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Crampin A, Kasimba S, Mwaungulu NJ, Dacombe R, Floyd S, Glynn JR, Fine PEM. Married to M. tuberculosis: risk of infection and disease in spouses of smear-positive tuberculosis patients. Trop Med Int Health 2011; 16:811-8. [PMID: 21447058 PMCID: PMC3378469 DOI: 10.1111/j.1365-3156.2011.02763.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To quantify the risk of infection and disease in spouses of tuberculosis patients and the extent to which intervention could reduce the risk in this highly exposed group. METHODS We compared HIV prevalence, TB prevalence and incidence and tuberculin skin test (TST) results in spouses of TB patients and community controls. HIV-positive spouses were offered isoniazid preventive therapy (IPT), and TST was repeated at 6, 12 and 24 months. RESULTS We recruited 148 spouses of smear-positive patients ascertained prospectively and 3% had active TB. We identified 203 spouses of previously diagnosed smear-positive patients, 11 had already had TB, and the rate of TB was 2.4 per 100 person years(py) over 2 years (95% CI 1.15-5.09). 116 were found alive and recruited. HIV prevalence was 37% and 39% in the prospective and retrospective spouse groups and 17% in controls. TST was ≥10 mm in 80% of HIV negative and in 57% of HIV-positive spouses ascertained retrospectively; 74% HIV negative and 62% HIV-positive spouses ascertained prospectively, and 48% HIV negative and 26% HIV-positive community controls. Of 54 HIV-positive spouses, 18 completed 6-month IPT. At 2 year follow-up, 87% of surviving spouses had TST ≥10 mm and the rate of TB was 1.1 per 100 py (95% CI 0.34-3.29). CONCLUSIONS Spouses are a high-risk group who should be screened for HIV and active TB. TST prevalence was already high by the time the spouses were approached but further infections were seen to occur. Uptake and adherence to IPT was disappointing, lessening the impact of short-duration therapy.
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Glynn J, Kayuni N, Banda E, Parrott F, Floyd S, Tanton C, Hemmings J, Molesworth A, Crampin A, French N. O2-S3.02 Assessing the validity of sexual behaviour reports in a whole population survey in rural Malawi. Br J Vener Dis 2011. [DOI: 10.1136/sextrans-2011-050109.80] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Glynn J, Price A, Floyd S, Molesworth A, Kayuni N, Chihana M, Nyirenda V, Crampin A, French N. P1-S6.53 Antiretroviral therapy reduces HIV transmission in discordant couples in Northern Malawi. Br J Vener Dis 2011. [DOI: 10.1136/sextrans-2011-050108.277] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Floyd S, O'Shea B, Darker C. General practitioners experience in dietary counselling; poor access to dietetic services. IRISH MEDICAL JOURNAL 2011; 104:59. [PMID: 21465883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
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Birdthistle IJ, Floyd S, Mwanasa S, Nyagadza A, Gwiza E, Glynn JR. Child sexual abuse and links to HIV and orphanhood in urban Zimbabwe. J Epidemiol Community Health 2010; 65:1075-82. [DOI: 10.1136/jech.2009.094359] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Jahn A, Floyd S, Crampin AC, Mvula H, Mwinuka V, Mwaiyeghele E, McGrath N, Zaba B, Fine PEM, Glynn JR. Declining child mortality in northern Malawi despite high rates of infection with HIV. Bull World Health Organ 2010; 88:746-53. [PMID: 20931059 DOI: 10.2471/blt.09.075085] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2009] [Revised: 03/01/2010] [Accepted: 03/01/2010] [Indexed: 10/19/2022] Open
Abstract
OBJECTIVE To determine whether routine surveys, such as the Demographic and Health Surveys (DHS), have underestimated child mortality in Malawi. METHODS Rates and causes of child mortality were obtained from a continuous-registration demographic surveillance system (DSS) in Malawi for a population of 32 000. After initial census, births and deaths were reported by village informants and updated monthly by project enumerators. Cause of death was established by verbal autopsy whenever possible. The likely impact of human immunodeficiency virus (HIV) infection on child mortality was also estimated from antenatal clinic surveillance data. Overall and age-specific mortality rates were compared with those from the 2004 Malawi DHS. FINDINGS Between August 2002 and February 2006, 38 617 person-years of observation were recorded for 20 388 children aged < 15 years. There were 342 deaths. Re-census data, follow-up visits at 12 months of age and the ratio of stillbirths to neonatal deaths suggested that death registration by the DSS was nearly complete. Infant mortality was 52.7 per 1000 live births, under-5 mortality was 84.8 per 1000 and under-15 mortality was 99.1 per 1000. One-fifth of deaths by age 15 were attributable to HIV infection. Child mortality rates estimated with the DSS were approximately 30% lower than those from national estimates as determined by routine surveys. CONCLUSION The fact that child mortality rates based on the DSS were relatively low in the study population is encouraging and suggests that the low mortality rates estimated nationally are an accurate reflection of decreasing rates.
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Floyd S, Pawashe C, Sitti M. Two-Dimensional Contact and Noncontact Micromanipulation in Liquid Using an Untethered Mobile Magnetic Microrobot. IEEE T ROBOT 2009. [DOI: 10.1109/tro.2009.2028761] [Citation(s) in RCA: 128] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Marston M, Slaymaker E, Cremin I, Floyd S, McGrath N, Kasamba I, Lutalo T, Nyirenda M, Ndyanabo A, Mupambireyi Z, Zaba B. Trends in marriage and time spent single in sub-Saharan Africa: a comparative analysis of six population-based cohort studies and nine Demographic and Health Surveys. Sex Transm Infect 2009; 85 Suppl 1:i64-71. [PMID: 19307343 PMCID: PMC2654103 DOI: 10.1136/sti.2008.034249] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/20/2009] [Indexed: 11/04/2022] Open
Abstract
OBJECTIVES To describe trends in age at first sex (AFS), age at first marriage (AFM) and time spent single between events and to compare age-specific trends in marital status in six cohort studies. METHODS Cohort data from Uganda, Tanzania, South Africa, Zimbabwe and Malawi and Demographic and Health Survey (DHS) data from Uganda, Tanzania and Zimbabwe were analysed. Life table methods were used to calculate median AFS, AFM and time spent single. In each study, two surveys were chosen to compare marital status by age and identify changes over time. RESULTS Median AFM was much higher in South Africa than in the other sites. Between the other populations there were considerable differences in median AFS and AFM (AFS 17-19 years for men and 16-19 years for women, AFM 21-24 years and 18-19 years, respectively, for the 1970-9 birth cohort). In all surveys, men reported a longer time spent single than women (median 4-7 years for men and 0-2 years for women). Median years spent single for women has increased, apart from in Manicaland. For men in Rakai it has decreased slightly over time but increased in Kisesa and Masaka. The DHS data showed similar trends to those in the cohort data. The age-specific proportion of married individuals has changed little over time. CONCLUSIONS Median AFS, AFM and time spent single vary considerably among these populations. These three measures are underlying determinants of sexual risk and HIV infection, and they may partially explain the variation in HIV prevalence levels between these populations.
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Mitrofanov IG, Sanin AB, Golovin DV, Litvak ML, Konovalov AA, Kozyrev AS, Malakhov AV, Mokrousov MI, Tretyakov VI, Troshin VS, Uvarov VN, Varenikov AB, Vostrukhin AA, Shevchenko VV, Shvetsov VN, Krylov AR, Timoshenko GN, Bobrovnitsky YI, Tomilina TM, Grebennikov AS, Kazakov LL, Sagdeev RZ, Milikh GN, Bartels A, Chin G, Floyd S, Garvin J, Keller J, McClanahan T, Trombka J, Boynton W, Harshman K, Starr R, Evans L. Experiment LEND of the NASA Lunar Reconnaissance Orbiter for high-resolution mapping of neutron emission of the Moon. ASTROBIOLOGY 2008; 8:793-804. [PMID: 18844457 DOI: 10.1089/ast.2007.0158] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The scientific objectives of neutron mapping of the Moon are presented as 3 investigation tasks of NASA's Lunar Reconnaissance Orbiter mission. Two tasks focus on mapping hydrogen content over the entire Moon and on testing the presence of water-ice deposits at the bottom of permanently shadowed craters at the lunar poles. The third task corresponds to the determination of neutron contribution to the total radiation dose at an altitude of 50 km above the Moon. We show that the Lunar Exploration Neutron Detector (LEND) will be capable of carrying out all 3 investigations. The design concept of LEND is presented together with results of numerical simulations of the instrument's sensitivity for hydrogen detection. The sensitivity of LEND is shown to be characterized by a hydrogen detection limit of about 100 ppm for a polar reference area with a radius of 5 km. If the presence of ice deposits in polar "cold traps" is confirmed, a unique record of many millions of years of lunar history would be obtained, by which the history of lunar impacts could be discerned from the layers of water ice and dust. Future applications of a LEND-type instrument for Mars orbital observations are also discussed.
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Crampin AC, Floyd S, Ngwira BM, Mwinuka V, Mwaungulu JN, Branson K, Fine PEM, Glynn JR. Assessment and evaluation of contact as a risk factor for tuberculosis in rural Africa. Int J Tuberc Lung Dis 2008; 12:612-618. [PMID: 18492326 PMCID: PMC2443279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023] Open
Abstract
SETTING A rural district in Malawi. OBJECTIVE To determine the effect of inaccurate recall on estimates of the proportion of tuberculosis (TB) cases attributable to contact with identifiable prior cases. DESIGN Case-control study of laboratory-confirmed TB cases and community controls, comparing family, household and area contacts identified from a database of TB cases with those named at interview. Estimation of prior contact as a risk factor for TB and identified factors associated with being a named contact. RESULTS Ninety-five per cent of named contacts were known TB cases. The proportion of total identified contacts who were named at interview was 75%, and was similar for cases and controls. Cases were twice as likely as controls to identify prior contacts. Adding database information did not affect odds ratios, but increased the proportion of TB cases attributable to prior contact. Smear-positive, male and human immunodeficiency virus (HIV) negative TB patients were more likely to be named by subsequent cases. Identifiable recent contact with known smear-positive cases accounted for 12.5% of the TB burden. CONCLUSIONS Reporting of putative source contacts showed little evidence of recall bias and gave estimates of the relative risk of TB associated with identifiable contact. The lower likelihood of HIV-positive cases being named as contacts may reflect reduced infectiousness.
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Jahn A, Floyd S, Mwinuka V, Mwafilaso J, Mwagomba D, Mkisi RE, Katsulukuta A, Khunga A, Crampin AC, Branson K, McGrath N, Fine PEM. Ascertainment of childhood vaccination histories in northern Malawi. Trop Med Int Health 2008; 13:129-38. [DOI: 10.1111/j.1365-3156.2007.01982.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Miiro GM, Todd J, Nakubulwa S, Watera C, Hughes P, Munderi P, Floyd S, Grosskurth H. Evaluating affordable screening markers to detect HIV-1-infected Ugandan adults with CD4 counts of less than 200 cells/mul. J Int AIDS Soc 2008. [DOI: 10.1186/1758-2652-11-s1-p11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Floyd S, Crampin AC, Glynn JR, Madise N, Mwenebabu M, Mnkhondia S, Ngwira B, Zaba B, Fine PEM. The social and economic impact of parental HIV on children in northern Malawi: retrospective population-based cohort study. AIDS Care 2007; 19:781-90. [PMID: 17573599 PMCID: PMC6485412 DOI: 10.1080/09540120601163227] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
From population-based surveys in the 1980s in Karonga district, northern Malawi, 197 'index individuals' were identified as HIV-positive. 396 HIV-negative 'index individuals' were selected as a comparison group. These individuals, and their spouses and children, were followed up in 1998-2000. 582 of 593 index individuals were traced. 487 children of HIV-positive, and 1493 children of HIV-negative, parents were included in analyses. Rates of paternal, maternal, and double orphanhood among children with one or both parents HIV-positive were respectively 6, 8, and 17 times higher than for children with HIV-negative parents. Around 50% of children living apart from both parents had a grandparent as their guardian; for most of the rest the guardian was an aunt, uncle, or sibling. There were no child-headed households. Almost all children aged 6-14 were attending primary school. There was no evidence that parental HIV affected primary school attainment among children <15 years old. Children of HIV-positive parents were less likely to have attended secondary school than those of HIV-negative parents. The extended family has mitigated the impact of orphanhood on children, but interventions to reduce the incidence of orphanhood, and/or which strengthen society's ability to support orphans, are essential, especially as the HIV epidemic matures and its full impact is felt.
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Weir RE, Black GF, Nazareth B, Floyd S, Stenson S, Stanley C, Branson K, Sichali L, Chaguluka SD, Donovan L, Crampin AC, Fine PEM, Dockrell HM. The influence of previous exposure to environmental mycobacteria on the interferon-gamma response to bacille Calmette-Guérin vaccination in southern England and northern Malawi. Clin Exp Immunol 2007; 146:390-9. [PMID: 17100757 PMCID: PMC1810413 DOI: 10.1111/j.1365-2249.2006.03222.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
We report a large study of the effect of BCG vaccination on the in vitro 6-day whole blood interferon-gamma (IFN-gamma) response to antigens from eight species of mycobacteria among schoolchildren in south-eastern England, where bacille Calmette-Guérin (BCG) vaccination is highly protective against pulmonary tuberculosis, and among young adults in northern Malawi, where BCG vaccination is not protective. In the UK children, BCG induced an appreciable increase in IFN-gamma response to antigens from most species of mycobacteria. The degree of change was linked to the relatedness of the species to Mycobacterium bovis BCG, and provides further evidence of the cross-reactivity of mycobacterial species in priming of the immune system. IFN-gamma responses to purified protein derivatives (PPDs) from M. tuberculosis and environmental mycobacteria were more prevalent in the Malawian than the UK group prior to vaccination; BCG vaccination increased the prevalence of responses to these PPDs in the UK group to a level similar to that in Malawi. There was no evidence that the vaccine-induced change in IFN-gamma response was dependent upon the magnitude of the initial response of the individual to environmental mycobacteria in the United Kingdom or in Malawi. These observations should assist the development and interpretation of human clinical trials of new vaccines against M. tuberculosis in areas of both low and high exposure to environmental mycobacteria.
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Dacombe RJ, Crampin AC, Floyd S, Randall A, Ndhlovu R, Bickle Q, Fine PEM. Time delays between patient and laboratory selectively affect accuracy of helminth diagnosis. Trans R Soc Trop Med Hyg 2006; 101:140-5. [PMID: 16824566 DOI: 10.1016/j.trstmh.2006.04.008] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2006] [Revised: 04/07/2006] [Accepted: 04/13/2006] [Indexed: 01/10/2023] Open
Abstract
Studies of intestinal helminth infections are influenced by the constraints of sample collection, as identification of helminth ova in stools is affected by the time since evacuation from the host. Different methods may be required to optimise diagnostic sensitivity under different study conditions. In the context of studies in rural Malawi, we collected stool samples with different time delays from production by subjects to sample collection by field staff, to examination in the laboratory. Stools were processed by Kato-Katz (KK) or formol-ether concentration (FEC) methods. Hookworm and Schistosoma mansoni were the most common helminths identified. The prevalence of hookworm was higher with KK (270/988, 27%) than with FEC (191/988, 19%). Comparison was made between the results from the two methods according to the timing of the processing steps. Delays in processing did not affect retrieval of S. mansoni. A decrease in sensitivity of almost 50% for detection of hookworm was observed with either method when preservation/refrigeration was delayed by more than 3h. A delay of 1 day from refrigeration or preservation to laboratory processing also reduced the sensitivity for hookworm by 50% for both methods. Care must be taken in studies of multiple helminth infections owing to the selective reduction of hookworm ova during transport. This is particularly critical when samples are not preserved, even over short periods of time, and even with formalin preservation.
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Colgan HA, Floyd S, Noone EJ, Gibney MJ, Roche HM. Increased intake of fruit and vegetables and a low-fat diet, with and without low-fat plant sterol-enriched spread consumption: effects on plasma lipoprotein and carotenoid metabolism. J Hum Nutr Diet 2004; 17:561-9; quiz 571-4. [PMID: 15546434 DOI: 10.1111/j.1365-277x.2004.00564.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Regular intake of plant sterol (phytosterol)-enriched foods enhances the cholesterol lowering effect of diets. One side effect associated with plant sterol consumption is a modest reduction in plasma carotenoid concentrations. This study investigated the effect of consuming a low-fat National Cholesterol Education Programme (NCEP) Step 1 diet, including a low-fat plant sterol ester (PSE)-enriched spread on cholesterol metabolism to determine if specific dietary advice to increase daily fruit and vegetable intake could prevent reduced plasma carotenoid concentrations. MATERIALS AND METHODS In this randomised, crossover double-blind trial, 48 hypercholesterolaemic men received 21 g day(-1) of a low-fat PSE-enriched spread or placebo for 3 weeks, interrupted by 3 weeks washout. Individuals also adhered to a NCEP Step 1 diet and repeated 3-day food diaries monitored adherence. Specific advice was provided to increase dietary fruit and vegetable intakes. Fasting blood samples were collected at pre- and post-intervention for lipoprotein and carotenoid analysis. RESULTS Plasma total and low-density lipoprotein (LDL) cholesterol concentrations were significantly (P <0.05) reduced, by 4.6 and 7.1%, respectively, after the PSE-enriched low-fat spread. Plasma apo B concentrations were significantly (P <0.0005) lower after the PSE spread. PSE consumption was also associated with significantly (P <0.05) lower total plasma beta-carotene concentrations, but this change was not significant after lipid standardisation. PSE consumption had no effect on retinol, alpha-carotene, gamma-tocopherol, alpha-tocopherol, lutein, zeaxanthin, beta-crypyoxanthin or lycopene concentrations. CONCLUSION Dietary advice to increase daily fruit and vegetable consumption may be effective in preventing a reduction in plasma carotenoid concentrations previously associated with PSE consumption. Further, PSE incorporated in a low-fat spread and consumed as part of a NCEP Step 1 diet are effective in reducing total and LDL cholesterol.
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Crampin AC, Glynn JR, Floyd S, Malema SS, Mwinuka VK, Ngwira BMM, Mwaungulu FD, Warndorff DK, Fine PEM. Tuberculosis and gender: exploring the patterns in a case control study in Malawi. Int J Tuberc Lung Dis 2004; 8:194-203. [PMID: 15139448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023] Open
Abstract
BACKGROUND In many populations there is an excess of tuberculosis in young women and older men. We explored possible explanations for these patterns, concentrating on human immunodeficiency virus (HIV) status, pregnancy, smoking, cooking smoke exposure, contact with tuberculosis cases within the household or outside, and gender differences in health service usage and diagnostic delay. DESIGN Case control study in Karonga District, Malawi. METHODS Cases were new tuberculosis patients with bacteriological or histological evidence of tuberculosis. Controls were selected in the community using field-based random sampling. RESULTS The study included 598 tuberculosis cases and 992 controls, with an excess of tuberculosis in young females and older males. This was more marked in HIV-positive individuals. HIV infection was a similarly strong risk factor for tuberculosis in both men and women. Tuberculosis was associated with having a family or household contact with tuberculosis for both men and women. For women, but not men, contacts outside the close family and household were also a risk factor for tuberculosis. Tuberculosis was not associated with current or recent pregnancy, or with smoking or smoke exposure. There were no differences between men and women in health service usage or delay. CONCLUSIONS In this population, HIV infection and contacts with known tuberculosis patients are important determinants of the gender distribution of cases.
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Weir RE, Fine PEM, Nazareth B, Floyd S, Black GF, King E, Stanley C, Bliss L, Branson K, Dockrell HM. Interferon-gamma and skin test responses of schoolchildren in southeast England to purified protein derivatives from Mycobacterium tuberculosis and other species of mycobacteria. Clin Exp Immunol 2003; 134:285-94. [PMID: 14616789 PMCID: PMC1808851 DOI: 10.1046/j.1365-2249.2003.02272] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The immune responses of schoolchildren in southeast England to Mycobacterium tuberculosis and other species of mycobacteria were studied prior to vaccination with bacille Calmette-Guérin (BCG). Data are presented for tuberculin (Heaf) skin test and interferon-gamma (IFN-gamma) responses to M. tuberculosis purified protein derivative (PPD), and IFN-gamma responses to PPDs from eight other environmental mycobacteria, measured in 424 schoolchildren (13-15 years of age). Responses to M. tuberculosis PPD were detected in 27% of schoolchildren by in vitro IFN-gamma response and in 20% by the Heaf test. IFN-gamma responses were more prevalent to PPDs from species of mycobacteria other than M. tuberculosis, predominantly those of the MAIS complex and M. marinum (45-60% responders). Heaf test and IFN-gamma responses were associated (P<0.001) for M. tuberculosis, MAIS and M. marinum. These findings have implications for appropriate implementation of vaccination against tuberculosis.
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Bierrenbach AL, Floyd S, Cunha SC, Dourado I, Barreto ML, Pereira SM, Hijjar MA, Rodrigues LC. A comparison of dual skin test with mycobacterial antigens and tuberculin skin test alone in estimating prevalence of Mycobacterium tuberculosis infection from population surveys. Int J Tuberc Lung Dis 2003; 7:312-9. [PMID: 12729335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2023] Open
Abstract
SETTING City of Manaus, Amazonas, Brazil. OBJECTIVE To compare estimates of Mycobacterium tuberculosis infection prevalence obtained using traditional tuberculin skin test (TST) criteria and dual skin test (DST) data. METHODS A total of 1070 schoolchildren received DST with tuberculin and four environmental mycobacteria sensitins. Responses were classified as sensitin-dominant, tuberculin-dominant or non-dominant. Positive predictive values (PPV) were defined using 'narrow' and 'wide' standards based on DST responses. These predictive values were derived for each category of tuberculin indurations, and were used to calculate the prevalence estimates. RESULTS Using DST data, the estimates of M. tuberculosis prevalence for scar-negative children were 7.4% (M. avium) and 7.8% (M. scrofulaceum) using the 'narrow' standard, and 16.9% (M. avium) and 15.2% (M. scrofulaceum) using the 'wide' standard. The percentage with TST > or =10 mm was 11.5%. Scar-positive children had higher estimates using both the 10 mm cut-off and DST data. CONCLUSION In settings with a relatively low prevalence of M. tuberculosis infection and high cross-reactivity with environmental mycobacteria, DST can help to assess the validity of traditional thresholds for estimating the prevalence of M. tuberculosis infection. DST data with environmental antigens and tuberculin do not distinguish BCG-induced cross-reactivity.
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Schmierer K, Grosse P, De Camilli P, Solimena M, Floyd S, Zschenderlein R. Paraneoplastic stiff-person syndrome: no tumor progression over 5 years. Neurology 2002; 58:148. [PMID: 11781426 DOI: 10.1212/wnl.58.1.148] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Randall AE, Perez MA, Floyd S, Black GF, Crampin AC, Ngwira B, Pistoni WN, Mulawa D, Sichali L, Mwaungulu L, Bickle Q, Fine PEM. Patterns of helminth infection and relationship to BCG vaccination in Karonga District, northern Malawi. Trans R Soc Trop Med Hyg 2002; 96:29-33. [PMID: 11925985 DOI: 10.1016/s0035-9203(02)90229-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Surveys of enteric and urinary helminth infections were carried out in 1999 among 501 schoolchildren and among 320 adolescents and young adults participating in a study of immune responses to BCG vaccine in Karonga District, northern Malawi. Hookworm, Schistosoma mansoni and S. haematobium infections were detected in 64%, 27% and 20% of schoolchildren and in 55%, 40% and 25% of the immunology study subjects, respectively. Other helminths were appreciably less common. The prevalence of 'at least one' helminth infection was 76% among schoolchildren, ranging from 60% to 92% in the 4 schools, and was 79% in the immunology study participants. There was no evidence for an association between the presence of a BCG scar and presence or intensity of infection with worms in the schoolchildren, nor evidence that BCG vaccination of adolescents and young adults had any effect on the prevalence of helminth infections 1 year later.
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Crampin AC, Floyd S, Mwaungulu F, Black G, Ndhlovu R, Mwaiyeghele E, Glynn JR, Warndorff DK, Fine PE. Comparison of two versus three smears in identifying culture-positive tuberculosis patients in a rural African setting with high HIV prevalence. Int J Tuberc Lung Dis 2001; 5:994-9. [PMID: 11716350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023] Open
Abstract
SETTING Karonga district, northern Malawi. OBJECTIVE To compare the sensitivity and specificity of two versus three smears for the diagnosis of pulmonary tuberculosis in a setting with high HIV prevalence. DESIGN A total of 1992 pulmonary tuberculosis suspects with three sputum smears taken over a 2-7 day period and at least one culture result were studied. Smears were auramine stained and examined using fluorescence microscopy, and positives were confirmed with Ziehl-Neelsen staining and light microscopy. Cultures were set up on Löwenstein-Jensen media. True negative and positive status was defined on the basis of culture. The sensitivity, specificity, and positive and negative predictive values of two and three smears were compared. RESULTS Compared to culture, the sensitivity, specificity, and positive and negative predictive values of three smears were 70%, 98%, 92%, and 92%, respectively. Restriction to the first two smears gave similar results. Of those detected as smear-positive using three smears, at least 97% would have been detected by two. Among those with HIV serology results available, the sensitivity of two smears for detecting culture-positive tuberculosis was identical to that using three. CONCLUSION In this setting, using fluorescence and light microscopy, collecting two smears rather than three would only marginally reduce sensitivity and would slightly improve the specificity of diagnosis of tuberculosis; this is unaffected by HIV status. The potential for improving specificity is important because of the costs of misdiagnosis. In practice, both sensitivity and specificity may be increased due to the time saved by examining two rather than three smears.
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Farsad K, Ringstad N, Takei K, Floyd SR, Rose K, De Camilli P. Generation of high curvature membranes mediated by direct endophilin bilayer interactions. J Cell Biol 2001; 155:193-200. [PMID: 11604418 PMCID: PMC2198845 DOI: 10.1083/jcb.200107075] [Citation(s) in RCA: 468] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Endophilin 1 is a presynaptically enriched protein which binds the GTPase dynamin and the polyphosphoinositide phosphatase synptojanin. Perturbation of endophilin function in cell-free systems and in a living synapse has implicated endophilin in endocytic vesicle budding (Ringstad, N., H. Gad, P. Low, G. Di Paolo, L. Brodin, O. Shupliakov, and P. De Camilli. 1999. Neuron. 24:143-154; Schmidt, A., M. Wolde, C. Thiele, W. Fest, H. Kratzin, A.V. Podtelejnikov, W. Witke, W.B. Huttner, and H.D. Soling. 1999. Nature. 401:133-141; Gad, H., N. Ringstad, P. Low, O. Kjaerulff, J. Gustafsson, M. Wenk, G. Di Paolo, Y. Nemoto, J. Crun, M.H. Ellisman, et al. 2000. Neuron. 27:301-312). Here, we show that purified endophilin can directly bind and evaginate lipid bilayers into narrow tubules similar in diameter to the neck of a clathrin-coated bud, providing new insight into the mechanisms through which endophilin may participate in membrane deformation and vesicle budding. This property of endophilin is independent of its putative lysophosphatydic acid acyl transferase activity, is mediated by its NH2-terminal region, and requires an amino acid stretch homologous to a corresponding region in amphiphysin, a protein previously shown to have similar effects on lipid bilayers (Takei, K., V.I. Slepnev, V. Haucke, and P. De Camilli. 1999. Nat. Cell Biol. 1:33-39). Endophilin cooligomerizes with dynamin rings on lipid tubules and inhibits dynamin's GTP-dependent vesiculating activity. Endophilin B, a protein with homology to endophilin 1, partially localizes to the Golgi complex and also deforms lipid bilayers into tubules, underscoring a potential role of endophilin family members in diverse tubulovesicular membrane-trafficking events in the cell.
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Black GF, Dockrell HM, Crampin AC, Floyd S, Weir RE, Bliss L, Sichali L, Mwaungulu L, Kanyongoloka H, Ngwira B, Warndorff DK, Fine PE. Patterns and implications of naturally acquired immune responses to environmental and tuberculous mycobacterial antigens in northern Malawi. J Infect Dis 2001; 184:322-9. [PMID: 11443558 DOI: 10.1086/322042] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2000] [Revised: 04/19/2001] [Indexed: 11/04/2022] Open
Abstract
Interferon (IFN)-gamma responsiveness to 12 purified protein derivative (PPD) and new tuberculin antigens from 9 species of mycobacteria was assessed, using a whole blood assay, in 616 young adults living in northern Malawi, where Mycobacterium bovis bacille Calmette-Guérin (BCG) vaccination provides no protection against pulmonary tuberculosis. The prevalence of IFN-gamma responsiveness was highest for PPDs of M. avium, M. intracellulare, and M. scrofulaceum (the MAIS complex). Correlations between responsiveness paralleled genetic relatedness of the mycobacterial species. A randomized, controlled trial was carried out, to assess the increase in IFN-gamma responsiveness to M. tuberculosis PPD that can be attributed to M. bovis BCG vaccination. The BCG-attributable increase in IFN-gamma response to M. tuberculosis PPD was greater for individuals with low initial responsiveness to MAIS antigens than for those with high initial responsiveness. Although not statistically significant, the trend is consistent with the hypothesis that prior exposure to environmental mycobacteria interferes with immune responses to BCG vaccination.
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Gudrups I, Floyd S, Kling JG, Bosque-Perez NA, Orchard JE. A comparison of two methods of assessment of maize varietal resistance to the maize weevil, Sitophilus zeamais Motschulsky, and the influence of kernel hardness and size on susceptibility. JOURNAL OF STORED PRODUCTS RESEARCH 2001; 37:287-302. [PMID: 11172865 DOI: 10.1016/s0022-474x(00)00031-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Fifty-two maize varieties were screened for resistance to infestation by the maize weevil, Sitophilus zeamais, using assessment methods proposed by Dobie (J. Stored Products Res. 10 (1974) 183-197) and Urrelo et al. (J. Stored Products Res. 26 (1990) 100). The two methods gave similar assessments of maize susceptibility to S. zeamais. The Dobie method is preferred due to the lower total time required for assessment of relative susceptibility of maize varieties. The greatest disadvantage of the Urrelo method is the intensive labour requirements in the early stages of a trial, when numbers of eggs have to be counted, although it has the advantage that the assessment may be terminated upon emergence of the first F(1) adult. Two explanatory variables, kernel size and hardness, were investigated to determine whether they may be used as indicators of resistance. Results suggested that kernel size is the more important in determining resistance to attack by S. zeamais, with large kernels appearing to show greater resistance than small ones. Contrary to expectations, of the varieties tested, including local, hybrid and improved open pollinated (IOP) varieties, the local varieties were generally more susceptible. This may be related to kernel size, as all IOPs and hybrids tested had large kernels, whereas the majority of the local varieties had small ones. No clear relationship between weevil susceptibility and kernel hardness could be detected, although there was an indication that differences associated with kernel size varied depending on kernel hardness. None of the varieties tested showed high levels of resistance to attack by S. zeamais.
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