Kriti Tilak

Modified Negative Staining of Heine for Fast and Inexpensive Screening of Cryptosporidium, Cyclospora, and Cystoisospora spp.

Negative staining technique of Heine is an easy, inexpensive, and rapid way of screening for coccidian parasites of the intestinal tract. But its use as a routine technique for screening of Cryptosporidium, Cyclospora, and Cystoisospora is restricted due to its sensitivity being lower than the gold standard method of modified Ziehl-Neelsen staining. This paper emphasises the modification of original Heine staining technique which has been attempted in order to increase the sensitivity and detection of oocysts of Cryptosporidium, Cyclospora, and Cystoisospora. Modified Heine staining technique using malachite green is a practical, safe, and sensitive method of detecting oocysts in stool specimens. While the modified Ziehl-Neelsen staining technique is still considered the gold standard for the detection of Cryptosporidium spp., modified negative staining technique of Heine using malachite green stain should be considered as the screening technique of first choice.

Identification and Preservation of Intestinal Parasites Using Methylene Blue-Glycerol Mount: A New Approach to Stool Microscopy

We have tried a new approach to routine stool microscopy by using a combination of methylene blue and glycerol in wet mount preparation of fresh faecal samples for the demonstration of medically important intestinal parasites. This combination was evaluated for finding differences in the details and clarity of morphology and internal structures of parasites under low- and high-power microscopy as compared to iodine and saline mount. It was further evaluated to estimate the time taken by methylene blue-glycerol mount to dry up as compared to iodine and saline wet mount.

An Unusual Case of Echinostomiasis in a Retropositive Patient: A Case Report

This report describes an unusual case of echinostomiasis in a retropositive patient with swelling, pain, and purulent discharge over back and right scapular region for 10 days. Stool examination revealed the presence of eggs of hookworm and echinostome. Diagnosis is challenging due to few characteristic features of eggs of echinostomes. They usually infect birds and mammals, and only limited species are implicated in the causation of human disease. Mild infections are of little significance, but heavy fluke burden may lead to significant abdominal symptoms. Incidence of echinostomiasis is higher in Southeast Asian countries, and this report is an unusual case in India. We discuss general desirability of awareness of this kind of infection and training for better detection.

Rare Case of Polymicrobial Keratitis With Balantidium coli.

Purpose: To report a rare case of polymicrobial keratitis due to Balantidium coli and gram-negative bacteria, Pseudomonas aeruginosa and Klebsiella pneumoniae, in a soft contact lens (CL) wearer. Methods: We report a case of CL-related keratitis due to B. coli, P. aeruginosa, and K. pneumoniae. Results: The culture of the corneal scrapings, the CL cleaning solution, and the CL revealed the growth of a rare ciliated parasite, B. coli, along with gram-negative bacteria, namely, P. aeruginosa and K. pneumoniae. The patient was successfully treated with topical broad-spectrum antibiotics and intravenous metronidazole. Conclusions: Polymicrobial keratitis has seldom been reported with B. coli as the causative agent. CL wear can be a risk factor for this infection. Treatment with topical antibiotics may not suffice, and the intravenous route of antiprotozoal drugs may be a useful adjunct. Increasing awareness, early diagnosis, and treatment may improve the final visual outcome.

Gauze Filtration Technique for Quick and Inexpensive Diagnosis of Intestinal Parasites

Intestinal parasitic infestation has been a major public health problem throughout the world, particularly in developing countries owing to unhygienic living conditions. Early and accurate diagnosis as well as improvement in detection rates of intestinal parasites is of prime importance in limiting the incidence of parasitic infestations and decreasing the disease burden. In the present study, we introduce a novel gauze filtration technique to improve the detection rates of intestinal parasites. The technique is simple, inexpensive and time-saving. Detection rate is 96.5% compared to the sedimentation technique, which was considered as the gold standard. This technique can be utilized in peripheral laboratory settings with limited resources and untrained personnel.

Blastocystis Species: Guilty or Innocent?

Blastocystis spp. was previously considered to be a member of normal intestinal flora; it is now receiving increased attention as a potential causative agent of human intestinal disease. The present study attempts to investigate the pathogenicity of Blastocystis spp. in clinically symptomatic patients. Eighty-six immunocompetent patients with intestinal Blastocystis spp. were evaluated clinically. Two consecutive stool samples were examined by wet mount, modified formol ethyl acetate concentration method and trichrome and Kinyoun acid-fast staining. Presence of more than 10 various morphological forms of Blastocystis spp. under 40× magnification was taken as a criterion for the presence of protozoan. Patients with other pathogens were excluded from the study. Metronidazole was administered for five to seven days. After treatment, stool sample of patients were re-examined for Blastocystis spp. There were 39 males and 47 females with a mean age of 39.8 years ± 18.8 (range 19–62 years). Abdominal pain was the most frequent symptom (77.9%) followed by diarrhea (65.1%). A second stool specimen was obtained from 61 (70.9%) patients after metronidazole therapy. Consecutive investigation revealed no intestinal protozoa in 56 (91.8%) patients. Symptoms persisted in five patients. Out of 56 patients who complained of diarrhea, 51 showed improvement in symptomology with no protozoan found. If all other pathogens and factors causing intestinal pathologies are ruled out and only Blastocystis spp. is present in symptomatic patients, it is logical to consider them as pathogenic rather than commensals and treatment can be initiated in such cases. However, further studies for genetic association and prevalence are needed to strengthen this view.

Rare Case of Meningoencephalitis Due to Aspergillus and Acanthamoeba Coinfection

Aspergillus and Acanthamoeba cause central nervous system (CNS) infection mostly in immunocompromised hosts, disseminating via the hematogenous route from a primary focus in the respiratory tract. We are presenting a case of an immunocompetent patient diagnosed with Aspergillus and Acanthamoeba coinfection of the CNS, a rare finding. A positive cerebrospinal fluid (CSF) galactomannan antigen test confirmed the presence of Aspergillus, and direct visualization in CSF sample and culture confirmed the presence of Acanthamoeba.