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Biomedical subjects

R Zachariah

Publications and source records attributed to R Zachariah.

At least 37 records · Page 2Linked to original sources
PubMed2003

Passive versus active tuberculosis case finding and isoniazid preventive therapy among household contacts in a rural district of Malawi.

SETTING: Thyolo district, rural Malawi. OBJECTIVES: To compare passive with active case finding among household contacts of smear-positive pulmonary tuberculosis (TB) patients for 1) TB case detection and 2) the proportion of child contacts aged under 6 years who are placed on isoniazid (INH) preventive therapy. DESIGN: Cross-sectional study. METHODS: Passive and active case finding was conducted among household contacts, and the uptake of INH preventive therapy in children was assessed. RESULTS: There were 189 index TB cases and 985 household contacts. Human immunodeficiency virus (HIV) prevalence among index cases was 69%. Prevalence of TB by passive case finding among 524 household contacts was 0.19% (191/100000), which was significantly lower than with active finding among 461 contacts (1.74%, 1735/100000, P = 0.01). Of 126 children in the passive cohort, 22 (17%) received INH, while in the active cohort 25 (22%) of 113 children received the drug. Transport costs associated with chest X-ray (CXR) screening were the major reason for low INH uptake. CONCLUSIONS: Where the majority of TB patients are HIV-positive, active case finding among household contacts yields nine times more TB cases and is an opportunity for reducing TB morbidity and mortality. The need for a CXR is an obstacle to the uptake of INH prophylaxis.

Adolescent↗
PubMed2002

Health seeking and sexual behaviour in patients with sexually transmitted infections: the importance of traditional healers in Thyolo, Malawi.

OBJECTIVES: To describe health seeking and sexual behaviour including condom use among patients presenting with sexually transmitted infections (STIs) and, to identify sociodemographic and behavioural risk factors associated with "no condom use" during the symptomatic period. METHODS: A cross sectional study of consecutive new STI cases presenting at the district STI clinic in Thyolo, Malawi. They were interviewed by STI counsellors after obtaining informed consent. All patients were treated according to national guidelines. RESULTS: Out of 498 new STI clients, 53% had taken some form of medication before coming to the STI clinic, the most frequent alternative source being the traditional healer (37%). 46% of all clients reported sex during the symptomatic period (median 14 days), the majority (74%) not using condoms. 90% of all those who had not used condoms resided in villages and had seen only the traditional healer. Significant risk factors associated with "no condom use" included visiting a traditional healer, being female, having less than 8 years of school education, and being resident in villages. Genital ulcer disease (GUD) was the most common STI in males (49%) while in females this comprised 27% of STIs. CONCLUSIONS: These findings, and especially the extremely high GUD prevalence is of particular concern, considering the high national HIV prevalence in Malawi (9%) and the implications for STI and HIV transmission. There is an urgent need to integrate traditional healers in control activities, encourage their role in promoting safer sexual behaviour, and to reorient or even change existing strategies on condom promotion and STI control.

Adult↗
PubMed2002

HIV prevalence and demographic risk factors in blood donors.

OBJECTIVES: To estimate HIV prevalence in various blood donor populations, to identity sociodemographic risk factors associated with prevalent HIV and to assess the feasibility of offering routine voluntary counselling services to blood donors. DESIGN: Cross-sectional study. SETTING: Thyolo district, Malawi. METHODS: Data analysis involving blood donors who underwent voluntary counselling and HIV testing between January 1998 and July 2000. RESULTS: Crude HIV prevalence was 22%, while the age standardised prevalence (>15 years) was 17%. Prevalence was lowest among rural donors, students and in males of the age group 15-19 years. There was a highly significant positive association of HIV prevalence with increasing urbanisation. Significant risk factors associated with prevalence for both male and female donors included having a business-related occupation, living in a semi-urban or urban area and being in the age group 25-29 years for females and 30-34 years for males. All blood donors were pre-test counselled and 90% were post test counselled in 2000. CONCLUSIONS: HIV prevalence in blood donors was alarmingly high, raising important concerns on the potential dangers of HIV transmission through blood transfusions. Limiting blood transfusions, use of a highly sensitive screening test, and pre-donation selection of donors is important. The experience also shows that it is feasible to offer pre and post test counselling services for blood donors as an entry point for early diagnosis of asymptomatic HIV infection and, broader preventive strategies including the potential of early access to drugs, for the prevention of opportunistic infections.

Adolescent↗
PubMed2002

Cotrimoxazole prophylaxis in HIV-infected individuals after completing anti-tuberculosis treatment in Thyolo, Malawi.

SETTING: Thyolo, rural southern Malawi. OBJECTIVES: To determine 1) the proportion who continue with cotrimoxazole prophylaxis for the prevention of opportunistic infections, and 2) the reasons for continuing or stopping prophylaxis, in human immunodeficiency virus (HIV) infected individuals with tuberculosis (TB) who complete anti-tuberculosis treatment. DESIGN: A cross-sectional study. METHODS: A questionnaire study of all HIV-infected TB patients who had been registered over a 3-month period to receive anti-tuberculosis treatment and cotrimoxazole prophylaxis and who had completed antituberculosis treatment 3-6 months earlier. RESULTS: Of 82 HIV-infected individuals who were alive at the time of interview, 76 (93%) were continuing with cotrimoxazole and wished to do so indefinitely. The most common reason for continuing the drug was to prevent illness associated with HIV, while the most common reason for stopping was long distances to the health facility. Ninety-six percent of patients received cotrimoxazole free of charge from a health centre. Of those who wished to continue indefinitely, the majority (63%) could not afford to pay for the drug. CONCLUSIONS: In a rural setting, the great majority of HIV-infected individuals continued with cotrimoxazole after completing anti-tuberculosis treatment. Making the drug available and providing it free of charge is essential if it is to remain accessible for longer term prevention.

AIDS-Related Opportunistic Infections↗
PubMed2001

Preliminary evaluation of diagnostic tests using horses experimentally infected with trypanosoma evansi.

Seven surra negative horses were intravenously inoculated with 3 x 10(6)Trypanosoma evansi parasites derived from a camel. One horse was maintained as an uninfected negative control. Three antigen and three antibody detection tests were evaluated for diagnosis of infection in horses. The microhaematocrit centrifugation test (MHCT) was the most sensitive, first detecting parasites between one and three days (x 2.4) post infection (p.i.). The antigen (ag)-ELISA detected antigen between three and ten days (x 6.6) p.i. The latex agglutination test (LAT) first gave positive results on day 3 (x 3.0) p.i. Following the treatment of horses with trypanocidal drugs, the MCHT and the mouse inoculation test (MIT) became negative. Antigen levels using LAT declined and reached pre-infection levels in five out of six horses during the period of observation (92-279 days). Antigen levels using the ag-ELISA declined as well but did not reach pre-infection levels in any of the six horses.Three antibody detection techniques, ab-ELISA, card agglutination test (CATT), and immunofluorescent antibody test (IFAT) detected antibodies in the blood of all seven infected horses but not in the uninfected control. However, the ab-ELISA did not discriminate clearly between sera from infected and uninfected horses because unacceptably high ELISA background readings were detected in 15% of the surra negative horses shipped to the UAE from the UK. The ELISA antibody increased above pre-infection levels in the six horses experimentally infected, but not in one horse. In this horse the ELISA antibody level exceeded the cut-off level only after the reoccurrence of the T. evansi infection. The IFAT detected antibodies 15.7 days p.i. in all infected horses.

Animals↗
PubMed2001

Compliance with cotrimoxazole prophylaxis for the prevention of opportunistic infections in HIV-positive tuberculosis patients in Thyolo district, Malawi.

OBJECTIVE: To verify compliance with cotrimoxazole prophylaxis in human immunodeficiency virus (HIV) infected tuberculosis (TB) patients during the continuation phase of anti-tuberculosis treatment, and to assess the sensitivity, specificity and positive predictive values of verbal verification and pill counts as methods of checking compliance. DESIGN: Cross-sectional study. METHODS: Cotrimoxazole compliance was assessed in a cohort of TB patients who were attending four TB follow-up centres during the continuation phase of anti-TB treatment between months 4 and 6. Verbal verification of drug intake, physical verification of pill count balance, and urine trimethoprim detection by gas chromatography and mass spectrometry were used for assessing compliance. RESULTS: Using urine trimethoprim detection as the gold standard for compliance, trimethoprim was detected in 82 (94%) of 87 patients in the cohort. Verbal verification of cotrimoxazole intake and objective pill count balances showed high sensitivity and positive predictive values compared with the gold standard of urine trimethoprim detection. CONCLUSIONS: In a rural district in Malawi, compliance with cotrimoxazole as an adjunct to anti-tuberculosis treatment in HIV-infected TB patients was good, and can be assessed simply and practically by verbal verification and pill counts.

AIDS-Related Opportunistic Infections↗
PubMed1999

Experimental camelpox infection in vaccinated and unvaccinated dromedaries.

Four dromedaries were infected with a virulent camelpox virus strain which was isolated from the lung of a Saudi Arabian camel. The camels which were infected intradermally and subcutaneously developed severe generalized camelpox. One of these camels had to be euthanized on humane grounds and the second one died 13 days after being infected. This dromedary also developed internal pox. Neither dromedary showed camelpox antibodies before infection. The other two camels which had been vaccinated with Ducapox 6 years prior to the viral challenge did not develop any clinical symptoms when given 5 ml of the field virus intravenously and intramuscularly. They seroconverted after the challenge. Although only two camels were used for this trial, the results indicate that a single dose of Ducapox can protect 1-year-old camels from camelpox infection for several years.

Animals↗
PubMed1998

Salmonellosis in relation to chlamydiosis and pox and Salmonella infections in captive falcons in the United Arab Emirates.

During the spring of 1995, 1996 and 1997 following tests on six peregrine falcons (Falco peregrinus) and two gyr falcons (Falco rusticolus), Salmonella typhimurium was isolated from liver, spleen and small intestines. Four of the falcons (two peregrines and two gyrs) had also contracted Chlamydia infection, three peregrines a pox infection and one peregrine a Herpesvirus infection. It is believed that this dual infection was fatal for these birds. The disease was marked by anorexia, dehydration and green-coloured droppings. Necropsy of all falcons revealed discolouration of the liver and enlargement of liver and spleen. Miliary necrosis was detected in all livers. A total of 12 salmonella serovars, including S. typhimurium, were cultured from faeces of 48 falcons which showed no clinical signs.

Animals↗
PubMed1998

Maternal transfer of paramyxovirus type 1 antibodies and antibody response to a live Newcastle disease vaccine in kori bustards.

Studies were conducted to monitor the decline of maternal antibodies to paramyxovirus type 1 (PMV-1) in kori bustard chicks (Ardeotis kori), and to determine the antibody response in birds with low levels of maternally derived immunity (MDI) after being given either one or five times the standard domestic fowl dose of a live PMV-1 La Sota vaccine intranasally. The results confirmed that PMV-1 antibodies were transferred to eggs and chicks derived from kori bustard hens immunized with inactivated vaccine 5 to 8 mo previously. The levels of inherited antibody in chicks varied considerably, with 21% of birds having no detectable antibodies at day 14 Chicks hatched from dams with high hemagglutination inhibition (HI) antibody titers had high titers of MDI. Mean antibody levels in seropositive chicks were log2 6.3 and log2 2.9 on days 14 and 42, respectively. The rate of decline of detectable antibodies (1 log2), was estimated to be 5.50 to 6.25 days and 12.25 days in 14 to 21 and 28 to 42 day old chicks, respectively. There was no significant HI antibody response in bustards given a primary vaccination of either one or five times the standard domestic fowl dose of live vaccine intranasally up to 3 wk post-vaccination. High levels of HI antibodies, log2 7.4, were detected in birds given a secondary dose of inactivated vaccine, but not in birds given a secondary dose of live vaccine at 2 wk post-vaccination.

Administration, Intranasal↗
PubMed1997

Research and practice in an academic community nursing center.

PURPOSE: To identify issues and describe strategies used in developing a successful program of clinical research focused on the vulnerable populations served by one urban academic nursing center. Academic community nursing centers provide ideal settings to implement programs of research. Understanding the challenges when integrating research into these practices and the strategies used is important. SETTING AND SCOPE: The University of Wisconsin-Milwaukee Silver Spring Community Nursing Center has provided primary health care services to a low-income urban population since 1987. A team of advanced practice nurse clinicians, community health nurses, and other health care professionals and community residents implemented a broad range of innovative, community-focused, clinical interventions that are routinely studied through an integrated program of nursing research. Their strategies for research implementation are analyzed. CONCLUSIONS AND IMPLICATIONS: Factors affecting the integration of research into the center include (a) community mistrust, (b) the need for participatory recruitment strategies, and (c) the need for multiple data collection methods. Meeting these challenges requires that research agendas and methods are consonant with community goals. The inclusion of clinicians, other providers, and community residents as active members of research teams is critical to success. Reframing research and practice role in terms of team effort that incorporates the community can strengthen research and practice-and benefit professionals and the populations they serve.

Academic Medical Centers↗
PubMed1994

Maternal-fetal attachment: influence of mother-daughter and husband-wife relationships.

Intergenerational attachment relationships between the pregnant woman and her mother, her husband, and her fetus were examined. Self-completed instruments were used to measure the attachment variables for a convenience sample of 115 middle-class mothers who attended urban prenatal classes. Results supported the hypothesis that mother-daughter and husband-wife attachment were correlated positively. Contrary to study predictions, maternal-fetal attachment scores were not related to mother-daughter and husband-wife attachment scores. Maternal-fetal attachment was related to length of gestation. Results provide only partial support for the intergenerational model of attachment relationships.

Adult↗
PubMed1994

Mother-daughter and husband-wife attachment as predictors of psychological well-being during pregnancy.

This study explores the influence of mother-daughter and husband-wife attachment, and social support on the psychological well-being of women during pregnancy. The design represents passive observational approach. Self-completed instruments were used to measure mother-daughter, and husband-wife attachment, social support, and psychological well-being for a convenience sample of 115 middle-class women, who attended prenatal classes at an urban health department in Canada. Multiple correlational and regression techniques were used to analyze the relationships among study variables. Results supported the hypothesis that mother-daughter and husband-wife attachment relationships were significant predictors of psychological well-being of women during pregnancy. There was significant pairwise relationship between psychological well-being and social support; however, after adjusting for husband-wife and mother-daughter attachment, there was no longer any significant relationship between the two variables. Findings provide new insights into the role of unique attachment relationships in promoting psychological well-being for pregnant women.

Adult↗
PubMed1994

Survey of cellular radiosensitivity parameters.

A model of the formation of particle tracks in emulsion has been extended through the use of biological target theory to formulate a theory of the response of biological cells and molecules of biological importance to irradiation with energetic heavy ions. For this purpose the response to gamma rays is represented by the single-hit, multitarget model with parameters m and D0, while additional parameters kappa (or a0) and sigma 0 are required to represent the size of internal cellular targets and the effective cross-sectional area of the cell nucleus, respectively, for heavy-ion bombardments. For one-or-more-hit detectors, only the first three of these parameters are required and m = 1. For cells m is typically 2 or more. The model is developed from the concept that response to secondary electrons follows the same functional form for gamma rays and for the gamma rays surrounding an ion's path. Originally applied to dry enzymes and viruses in 1967, the model of the one-hit detector has been extended to emulsions, to other physical and chemical detectors, to single- and double-strand breaks in DNA in EO buffer and to three E. coli strains. The two-hit response has been observed for "track core" effects in radiation chemistry, for supralinearity in thermoluminescent dosimeters and for desensitized nuclear emulsions, where hit numbers up to 6 have been observed. In its extension to biological cells, additional concepts are required relating to the character of the track, namely the grain-count and track-width regimes, and to the ability of multitarget systems to acquire damage from intertrack delta rays (called gamma kill) as well as from intratrack delta rays (called ion kill). The model has been applied to some 40 sets of radiobiological data obtained from gamma, track-segment heavy-ion and neutron irradiations. Here we elaborate on the meaning of these concepts, tabulate the cellular parameters, and display their systematic behavior and the relationships among them. In particular the parameter kappa, which serves to determine the location in Z*2/beta 2 of the maximum value of the RBE, shows little variation among cell types, while D0, which describes the response to gamma rays and sigma 0, which appears to indicate the target size, varies over many orders of magnitude.

Animals↗
PubMed1993

Experimental and theoretical cross sections for Escherichia coli mutants B, B/r, and Bs-1 after heavy-ion irradiation.

Data for the inactivation of three Escherichia coli mutants by energetic heavy ions are fitted by the track theory of a one-hit detector in an extended target mode. The respective E0's are 46, 36.5, and 12.6 Gy for E. coli B, B/r, and Bs-1 and a0, the assumed target radius, is 0.5 microns for all three. The parameter E0, the D37 with gamma rays, is measured directly, while a0 is fitted to the data. It is significant that neither a point target model nor calculations with a0 = 0.2 and 1.0 micron fit the data. Our fitted target radius, a0, approximates the size of the bacterium. These results raise questions as to why the E. coli mutants are one-hit detectors, and concerning the differences in the E0's in relation to a mechanistic interpretation of cell killing.

Acceleration↗
PubMedDate not supplied

Behavioural characteristics, prevalence of Chlamydia trachomatis and antibiotic susceptibility of Neisseria gonorrhoeae in men with urethral discharge in Thyolo, Malawi.

A study was carried out in 2000/2001 in a rural district of Malawi among men presenting with urethral discharge, in order to (a) describe their health-seeking and sexual behaviour, (b) determine the prevalence of Neisseria gonorrhoeae and Chlamydia trachomatis, and (c) verify the antibiotic susceptibility of N. gonorrhoeae. A total of 114 patients were entered into the study; 61% reported having taken some form of medication before coming to the sexually transmitted infections clinic. The most frequent alternative source of care was traditional healers. Sixty-eight (60%) patients reported sexual encounters during the symptomatic period, the majority (84%) not using condoms. Using ligase chain reaction on urine, N. gonorrhoeae was detected in 91 (80%) and C. trachomatis in 2 (2%) urine specimens. Forty five of 47 N. gonorrhoeae isolates produced penicillinase, 89% showing multi-antimicrobial resistance. This study emphasizes the need to integrate alternative care providers and particularly traditional healers in control activities, and to encourage their role in promoting safer sexual behaviour. In patients presenting with urethral discharge in our rural setting, C. trachomatis was not found to be a major pathogen. Antimicrobial susceptibility surveillance of N. gonorrhoeae is essential in order to prevent treatment failures and control the spread of resistant strains.

Adolescent↗