Lekha Tuli

A multiattribute utility evaluation of different methods for the detection of enteric protozoa causing diarrhea in AIDS patients.

BackgroundEnteric protozoa and sporozoa have emerged as important opportunistic parasites and can cause fatal infections in AIDS patients. The line of treatment being different for them necessitates an accurate and prompt identification of these to avoid empirical treatment. In this study which is the first of its kind from India we did a comprehensive evaluation of different techniques, comparing them on the basis of the attributes like yield, cost, time taken, expertise and infrastructure. For the first time combination of Calcoflour White and DAPI, a nuclear stain, were used to identify Microsporidia spp. Thus, a diagnostic protocol was devised for rapid, sensitive and cost effective identification of the opportunistic enteric protozoa.ResultsThe organisms isolated from the stool samples of the cases (450 HIV patients) were predominantly Cryptosporidium spp., Microsporidia spp. and Cyclospora spp. Interestingly, the control group (200 relatives of the patients who were HIV negative) showed a high incidence (21%) of Cryptosporidium spp. We found a significant increase in the sensitivity of microscopy in detecting Cryptosporidium spp. and Cyclospora spp. after formol ether concentration. Kinyouns staining was better compared to Modified safranin staining for Cryptosporidium spp. identification. Although ELISA had a sensitivity of 93.25% and specificity of 97% for Cryptosporidium spp. detection, we ranked Kinyouns staining better than ELISA because it is not affordable to most of our patients. For detecting Cyclospora cayetanensis, autoflourescence was the easiest and most cost effective method followed by Safranin technique. Combination of Calcoflour White stain and DAPI gave good results for the identification of Microsporidia spp. We assessed the above techniques and graded the attributes in the following descending order: cost effectiveness, sensitivity, ease of use and interpretation, time taken for the procedure and batch testing.ConclusionThus, we conclude that a combination of minimum three procedures should be carried out for the screening of stool specimens of HIV positive patients. Kinyouns staining should be made mandatory for every diarrheal stool sample from HIV patients. Also every laboratory should assign its own value to the attributes and apply Multiattribute utility theory or the Analytical hierarchy process to decide the most appropriate methodology.

Correlation between CD4 counts of HIV patients and enteric protozoan in different seasons – An experience of a tertiary care hospital in Varanasi (India)

BackgroundProtozoan infections are the most serious among all the superimposed infections in HIV patients and claim a number of lives every year. The line of treatment being different for diverse parasites necessitates a definitive diagnosis of the etiological agents to avoid empirical treatment. Thus, the present study has been aimed to elucidate the associations between diarrhoea and CD4 counts and to study the effect of HAART along with management of diarrhoea in HIV positive patients. This study is the first of its kind in this area where an attempt was made to correlate seasonal variation and intestinal protozoan infestations.MethodsThe study period was from January 2006 to October 2007 wherein stool samples were collected from 366 HIV positive patients with diarrhea attending the ART centre, inpatient department and ICTC of S.S. hospital, I.M.S., B.H.U., Varanasi. Simultaneously, CD4 counts were recorded to assess the status of HIV infection vis-à-vis parasitic infection. The identification of pathogens was done on the basis of direct microscopy and different staining techniques.ResultsOf the 366 patients, 112 had acute and 254 had chronic diarrhea. The percentages of intestinal protozoa detected were 78.5% in acute and 50.7% in chronic cases respectively. Immune restoration was observed in 36.6% patients after treatment on the basis of clinical observation and CD4 counts. In 39.8% of HIV positive cases Cryptosporidium spp. was detected followed by Microsporidia spp. (26.7%). The highest incidence of intestinal infection was in the rainy season. However, infection with Cyclospora spp. was at its peak in the summer. Patients with chronic diarrhea had lower CD4 cell counts. The maximum parasitic isolation was in the patients whose CD4 cell counts were below 200 cells/μl.ConclusionThere was an inverse relation between the CD4 counts and duration of diarrhea. Cryptosporidium spp. was isolated maximum among all the parasites in the HIV patients. The highest incidence of infection was seen in the rainy season.

Dark secrets behind the shimmer of contact lens: the Indian scenario.

BackgroundWe studied the bacteriological profile of soft contact lens and its accessories among the asymptomatic subjects and monitored the compliance level with the lens use and its cleaning protocol.FindingsA total of 115 (104 daily wear and 11 extended wear) subjects using contact lens were studied. Data regarding the duration of use and frequency and method of cleaning were recorded. Contact lens, lens cases, preserving solutions and tips of solution bottles were the samples collected. The isolates were identified on the basis of their phenotypic characters. Samples from 24 subjects (21 daily wear and 3 extended wear) were found contaminated. Of the 24 contaminated cases, 23 showed medium adherence to the cleaning protocol. Contamination rate was higher among the 56 daily wear lens users who used same lens for 2 years and more, than the 48 users who used their lenses for less than 2 years. Lens case contamination was found in all the 24 cases. The bacteria isolated were Citrobacter freundii, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus epidermidis and Streptococcus pneumoniae. In extended wear lens users, there was no change in microbial flora on repeating the cultures on day 7 and 14.ConclusionNon-compliance with contact lens use may lead to invitation of microbial flora. The accumulation of these bacteria may act as a precursor to biofilm formation, thus colonizing the lens accessories as well. The bacteria isolated in this study were similar to the ones causing microbial keratitis thus, predisposing the otherwise asymptomatic subjects to permanent visual damage.

Obesity and its mechanisms--who to blame after marriage?

While the idea is very fascinating and testable as elaborated by the author, I have to point out several issues for discussion before further experiments are planned to test the hypothesis. First, the author based the hypothesis on the theory that sickle cells become vaso-occlusive under similar conditions found in the tumor milieu, which are acidosis and hypoxemia. Therefore, sickle cells show selective sickling only around the tumor. Unfortunately, I found this view is less convincing. Acidosis and hypoxemia can happen in the body in many other pathological conditions besides tumor, such as emergency, infection and drug poisoning. Furthermore, many patients with malignant diseases are seniors accompanied by diabetics or chronic obstructive pulmonary disease (COPD), which are usually associated with acidosis and hypoxemia. Those conditions will limit the application of transfusion of sickle cells as a therapeutic option. Second, in order to reduce the tumor burden, the overall units of cells transfused will be in large amount. Recurrent transfusion inevitably results in many adverse consequence: chronic hemolysis, stone disease, secondary hemachromatosis and even infection with virus diseases, such as HIV, hepatitis. In addition, as the author stated ‘‘the therapy could cause pain which would need to be controlled with analgesics and possibly anesthesia”, another safety issue should be evaluated, that is, pain caused by sickle cell disease is more severe than that reported in cancer patients [2]. Therefore, notwithstanding prolonged survival period, the quality of life for patients will decrease because of pain due to vasoocclusive. Third, in practice, it is very difficult to avoid the destruction of red cells and production of acidosis during the storage and transfusion of blood containing sickle cells. Furthermore, the incidence of sickle cell disease is considerably low, making the blood production far insufficient to meet the need from patients suffering metastatic disease. Based on the above arguments, the safety and feasibility of the therapy option the author claimed could be better elaborated if further evidence is provided.