a panel of three antigens, namely: unfractionated Schistosoma mansoni soluble egg antigen (SEA); CEF6, a cationic fraction of SEA; and crude S margrebowiei egg antigen, prepared from an animal schistosome closely related to S haematobium. RESULTS: The optical densities (ODs) obtained using CEF6 as antigen were significantly higher in sera from S mansoni infected patients than in sera from S haematobium infected patients (median OD, 0.810 v 0.595). Using S margrebowiei egg antigen, the optical densities were significantly higher in S haematobium sera than in S mansoni sera (median OD, 0.794 v 0.544). There was no significant difference in optical densities between S mansoni and S haematobium sera using SEA (median OD, 0.725 v 0.737). The ratio of ODs (CEF6 to S margrebowiei egg antigen) was calculated: a ratio of >1 indicated S mansoni infection (sensitivity, 88%) and a ratio of <1 indicated S haematobium infection (sensitivity, 84%). The odds ratio for S haematobium having an OD ratio of <1 was 36.8 (95% confidence interval, 7.0 to 194). CONCLUSIONS: The identity of the infecting species of schistosome can be determined using the panel of antigens described. SEA should be used to screen serum samples, and the CEF6 : S margrebowiei egg antigen ELISA optical density ratio can be used where serological speciation is required.

Animals↗
PubMed2004

Comparison of PCR and antigen detection methods for diagnosis of Entamoeba histolytica infection.

AIMS: To assess different laboratory methods for the identification of Entamoeba histolytica in clinical samples. METHODS: Antigen detection enzyme linked immunosorbent assay, polymerase chain reaction solution hybridisation enzyme linked immunoassay (PCR-SHELA), and a commercial Lightcycler PCR were compared using 101 stool and pus samples. RESULTS: Fifteen of the 101 samples were positive for E histolytica by one or more method. There were discrepancies between the results in five of these 15 samples when the assays were compared. CONCLUSIONS: All three methods performed adequately, so that the choice of assay will depend on each individual laboratory's budget and projected turnaround time.

Animals↗
PubMed2003

Investigation of tropical eosinophilia; assessing a strategy based on geographical area.

OBJECTIVES: Patients with eosinophilia are an important clinical problem. This study aimed to assess the most efficient manner of investigating patients with peripheral eosinophilia (eosinophil count >0.5x10(9)ml(-1)) presenting from the tropics. METHODS: Patients attending the Hospital for Tropical Diseases, London, from October 1997 to March 2002 for investigation of eosinophilia were identified prospectively. Laboratory, clinical and demographic data were recorded from laboratory and clinical records. An investigation set was proposed prospectively and assessed for all geographical areas (stool microscopy, strongyloides culture and serology), all of Africa (additional schistosomal serology, terminal urine microscopy and filarial serology) and West Africa (additional day-bloods for microfilaria). RESULTS: Data was analysed for 261 patients. At least one helminthic cause for eosinophilia was found in 64% of patients (median eosinophilia 1.2x10(9)ml(-1)). Seventeen per cent of patients had more than one helminth species found. Median eosinophilia increased with number of diagnoses per patient. The proposed investigation sets were validated, with high yield for all proposed tests apart from filarial serology outside West Africa, and good sensitivity. CONCLUSIONS: Initial investigation of eosinophilia in patients presenting from the tropics may be guided by a simple investigation set depending on broad area of travel which has high sensitivity and yield. Patients frequently have more than one helminthic cause of eosinophilia.

Adolescent↗
PubMed2003

Best Practice No 174. Best practice guidelines for the examination of specimens for the diagnosis of parasitic infections in routine diagnostic laboratories.

Although most routine microbiology diagnostic laboratories process specimens for the diagnosis of parasitic infections, there are no best practice guidelines either for processing or for referral to specialist centres. Microscopy for parasites is most often requested on faecal samples, but urine, sputum, liver aspirates, duodenal aspirates, bile, corneal scrapings, contact lens fluid, and tissue are also encountered. Diagnosis of certain parasitic infections requires serology or polymerase chain reaction. These are undertaken in specialist laboratories, which should be consulted for expert advice on diagnosis and management of parasitic infections. Clinical Pathology Accreditation UK (CPA) has defined standards for assessing the quality of service provided by laboratories, but these do not include scientific and technical aspects. The Association of Medical Microbiologists has recently published Standards for laboratory practice in medical microbiology, which covers scientific and technical aspects, mainly bacteriological examination of specimens in routine diagnostic microbiology laboratories. These guidelines are complementary to the CPA standards and aim to ensure a consistent and high quality of service. This article provides best practice guidelines for the diagnosis of parasitic infections.

Biopsy↗
PubMed2003

External quality assessment schemes raise standards: evidence from the UKNEQAS parasitology subschemes.

BACKGROUND: The burden of parasitic disease imported into the temperate zone is increasing, and in the tropics remains very high. Thus, high quality diagnostic parasitology services are needed, but to implement clinical governance a measure of quality of service is required. AIM: To examine performance in the United Kingdom National External Quality Assessment Scheme for Parasitology for evidence of improved standards in parasite diagnosis in clinical specimens. METHODS: Analysis of performance was made for the period 1986 to 2001, to look for trends in performance scores. RESULTS: An overall rise in performance in faecal and blood parasitology schemes was found from 1986 to 2001. This was seen particularly in the identification of ova, cysts, and larvae in the faecal scheme, the detection of Plasmodium ovale and Plasmodium vivax in the blood scheme, and also in the correct identification of non-malarial blood parasites. Despite this improvement, there are still problems. In the faecal scheme, participants still experience difficulty in recognising small protozoan cysts, differentiating vegetable matter from cysts, and detecting ova and cysts when more than one species is present. In the blood scheme, participants have problems in identifying mixed malarial infections, distinguishing between P ovale and P vivax, and estimating the percentage parasitaemia. The reasons underlying these problems have been identified via the educational part of the scheme, and have been dealt with by distributing teaching sheets and undertaking practical sessions. CONCLUSIONS: UK NEQAS for Parasitology has helped to raise the standard of diagnostic parasitology in the UK.

Feces↗
PubMed2003

Use of a rapid, single-round, multiplex PCR to detect malarial parasites and identify the species present.

A new, rapid assay, based on a single-round, multiplex PCR, can be used to detect Plasmodium falciparum, P. vivax, P. malariae or P. ovale in human blood. The PCR, which targets the conserved 18S small-subunit RNA genes of the parasites, not only permits a malarial infection to be detected but also allows each Plasmodium species present to be identified, even in cases of mixed infection.

Animals↗
PubMed2002

Non-microscopic method for malaria diagnosis using OptiMAL IT, a second-generation dipstick for malaria pLDH antigen detection.

Rapid diagnostic tests for malaria are now a commonly used procedure for malaria diagnosis. New or improved devices need to be evaluated against a recognised gold-standard procedure and subjected to conditions of temperature and humidity that may affect their performance. The OptiMAL 48 RDT has now been available commercially for several years and a second-generation OptiMAL IT test is now coming onto the market. In this study the problems associated with the routine use of OptiMAL 48 is investigated and its performance compared with a second-generation individual test, OptiMAL IT. Sensitivity and specificity for detection of all malaria species for both tests were comparable but loss of sensitivity of the test strips due to humidity or temperature found with the routine use of OptiMAL 48 was not seen with the individual OptiMAL IT. False-positive results for Plasmodium falciparum, seen in two negative blood samples, were attributed to the presence of high levels of heterophile antibodies.

Animals↗
PubMed2001

Chemotherapy for patients with multiple parasitic infections.

Multiple parasitic infections have become increasingly recognized as a result of improvements in laboratory diagnosis and a growing population of immunocompromised individuals. This review examines the principles of chemotherapy in groupings of multiple infections which are of particular clinical significance.

Acquired Immunodeficiency Syndrome↗
PubMed2001

Trichinellosis acquired in the United Kingdom.

An outbreak of trichinellosis that occurred in the United Kingdom is described. Members of four households consumed pork salami from northern Serbia, the Federal Republic of Yugoslavia. Eight cases of trichinellosis occurred. Clinical and laboratory features of the cases were typical with myalgia (7 cases), fever (6), headache (5), periorbital oedema (4), non-specific ST/T wave changes on electrocardiogram (3), Trichinella antibodies (6), eosinophilia (7) and raised serum creatine kinase (3). All recovered. Trichinella larvae were detected in the salami. During pre-travel counselling, travellers should be advised about possible risk from cured pork products which have been produced locally in Trichinella endemic areas.

Adult↗
PubMed2001

Parasitic infections of the intestine.

Intestinal protozoal infections cause significant disease not only in the tropics but also in immunocompromised hosts and returning travellers in the developed world. Precise diagnosis of protozoal intestinal infection by microscopy can be difficult. Enzyme immunoassays for antigen detection are being used for some protozoal infections with some limitations which will, it is hoped, be overcome by molecular techniques. Nucleic acid amplification techniques could help improve detection of microsporidial species, which are difficult to detect microscopically and allow differentiation between Entamoeba histolytica and Entamoeba dispar. Definitive treatment for Cryptosporidium parvum infection remains elusive but new drugs are being evaluated. Cessation of thiabendazole production should not affect therapy of intestinal nematode infections as potent alternative therapy is available.

Animals↗