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P G Babu

Publications and source records attributed to P G Babu.

At least 19 recordsLinked to original sources
PubMed2001

A pilot study of HTLV-I infection in high-risk individuals & their family members from India.

BACKGROUND & OBJECTIVES: Human T lymphotropic virus-I (HTLV-I) has been associated with adult T cell lymphoma/leukemia (ATLL). There are Indian studies on HTLV-I infection among people with sexually transmitted infection, but no large study has been conducted on individuals with haematological malignancies. In this group of individuals, serology is known to under-diagnose HTLV-I infection. This study was carried out to identify serologically and where possible with molecular techniques, HTLV-I infection in individuals with haematological malignancies. To understand the modes of transmission, family members of individuals with proven HTLV-I infection were also studied. Individuals with sexually transmitted infection (STI), blood donors and pregnant women were also studied. METHODS: Particle agglutination test was used to detect antibody to HTLV-I. HTLV genome was amplified by polymerase chain reaction (PCR) and detected with probes by digoxiginin (Dig) ELISA. RESULTS: There was no serological evidence of HTLV-I infection among the healthy blood donors and pregnant women studied. High prevalence of anti-HTLV-I antibody was identified in the patients with haematological malignancies (8 of 86 patients, 9.3%) and a lower prevalence in individuals with STI (8 of 670 individuals, 1.2%). In the STI group, all 8 individuals seroreactive to HTLV-I were coinfected with human immunodeficiency virus (HIV). In the group with haematological malignancies, three of 22 (13.6%) patients with leukemia, 3 of 11 (27.3%) with cutaneous T-cell lymphoma (CTCL) and 2 of 53 (3.8%) with lymphoma were reactive for anti-HTLV-I antibody. In this group, PCR identified all the seroreactive individuals tested. There were also seronegative infected individuals who were only identified by PCR. There was also a large number of seronegative family members who were only positive by PCR. INTERPRETATION & CONCLUSION: The study revealed a strong disease association of HTLV-I with haematological malignancies and evidence for both horizontal and vertical transmission of the infection in the Indian population. HTLV-I infection appears to be common among family members of individuals with HTLV-I associated haematological malignancies.

Adult↗
PubMed1998

Diagnosis of typhoid fever by the detection of anti-LPS & anti-flagellin antibodies by ELISA.

In a developing country like ours where typhoid fever is endemic and there are very few microbiology laboratories to provide diagnosis by culture, a search for non culture techniques for rapid and reliable diagnosis continues. The Widal test has a low sensitivity. We have attempted to adapt the well established enzyme linked immunosorbent assay (ELISA) technique to provide a serological test of better sensitivity and specificity. The ELISA described here to detect anti-LPS antibodies was found to have a sensitivity of 89.4 per cent and a specificity of 94.9 per cent. The sensitivity for the antiflagellin ELISA was 68.1 per cent and specificity was 97.4 per cent. The likelihood ratio was 17.5 for anti-LPS ELISA and 26.2 for the anti-flagellin ELISA. Considering the positivity of either one ELISA as diagnostic, the sensitivity was 93.6 per cent and specificity was 94.9 per cent.

Antibodies, Bacterial↗
PubMed1998

Increasing prevalence of HIV antibody among blood donors monitored over 9 years in one blood bank.

To determine the time trend of HIV infection among non-professional blood donors at the Christian Medical College and Hospital, Vellore, the annual HIV prevalence among them for the years 1993-1997 was compared with that of the previous 5 yr. Since confirmed number of HIV positive blood donors is required for calculation of prevalence, the serum samples which were reactive for HIV 1/2 antibody by ELISA, were confirmed by Western blot. The annual prevalence of HIV antibody gradually increased from 1.6 per 1000 in 1988-1989, to 3.8 per 1000 in 1996-1997. The mean tri-annual prevalences for the years 1988-91, 1991-94 and 1994-97 were 1.3, 2.7 and 3.6 per 1000 respectively, suggesting a slow but steady increase in HIV prevalence over time. Our findings provide an insight into the dynamics of HIV infection in the general population of our country, whom the nonprofessional blood donors at our hospital represent.

Blood Banks↗
PubMed1998

Importance of RT-PCR for detection of hepatitis C virus among different patient groups.

A pilot study was undertaken to evaluate a sensitive single step reverse transcription polymerase chain reaction (RT-PCR) to detect hepatitis C virus (HCV) RNA in plasma samples as an adjunct to antibody detection. In this study, digoxiginin labelling of the amplicon was carried out during the PCR and the product was detected by an ELISA format (DIG-ELISA) as well as ethidium bromide stained gel detection. DIG-ELISA detection of PCR product compared favourably with gel detection. We tested 42 individuals with either parenteral risk factors or chronic liver disease and found the RT-PCR enhanced the detection rate by 19 per cent. Considering either plasma RNA or antibody positivity, HCV infection was detected in 64.3 per cent of patients.

Chronic Disease↗
PubMed1998

A primate model of respiratory syncytial virus infection.

To determine whether bonnet monkeys are susceptible to infection and disease due to respiratory syncytial virus (RSV), 4 juvenile bonnet monkeys (Macaca radiata) were inoculated with RSV intratracheally and sacrificed at 3, 5, 7 and 9 days post infection. RSV was cultured from pre-autopsy broncheoalveolar lavage fluid from all 4 animals with a peak titre of virus on day 9. Serum RSV neutralizing antibody was present by day 7. Animals developed tachypnoea and chest retractions by 5th day post infection and 2 animals had lobular pneumonia on chest radiography. The pathological changes were of a bronchovascular inflammation, interstitial pneumonia and alveolitis, akin to that seen in humans. These findings show that bonnet monkeys can be infected with RSV, and can develop immune response and clinical and pathological changes similar to those seen in human infants with RSV disease. Thus intractracheal RSV inoculation of juvenile bonnet monkeys appears to be a good model to study pathogenesis of RSV disease.

Animals↗
PubMed1997

Immunologic profiles of HIV-infected and uninfected commercial sex workers in the Vellore region of Southern India.

Female commercial sex workers (CSW) play a major role in the transmission of HIV infection in India. Their immunology has not been characterized. To determine HIV-related immunologic changes and establish baseline data for CSW, blood cell counts and serum immunoglobulin levels of 35 HIV-positive, asymptomatic CSW; 37 HIV-negative CSW, and 35 age-matched, non-CSW, healthy women controls were compared. The CSW, irrespective of their HIV status, had abnormalities that included high eosinophil, lymphocyte, and CD8 counts and low CD4:CD8 ratios. The only significant difference between the HIV-positive and HIV-negative CSW was in their neutrophil and CD8 counts (p < 0.05, ANOVA). Compared with normal controls, the CSW had significantly elevated serum IgG, IgA, and IgM levels; however, no significant difference was shown between CSW who tested positive for HIV and those who did not. These results suggest that the CSW of Vellore region in Southern India have hyperimmunoglobulinemia irrespective of their HIV status and thus highlight the need to use appropriate controls when immunologic evaluation studies are done.

Adult↗
PubMed1997

Epidemiological features of acquired immunodeficiency syndrome in southern India.

AIDS was diagnosed in 187 men and 24 women (M:F = 8:1) from April 1987 till December 1994 at the Christian Medical College Hospital, Vellore. The doubling time of the occurrence of AIDS cases was 14 months; during 1987-90 there were an average of 5.7 cases per year; in 1991-93 there were 28 per year; in 1994 there were 104 cases. The mean age of patients was 33 yr for men and 31 for women. Among men, the primary mode of infection was heterosexual contact with female commercial sex workers. Among women, the most common source of infection was their husbands. There were 4 bisexuals and one homosexual subject who might have acquired infection by having sex with other men. There were 135 subjects from urban and 76 from rural communities. Most subjects belonged to the lower socio-economic classes. These data show that HIV infection had been very widespread in this region, both urban and rural.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Detection of HIV type 1 env subtypes A, B, C, and E in Asia using dried blood spots: a new surveillance tool for molecular epidemiology.

Global surveillance of HIV-1 subtypes for genetic characterization is hampered by the biohazard of processing and the difficulties of shipping whole blood or cells from many developing country regions. We developed a technique for the direct automated sequencing of viral DNA from dried blood spot (DBS) specimens collected on absorbent paper, which can be mailed unrefrigerated in sturdy paper envelopes with low biohazard risk. DBS were collected nonrandomly from HIV-1-infected, mostly asymptomatic, patients in five Asian countries in 1991, and shipped via airmail or hand carried without refrigeration to Bangkok, and then transshipped to North America for processing. After more than 2 years of storage, including 6 months at ambient temperatures, proviral DNA in the DBS was amplified by nested PCR, and a 389-nucleotide segment of the C2-V3 env gene region was sequenced, from which 287 base pairs were aligned and subtyped by phylogenetic analysis with neighbor-joining and other methods. From southern India, there were 25 infections with subtype C and 2 with subtype A. From Myanmar (Burma), we identified the first subtype E infection, as well as six subtype BB, a distinct cluster within subtype B that was first discovered in Thailand and that has now appeared in China, Malaysia, and Japan. From southwest China, one BB was identified, while a "classical" B typical of North American and European strains was found in Indonesia. From Thailand, five DBS of ambiguous serotype were identified as three B, one BB, and one E. A blinded control serotype E specimen was correctly identified, but a serotype BB control was not tested. Most HIV-1 in southern India appears to be env subtype C, with rare A, as others have reported in western and northern India. The subtypes BB and E in Myanmar, and the BB in China, suggest epidemiological linkage with these subtypes in neighboring Thailand. DBS are a practical, economical technique for conducting large-scale molecular epidemiological surveillance to track the global distribution and spread of HIV-1 variants.

China↗
PubMed1995

Prevalence of HTLV-I/II antibodies in HIV seropositive and HIV seronegative STD patients in Vellore region in southern India.

This retrospective study was designed to determine the relationship between human T-lymphotropic virus (HTLV) type-I/II infection and human immunodeficiency virus (HIV) infection among sexually promiscuous persons in southern India. Stored sera collected between 1986 and 1993 from 822 male and 488 female patients attending clinics for sexually transmitted diseases (STD), for the purpose of HIV serosurveillance, were used. They comprised 376 HIV-positive sera and 934 HIV-negative sera. They were screened for HTLV-I/II antibody by a particle agglutination test and repeatedly reactive sera were confirmed by an immunofluorescence test and a western blot test. Five (2.4%) of 212 HIV-seropositive men were confirmed positive for HTLV-I/II antibody, while none of the 610 HIV-seronegative men were positive; the difference in prevalence between HIV-seropositive and seronegative men was statistically significant (p < 0.001). Nine (5.5%) of 164 HIV-seropositive women and 3 (0.9%) of 324 HIV-seronegative women were positive for HLTV-I/II antibody (p < 0.005). All HIV-seropositives taken together, had a significantly higher prevalence of HTLV-I/II (3.7%; 14/376) compared with HIV seronegatives (0.3%; 3/934; p < 0.001). Thus, in southern India, HTLV infection, like HIV infection, is sexually transmitted, though less effectively.

Adolescent↗
PubMed1995

Increasing prevalence of human immunodeficiency virus infection among patients attending a clinic for sexually transmitted diseases.

Of 5883 patients screened during 1986 to 1993 in the sexually transmitted diseases (STD) clinic at a hospital in Vellore, south India, 105 (1.79%) were positive for human immunodeficiency virus (HIV) antibody. The prevalence of HIV infection increased from 0.26 per cent in 1986 to 2.64 per cent in 1993. In 1992 the prevalence was even higher, namely 3.94 per cent. The overall prevalence in these 8 yr was 1.98 per cent among men (n = 4392) and 1.21 per cent among women (n = 1491), the difference being statistically significant (P < 0.05). The prevalence in men rose from 0.36 per cent in 1986 to 4.24 per cent in 1992, and in women from 0 to 3.04 per cent during the same period. The major source of infection in men was female commercial sex workers, but among women it was mostly their husbands. The increase in prevalence of HIV infection is alarming, and indicates that the massive educational campaigns and other preventive measures have not resulted in decreased transmission.

Ambulatory Care Facilities↗
PubMed1995

Clinical profile of AIDS in India: a review of 61 cases.

Among 61 patients with AIDS seen in our hospital from February 1986 to June 1992, 38 (62%) had significant weight loss, 34 (56%) had fever of more than a month and 19 (31%) had chronic diarrhoea; 43 (70%) patients had at least one of the above symptoms. Tuberculosis diagnosed in 32 (52%) patients was the commonest secondary infection: 10 had only pulmonary, 15 had pulmonary and extrapulmonary and 7 only extrapulmonary tuberculosis. Secondary infections commonly found in the general population, predominantly with pathogenic bacteria were found in 27 (44%) patients, 45 (74%) patients had opportunistic infections such as oropharyngeal candidiasis 25 (41%) cryptococcal meningitis 4 (7%), recurrent zoster 1 (1.6%). Two (3.3%) patients had interstitial pneumonitis of unknown aetiology. One (1.6%) patient each had oral hairy leukoplakia or immunoblastic lymphoma. Kaposi's sarcoma was not seen in any patient. At the time of writing this, 33 (54%) patients have died; the mean duration from diagnosis of AIDS to death was 4.5 months.

AIDS-Related Opportunistic Infections↗
PubMed1994

Comparison of the indirect immunofluorescence assay with western blot for the detection of HIV antibody.

With the increase in the prevalence of human immunodeficiency virus (HIV) infection in India, there is an urgent need to explore cost-containing methods of HIV antibody detection. We compared the indirect immunofluorescence assay (IFA) with the widely used but expensive confirmatory test, the Western blot (WBT). A panel of sera comprising 42 WB positive, 46 antibody negative (27 ELISA negative and 19 ELISA reactive but WB negative) and 58 sera with indeterminate WB profiles were tested by a commercial IFA kit. The sensitivity of IFA was found to be 97.6 per cent and specificity 97.8 per cent. Of the indeterminate sera, 18 (31%) were positive in IFA while 26 (45%) were negative and 14 (24%) were equivocal. In general, the IFA positivity was associated with the presence of the gag and env antibodies of HIV while negativity associated with the presence of lone antibodies. The cost of testing by IFA is less than 20 per cent of that of WB testing. Thus IFA appears to be a cost-containing alternative to WB in centres in India where immunofluorescent microscopy is routinely done.

Blotting, Western↗
PubMed1994

Rising trend in the prevalence of HIV infection among blood donors.

The prevalence of HIV infection among blood donors was analysed, for the five year period from April 1988 to March 1993. All donors were patients' relatives or volunteers; no paid/commercial donors were accepted. Each year between 14,084 and 15,544 donor blood samples were screened by ELISA and those found reactive were tested by Western blot. Western blot positive samples were considered to be infected with HIV. The prevalence rates were 1.5 per 1000 (1988-89), 1.1 per 1000 (1989-90 and 1990-91) 1.9 per 1000 (1991-92) and 3.1 per 1000 (1992-93). When the mean prevalence rate over the first three years [1.3 per 1000 (1988-89 to 1990-91)] was compared to the prevalence in 1991-92 (1.9/1000), increase was statistically significant (P < 0.05). The prevalence rate in 1992-93 (3/1000) was significantly higher than that of the previous year (P < 0.01). These data suggest that the prevalence of HIV infection in blood donors is increasing and this could be a reflection of the rising prevalence of HIV infection in the general population.

Blood Donors↗
PubMed1994

Transfusion associated HIV infection in patients with haematologic disorders in southern India.

Seventy patients with congenital coagulation disorders (group A) and 202 other patients (group B) attending the Haematology clinic at the Christian Medical College and Hospital, Vellore (India) were screened for HIV infection between March 1989 and April 1991. Fifty five patients in group A and 131 patients in group B had received blood or blood products in the past. Nineteen transfused patients (9 in group A and 10 in group B) had received blood or blood products exclusively from the hospital blood bank and none of them was HIV infected. Among the remaining 167 transfused patients, 14 (30.4%) of the 46 patients in group A and 6 (4.9%) of the 121 patients in group B were found to be positive for HIV. In group A, 13 of the 14 infected patients had received commercially available cryoprecipitate which was thus found to be the most frequent source of infection. In group B the source of infection was most probably unscreened HIV infected blood which was transfused.

Adolescent↗
PubMed1993

The epidemiology of AIDS in the Vellore region, southern India.

OBJECTIVE: To describe the epidemiology of patients with AIDS in Vellore region, Southern India. DESIGN AND METHODS: Sixty-one patients with AIDS were diagnosed and treated between July 1987 and June 1992. Information on their demographic characteristics and probable modes of acquiring HIV infection was collected at interviews with them and their spouses. RESULTS: There was a progressive increase in the number of patients seen over the 5 years. The mean ages of the 51 men and the 10 women were 33 and 29 years, respectively. Of the 44 patients from our district (population, 5 million), 28 were from Vellore town and 10 from rural areas. Forty-seven (92%) men had frequently used prostitutes. Of the women, four were prostitutes, one had had multiple sex partners and five had not had extramarital sexual contact. One man and one woman had no other risk factor except blood transfusion. Thirty-one (51%) patients had died by August 1992. CONCLUSION: The AIDS epidemic in this region is in its early ascending phase, with a doubling time of approximately 1 year. Most men with AIDS were infected by heterosexual contact with prostitutes, while some women were prostitutes themselves. Together with the male-to-female ratio of 5:1, these results suggest that the male population at risk has sex with a much smaller population of female prostitutes, constituting the major chain of transmission. HIV infection is occurring in both urban and rural populations.

Acquired Immunodeficiency Syndrome↗