Modern biology and genomic sciences are rooted in parasitic disease research. Genome sequencing efforts have provided a wealth of new biological information that promises to have a major impact on our understanding of parasites. Microarrays provide one of the major high-throughput platforms by which this information can be exploited in the laboratory. Many excellent reviews and technique articles have recently been published on applying microarrays to organisms for which fully annotated genomes are at hand. However, many parasitologists work on organisms whose genomes have been only partially sequenced. This review is mainly focused on how to use microarray in these situations.

Emerging protozoal pathogens have become a major threat to human health. The number of protozoal pathogens causing human disease has been on the rise since the last two to three decades. Significant increase in the number of immunocompromised people, increase in international travel, deforestation, and widespread urban dwellings are some of the factors contributing to this changing epidemiology of protozoal diseases. Apart from Naegleria and Acanthamoeba, other free-living amoebae like Balamuthia and Sappinia are being reported to cause meningoencephalitis in humans. Plasmodium knowlesi, a zoonotic malarial parasite, has become a major cause of human malaria in Southeast Asia. Trypanosoma evansi and Trypanosoma lewisi, which normally infect horses and rodents respectively, have been reported to cause human trypanosomiasis in India. Balantidium coli is emerging as an important cause of dysentery especially in the immunocompromised population. In India, where a significant proportion of population lives in close proximity to cattle and pigs, B. coli can emerge as a significant pathogen in cases of dysentery, especially in the immunocompromised population. Babesia microti has become an important cause of transfusion transmitted babesiosis (TTB) in countries like the United States. As Babesia can be misdiagnosed as Plasmodium and blood transfusion is becoming common in India, it is necessary to develop diagnostic tests to rule out this pathogen in blood donors. Increased awareness among clinicians, pathologists, and microbiologists along with other factors like constant surveillance, improved diagnostic tests, and a high index of suspicion are important to detect and properly treat such emerging protozoal pathogens in humans.

Background and Objectives: Cryptosporidiosis is a very important opportunistic infection and is responsible for significant morbidity and mortality in HIV/AIDS patients. The objective of this study is to evaluate Ziehl-Neelsen staining, auramine phenol staining, antigen detection enzyme linked immunosorbent assay and polymerase chain reaction, for the diagnosis of intestinal cryptosporidiosis. Materials and Methods: The study was designed to determine the efficacy of modified Ziehl-Neelsen (ZN), Auramine-Phenol (AP) staining, antigen detection enzyme linked immunosorbent assay (ELISA) and nested polymerase chain reaction (PCR) for detection of cryptosporidia in 671 HIV-seropositive patients, 353 HIV-seronegative patients including 198 children with diarrhea and 50 apparently healthy adults. Results: Cryptosporidium was detected in 26 (3.9%), 37 (5.5%), 32 (4.8%) and 40 (6%) HIV-seropositive and 8 (2.3%), 10 (2.9%), 9 (2.6%) and 9 (2.6%) HIV-seronegative patients by ZN staining, AP staining, antigen detection ELISA and PCR, respectively. None of the healthy controls were infected with Cryptosporidium. Based on criteria of 'true positive' samples, i.e. positive by any two of the four techniques out of ZN, AP, antigen detection ELISA and PCR, sensitivity of ZN and ELISA was 79.06% and 95.35% respectively. AP and PCR were found to be 100% sensitive. Specificity of ZN and ELISA was 100% while specificity of AP and PCR was 99.59% and 99.39% respectively. Conclusions: Auramine phenol staining is a rapid, sensitive and specific technique for diagnosis of intestinal cryptosporidiosis.

Background: In recent times, soil-transmitted helminth (STH) infections seem to loose more and more interest due to the fact that resources are being justifiably diverted to more recent priorities such as HIV/AIDS and malaria. In developing countries, the upsurge of intestinal helminth infections constitutes a problem not only of public health concern but also of development. Aim : To find out the prevalence of STH infections in persons visiting the traditional health care centre in west Cameroon. Materials and Methods: In order to evaluate the prevalence and intensity of STH infections, in persons visiting the centre of phytomedecine, a parasitological investigation of feces was carried out in 223 stools, using three techniques (direct examination, concentration method of Willis, and Mc Master technique). Results: 130 stools were collected from male and 93 from female subjects, hence a sex ratio of 1.4:1. Among the 223 stools examined, 97 specimens were found to be positive with one or several parasite species, thus giving a prevalence of 45.3%. The parasitism occurs from early age (1-10 years) reaching 4.5%. The most infected age group was 21-30 years (31%). Female subjects (28.3%) were statistically more infected than males (15.2%). The intestinal nematode species found were Trichuris trichiura (19.2%), Ascaris lumbricoides (13.4%), and hookworm (10.7%). These parasites occurred as single (19.2%) or multiple infections (10.3%). The mean fecal eggs count was 3722±672, 875±462, and 563±283 for A. lumbricoides, hookworm, and T. trichiura, respectively. Conclusion: These results show the necessity of the application of suitable measures which are aimed at reducing the extent of STH.

Background and Objectives: Opportunistic parasitic infections are among the most serious infections in human immunodeficiency virus (HIV) positive patients and claim number of lives every year. The present study was conducted to determine the prevalence of intestinal parasites and to elucidate the association between intestinal opportunistic parasitic infection and CD4 (CD4+ T lymphocyte) counts in HIV-positive patients. Materials and Methods: The study was done on 266 HIV-positive patients presenting with diarrhoea and 100 HIV-positive patients without diarrhoea attending the integrated counselling and testing centre (ICTC) of SMS hospital, Jaipur. Simultaneously, CD4+ T-cell count estimation was done to assess the status of HIV infection vis-à-vis parasitic infections. The identification of pathogens was done on the basis of direct microscopy and different staining techniques. Results: Out of 266 patients with diarrhoea, parasites were isolated from 162 (i.e. 60.9%) patients compared to 16 (16%) patients without diarrhoea. Cryptosporidium parvum (25.2%) was the predominant parasite isolated in HIV-positive patients with diarrhoea followed by Isospora belli (10.9%). Parasites were more commonly isolated from stool samples of chronic diarrhoea patients, (77% i.e. 128/166) as compared to acute diarrhoea patients (34% i.e. 34/100) (P<0.05). The maximum parasitic isolation was in the patients with CD4+ T cell counts below 200 cells/μl. Conclusions: Chronic diarrhoea in HIV-positive patients with CD4+ T-cell counts <200/μl has high probability of association with intestinal parasitic infections. Identification of these parasitic infections may play an important role in administration of appropriate therapy and reduction of mortality and morbidity in these patients.

Background: Recent WHO guidelines recommended a universal "test and treat" strategy for malaria mainly by use of the rapid diagnostic test (RDT) in all areas. There are concerns about RDT that use the antigen histidine-rich protein2 (HRP2) to detect Plasmodium falciparum, because infection can persist after effective treatment. Aim: The aim of this paper is to describe the accuracy of the first response (HRP2)-RDT compared with malaria microscopy used for guiding the field treatment of patients in an outbreak situation in the Al-Rahabah area in Al-Rydah district in Hadramout/Yemen. Materials and Methods: An ad hoc cross sectional survey of all febrile patients in the affected area was conducted in May 2011. The field team was developed including the case management group and the entomology group. The group of case management prepared their plan based on "test and treat" strategy by using First Response Malaria Antigen HRP2 rapid diagnostic test for falciparum malaria, artemsinin-based combination therapy (ACT) according to the national policy of anti-malaria drugs in Yemen were supplied to treat those who were found to be RDT positive in the field; also blood smear films were taken from every patient with fever in order to validate the use of the RDT in the field. Blood film slides prepared and read by skilled lab technicians, the fourth reading was done by one lab expert in the malaria referral lab. Results: The accuracy parameters of HRP2 compared with microscopy are: Sensitivity (74%), specificity (94%). The positive predictive value is 68% and the negative predictive value is 96%. Total agreement is 148/162 (93%) and the overall prevalence is 14%. All the positive malaria cases were of P. falciparum either coming from RDT or microscopy. Conclusions: HRP2-rapid test is an acceptable test as a guide for field treatment in an outbreak situation where prompt response is indicated. Good prepared blood film slides should be used as it is feasible to evaluate the accuracy of RDTs as a quality control tool.

Background: Several serological assays are used for detection of a hydatid antigen in serum for diagnosis of cystic echinococcosis (CE). However, it requires technical expertise and is associated with the risk of acquiring blood-borne infections. Of late, interests have been shifted to other body fluids like urine, saliva, tear drops as alternate specimens in the diagnosis of CE. Aim: The aim of the study was to evaluate the dot enzyme-linked immunosorbent assay (Dot-ELISA) and electro-immunotransfer blot (EITB) for detection of a hydatid antigen in the urine for diagnosis of CE. Materials and Methods: 100 ml of urine samples were collected from the patients with confirmed CE (n=30), patients with suspected CE (n=30), patients with other diseases (n=30) and healthy controls (n=30). A hydatid antigen in urine was detected by Dot-ELISA and EITB using only polyclonal antibodies raised against a complete homogenate hydatid (CHH) antigen in rabbits. Results and Conclusions: The Dot-ELISA using polyclonal antibodies showed a sensitivity of 53.33% and specificity of 96.66%, whereas EITB showed a sensitivity of 46.66%. The Dot-ELISA and EITB employing polyclonal antibodies showed no significant difference in sensitivity (P=0.426). Hence, the Dot-ELISA being a simple procedure can be used for detection of a hydatid antigen in urine for diagnosis of CE.

Background: It is important to understand the biology and health impact of parasites affecting horses in the Western highlands of Cameroon. Aim: to evaluate the prevalence and intensity of infection of gastrointestinal helminths in these animals. Materials and Methods: A total of 894 horses (367 males and 527 females), and aged ≤1 to ≥7 years old were examined. A parasitological investigation of faeces was carried out using two techniques: concentration method of Full Born Willis (flotation in saturated solution of sodium chloride) and Mc Master Technique. Results and conclusions: From the results the overall prevalence was 100%. Nine species of nematode (Parascaris equorum, Oxyuris equi, Habronema sp., Strongyloides westeri, Dictyocaulus arnfieldi, Trichostrongylus axei, Cyathostome sp., Triodontophorus sp., Strongylus sp.) were identified with the prevalence of 18.48%, 16.94%, 2.99%, 6.05%, 5.22%, 7.75%, 12.49%, 1.09%, and 22.26%, respectively, and one species of cestode (Anoplocephala magna) with a prevalence of 6.73%. Strongylus sp. had the highest mean intensity of infection (1270±942) in female horses. Poly-parasitic infections (92.28%) were more common than mono-parasitic infections (7.72%).

Background: Complicated falciparum malaria remains a major cause of morbidity and mortality worldwide. Plasmodium falciparum malaria is a syndrome and a disease of protean clinical manifestations. All cases of falciparum malaria are potentially severe and life threatening, especially when managed inappropriately. Aim: The aim of the present study is to study clinical presentation and complications of patients with complicated P. falciparum malaria and its outcome. Settings and Design: This was retrospective observational study, conducted at tertiary care center in western Maharashtra from January 2011 to December 2011. Materials and Methods: Total 47 patients fulfilling criterion of complicated malaria due to P. falciparum who presented with fever having positive trophozoites of P. falciparum in blood smear were included in this study. Statistical analysis was done by EPI Info 6 statistical software. Results and Conclusion: A total 47 patients had smear positive complicated P. falciparum malaria with 39 were male and 8 were female patients. Total three (6.38%) patients had hypoglycemia at the time of admission. Total 29 (61.70%) patients had jaundice of which 20 were with anemia. Total 22 (46.80%) had anemia of which 20 were with jaundice. Total 6 (12.76%) had cerebral malaria, 6 (12.76%) had acute renal failure (ARF), 5 (10.63%) had acute respiratory distress syndrome (ARDS) and 1 (2.12%) had thrombocytopenia. Total 26 patients had single complication in the form of cerebral malaria 6 (12.76%), jaundice 9 (19.14%), ARF 5 (10.63%), ARDS 4 (8.51%) and anemia 2 (4.25%). Total 20 patients had two complications in the form of jaundice with anemia 20 (42.55%). One (2.12%) patient had four complications in the form of cerebral malaria with ARF with ARDS with thrombocytopenia with 100% mortality. Overall case fatality rate was 10.63% (5/47). The case fatality rate for isolated ARDS was 50% (2/4), with ARF was 20% (1/5) and with cerebral malaria it was 16.66% (1/6). Case fatality rate was highest in patients with ARDS compared to ARF and cerebral malaria with 'P' = 0.0221. Conclusions: In present study most common presentation was jaundice and anemia. Cerebral malaria, ARF and ARDS were uncommon presentation. Overall case fatality rate of complicated P. falciparum malaria was 10.63%. The case fatality rate was highest with multi-organ dysfunction (100%). This study highlights the significant burden of P. falciparum complicated malaria with isolated complication like ARDS with high mortality rate of 50% in present population.

Cysticercosis is a parasitic infection caused by the larvae of the tapeworm Taenia solium which occurs in neural and extraneural forms. Latter commonly involves subcutaneous tissue, skeletal muscles, and eyes. Head and neck sites commonly involved are buccal mucosa, tongue, and lips. It presents as single or multiple submucosal/cutaneous firm nodules. We report a case of cysticercosis of the supraclavicular region of the neck where it presented as a large soft cystic swelling. The diagnosis was made by sonography and confirmed by gross and microscopic examination to be racemose cysticercosis. This is a very rare cause of a neck swelling not reported previously in the literature.

Renal hydatidosis represents only 2-3% of hydatid disease. It is endemic in parts of eastern Europe, middle East, south America, Australia, New Zealand, Alaska, and Canada. Cystic rupture into the collecting system causes hydaturia; isolated renal involvement is even rarer. Here we report a case of left renal hydatid cyst in a 40 year old man presenting as hematuria and macroscopic hydaturia since last ten years. The patient underwent exploratory laparotomy and recovered.

Filariasis is a major public health problem in India and microfilaria is sometimes seen during routine fine needle aspiration cytology (FNAC) smears, but it is very rare to find microfilaria coexistent with neoplastic lesions. Here we report a series of seven cases in which microfilaria is associated with neoplastic lesions. Out of these seven cases one is benign and six are malignant. Also we first time report the microfilaria coexistent with parotid pleomorphic adenoma, undifferentiated carcinoma thyroid and gall bladder carcinoma.

Strongyloides stercoralis is an intestinal nematode producing mild infection in the immunocompetent and fatal hyperinfection syndrome in the immunocompromised. An elderly HIV-negative male presented with symptoms of chronic respiratory disease and vague abdominal symptoms. Examination of sputum and stools showed larvae of S. stercoralis. Bacterial and fungal causes of respiratory infections were ruled out. The patient responded to oral ivermectin.

Dirofilariasis is primarily confined to animals such as dogs, cats, foxes and raccoons. Human dirofilariasis is an accidental zoonotic infection acquired through mosquitoes. Human dirofilariasis due to Dirofilaria repens though endemic in Kerala, reports from Karnataka state are rare. We report a case of solitary subcutaneous dirofilariasis of the eyelid due to D. repens in a 47-year-old woman. She presented with periorbital edema. The swelling was soft, cystic with associated tenderness. A thin, white worm was noticed in the lesion and was removed by traction which was subsequently identified to be D. repens.

Hydatidosis is one of the most important zoonotic diseases in the world. In this report, we describe a 25-year-old patient from Guntur district of Andhra Pradesh who presented with cough, chest pain, dyspnoea, and hemoptysis due to hydatid disease of the lung. Although it is one of the less common causes of hemoptysis, hydatid disease of the lung requires greater attention in countries such as India, where hydatid cyst disease is common.

Meckel's diverticulum is the most common congenital anomaly of the gastrointestinal tract, which is usually asymptomatic. In patients with intestinal ascariasis, Meckel's diverticulum may pursue a silent course or may be complicated by diverticulitis, gangrene and perforation. We report an unusual complication of volvulus of Meckel's diverticulum and an adjacent segment of ileum due to incarceration of worm bolus in a narrow based Meckel's diverticulum leading to gangrene and perforation.

Hydatid cyst is endemic in central parts of India, caused by infection with Echinococcus granulosus larva leading to development of cysts. Liver is most commonly involved organ. Isolated splenic hydatidosis is a very rare entity and only small clinical series or case reports have addressed the issue of splenic echinococcosis. We, hereby, present a case of an isolated giant hydatid cyst in spleen of a 30-year-old lady. Splenectomy was done and the diagnosis was confirmed on histopathological examination. Thus, a hydatid cyst should be kept in mind in the differential diagnosis of cystic lesions of spleen.

Cytological demonstration of microfilaria and adult worms often helps in diagnosis of asymptomatic filarial cases. But demonstration of microfilaria in cytological smears from upper extremity lesions is seldom reported. We are presenting a 32-year-old female patient with elongated, small subcutaneous swelling in the medial aspect of right lower arm. Aspirates from the lesion demonstrate microfilaria though there is no eosinophilia or microfilaremia on subsequent examination of blood sample. In endemic areas, filariasis should always be considered as a possible diagnosis during cytological assessment of any swelling.

We report a case of 35-year-old male patient who presented with painful right side of scrotum and worm pouting out of the scrotum. The patient had undergone surgery for strangulated right inguinal hernia 2 years back. On exploration we found multiple adult Ascaris worms in the scrotum with right-sided hydrocele. All the worms were removed and eversion of sac was done.