An ocular cysticercosis case: Caused by Asian genotype of Taenia solium.

An ocular cysticercosis case of a 42-year-old male, who presented with anterior uveitis is being reported. Microscopical examination of the cyst revealed presence of only one hooklet suggestive of T. solium cysticercus. Mitochondrial DNA analysis confirmed it to be T. solium cysticercus of Asian genotype. This is the first report on molecular typing of cysticercus isolate from ocular cysticercosis patient in India. The study suggests that the molecular analysis of cox1 gene may be a useful diagnostic tool in cases where microscopic examination is not confirmatory.

The presence of dsRNA virus in Trichomonas vaginalis isolates from symptomatic and asymptomatic Indian women and its correlation with in vitro metronidazole sensitivity.

Purpose: Trichomonas vaginalis, a protozoan parasite, is the causative agent of human trichomoniasis, the most common non-viral sexually transmitted disease. The infection encompasses from a complete asymptomatic presentation to severe sequelae; yet, the virulence markers have been poorly understood. It is suggested that the presence of Trichomonas vaginalis virus (TVV) in T. vaginalis may have an impact on its virulence, and its relatedness to in vitro metronidazole resistance has been reported. The aim of the study was to assess the presence of TVV in fresh and Long -Term Cultivated ( LTC) maintained T. vaginalis isolates from symptomatic (S) and asymptomatic (AS) Indian women and its relatedness, if any, with symptomatology and in vitro drug sensitivity. Materials and Methods: One thousand women (537 S and 463 AS) were screened for the presence of T. vaginalis by wet smear and culture examination of vaginal swab and urine sample. Fresh and LTC (6 months-2 years) maintained 15 isolates each from 15 S and 15 AS women were subjected to agarose gel electrophoresis following total cellular RNA extraction to evaluate the presence of double stranded (ds) RNA viral infection. The susceptibility of isolates to metronidazole was determined in vitro. Results: On agarose gel electrophoresis, three bands (5.5, 2.5 and 1.5 kb) were observed in all the 30 fresh isolates from 15 S and 15 AS women and only in 7 LTC isolates from 3 S and 4 AS women. All the fresh isolates harbouring TVV were found to be sensitive to metronidazole in vitro irrespective of the symptomatology of subjects, and out of seven LTC isolates harbouring TVV, six were sensitive to metronidazole and one showed borderline resistance. Conclusions: The results suggest that the presence of TVV alone may not be a virulence marker and loss of TVV on LTC appears to be related to drug resistance. The T. vaginalis Indian isolates are sensitive to metronidazole.

Human subcutaneous dirofilariasis in India: A report of three cases with brief review of literature.

Human subcutaneous dirofilariasis is a rare infection caused by filarial worms of the genus Dirofilaria. The parasites are transmitted to man by mosquitoes and the infection is manifested as subcutaneous nodules. Excision of the lesion is both diagnostic and therapeutic. Hereby we report three cases of human subcutaneous dirofilariasis. The worms were sent to our department for identification over a period of four years (2006-2009). Of these three patients, two men and one woman were between 15 and 45 years of age. In two cases, the infection manifested as a nodule on face, in one case near lower eyelid and in the other on the cheek, while in the third case as an itchy nodule on the abdomen. It is emphasized that both clinicians and microbiologists should have an increased awareness of this entity and include dirofilariasis in the differential diagnosis of patients presenting with subcutaneous nodules.

Ophthalmomyiasis: Three cases from North India.

Three cases of external ophthalmomyiasis are reported here. The larvae were identified to be Oestrus ovis in two cases and Cochliomyia hominivorax in one. Two of the patients were immunocompetent while one was undergoing treatment for squamous cell carcinoma of eyelid. In the latter myiasis led to complete destruction of the eye.

Serological screening for antenatal toxoplasma infection in India.

Purpose: Detection of infection caused by Toxoplasma gondii during pregnancy to prevent congenital infection. Materials and Methods: This study was carried out from January 2005 to 2006 in 300 pregnant women. Antitoxoplasma IgG, IgM, IgA antibody and IgG avidity were assessed using ELISA. Atleast two samples were taken atleast 3 weeks apart preferably one in each trimester. Result: Of these 300 pregnant women, anti toxoplasma IgG antibodies were detected in 46 (15.33%) cases, while 9 (3%) had positive anti toxoplasma IgM with IgA and /low IgG avidity antibodies suggestive of acute infection during or just before pregnancy. Conclusion: The results indicate that about 85% of female population of Chandigarh is susceptible to toxoplasma infection and thus should be specifically educated about prevention of this infection during pregnancy

Polymorphism in merozoite surface protein-1 gene in north & northwest indian field isolates of Plasmodium vivax.

Background & objective: Merozoite surface protein-1 of Plasmodium vivax (Pvmsp-1) is a strong vaccine candidate against asexual blood stages. Extensive polymorphism in msp-1 gene has been reported in P. vivax isolates from different geographical regions which is necessary before a field trial of any malaria vaccine based on msp-1 is undertaken. There are only a few reports available on polymorphism in msp-1 gene in Indian field isolates of P. vivax. The aim of the present study was therefore to investigate the polymorphism in Pvmsp-1 gene in 25 isolates of P. vivax collected from malaria patients from regions of north and northwest India. Methods: Parasite DNA was extracted from whole blood samples collected in citrated anticoagulant. The polymorphic region-5, the most variable region of the Pvmsp-1 gene was amplified by PCR. The PCR products were further analyzed by restriction fragment length polymorphism (RFLP) using Mva-1 restriction enzyme. The DNA fragments obtained on PCR and RFLP were analyzed by agarose gel electrophoresis. Results: On the basis of PCR, significant size polymorphism was seen and 4 allelic types were observed amongst the 25 isolates. Further analysis by RFLP discriminated these 4 allelic types into 9 sub-allelic types indicating that PCR-RFLP can be a good tool to study polymorphism in msp-1 gene of Plasmodium. Interpretation & conclusion: Marked genetic polymorphism was observed in msp-1 gene among the isolates of P. vivax. These observations stress the need to study larger numbers of isolates from different regions of India. The findings could have important implications on the vaccine development strategies for P. vivax.

Genetic Polymorphism in msp-2, ama-1 and csp genes in Plasmodium falciparum field isolates from north and north-western India.

Background & objectives: Malaria is a major public health problem in tropical and sub-tropical countries. Malaria vaccine is highly desirable as an adjunct to existing malaria control measures. The polymorphism in vaccine candidate antigens might be a hurdle in developing an effective vaccine. Merozoite surface protein-2, apical membrane antigen-1 and circumsporozoite protein of Plasmodium falciparum are vaccine candidate antigens. The aim of this study was to detect extent of genetic polymorphism in potential vaccine candidate antigen genes, i.e. msp-2, ama-1 and csp of P. falciparum isolates prevalent in northern and north-western parts of India. Methods: Overall 88 parasite isolates of P. falciparum were collected during July 1998–March 2002 from different parts of northern and north-western India. DNA was extracted and analyzed for genetic polymorphism by PCR-RFLP method. For msp-2 gene, family-specific (FC-27 and 3D7) nested PCR was also performed. Results: PCR showed size polymorphism in all the target genes. Three alleles were observed in msp-2 and ama-1, while only two in csp. RFLP of ama-1 and csp with Dra-1 and Ssp-1 endonucleases respectively, failed to differentiate isolates in sub-allelic types, while Hinf-I digestion of msp-2 amplicons differentiated three alleles into two distinct allelic families, i.e. FC-27 and 3D7. The allelic family-specific PCR generally confirmed the results of PCR-RFLP except in a few isolates, which showed mixed (two) clones of msp-2 gene. Interpretation & conclusion: There was extensive polymorphism in msp-2 gene while ama-1 and csp genes showed low polymorphism which may be due to the functional constraints of these proteins. The low level transmission of malaria in the study area may also be a factor for low polymorphism.

Concomitant intestinal parasitism and noncholera vibrio infection.

Concomitant parasitism is not uncommon especially in tropical countries with low socioeconomic status. Here we report an unusual combination of intestinal infection due to Strongyloides stercoralis, Blastomyces hominis and non-cholera Vibrio in a patient suffering from acute gastroenteritis and hypoalbuminemia. Early recognition and accurate treatment of gastrointestinal infections and infestations before the patient develops complications is important.

Genetic polymorphism in Plasmodium falciparum vaccine candidate antigens.

Malaria is still a major public health problem in many tropical and subtropical countries. Malaria vaccine is highly desirable as an adjunct to existing malaria control measures. The polymorphisms in malaria vaccine candidates antigens might be a hurdle in developing an effective vaccine. The present article reviews the genetic polymorphism in several antigens expressed on the parasite surface, which are targets for immunological responses of the host and are good candidates for vaccine development against P. falciparum. Variable regions of most genes are generally dimorphic probably as a result of intragenic recombinations. Each allele in turn shows polymorphism resulting from point mutations, or other mechanisms. Several antigens like merozoite surface protein-1 and 2 (MSP-1 and MSP-2) and S antigen show high polymorphism while in others like circumsporozoite protein (CSP), apical membrane antigen-1 (AMA-1) and erythrocyte binding antigen-175 (EBA-175) functional constraints limit the degree of polymorphism. Polymorphism reported in these genes is discussed.

Association of parasitic infections and cancers.

Recent advances in the fields of molecular biology, epidemiology and infectious diseases have led to significant revelations to clarify the relationship between cancer and infective agents. This article reviews the relationship between parasitic infections and carcinogenesis and the possible mechanisms involved. Few parasites, e.g., Schistosoma haematobium and Opisthorchis viverrini have been found to be strongly associated with bladder cancer and cholangiocarcinoma respectively. The evidence for the association of several other parasites and cancers has also been postulated.

Kinetics of humoral & cellular immune responses in experimental cysticercosis in pigs infected with Taenia solium.

Studies were undertaken to assess the kinetics of antibody responses, lymphocyte transformation to Taenia solium larval antigens (crude soluble extract antigen and antigen B), and T cell subpopulation in piglets following experimental infection. Cysticercosis was established in 1-2 month old piglets after feeding 5,00,000 T. solium eggs per pig. The anti-CD4 and anti-CD8 monoclonal antibodies against swine T cells were raised indigenously. It was observed that at 60 days post infection (PI) there was a significant increase (P < 0.01) in CD4+ T cells without any change in CD8+ T cells. Increased 3H-thymidine uptake was found in infected piglets at 45 days PI using both CSE and antigen B. Kinetics of antibody responses indicated significant increase (P < 0.01) at 15 days PI (with CSE antigen) and 30 days PI (with antigen B) by ELISA. This increase persisted till 90 days PI (the time up to which the animals were followed). It was also observed that the cellular mechanisms were triggered in late stage (60 days PI) as compared to humoral responses (15-30 days PI) and may persist longer as seen by both lymphocyte transformation and T cell subpopulation studies. The study suggests that in cysticercosis, both humoral and cellular mechanisms may play a role in the host defences.

Isolation of emetine resistant clones of Entamoeba histolytica by petri dish agar method.

Emetine resistant clones of Entamoeba histolytica strain HM1:IMSS were isolated by using petri dish agar method after mutation with ethyl-methanesulphonate. Two emetine resistant clones were obtained and both were resistant to emetine at a concentration of 24 micrograms/ml of emetine. The 50 per cent inhibitory concentration (IC50) for both emetine sensitive and resistant clones was 5 and 14 micrograms/ml respectively. The colony forming efficiency of E. histolytica strain HM1:IMSS varied from 44 to 54 per cent. This method is useful for isolating clones from different strains of the parasite for molecular and immunological studies.

Fasciolopslasis--a re-emerging infection in Azamgarh (Uttar Pradesh).

Fasciolopsiasis is endemic in the far east. In India, there have been a few reports of the infection, prior to the 1990's. We report two cases from Azamgarh district of Uttar Pradesh. Both the cases were from nearby villages where water chestnuts are cultivated. These may be a source of infection. Pigs are commonly observed in these areas and and may be the source of ova. The only missing link is the finding of infected snails. Presence of at least three cases (one reported earlier) in the area indicates the potential for the infection to re-emerge. Further epidemiological studies are needed to analyse the various ecological factors of transmission. Fasciolopsiasis is endemic in China, Taiwan, Vietnam and Thailand. In India, (Fascilopsis buski) infections in man have been reported earlier from Assam, Maharashtra, Tamil Nadu and parts of Uttar Pradesh. However, to the best of our knowledge, no such reports have been made since 1990's. We herewith report two recent cases from district Azamgarh, Uttar Pradesh (U.P.), India. Factors, such as cultivation of water chestnuts, presence of snails as intermediate hosts and pigs as definitive host in this geographical area seem to be suggestive of an endemic focus and thus needs further epidemiological survey for preventive and control measures, at the earliest.

Cryptosporidiosis in a tertiary care hospital.

BACKGROUND: Cryptosporidium, an important cause of diarrhoea, has been reported worldwide both in immunocompetent and immunocompromised individuals and has emerged as a serious public health problem. This study was undertaken to assess the present status of cryptosporidiosis in children and adults with diarrhoea who attended the Nehru Hospital, Chandigarh which is a tertiary care hospital. METHODS: Routine stool examination was done using saline and iodine stained preparations for various parasites. Modified Ziehl-Neelsen and rapid safranin-methylene blue techniques were used to detect Cryptosporidium in 2000 stool samples (1645 adults, 355 children) from March to November 1998. RESULTS: Of the 2000 samples, 205 (10.2%) were positive for various parasites. Five (1.4%) children were positive for Cryptosporidium and one child was positive for human immunodeficiency virus. In adults, Cryptosporidium was found in only one patient (0.06%). Giardia lamblia was the commonest parasite detected both in adults (4%) and children (15.2%). CONCLUSION: The present study highlights the importance of Cryptosporidium as a cause of diarrhoea, especially in children. Thus, there is a need for specific staining techniques to detect Cryptosporidium in routine diagnostic laboratories.

Diagnostic accuracy of rapid enzyme linked immunosorbent assay for the diagnosis of human hydatidosis.

Rapid enzyme linked immunosorbent assay (ELISA) was compared with the standard ELISA and indirect haemagglutination (IHA) techniques for the diagnosis of human hydatidosis. Eighty nine serum samples including 17 from hydatidosis patients (10 surgically confirmed and 7 clinically suspected), 50 from patients with other parasitic diseases and 22 samples from normal healthy individuals were analysed for anti-hydatid IgG antibodies using sheep hydatid cyst fluid antigen. The sensitivity and specificity respectively was found to be 82.3 and 100 per cent by rapid ELISA; 88.23 and 90.27 per cent by standard ELISA and 70.58 and 100 per cent by IHA technique. No cross reactions were observed with rapid ELISA technique using samples from cysticercosis and amoebiasis patients and normal healthy controls. The present study indicates that rapid ELISA can easily be performed in place of the standard ELISA for the serodiagnosis of human hydatidosis with the advantage of minimising reporting time and manpower hours.

Increasing toxoplasma seropositivity in women with bad obstetric history and in newborns.

BACKGROUND: Most infants with congenital Toxoplasma gondii infection have no symptoms at birth but few may develop retinal diseases or neurological abnormalities later in life. The presence of significant titres of antitoxoplasma antibodies in women in the reproductive age group indirectly indicates that Toxoplasma gondii is the cause of such congenital abnormalities and also sporadic abortions in some women. METHODS: We did a retrospective analysis of antitoxoplasma antibodies detected by indirect haemagglutination assay, in women with bad obstetrical history and in newborns clinically suspected of congenital toxoplasmosis during 1981-91. RESULTS: A significant increase in seropositivity in women and newborns was seen during 1989-91 as compared to 1981-88. More seropositive patients were recorded between April-June and October-December. However, no significant correlation could be observed between rising incidence of seropositivity and the seasonal distribution or age of women. CONCLUSION: Epidemiological studies are required to ascertain the reason for the increasing trend of toxoplasma seropositivity and to suggest appropriate control strategies as it is possible to prevent congenital infection.

Role of calcium influx & energy metabolism in histamine release by filarial antigen in Mastomys natalensis experimentally infected with Brugia malayi.

The present work was undertaken to study the biochemical pathways involved in terms of role of calcium influx and status of energy metabolism in the activation of mast cells obtained from Mastomys natalensis infected with Brugia malayi when challenged in vitro with a potentially allergenic antigen (60 kDa) of Brugia malayi. It was observed that histamine release from sensitized lung and peritoneal mast cells was associated with intracellular influx of radioactive Ca2+, thus establishing the role of calcium in histamine release. The process of activation of mast cells by 60 kDA antigen was an energy requiring process as it utilized the energy phosphates in the form of ATP and the cells followed the aerobic respiratory pathway for the generation of energy molecules.

Evaluation of RNA rich fraction of Litmosoides carinii in induction of protection in infected rats.

The RNA rich fraction of adult L. carinii worms was evaluated in evoking a protective response in infected rats. The RNA immunization was seen to be effective in limiting the microfilaraemia in peripheral blood as well as the adult worm burden. The antibodies to both RNA antigen and adult worm antigen were high in this group of animals at the peak of infection. The RNA immunization was seen to evoke hyperresponsiveness in lymphocytes to mitogens like adult worm antigen, PHA and Con A.

Correlation of zymodeme patterns, virulence & drug sensitivity of Trichomonas vaginalis isolates from women.

Characterization of T. vaginalis strains isolated from symptomatic and asymptomatic subjects was done by isoenzyme analysis. The pathogenicity of these isolates was checked in mouse model and in vivo drug susceptibility was determined. The isolates from symptomatic and asymptomatic individuals could not be grouped on the basis of isoenzyme analysis alone. All the strains except one, were pathogenic for mice, and metronidazole (50 mg/kg body weight) was effective in protecting the mice from T. vaginalis infection.