Shashi Khare

Comparison of the conventional diagnostic modalities, bactec culture and polymerase chain reaction test for diagnosis of tuberculosis.

PURPOSE To evaluate the performance of 65 kDa antigen based PCR assay in clinical samples obtained from pulmonary and extrapulmonary cases of tuberculosis. METHODS One hundred and fifty six samples were processed for detection of Mycobacterium tuberculosis by ZN smear examination, LJ medium culture, BACTEC radiometric culture and PCR tests. RESULTS A significant difference was seen in the sensitivities of different tests, the figures being 74.4% for PCR test, 33.79% for ZN smear examination, 48.9% for LJ culture and 55.8% for BACTEC culture (P< 0.05). However, there was no significant difference (P>0.05) as far as specificity of different tests was concerned. PCR test sensitivity in pulmonary and extrapulmonary clinical samples were 72.7% and 75.9% respectively and found to be significantly higher (P< 0.05) when compared with those of other tests. The mean detection time for M.tuberculosis was 24.03 days by LJ medium culture, 12.89 days by BACTEC culture and less than one day by PCR test. CONCLUSIONS PCR is a rapid and sensitive method for the early diagnosis of pulmonary and extrapulmonary tuberculosis.

Diethylene glycol poisoning in Gurgaon, India, 1998

OBJECTIVE To discover the cause of acute renal failure in 36 children aged 2 months to 6 years who were admitted to two hospitals in Delhi between 1 April and 9 June 1998. METHODS Data were collected from hospital records, parents and doctors of the patients, and district health officials. Further information was obtained from house visits and community surveys; blood and stool samples were collected from other ill children, healthy family members and community contacts. Samples of drinking-water and water from a tube-well were tested for coliform organisms. FINDINGS Most of the children (26/36) were from the Gurgaon district in Haryana or had visited Gurgaon town for treatment of a minor illness. Acute renal failure developed after an episode of acute febrile illness with or without watery diarrhoea or mild respiratory symptoms for which the children had been treated with unknown medicines by private medical practitioners. On admission to hospital the children were not dehydrated. Median blood urea concentration was 150 mg/dl (range 79-311 mg/dl) and median serum creatinine concentration was 5.6 mg/dl (range 2.6-10.8 mg/dl). Kidney biopsy showed acute tubular necrosis. Thirty-three children were known to have died despite being treated with peritoneal dialysis and supportive therapy. CONCLUSION Cough expectorant manufactured by a company in Gurgaon was found to be contaminated with diethylene glycol (17.5% v/v), but a sample of acetaminophen manufactured by the same company tested negative for contamination when gas-liquid chromatography was used. Thus, poisoning with diethylene glycol seems to be the cause of acute renal failure in these children.

Diagnostic potential of IS6110, 38kDa, 65kDa and 85B sequence-based polymerase chain reaction in the diagnosis of Mycobacterium tuberculosis in clinical samples

PURPOSE The correlation between the presence of specific gene sequence of M. tuberculosis and specific diagnosis of clinical tuberculosis is not known. This study compared the results of polymerase chain reaction (PCR) amplification of M. tuberculosis specific DNA sequences (IS6110, 65kDa, 38kDa and mRNA coding for 85B protein) from different clinical samples of pulmonary and extrapulmonary tuberculosis. METHODS One hundred and seventy-two clinical samples from suspected tuberculosis patients were tested for smear examination, culture (LJ and rapid BACTEC 460 TB system) and PCR. PCR was performed with specific primers for the targets: IS6110, 65 kDa, 38 kDa and 85 B. RESULTS Each PCR test was found to have a much higher positivity than conventional test and BACTEC culture (P < 0.05). Smear positive samples (56) and the samples (36) showing positive results by conventional methods (smear and LJ medium culture) and BACTEC were found to be positive by all PCR protocols. No significant difference was found between the four PCR protocols (P> 0.05). The primer specific for amplifying the 123bp IS6110 fragment gave the highest positivity (83%), followed by 65kDa, 38kDa and 85B RT-PCR in descending order. CONCLUSIONS These data suggest that the presence of IS6110 correlates more closely with the diagnosis of clinical tuberculosis than that of 65kDa, 38kDa and 85B proteins.

Post-earthquake outbreak of rotavirus gastroenteritis in Kashmir (India): An epidemiological analysis

OBJECTIVE An earthquake struck Kashmir on 8 October 2005. A central team of public health specialists was sent to Kashmir to assess the public health measures required following the earthquake, and to assist in institution of public health measures. STUDY DESIGN Epidemiological and environmental investigation in Tangdar block (Kupwara district) and Uri Tehsil (Baramula district). METHODOLOGY Visits to villages affected by the earthquake, rehabilitation camps and health care, examination of cases with acute diarrhoeal disease (ADD), environmental observations, collection of clinical samples from ADD cases and environmental samples from drinking water sources, and laboratory methods. RESULTS In total, 1783 cases of ADD were reported between 14 October and 17 December 2005 in Tangdar (population 65000). The overall attack rate was 20% in children under 4 years of age. Twelve cases of ADD with loose motions without blood were studied, and 11 rectal swabs and one stool sample were processed. No bacterial enteropathogens could be isolated, but three of the 12 samples yielded rotavirus antigen on enzyme-linked immunosorbent assay. Twelve of 13 (92.3%) water samples, collected from various stream or tap water (source: spring/stream) sources, were unsatisfactory (P=0.001) using the H(2)S strip method compared with other sources (well/mineral water). All eight water sources in Tangdar block were unsatisfactory, indicated by blackening of H(2)S filter paper strips. Following the earthquake, drinking stream water or tap water without boiling or chlorination may have led to a common source water-borne outbreak of rotavirus gastroenteritis. Other contributing factors were: overcrowding; poor sanitation; open-air defaecation; poor hygiene; and living in makeshift camps near streams. Person-to-person transmission may also have contributed to perpetuation of the outbreak. Following the establishment of medical camps and information, education and communication regarding the need to drink boiled water and follow safer hygienic practices, the outbreak was brought under control. CONCLUSIONS The earthquake in Kashmir in 2005 led to widespread contamination of drinking water sources such as stream and tap water (source: stream or spring). This appears to have led to a common source outbreak of rotavirus between October and December 2005, leading to ADD, amongst infants and small children, transmitted by the faecal-oral route and perpetuated by person-to-person transmission.

Etiology and clinico-epidemiological profile of acute viral encephalitis in children of western Uttar Pradesh, India

OBJECTIVES To study the etiology of viral encephalitis (VE) in the children of western Uttar Pradesh, India and to assess the clinico-epidemiological profile of these children in relation to VE. METHODS Both cerebrospinal fluid and serum samples were collected from pediatric patients suffering from encephalitis hospitalized at Jawaharlal Nehru Medical College, Aligarh from July 2004 to November 2006. Viral isolation was done on RD cells, HEp-2 cells, and Vero cells from the cerebrospinal fluid samples of children with suspected VE. A microneutralization test was performed for enterovirus 71. An enzyme immunoassay for IgM antibodies was performed for measles virus, mumps virus, varicella zoster virus, herpes simplex virus 1, and Japanese encephalitis virus. RESULTS Eighty-seven patients were enrolled in the study. The most common etiology of VE was enterovirus 71 (42.1%), followed by measles (21.1%), varicella zoster virus (15.8%), herpes simplex virus (10.5%), and mumps (10.5%). Japanese encephalitis virus was not found in any case. Enterovirus 71 infection caused significant morbidity in children; mortality occurred in 50%. A preponderance of cases occurred in December. In our study generalized convulsions along with altered sensorium were the significant findings in patients with VE. CONCLUSIONS Enterovirus 71, the major etiology of VE in our study, was associated with significant mortality and morbidity. Such studies should be conducted frequently to assess the role of emerging VE in different regions.

Congenital CMV infection in symptomatic infants in Delhi and surrounding areas

Many viral infections are associated with significant maternal and fetal consequences during pregnancy among which cytomegalovirus is one of the most important agent, globally. Both primary and recurrent infection due to this virus can result in fetal infection. Samples from Congenital Anoammaled babies are referred to NICD from Delhi based Government hospitals and surrounding areas for diagnosis of congenital infections like Toxoplasm, Rubella, CMV and Herpes. In the present study, accumulated data is presented for the most common teratogenic virus—Cytomegalovirus prevalence as a causative agent for congenital infection in New Born babies at Delhi and surrounding areas. 96 samples from symptomatic babies in the age group of few days to 6 months exhibiting different congenital anomalies, were reported between 1 st Jan 04 to 30 th April/05. All the blood samples were tested for the detection of CMV (IgM) antibodies using μ-capture ELISA technique. 18(18.75%) samples from babies showed positive titres for CMV-IgM antibodies. None of the mothers of positive babies were found positive for CMV-IgM antibodies but all were serologically exposed to CMV virus previously as their serum samples were positive for CMV-IgG antibodies indicating primary infection in the past or reactivation/reinfection with a different strain of CMV in the early pregnancy.

Hand-foot-and-mouth disease in calicut

Objective: Hand-Foot-and-Mouth Disease (HFMD) is a mild exanthematous illness seen worldwide, affecting mainly children under ten years of age. The causative agents were initially Coxsackie virus type A 16 and related serotypes. The situation changed drastically about thirty years ago with the advent of a new aetiological agent, Enterovirus type 71 (EV 71), which has caused very large outbreaks with severe complications and many deaths.Methods: The authors report an outbreak of papulovesicular lesions on the skin and oral mucosa compatible with the diagnosis of HFMD in children in and around Calicut in October 2003. Clinical and laboratory study in collaboration with the National Institute of Communicable Diseases, Delhi. Eighty one children with the syndrome were examined and followed up from October 2003 to February 2004, when the outbreak subsided.Result: The outbreak was mild and all children recovered within 1 to 2 weeks.Conclusion: Acute and convalescent paired serum samples collected from 19 patients were examined at the NICD for IgM antibody against EV 71 by microneutralisation test in cell culture. All the paired samples tested showed significant rise in titre of antibodies, confirming the diagnosis of EV 71 infection in each of them.

Diagnosis of tuberculosis in an era of HIV pandemic: A review of current status and future prospects

HIV and tuberculosis co-infection interact in fundamentally important ways. This interaction is evident patho-physiologically, clinically and epidemiologically. There are several differences between HIV-infected and HIV-uninfected patients with tuberculosis (TB) that have practical diagnostic implications. TB is more likely to be disseminated in nature and more difficult to diagnose by conventional diagnostic procedures as immunosuppression progresses. As TB rates continue to increase in HIV-endemic regions, improved diagnostic techniques merit consideration as TB-control strategies. There is a need to develop more user friendly techniques, which can be adapted for use in the high-burden and low-income countries. This review focuses on the diagnostic challenges in HIV-TB co-infection with an update on the current techniques and future prospects in an era of HIV pandemic.

SEROPREVALENCE AND INCIDENCE OF RUBELLA IN AND AROUND DELHI (1988-2002)

National Institute of Communicable Diseases (NICD) has been engaged in rubella testing for serodiagnosis of the infection and screening for immunity status. The compiled and evaluated data of the work done on rubella testing for the past fifteen years has been presented here to show the trend and changing scenario of the disease in Delhi. Blood samples were from 7424 patients referred to NICD, Delhi for serodiagnosis of congenital Rubella syndrome (CRS) in malformed babies, in utero rubella infection in women and immunity status of pregnant women and women with bad obstetric history. They were tested for rubella IgG and/or rubella IgM antibodies using commercially available reagents and kits. The data from the 15 years of testing was then compiled and evaluated. From the available data it was seen that immunity status against rubella in childbearing age group of women increased steadily from 49% in 1988 to 87% in 2002. Reported cases of CRS at NICD are also on the decline over the time period. There is periodic indication of high incidence of rubella in the year 1988; 1991 and 1998 as the reported cases of acute rubella infection in childbearing age group is high during these years.

A severe and explosive outbreak of hepatitis B in a rural population in Sirsa district, Haryana, India: unnecessary therapeutic injections were a major risk factor

Most outbreaks of viral hepatitis in India are caused by hepatitis E. This report describes an outbreak of hepatitis B in a rural population in Haryana state in 1997. At least 54 cases of jaundice occurred in Dhottar village (population 3096) during a period of 8 months; 18 (33.3%) of them died. Virtually all fatal cases were adults and tested positive for HBsAg (other markers not done). About 88% (21/24) of surviving cases had acute or persistent HBV/HCV infections; 54% (13/24) had acute hepatitis B. Many other villages reported sporadic cases and deaths. Data were pooled from these villages for analysis of risk factors. Acute hepatitis B cases had received injections before illness more frequently (11/19) than those found negative for acute or persistent HBV/HCV infections (3/17) (P = 0.01). Although a few cases had other risk factors, these were equally prevalent in two groups. The results linked the outbreak to the use of unnecessary therapeutic injections.