Utility of smear examination, culture, and serological tests in the diagnosis of visceral leishmaniasis/post-kala-azar dermal leishmaniasis at National Centre for Disease Control, Delhi.

Introduction: A range of assays have been developed to detect specific antileishmanial antibody, such as rK 39 immunochromatographic test (ICT), KE 16 ICT, ELISA test, and indirect immunofluorescent antibody test (IFAT), which play a crucial role in serological diagnosis of visceral leishmaniasis (VL). However, limited published reports are available on the utility of serological test (IFAT test/rk 39), smear examination, and culture in the diagnosis of VL and post-kala-azar dermal leishmaniasis (PKDL) in our country. Materials and Methods: We present utility of serological test (IFAT test/rK 39), smear examination for Leishmania donovani (LD) bodies, and culture in 2589 samples from 2294 VL/PKDL suspected patients (January 2009-December 2019) tested in Centre for Arboviral and Zoonotic diseases, National Centre for Disease Control, New Delhi, India, for laboratory diagnosis of VL/PKDL. Results: A total of 80/553 (14.4%) cases were confirmed of VL (74/522 cases by demonstration of LD bodies in bone marrow smear examination, 5/12 in splenic smear examination 1/19 by culture) and 4/21 (19.0%) cases were confirmed of PKDL (demonstration of LD bodies in slit skin smear examination. In our study 197/1368 (14.4%) cases were diagnosed positive by IFAT, 34/646 (5.2%) cases by rk 39 ICT for VL/PKDL by demonstration of specific antileishmanial antibodies. Conclusion: As the goal of elimination of VL as a public health problem is approaching, apart from serological tests such as rk 39 and IFAT, direct methods of detection such as (parasitic demonstration in BM smear, culture, and molecular tests) for Leishmania may play a crucial role for achieving a correct diagnosis and treatment. We also concluded that IFAT though not field-friendly, its optimal use as an adjunct test with BM smear in all stages of infections may be required. Further rk39 is a simple, reliable, noninvasive, and field-friendly test for diagnosis VL, especially in endemic areas.

Validation of a competitive ELISA and a virus neutralization test for the detection and confirmation of antibodies to Senecavirus A in swine sera.

Senecavirus A (SVA; family Picornaviridae) is a nonenveloped, single-stranded RNA virus associated with idiopathic vesicular disease (IVD) in swine. SVA was detected in pigs with IVD in Brazil, United States, Canada, and China in 2015, triggering the need to develop and/or validate serologic assays for SVA. Our objective was to fully validate a previously developed competitive enzyme-linked immunosorbent assay (cELISA) as a screening test for antibodies to SVA. Additional objectives included the development and validation of a virus neutralization test (VNT) as a confirmatory test for SVA antibody detection, and the comparison of the cELISA, VNT, and an existing immunofluorescent antibody test (IFAT) for the detection of SVA antibodies in serial bleeds from SVA outbreaks. The diagnostic specificity and sensitivity were 98.2% (97.2-98.9%) and 96.9% (94.5-98.4%) for the cELISA, and 99.6% (99.0-99.9%) and 98.2% (95.8-99.4%) for the VNT, respectively. There was strong agreement among cELISA, VNT, and IFAT when compared based on kappa coefficient. Based on these performance characteristics, these tests are considered suitable for serologic detection of SVA in pigs.

Frequency of Toxoplasma gondii antibodies in bovines in the state of Pernambuco, Brazil / Frequência de anticorpos anti-Toxoplasma gondii em bovinos do estado de Pernambuco, Brasil

Toxoplasmosis is a parasitic disease caused by Toxoplasma gondii that affects homeothermic animals, including humans. Felines are considered the definitive host of this parasite, while other animals act as intermediate hosts. The purpose of this study was to assess the frequency of anti-T. gondii IgG antibodies in bovines in the state of Pernambuco, Brazil. Serum samples (n = 427) from animals in 13 municipalities of the coastal forest/plantation region of the state were analyzed using the immunofluorescent antibody test (IFAT). The overall results revealed a prevalence rate of 16.63% (27/427). High percentages of positivity were found among animals aged 25 to 36 months (28.57%; 30/42) and in males (22.22%; 2/9). The present findings suggest that bovine toxoplasmosis is endemic in the area under study.

Toxoplasmose é uma doença parasitária que infecta todos os animais homeotérmicos, incluindo o homem. Na epidemiologia da infecção, os felinos são os hospedeiros definitivos, e outros animais são os hospedeiros intermediários do Toxoplasma gondii. O objetivo deste trabalho foi determinar a frequência de anticorpos IgG anti-Toxoplasma gondii em bovinos do Estado de Pernambuco. Para tanto, foram coletadas 427 amostras de soro sanguíneo de bovinos provenientes de 13 municípios localizados na Zona da Mata do Estado de Pernambuco. Tais amostras foram analisadas pela técnica de Imunofluorescência Indireta para pesquisa de anticorpos anti-Toxoplasma gondii. A frequência observada foi de 16,63% (27/427). Anticorpos anti-Toxoplasma gondii foram mais frequentes (28,57%) em animais com idade entre 25-36 meses de idade. Considerando-se por sexo, observou-se uma maior positividade entre os machos que apresentaram 22,22% (2/9). Os resultados demonstram que a toxoplasmose é endêmica nessa região.

IgG avidity ELISA test for diagnosis of acute toxoplasmosis in humans.

Serum samples, 100 in the total number, were collected from different laboratories in Tehran, Iran and tested for anti-Toxoplasma specific IgG and IgM antibodies using indirect immunofluorescent antibody test (IFAT). Using the IgG (chronic) and IgM (acute) positive samples, the IgG avidity test was performed by ELISA in duplicate rows of 96-well microtiter plates. One row was washed with 6 M urea and the other with PBS (pH 7.2), then the avidity index (AI) was calculated. Sixteen out of 18 (88.9%) sera with acute toxoplasmosis showed low avidity levels (AI ≤ 50), and 76 out of 82 (92.7%) sera in chronic phase of infection showed high avidity index (AI>60). Six sera had borderline ranges of AI. The results showed that the IgG avidity test by ELISA could distinguish the acute and chronic stages of toxoplasmosis in humans.

IgG Avidity ELISA Test for Diagnosis of Acute Toxoplasmosis in Humans

Serum samples, 100 in the total number, were collected from different laboratories in Tehran, Iran and tested for anti-Toxoplasma specific IgG and IgM antibodies using indirect immunofluorescent antibody test (IFAT). Using the IgG (chronic) and IgM (acute) positive samples, the IgG avidity test was performed by ELISA in duplicate rows of 96-well microtiter plates. One row was washed with 6 M urea and the other with PBS (pH 7.2), then the avidity index (AI) was calculated. Sixteen out of 18 (88.9%) sera with acute toxoplasmosis showed low avidity levels (AI60). Six sera had borderline ranges of AI. The results showed that the IgG avidity test by ELISA could distinguish the acute and chronic stages of toxoplasmosis in humans.

IgG Avidity ELISA Test for Diagnosis of Acute Toxoplasmosis in Humans

Serum samples, 100 in the total number, were collected from different laboratories in Tehran, Iran and tested for anti-Toxoplasma specific IgG and IgM antibodies using indirect immunofluorescent antibody test (IFAT). Using the IgG (chronic) and IgM (acute) positive samples, the IgG avidity test was performed by ELISA in duplicate rows of 96-well microtiter plates. One row was washed with 6 M urea and the other with PBS (pH 7.2), then the avidity index (AI) was calculated. Sixteen out of 18 (88.9%) sera with acute toxoplasmosis showed low avidity levels (AI60). Six sera had borderline ranges of AI. The results showed that the IgG avidity test by ELISA could distinguish the acute and chronic stages of toxoplasmosis in humans.

Prevalence of herpes simplex virus infection in patients with genital herpes using the immunofluorescent antibody test

Background Herpes genitalis (HG) is the commonest cause of sexually transmitted ulcerative disease in the world, including Malaysia1. Herpes simplex virus (HSV) type 2 is more frequently implicated than HSV type 1. This pattern has seen some changes in many parts of the world, with increasing HSV type 1 rates2. Objective The aim of this study was to determine the type of HSV implicated in patients with herpes genitalis at the Genito-Urinary Medicine Clinic, Department of Dermatology, Hospital Kuala Lumpur. Methods A retrospective study was undertaken on 242 patients with a diagnosis of herpes genitalis at the Genito-Urinary Medicine Clinic from January 2000 to December 2004. The study included all cases of genital herpes in patients aged over 12 years. The typing was done by a immunofluorescent - labeled monoclonal antibody technique specific for HSV antigens. Results Majority (76%) were between the ages of 20-49 years. Males outnumbered females by 1.6:1. Younger women (20-29 years old) tend to be more frequently affected than their male counterpart. One fourth (25.7%) of the patients reported having sex with sex workers and less than 1% (0.4%) were sex workers. A significant percentage (30.5%) of married men reported extramarital relationship with sex workers or had a casual or regular partner. Usage of condoms was low at 12%. Clinical diagnosis at presentation was primary herpes genitalis (56%) and recurrent (44%). 162 (67%) out of a total of 242 patients had the herpes immunofluorescent test done. 110 (68%) of those done were negative. Only 34 (21%) of patients with herpes genitalis had a positive immunofluorescent antibody test. Of the 21%, herpes simplex virus type 2 was found in 19 (12%) of patients with herpes genitalis, HSV type 1 in 10 (6%) and HSV types 1 & 2 coinfection in 5 (3%) patients. Conclusions In our study, HSV-2 was still more common causing 57% of the cases seen, HSV-1 29% and HSV-1 and HSV-2 coinfection in 14%. An increased rate of HSV-1 seen could possibly be due to a change in sexual behavior of the patients especially with regards to oro-genital sexual contact.

Prevelance and Clinical Characteristics of Human Metapneumovirus in Hospitalized Children with Acute Respiratory Tract Infection / 实用儿科临床杂志

0.05).5.The clinical symptoms of hMPV infection could not be discriminated from the infection of other common respiratory viruses.Conclusion The acute respiratory-tract infections among children of Xi'an city are associated with cough and fever are major clinical symptoms.

Clinical observation of patients with tsutsugamushi disease at Pyoungtaek area

BACKGROUND: The purpose of this stady is to define the clinical characteristics of Tsutsugamushi disease. METHODS: We analyzed 12 cases of tsutsugamushi disease admitted to BAG AE general hospital from 1999. Oct. 1st to Dec. 10. Tsutsugamushi disease was diagnosed by indirect immunofluorescent antibody test. RESULTS: 1) Among them, 8 cases were female and 4 cases were male. The prevalence was predominantly high in female. 2) The age distribution ranged from 40 to 80 years old. The high incidence of age was 70's and 80's. 3) The peak incidene was showed between October and November.(91.6%). 4) The most frequent symptoms were fever and chills(91.6%). 5) Rash and eschar were observed in 83.3%(10 of 12) both. 6) Hepatosplenomegaly and lymphadenopathy were also observed in 25%(3 of 12), 16.6%(2 of 12) respectively. 7) The Laboratory finding showed the elevation of AST 66.6% (8 of 12), ALT 58.3%(7 of 12), alkaline phosphatase 25%(3 of 12) and LDH 25%(3 of 12). Albuminuria and hypoalbuminuria were also observed in 25%(3 of 12), 58.3%(7 of 12) respectively. 8) The therapeutic efficacy of doxycycline was excellent. CONCLUSION: Tsutsugamushi disease which appeared in Pyoungtack area showed typical clinical pattern and was effective to doxycycline treatment.

Efficacy of Indirect Immunofluorescent Antibody Test in Herpes Simplex Keratitis

Herpes simplex virus keratits(HSK) is one of the most common external eye diseases that cause corneal blindness, Therefore early diagnosis and proper treatment of HSK are essential. However it is frequently misdiagnosed because it shows non-specific corneal lesion than other infectious corneal disease. And also diagnosis of HSK mostly rely on clinical examination and patient history. We evaluated suspicious HSK patients by indirect immunofluofluorescent(IF) antibody test and analyzed its efficacy in the early diagnosis of HSK. Among 47 patients(47 eyes), 37 patients were suspicious heretic keratitis and others not. Dendritic keratitis patients existed in 17 out of 37 patients and they were evaluated with virus culture and indirect IF test. The result of indirect IF test was confirmed under the immunofluorescent microscope and for virus culture the specimens were inoculated on Vero cells(monkey kidney cells). The positive results of indirect IF test was 28 out of 37 suspicious HSK patients and 1 out of 10 non-suspicious HSK patients. Dendritic HSK patients showed IF positive in 15 out of 17 patients(82.3%). Sensitivity of indirect IF test in suspicious HSK patients was 75.7%(2837) and 88.2%(15/17) in dendritic HSK patients. Indirect IF test was all positive(14/14) in dendritic HSK patients that showed culture positive. From these results, indirect IF test has a high sensitivity in early diagnosis of HSK and might be ussful as a rapid diagnostic tool in HSK patients.

Study on Pathogenicity of Borrelia burgdorferi Sensu Lato Isolated in Korea

Spirochetes were isolated from the midgut of Ixodes persulcatus ticks captured at Chungju, Korea and identified as Borrelia afzelii strains by polymerase chain reaction. To determine the pathogenicity of the B. afzelii strains isolated in Korea, the microbiological and pathological features of Lyme disease were observed in C3H/He mice after intraperitoneal inoculation of the fresh isolate of B. afzelii strain. The results are summarized as follows 1) The Borrelia were detected in the tissues of heart, spleen, kidney, urinary bladder and knee joint within 7 days after inoculation of infection by dark field microscopic examination. The isolation rate from heart, urinary bladder and joint was significantly higher than the rate from spleen, kidney, and blood samples. 2) The Borrelia was detected in heart muscle by indirect immunofluorescent antibody test. 3) Antibody to the Borrelia was detected as early as one week after inoculation. 4) The marked tropism of the Borrelia was observed in myocardial, urinary tract and joint tissue. The main pathological features are inflammation in tissues of heart, kidney, joint and urinary bladder. From these results, the Borrelia afzelii strain isolated in Korea were determined as pathogenic strain.

Efficacy of Indirect Immunofluorescent Antibody Test in Herpes Simplex Keratitis

Herpes simplex virus keratits(HSK) is one of the most common external eye diseases that cause corneal blindness, Therefore early diagnosis and proper treatment of HSK are essential. However it is frequently misdiagnosed because it shows non-specific corneal lesion than other infectious corneal disease. And also diagnosis of HSK mostly rely on clinical examination and patient history. We evaluated suspicious HSK patients by indirect immunofluofluorescent(IF) antibody test and analyzed its efficacy in the early diagnosis of HSK. Among 47 patients(47 eyes), 37 patients were suspicious heretic keratitis and others not. Dendritic keratitis patients existed in 17 out of 37 patients and they were evaluated with virus culture and indirect IF test. The result of indirect IF test was confirmed under the immunofluorescent microscope and for virus culture the specimens were inoculated on Vero cells(monkey kidney cells). The positive results of indirect IF test was 28 out of 37 suspicious HSK patients and 1 out of 10 non-suspicious HSK patients. Dendritic HSK patients showed IF positive in 15 out of 17 patients(82.3%). Sensitivity of indirect IF test in suspicious HSK patients was 75.7%(2837) and 88.2%(15/17) in dendritic HSK patients. Indirect IF test was all positive(14/14) in dendritic HSK patients that showed culture positive. From these results, indirect IF test has a high sensitivity in early diagnosis of HSK and might be ussful as a rapid diagnostic tool in HSK patients.

Sensitivity and Specificity of Vi-Indirect Fluore scent Antibody Test in Diagnosis of Typhoid Fever / 감염

BACKGROUND: Typhoid fever is diagnosed by culture or serological study. The confirmative diagnosis of typhoid fever is made by culture of the causative orga-nism usually from body fluids. Serological test is a supportive diagnostic tool, which is useful for early dia-gnosis. In Severance Hospital, Vi-indirect fluorescent antibody test(Vi-IFAT) using the Vi-antigen of Salmo-nella typhi has been used in the diagnosis of typhoid fever since 1989. We investigated the test results from the past 7 years, in order to clarify the sensitivity and specificity of Vi-IFAT. METHODS: A retrospective study was done on pa-tients whose chief complaint was fever and who were tested using Vi-IFAT in the Severance Hospital from 1989 to 1996. The positive value for Vi-IFAT was de- fined as 1:64 or higher. RESULTS: The sensitivity and specificity of Vi-IFAT for typhoid fever was 94.4% and 95.1%, respectively. The positive and negative predictive values were 85.7% and 98.2% respectively. Positive rates of Vi-IFAT after fever onset increased with time and 68% were positive before the first week. From the first to the second week, 89.5% were positive and after the second week, 100% were positive. CONCLUSION: Vi-IFAT is not only a valuable sero-logic test for the diagnosis of typhoid fever, but also useful in the early diagnosis of the disease.

A Clinical and Serologic Study of 21 Cases of Tsutsugamushi Disease Confirmed by Serologic test / 영남의대학술지

Tsutsugamushi disease is an acute febrile disease caused by Rickettsia tsutsugamushi, and which has been reported with increasing frequency thorough the nation since 1986. We experienced 21 cases of Tsutsugamushi Disease diagnosed with serologic test occurring in Taegu city and Kyungpook province during October-November, 1989. The results of survey are as follow. 1) Of 21 cases, 12 (57%) were males and 9 (43%) were females, and the peak incidence was the 4th decade. 2) The outbreak was in October to November and the peak incidence was in October. 3) The most frequent symptoms were fever and chill (100%), myalgia (95%), headache (90%), Eschar and rash were observed in 18 patients (86%) and the eschar was detected in all over the body, especially thorax (33%) and lower extremity (22%). 4) Laboratory features were SGOT elevation (83%), SGPT elevation (61%), LDH elevation (67%), leukocytosis (38%). 5) Indirect immunofluorescent antibody test was done in 18 patients and the antibody titer was above 1:320 in all patients. 6) The chloramphenicol, tetracycline or doxycycline regimens were very effective and mean duration of defervescence from initiation of therapy was 1.3 days. 7) The complication such as meningitis or shock, was not seen.