Positive Enzyme-linked Immunosorbent Assay Test Research Articles

3Ts Score, an Attempt for Less Testing in Thrombocytopenia Patients with Suspected Heparin Induced Thrombocytopenia (HIT): Retrospective Analysis in a University Hospital Setting

Background: Heparin-induced thrombocytopenia (HIT) is a prothrombotic and potentially fatal adverse drug reaction mediated by platelet-activating antibodies against multimolecular complexes of platelet factor 4 (PF4) and heparin. The 4Ts is a pretest scoring system for HIT that was developed to improve and standardize clinical diagnosis. The strength of the 4Ts score lies in the negative predictive value of a low pretest probability score. Those with a 4T score ≥4 is considered to have moderate to high probability of HIT and should undergo confirmatory laboratory test. Delays in treatment are associated with risk of thrombosis. Immediate cessation of heparin and initiation of a non-heparin anticoagulant is therefore standard of care. Method: This is a single institutional retrospective study. We reviewed the charts of 219 patients with thrombocytopenia with suspected HIT to evaluate the appropriateness of ordering the HIT testing based on the pretest probability of the 4Ts scoring system. All patients had enzyme linked immunosorbent assay (ELISA) test for HIT antibodies (the screening test). We studied tests that were sent from 03\16\2021 through 07\03\2023. The serotonin release assay (SRA) which is the confirmatory test for HIT was only sent for patients who had a positive ELISA test. 4T scores were calculated retrospectively using chart's information available to clinicians at the time of the HIT tests were sent. Results: Out of the 219 patients, 80(36.5%), 120(54.7%) and 19(8.6%) patients had a low, intermediate and high pretest probability respectively. The HIT ELISA test was positive in 33 (15.7%) patients and 196 (84.9%) patients had negative results. HIT ELISA had 100% and 93.5% sensitivity and specificity respectively while the positive and negative predicative values were 60% and 100% respectively. A positive SRA test was reported in 23 patients (10.5% of the total study population). Seventy-nine patients (36% of our total sample) scored 4 points which represents intermediate pretest probability. Out of these 79 patients only 6 (11.3%) patients had a positive ELISA test, and 5 (6.3%) patients had a positive SRA test. Aiming to minimize the HIT over testing we examined the increase in the cutoff point of the intermediate pretest probability from 4 points to 5 points which resulted in significant increase in the sensitivity and positive predictive value of the intermediate pretest probability (75.4% and 21% versus 39% and 12.9% respectively). However, the sensitivity dropped from 90% to 65%. The 4th part of 4Ts score gives points based on the probability of HIT versus other pathology as a cause of the thrombocytopenia. Most of the patients with suspected HIT will score one point out of the 4th part of 4Ts score which makes this part of the score is less helpful in distinguishing between patients with suspected HIT and will result in higher overall pretest probability and more testing. We studied the 3Ts score (the 4Ts scoring system after elimination of the 4th part) effect on the intermediate pretest probability. The cutoff points for the 3Ts score are 1-3, 4-5 and 6 for low, intermediate and high pretest probability respectively. The 3Ts score model resulted in significant increase in the specificity and the positive predictive value (76% and 21.7% versus 39.2% and 12.9% respectively) however the sensitivity dropped from 90% to 65%. The average turnaround time for HIT ELISA test and the SRA test was 2.3 days and 4.4 days respectively. Fifteen patients (21% out the patient had low pretest probability on the 4Ts score), 41 patients (59% of the patient who had an intermediate pretest probability on the 4Ts score) and 13 patients (18.8% of the patients who had high pretest probability on the 4Ts score) started on non-heparinoid anticoagulation meanwhile awaiting on the HIT testing result. Conclusion: Over testing of HIT is common secondary to underuse of 4Ts scoring system. Multicomponent educational interventions to increase the awareness and utility of the 4Ts score in addition to implantation of clinical decision support based on HIT computerized score will help to reduce unnecessary diagnostic testing of HIT in patients with low pretest probability. Increasing the cutoff point of the intermediate pretest probability or applying the 3Ts score model resulted in significant increase in the specificity and the positive predictive value of the 4Ts scoring system on expense of the scoring system sensitivity.

Efficiency of sandwich enzyme immunoassay for the diagnosis of larval echinococcus infection in cattle in the Republic of Azerbaijan

The purpose of the research is to develop a sandwich enzyme-linked immunosorbent assay (ELISA) for laboratory diagnosis of echinococcosis in animals. Materials and methods. The diagnostic efficiency of the ELISA test system developed by us against cystic echinococcus infection in cattle was studied by comparing the obtained results with the data of a postmortem examination of animal carcasses. The sera from 80 animals delivered to the slaughterhouse from farms of different regions of the Republic of Azerbaijan were tested. Results and discussion. A positive ELISA test result was obtained in 42 animals, which was 52.5% of the total number of the animals studied. The postmortem diagnosis was confirmed in 32 animals, which was 40.0%. The comparison of the ELISA diagnostic efficiency with the postmortem examination data was 68.75%. Fasciola species were found in the bile ducts in 7 animals with a positive ELISA test response to echinococcosis and a negative diagnosis in the postmortem examination, and Cysticercus tenuicollis was found in one animal.

Prevalence of asymptomatic strongyloidiasis co-infection in COVID-19 patients residing in endemic areas

BackgroundFatal forms of strongyloidiasis, hyperinfection syndrome (HS) and disseminated strongyloidiasis (DS), are caused by exaggerated autoinfection of the intestinal nematode, Strongyloides stercoralis (S. stercoralis). Corticosteroids, frequently administered to patients with severe COVID-19, can transform chronic asymptomatic strongyloidiasis into the above-mentioned fatal diseases. This study aimed to investigate the prevalence of strongyloidiasis in COVID-19 patients receiving corticosteroids in a hypoendemic region.MethodsThe present cross-sectional study enrolled 308 COVID-19 patients admitted to two hospitals in Ahvaz and Abadan in the southwest of Iran between 2020 and 2022. A real-time reverse transcription polymerase chain reaction (RT-PCR) test and chest computed tomography (CT) scan were employed to detect and monitor the disease’s severity in the patients, respectively. All patients were evaluated for IgG/IgM against S. stercoralis using Enzyme-linked immunosorbent assay (ELISA) test. Subsequently, individuals with a positive ELISA test were confirmed using parasitological methods, including direct smear and agar plate culture (APC).ResultsThe patients were between 15 and 94 years old, with a mean age of 57.99 ± 17.4 years. Of the 308 patients, 12 (3.9%) had a positive ELISA test, while 296 (96.1%) had negative results. Three of the 12 patients with a positive ELISA result died, and three failed to provide a stool sample. To this end, only six cases were examined parasitologically, in which S. stercoralis larvae were observed in five patients. Significant differences were found between S. stercoralis infection with sex (p = 0.037) and age (p = 0.027). Binary regression analysis revealed that strongyloidiasis was positively associated with sex (odds ratio [OR]: 5.137; 95% confidence interval [CI]: 1.107–23.847), age (OR: 5.647; 95% CI 1.216–26.218), and location (OR: 3.254; 95% CI: 0.864–12.257).ConclusionsOur findings suggest that screening for latent strongyloidiasis in COVID-19 patients in endemic areas using high-sensitivity diagnostic methods, particularly ELISA, before receiving suppressive drugs should be given more consideration.

Clinical outcomes for Clostridioides difficile associated diarrhea in inflammatory bowel disease patients versus non-IBD population: A retrospective cohort study.

Patients with inflammatory bowel disease (IBD) have a higher incidence of Clostridioides difficile infection (CDI). Previous studies have demonstrated negative clinical outcomes in IBD patients with CDI compared to patients without CDI. The clinical presentation of CDI is indistinguishable from IBD exacerbation, thus posing a frequent clinical dilemma on the role of Clostridioides infection in the testing, diagnosis, and treatment of these patients. To compare clinical outcomes of CDI in patients with IBD to those without IBD. Retrospective cohort of adult patients admitted to Rabin Medical Center Israel between the years 2014 and 2020 with a concurrent diagnosis of IBD and CDI. Matching 1:2 was performed between the IBD patients and the non-IBD population with respect to age and sex. Sixty-seven patients with IBD and 134 patients without IBD were included in the study. The groups' median age was 40.6 (interquartile range [IQR] of 29.8-68.9), with 45.8% male and 54.2% female. The non-IBD group had a higher Charlson score with 2 (IQR 0; 5) versus 0 (IQR 0; 4) in the IBD group (P value <.01). Patients with IBD had more exposure to systemic antibiotics, 71.1% versus 26.3% (P value <.01). In a multivariable analysis we found no difference in 90-day mortality and rate of relapse between the 2 study groups with an odds ratio of 1.709 (95% confidence interval 0.321-9.905) and odds ratio of 0.209 (95% confidence interval 0.055-1.513) respectively. In our cohort patients with IBD who present with diarrhea and concomitant CDI have similar rates of relapse and mortality compared with patients without IBD.

Effect of Culling Management Practices on the Seroprevalence of Johne's Disease in Holstein Dairy Cattle in Central Italy.

A study was performed in Umbria, central Italy, to find out whether different culling strategies adopted by farms to control Johne’s disease (JD) infection exerted effects on the seroprevalence in dairy cattle. Fifty Fresian dairy herds in the Perugia and Assisi districts were visited and an audit of herd management was conducted. Among the 50 herds, 20 were selected for the consistency of management practices and, according to the culling strategy, two groups were created: group A (aggressive culling protocol, with average herd productive life <1100 days) and group B (lower culling rate, with productive life greater than 1500 days). The presence of antibodies to Mycobacterium avium subspecies paratuberculosis (Map) in the serum was determined using a commercial enzyme-linked immunosorbent assay (ELISA) kit. It was found that 3.3% (n = 14) of the cows of group B (n = 422, from 17 herds) were positive for Map antibodies, in comparison with 5.7% (n = 21) of the cows from group A (n = 366, from three herds). The odds ratio from multiple logistic regression (adjusted odds ratio 2.446, 95% confidence interval 0.412 to 14.525) showed that Johne’s disease prevalence in herds with a greater productive life was not higher than in herds with typical modern management characterized by more aggressive culling. This is a significant finding, indicating that aggressive culling may not be necessary. Current JD control recommendations are derived from data obtained in high-prevalence paratuberculosis areas (northern Europe, including northern Italy), while methods of information transfer to dairy farms in low-prevalence areas should be reassessed to ensure that the correct measures, including basic calving management and calf-rearing practices, are thoroughly implemented. Using the manufacturer’s suggested cut-off for a positive ELISA test and the sensitivity and specificity claimed, the overall true prevalence in Umbria dairy cattle was calculated as 7% (95% confidence interval 5.2% to 8.8%).

Household Transmission of Severe Acute Respiratory Syndrome Coronavirus-2 in the United States.

BackgroundAlthough many viral respiratory illnesses are transmitted within households, the evidence base for SARS-CoV-2 is nascent. We sought to characterize SARS-CoV-2 transmission within US households and estimate the household secondary infection rate (SIR) to inform strategies to reduce transmission.MethodsWe recruited laboratory-confirmed COVID-19 patients and their household contacts in Utah and Wisconsin during March 22–April 25, 2020. We interviewed patients and all household contacts to obtain demographics and medical histories. At the initial household visit, 14 days later, and when a household contact became newly symptomatic, we collected respiratory swabs from patients and household contacts for testing by SARS-CoV-2 rRT-PCR and sera for SARS-CoV-2 antibodies testing by enzyme-linked immunosorbent assay (ELISA). We estimated SIR and odds ratios (OR) to assess risk factors for secondary infection, defined by a positive rRT-PCR or ELISA test.ResultsThirty-two (55%) of 58 households had evidence of secondary infection among household contacts. The SIR was 29% (n = 55/188; 95% confidence interval [CI]: 23–36%) overall, 42% among children (<18 years) of the COVID-19 patient and 33% among spouses/partners. Household contacts to COVID-19 patients with immunocompromised conditions had increased odds of infection (OR: 15.9, 95% CI: 2.4–106.9). Household contacts who themselves had diabetes mellitus had increased odds of infection (OR: 7.1, 95% CI: 1.2–42.5).ConclusionsWe found substantial evidence of secondary infections among household contacts. People with COVID-19, particularly those with immunocompromising conditions or those with household contacts with diabetes, should take care to promptly self-isolate to prevent household transmission.

First Report of the Prevalence of Human T-Lymphotropic Virus Type 1 (HTLV-1) for Hemodialysis Patients in Tehran

Background: Human T-lymphotropic virus type 1 (HTLV-1) virus belongs to retroviruses and is involved in the etiology of adult T-lymphocytic leukemia (ATL) and tropical spastic paraparesis (TSP). This virus could be transmitted through transfusion of contaminated blood or blood products, from the mother to the child or fetus, sexual intercourse, and sharing contaminated syringe needles among addicted individuals. There is no report regarding the prevalance of HTLV-1 among hemodialysis patietns in Tehran. Methods: In this descriptive study, 150 patients, who were under hemodialysis from four military hospitals of Tehran were included. Serum samples were screened to measure the titer of HTLV-1 antibodies by Dia-Pro ELISA kits. Enzyme linked immunosorbent assay (ELISA) positive samples were checked by the western blot method. Results: The results indicated that age of the patients was in the range of 24 to 88 years old and the mean age of patients was 63.58 ± 13.41 years. Among all patients, only one patient (0.66%) had positive anti HTLV-1 ELISA test in the serum while other patients (99.4%) had negative results. The positive sample was confirmed by Western blot analysis. Conclusions: The prevalence rate of HTLV-1 among hemodialysis patients was not high in Tehran. However, it is necessary to take preventive measures to reduce its spread, especially through infectious hemodialysis machines.

Sero-survey of Avian Influenza in backyard poultry and wild bird species in Iran—2014

In almost all villages in Iran backyard birds, especially chickens, are kept for egg and meat production. AI H9N2 subtype is endemic in Iran. Therefore, estimation of AI prevalence among these birds is important to determine the risk of transmission of infection to commercial farms. The aim of this study was to estimate subclinical infections or previous exposure to H5, H7, and H9 subtypes and to identify potentially important determinants of prevalence of this infectious at premises level in backyard poultry, bird gardens, zoos, and wild bird markets in Iran.A survey was conducted using a cross-sectional design throughout the entire country. A total of 329 villages, seven bird gardens, three zoos and five wild bird markets were included. In each village four families that kept birds were included in the collection of biological samples and background information. The Enzyme-Linked Immunosorbent Assay (ELISA) was used as the screening test and all ELISA-positive samples were examined with the HI test to differentiate H5, H7, and H9.Among the bird gardens, eight of 15 premises (53.3%) were positive in both the ELISA test and HI for H9N2. Testing of samples collected in the villages revealed that 296 out of 329 villages (90%) had positive ELISA tests and also HI tests for H9. The HI–H9 mean titers in positive units were significantly higher than negative units (P<.001). This study revealed no significant statistical differences between risk variables in seropositive and seronegative bird gardens in the case of H9 (P>.05). The results of this study showed that among the risk variables, mountainous area was a protective factor and lack of hygienic disposal of dead birds was a risk factor for AI; this was also observed in rural poultry.The high sero-prevalence of influenza H9N2 in rural domestic poultry indicates that the disease is endemic. It is necessary to include backyard poultry in any surveillance system and control strategy due to the existence of AIV in backyard poultry and the possibility of transmission of infection to commercial poultry farms. Implementation of an AI surveillance program and biosecurity measures can be useful to control this infection and prevent AI from spreading to commercial farms. Furthermore in Iran there is no program for destruction of birds infected with the H9N2, so an effective vaccination program with regard to issues such as acceptability and cost-benefit must play an important role in reducing infections in backyard poultry.

A concise critical analysis of serologic testing for the diagnosis of lyme disease.

Diagnostic testing for Lyme disease in the clinical setting primarily relies on assessment of serologic responses to infection, with the exception of the early localized phase of disease, in which the diagnosis must be made clinically, due to the recognized insensitivity of serologic testing at this phase of disease. For the diagnosis of early disseminated and late disease, the Centers for Disease Control and Prevention (CDC) recommends a two-tiered approach to testing consisting of initial IgM and IgG quantitative enzyme-linked immunosorbent assay (ELISA), followed by confirmation of all indeterminate or positive ELISA tests with separate IgG and IgM Western blots. This critical analysis addresses the sensitivity, specificity, and predictive value of serologic testing for Lyme disease in early localized, early disseminated, and late disease. Other testing modalities currently under evaluation are also discussed, including IgG vlsE C6 peptide ELISA, other two-tiered testing strategies, rapid diagnostics, and PCR. An understanding of the strengths and limitations of currently available testing for Lyme disease is critical for appropriate diagnosis.

HIV Indeterminate Western Blot Results in Blood Donors in Northeast of Iran, 2009-2014

Background and Aims: HIV is spreading rapidly among people word wide. Infection with this virus leads to immune suppression and finally acquired immune deficiency syndrome (AIDS).Early HIV detection is depended on antibody screening against virus by Enzyme Linked Immunosorbent Assay (ELISA).Some confirmatory tests such as; Western Blot and Recombinant Immunobloting Assay (RIBA), are used to verify viral infection. Many of confirmatory tests results are indeterminate. The aim of this study is comparing the frequency and patterns of indeterminate results in two groups; blood donors and patients with high risk behaviors, in northeast of Iran. Materials and Methods: From October 2009 to March 2014 total number of 1055 serum samples with previous positive HIV ELISA test history, were tested in our laboratory. Some by RIBA and some by western blot method. Results: Most of indeterminate results belonged to blood donors that were tested by Western Blot analysis and were positive. The most reacting band was P24 in both methods and groups. Conclusion: RIBA assay is more sensitive and reliable than western Blot; but it’s necessary to use other supplementary tests with less indistinctive results.

Hepatitis C Virus Serosorting in People Who Inject Drugs: Sorting Out the Details

Hepatitis C Virus Serosorting in People Who Inject Drugs: Sorting Out the Details

Reading between the Lyme: isBorrelia burgdorferia cause of dilated cardiomyopathy? The debate continues

Reading between the Lyme: is<i>Borrelia burgdorferi</i>a cause of dilated cardiomyopathy? The debate continues

The occurrence of Helicobacter pylori in hydatid liver disease

ObjectiveTo detect the prevalence of Helicobacter pylori (H. pylori) in hydatid liver disease. MethodsA total of 58 patients with hydatid liver disease attending AL-Sadder Teaching Hospital in Al-Najaf and Al-Basrah governorate from February to August, 2008 were included in the study and served as group A. One hundred and twenty 1st degree relative patients (group B) and 20 normal persons including 10 male and 10 female (group C) as control were detected for the presence of H. pylori infection in general population. Chest X-ray was done for the above groups to exclude lung hydrated cyst. The patients were screened by ultrasound to obtain intra abdominal hydrated cyst and enzyme-linked immuno sorbent assay (ELISA) test was utilized to detect the H. pylori infection. ResultsFifty eight patients from group A with hydatid liver disease, 30 male (51.7%) and 28 female (48.3%) were screened for the presence of H. pylori infection by using ELISA test. We found that 28 patients from group A had positive ELISA test including 19 male (32.8%) and 9 female (15.5%) (P<0.01). However, there were no positive results of H. pylori infection in group B and C by chest X-ray, ultrasound and ELISA test. ConclusionsIt can be concluded that there is a strong relationship between hydatid liver disease and presence of H. pylori.

Letter to the editor: Role of imaging in the diagnosis of cerebral sparganosis

The Editor, I read with interest the letter by Wiwanitkit [1] on the paper by Chiu et al [2]. The case report by Chiu et al describes imaging findings in cerebral sparganosis, a rare parasitic infection caused by the larval cestode of the genus Spirometra. The authors discuss three important MRI findings in this disease: the tunnel sign, described by Song et al [3] and characterised by columnar or fusiform-shaped hypointense lesions on post-contrast T1 weighted images and iso- or hyperintense lesions on post-contrast T2 weighted images (corresponding to the track of motion of a migrating worm); conglomerated ring or bead-shaped lesions, whose walls show hypointense signal on T1 weighted images, and iso- or hyperintense signal on T2 weighted images with post-contrast ringlike enhancement [2,3]; and different stages of the associated inflammatory process [2]. The authors have also described the MR spectroscopy and diffusion-weighted (DW) imaging findings in this case and reported MR perfusion imaging characteristics in a case of cerebral sparganosis [2], showing no definite increase in cerebral perfusion of the lesion, nor in its adjacent area, which might represent a benign characteristic of the lesion, thus helping in the differentiation from a cerebral malignancy [2]. Wiwanitkit commented in the letter [1] that “there is still no clear conclusion on the clinical usefulness of neuroimaging for its diagnosis”, and that “in a large case series of sparganosis from Thailand, the final diagnosis of cerebral sparganosis was not obtained from neuroimaging”. It should be pointed out that the aforementioned case series [4], carried out by Wiwanitkit, comprises only five cases presenting with cerebral involvement (corresponding to 15% of all 34 cases), 3 of which were published more than 25 years ago (1985 and before). This case series, therefore, seems to be too limited and obsolete to support this conclusion. The study by Song et al (2007) [3], in contrast, comprises 25 cases of proven cerebral sparganosis, 23 of which were studied by advanced MRI techniques. Song et al concluded that in association with clinical data and enzyme-linked immunosorbent assay (ELISA), diagnosis of cerebral sparganosis could be proposed pre-operatively based on MRI. Chiu et al [2], in their article in the British Journal of Radiology, reached the same conclusion. More recently, Kim et al (2010) studied features distinguishing between live and degenerated worms on CT and MRI analysis of cases of cerebral sparganosis. The authors assert in the methods section that a preoperative diagnosis was reached based on clinical data, CT and MRI imaging findings, and a positive ELISA test [5]. Shirakawa et al, also in 2010, reported a well-illustrated case of cerebral sparganosis, depicting by consecutive MRI scans a lesion which have migrated from the cerebellar hemisphere to the vermis over a period of 7 weeks; the tunnel sign is demonstrated and the authors also comment that this is a characteristic finding [6]. Indeed, studying the role of MRI in the diagnosis of cerebral sparganosis in a cohort of 17 children with this disease, Gong et al [7] found a diagnostic accuracy rate of up to 85.7% after radiologists were trained in the imaging characteristics of this disease. The authors conclude that MRI findings of cerebral sparganosis are specific, although radiologists should be aware of the imaging findings in this condition to make a correct diagnosis. In conclusion, recent publications seem to illustrate the growing importance of imaging studies in the diagnosis of this rare disease.

Cryptococcal phospholipase B antigen is not detected in serum of patients infected withCryptococcus neoformansusing a sandwich enzyme-linked immunosorbent assay

Extracellular phospholipase B (PLB) is a virulence determinant of Cryptococcus neoformans and Cryptococcus gattii. In this study, we developed a sensitive enzyme-linked immunosorbent assay (ELISA) for PLB antigen with a detection limit of 3.9 ng mL(-1). PLB was detected in culture supernatants of C. neoformans and C. gattii. PLB, however, was not detected in sera of seven human patients and 10 feline patients with active cryptococcosis. Furthermore, none of five rats with extensive pulmonary C. gattii infection had a positive ELISA test result. In conclusion, cryptococcal PLB could not be detected in serum using a PLB antigen-based ELISA. Despite its sensitivity, this ELISA is of limited diagnostic value. Exploration of further extracellular molecules suitable for serodiagnosis of active cryptococcal infection is warranted.

Monitoring of Classical Swine Fever in Wild Boar (Sus scrofa) in Slovenia

Classical swine fever (CSF) is a highly contagious multi-systemic haemorrhagic viral disease of pigs. Not only domestic pigs, but also wild boar appear to play a crucial role in the epidemiology of CSF. Spleen (n = 739) and blood coagulum (n = 562) sampled from wild boars (Sus scrofa) shot in 2002, and serum samples from 746 wild boar shot in 2003 and 2004, were tested throughout Slovenia. In 2002, 17 samples were positive on enzyme-linked immunosorbent assay (ELISA) test for antibodies against classical swine fever virus (CSFV). Positive ELISA test was confirmed by a virus neutralization test. All other samples were negative. This is the first report that describes the epidemiology of CSFV from 2002 on, and the monitoring of the wild boar population in Slovenia at present.

Tomato spotted wilt virus in peanut tissue types and physiological effects related to disease incidence and severity*

Three peanut cultivars, Georgia Green, NC‐V11, and ANorden, were grown using production practices that encouraged the development of Tomato spotted wilt virus (TSWV). The progression of TSWV infection was examined through the season using enzyme‐linked immunosorbent assay (ELISA) tests on different tissue types [roots, leaves, pegs (pod attachment stem structures) and pods] and the effect of TSWV infection on physiological functions was examined at three harvest dates. Plants were classed into three severity categories: (i) no TSWV symptoms or previous positive ELISA tests; (ii) less than 50% of leaf tissue exhibiting TSWV symptoms; and (iii) greater than 50% of leaf tissue affected. TSWV showed a slow rate of infection at the beginning of the season and a greater percentage of infection of the roots than in the leaves. Photosynthesis was reduced in virus‐affected infected plants by an average of 30% at the mid‐season harvest and 51% at the late season harvest compared with virus‐free plants across all three cultivars. Leaf tissue with symptoms had lower photosynthetic rates than healthy leaves. There were small differences among cultivars, with cv. ANorden maintaining higher average photosynthetic levels than cv. Georgia Green and higher transpirational levels than cv. NC‐V11. The ability to maintain high assimilation physiology in the presence of the virus may help cultivars withstand TSWV infection and maintain final yields.

Concurrent Outbreak of Leptospirosis and Dengue in Mumbai, India, 2002

This prospective study was undertaken to investigate the possibility of a concurrent outbreak of leptospirosis and dengue and to describe the clinical illnesses. From 20 June to 14 November 2002, children who presented to our hospital with a suspected diagnosis of leptospirosis or dengue were admitted. In every child with suspected leptospirosis, a screening latex agglutination test was carried out to detect anti-Leptospira antibodies. The diagnosis of leptospirosis was confirmed by a positive enzyme-linked immunosorbent assay (ELISA) test or microagglutination test. The diagnosis of dengue was confirmed by a positive IgM antibody capture ELISA test. Clinical features in the leptospirosis and leptospirosis-negative groups, and dengue and dengue-negative groups were analysed. Of 90 children screened, 15 (16.7 per cent) had leptospirosis. Two children with Weil's disease died and the remaining 13 responded well to intravenous penicillin. Five clinical features were significantly associated with leptospirosis, namely conjunctival suffusion (p=0.007), haemorrhage (p=0.020), abdominal pain (p=0.011), hepatosplenomegaly (p=0.044), and oedema (p=0.007). As the number of these five features concomitantly present increased, the chances of the child having leptospirosis also increased significantly (p<0.0001). Of 90 children screened, 16 (17.8 per cent) had dengue. All responded well to the treatment and went home. Two clinical features were significantly associated with dengue, namely arthralgia (p=0.020) and thrombocytopenia (p=0.001). If both these features were present, the chances of the child having dengue increased significantly (p=0.001). Our study shows that a concurrent outbreak of leptospirosis and dengue had occurred in the slums of Mumbai city.

Bermuda Grass as a Potential Reservoir Host for Grapevine fanleaf virus.

Grapevine fanleaf virus (GFLV) was detected in samples of Bermuda grass (BG) from Iran by reverse transcription-polymerase chain reaction (RT-PCR) using two different pairs of GFLV-specific primers, and also by enzyme-linked immunosorbent assay (ELISA) using antiserum specific for a North American isolate of the virus. RT-PCR detected GFLV in both fresh and dried BG tissues and in virus preparations purified from these plants. Cloning and sequencing of the RT-PCR products confirmed that the amplified sequences were sections of the GFLV coat protein gene. Similar results were obtained when random and oligo(dT) primers were used on viral RNA templates recovered from BG to synthesize cDNA for cloning and sequencing. The virus induced few or no symptoms in BG, but could nonetheless be transmitted from BG to Chenopodium quinoa by mechanical inoculation. Some isolates induced systemic chlorotic spots and leaf deformation; others remained symptomless in this plant. Both symptomatic and symptomless C. quinoa plants were found to be infected with GFLV, giving positive ELISA and RT-PCR tests. A North American isolate of GFLV was found to be mechanically transmissible to BG as indicated by positive RT-PCR results from root samples of inoculated plants. GFLV-infected BG was widely distributed in the Fars province of Iran.

Diagnosis of human immunodeficiency virus infection in perinatally exposed orphaned infants in a resource-poor setting.

Diagnosis of human immunodeficiency virus infection in perinatally exposed orphaned infants in a resource-poor setting.