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Featured researches published by Laban Mtimavalye.


AIDS | 1998

Bacterial vaginosis and disturbances of vaginal flora : association with increased acquisition of HIV

Taha E. Taha; Donald R. Hoover; Gina A. Dallabetta; Newton Kumwenda; Laban Mtimavalye; Li Ping Yang; George N. Liomba; Robin L. Broadhead; John D. Chiphangwi; Paolo G. Miotti

Background:Cross-sectional studies suggest an association between bacterial vaginosis (BV) and HIV-1 infection. However, an assessment of a temporal effect was not possible. Objectives:To determine the association of BV and other disturbances of vaginal flora with HIV seroconversion among pregnant and postnatal women in Malawi, Africa. Design:Longitudinal follow-up of pregnant and postpartum women. Methods:Women attending their first antenatal care visit were screened for HIV after counselling and obtaining informed consent. HIV-seronegative women were enrolled and followed during pregnancy and after delivery. These women were again tested for HIV at delivery and at 6-monthly visits postnatally. Clinical examinations and collection of laboratory specimens (for BV and sexually transmitted diseases) were conducted at screening and at the postnatal 6-monthly visits. The diagnosis of BV was based on clinical criteria. Associations of BV and other risk factors with HIV seroconversion, were examined using contingency tables and multiple logistic regression analyses on antenatal data, and Kaplan–Meier proportional hazards analyses on postnatal data. Results:Among 1196 HIV-seronegative women who were followed antenatally for a median of 3.4 months, 27 women seroconverted by time of delivery. Postnatally, 97 seroconversions occurred among 1169 seronegative women who were followed for a median of 2.5 years. Bacterial vaginosis was significantly associated with antenatal HIV seroconversion (adjusted odds ratio = 3.7) and postnatal HIV seroconversion (adjusted rate ratio = 2.3). There was a significant trend of increased risk of HIV seroconversion with increasing severity of vaginal disturbance among both antenatal and postnatal women. The approximate attributable risk of BV alone was 23% for antenatal HIV seroconversions and 14% for postnatal seroconversions. Conclusions:This prospective study suggests that progressively greater disturbances of vaginal flora, increase HIV acquisition during pregnancy and postnatally. The screening and treating of women with BV could restore normal flora and reduce their susceptibility to HIV.


The Journal of Infectious Diseases | 1999

Human Immunodeficiency Virus Load in Breast Milk, Mastitis, and Mother-to-Child Transmission of Human Immunodeficiency Virus Type 1

Richard D. Semba; Newton Kumwenda; Donald R. Hoover; Taha E. Taha; Thomas C. Quinn; Laban Mtimavalye; Robert J. Biggar; Robin L. Broadhead; Paolo G. Miotti; Lori J. Sokoll; Len van der Hoeven; John D. Chiphangwi

Human immunodeficiency virus (HIV) type 1 load in breast milk and mastitis were examined as risk factors for vertical transmission of HIV-1. Six weeks after delivery, HIV-1 load and sodium (an indicator of mastitis) were measured in breast milk from 334 HIV-1-infected women in Malawi. Median breast milk HIV-1 load was 700 copies/mL among women with HIV-1-infected infants versus undetectable (<200 copies/mL) among those with uninfected infants, respectively (P<. 0001). Elevated breast milk sodium levels consistent with mastitis occurred in 16.4% of HIV-1-infected women and were associated with increased vertical transmission of HIV-1 (P<.0001). Median breast milk HIV-1 load was 920 copies/mL among women with versus undetectable among those without elevated breast milk sodium levels, respectively (P<.0001). Mastitis and breast milk HIV-1 load may increase the risk of vertical transmission of HIV-1 through breast-feeding.


AIDS | 1998

Trends of HIV-1 and Sexually Transmitted Diseases Among Pregnant and Postpartum Women in Urban Malawi

Taha E. Taha; Gina Dallabetta; Donald R. Hoover; John D. Chiphangwi; Laban Mtimavalye; George N. Liomba; Newton Kumwenda; Paolo G. Miotti

Objectives: To examine rates of HIV-1 and sexually transmitted disease (STD) among pregnant and postpartum women in urban Malawi, Africa. Design: Serial cross-sectional surveys and a prospective study. Methods: Three major surveys were conducted in 1990, 1993 and 1994/1995. Consecutive first-visit antenatal women and women giving birth at the Queen Elizabeth Central Hospital were tested for HIV and STD after counseling and obtaining informed consent. Unlinked, anonymous HIV testing was also conducted on smaller samples of antenatal women in the same hospital to provide annual prevalence data. HIV-seronegative postpartum women from the 1990 and 1993 surveys were enrolled in a prospective study to determine HIV incidence. Results: HIV seroprevalence rose from 2.0% in 1985 to 32.8% in 1996, a 16-fold increase. The highest age-specific HIV prevalence was in the following age-groups: 20–24 years during 1990, 25–29 years during 1993, and 30–34 years during 1996. Among 1173 women followed for a median of 30.9 months, HIV incidence was 5.98 per 100 person-years in women aged < 20 years and declined steadily in older women. The prevalence of STD significantly declined among both HIV-positive and negative women. This decline in STD prevalence, however, was not accompanied by increased condom use over time. Conclusions: Among urban childbearing women in Malawi, incidence of HIV is highest among young women while, currently, prevalence is highest among older women. Recent declines in STD prevalence suggest that HIV prevention programs are having an impact either through improved STD diagnosis and treatment or reduced risk behaviors. Sequential cross-sectional STD prevalence measures may be useful in monitoring effectiveness of STD and HIV prevention activities.


BMJ | 1997

Effect of cleansing the birth canal with antiseptic solution on maternal and newborn morbidity and mortality in Malawi: clinical trial.

Taha E. Taha; Robert J. Biggar; Robin L. Broadhead; Laban Mtimavalye; Aafke Justesen; George N. Liomba; John D. Chiphangwi; Paolo G. Miotti

Abstract Objective: To determine if cleansing the birth canal with an antiseptic at delivery reduces infections in mothers and babies postnatally. Design: Clinical trial; two months of no intervention were followed by three months of intervention and a final month of no intervention. Setting: Queen Elizabeth Central Hospital (tertiary care urban hospital), Blantyre, Malawi. Subjects: A total of 6965 women giving birth in a six month period and their 7160 babies. Intervention: Manual wipe of the maternal birth canal with a 0.25% chlorhexidine solution at every vaginal examination before delivery. Babies born during the intervention were also wiped with chlorhexidine. Main outcome measures: Effects of the intervention on neonatal and maternal morbidity and mortality. Results: 3635 women giving birth to 3743 babies were enrolled in the intervention phase and 3330 women giving birth to 3417 babies were enrolled in the non-intervention phase. There were no adverse reactions related to the intervention among the mothers or their children. Among infants born in the intervention phase, overall neonatal admissions were reduced (634/3743 (16.9%) v 661/3417 (19.3%), P<0.01), as were admissions for neonatal sepsis (7.8 v 17.9 per 1000 live births, P<0.0002), overall neonatal mortality (28.6 v 36.9 per 1000 live births, P<0.06), and mortality due to infectious causes (2.4 v 7.3 per 1000 live births, P<0.005). Among mothers receiving the intervention, admissions related to delivery were reduced (29.4 v 40.2 per 1000 deliveries, P<0.02), as were admissions due to postpartum infections (1.7 v 5.1 per 1000 deliveries, P=0.02) and duration of hospitalisation (Wilcoxon P=0.008). Conclusions: Cleansing the birth canal with chlorhexidine reduced early neonatal and maternal postpartum infectious problems. The safety, simplicity, and low cost of the procedure suggest that it should be considered as standard care to lower infant and maternal morbidity and mortality.


Journal of Acquired Immune Deficiency Syndromes | 1999

HIV infection and disturbances of vaginal flora during pregnancy

Taha E. Taha; Ronald H. Gray; Newton Kumwenda; Donald R. Hoover; Laban Mtimavalye; George N. Liomba; John D. Chiphangwi; Gina A. Dallabetta; Paolo G. Miotti

Disturbances of vaginal flora are common among women of reproductive age. In areas of sub-Saharan Africa where the prevalence of HIV is high, the frequency of bacterial vaginosis (BV) is also high. In this study, we assessed the association of BV and other disturbances of vaginal flora with prevalent HIV infection in two cross-sectional studies among pregnant women in urban Malawi. The prevalence of HIV-1 was 23% in 1990 and 30% in 1993. Overall, 30% of the women had BV, 59% had mild or moderate disturbance of vaginal flora, and only 11% had normal vaginal flora. Increasing prevalence of HIV was significantly associated with increasing severity of disturbance of vaginal flora (p < .00001, chi2 trend test). This trend of increased prevalence persisted after controlling for concurrent sexually transmitted diseases (STDs), sexual activity, and socioeconomic factors. After multivariate adjustment for potential confounders, the odds ratio for the association of BV with prevalent HIV infection was 3.0 (95% confidence interval [CI], 2.4-3.8), that of moderate vaginal disturbance with HIV infection was 2.2 (95% CI, 1.7-2.8), and that of mild vaginal disturbance with HIV infection was 1.6 (95% CI, 1.3-2.1). Among women with BV, HIV infection was higher among younger women than older, implying more recent infection. Although these studies were cross-sectional, our data suggest that BV could be associated with increased susceptibility to HIV infection.


AIDS | 1996

Reported condom use is not associated with incidence of sexually transmitted diseases in Malawi.

Taha E. Taha; Joseph K. Canner; John D. Chiphangwi; Gina Dallabetta; Li Ping Yang; Laban Mtimavalye; Paolo G. Miotti

Objectives:To establish frequency of reported condom use and validate reliability of self-reporting among urban women in Malawi. Design:Cross-sectional survey in antenatal women in 1989 and 1993. Prospective study in cohort first surveyed in 1989. Methods:A total of 6561 women in 1989 and 2460 women in 1993 answered questions about condom use and sexual activity, had a physical examination and were screened for HIV. A subset of women from the 1989 screening were administered a questionnaire and tested for syphilis, Neisseria gonorrhoeae and Trichomonas vaginalis infections every 6 months. Results:Although between the two cross-sectional studies intermittent condom use increased from 6 to 15% (P<0.001) with no difference according to HIV infection, consistent use was reported by less than 1%. In the prospective study, women reported a higher condom use at any visit than either group assessed cross-sectionally. Consistent condom use peaked at 62% in the first 6 months, but declined to as low as 8% in the second year of follow-up. Condom use at each visit, either intermittent or consistent, was higher in HIV-seropositive than HIV-seronegative women. Overall, the incidence of gonorrhea, trichomoniasis and syphilis did not decline in women reporting consistent condom use. Conclusions:In prospectively followed women reports of consistent condom use was substantially higher than in cross-sectional surveys, but rapidly decreased over time, irrespective of HIV status. The presence of new sexually transmitted diseases suggests that this population of urban women overreports condom use or underreports sexual activity, or both. Intensive and sustained education is needed to achieve consistent condom use. Biologic markers of sexual activity are useful in interpreting reported condom use.


Journal of Human Lactation | 1999

Mastitis and Immunological Factors in Breast Milk of Human Immunodeficiency Virus-Infected Women

Richard D. Semba; Newton Kumwenda; Taha E. Taha; Donald R. Hoover; Thomas C. Quinn; Yin Lan; Laban Mtimavalye; Robin L. Broadhead; Paolo G. Miotti; Len van der Hoeven; John D. Chiphangwi

Human milk contains important immunological factors that protect the breast from infection and are thought to protect infants from infection, including human immunodeficiency virus (HIV) infection. Human milk immunological factors have not been well characterized in HIV infected lactating women. Lysozyme, secretory leukocyte protease inhibitor (SLPI), sodium (an indicator of mastitis), and HIV were measured in breast milk of 334 HIV-infected women at 6 weeks postpartum. Women with mastitis, as indicated by elevated breast milk sodium concentrations, had higher median levels lysozyme (290 vs 221 mg/L,p<0.04), SLPI (38 vs 19 mg/L,p<0.0001) and HIV (920 copies/mL vs undetectable,p<0.0001) compared with women without mastitis. Lower total plasma carotenoid levels (p<0.02) and higher maternal HIV load (p<0.006) by quartile were risk factors for mastitis. Mastitis, as indicated by elevated breast milk sodium levels, is associated with high concentrations of immunological factors and higher HIV load in breast milk.


Clinical Infectious Diseases | 2001

Iron Status and Indicators of Human Immunodeficiency Virus Disease Severity among Pregnant Women in Malawi

Richard D. Semba; Taha E. Taha; Newton Kumwenda; Laban Mtimavalye; Robin L. Broadhead; Paolo G. Miotti; John D. Chiphangwi

The relationships among hemoglobin, ferritin, and transferrin receptor levels and 2 markers of human immunodeficiency virus (HIV) disease severity--HIV load and CD4(+) lymphocyte count--were characterized among 483 pregnant women in Malawi, Africa. The only significant correlation was an inverse correlation between hemoglobin level and plasma HIV load (r=-.104; P<.03). The prevalence of iron deficiency anemia was not significantly different across quartiles of HIV load or CD4(+) lymphocyte count. In contrast to previous studies, these data suggest that iron status is not related to markers of HIV disease severity in pregnant women in Africa.


European Journal of Clinical Nutrition | 2000

Assessment of iron status using plasma transferrin receptor in pregnant women with and without human immunodeficiency virus infection in Malawi

Richard D. Semba; Newton Kumwenda; Donald R. Hoover; Taha E. Taha; Laban Mtimavalye; Robin L. Broadhead; Ward Eisinger; Paolo G. Miotti; John D. Chiphangwi

Background: Although anemia is highly prevalent during pregnancy and is common during human immunodeficiency virus (HIV) infection, anemia and iron status have not been well characterized in HIV-infected pregnant women.Objective: To gain insight into iron status in HIV-infected pregnant women using plasma transferrin receptor and related indicators of anemia.Study design: Plasma transferrin receptor, ferritin, α1-acid glycoprotein, C-reactive protein and hemoglobin concentrations were measured in pregnant women, gestational age 18–28 weeks, seen in an urban antenatal clinic in Blantyre, Malawi.Results: The prevalence of anemia among 662 HIV-positive and 190 HIV-negative pregnant women was 73.1% and 50.0%, respectively (P<0.0001). Among HIV-positive and HIV-negative women, median plasma transferrin receptor concentrations were 24.4 and 24.1 nmol/l (P=0.5), respectively, and median plasma ferritin concentrations were 17.8 and 20.8 µg/l (P<0.05), respectively. There was a large overlap in plasma transferrin receptor concentrations among women with and without anemia. Using the combination of hemoglobin and ferritin as a standard, the sensitivity and specificity of plasma transferrin receptor in diagnosing iron deficiency anemia was estimated at 45.9% and 68.1%, respectively.Conclusion: The use of plasma transferrin receptor concentrations as an indicator of iron deficiency anemia may be limited in pregnant women with chronic inflammation and infection.Sponsorship: The National Institutes of Health (HD32247, HD30042, HIVNET contract N01-AI-35173-117), the Fogarty International Center, and the United States Agency for International Development (Cooperative Agreement HRN-A-00-97-00015-00).European Journal of Clinical Nutrition (2000) 54, 872–877


AIDS | 1997

Does umbilical cord blood polymerase chain reaction positivity indicate in utero (pre-labor) Hiv infection?

Robert J. Biggar; Laban Mtimavalye; Aafke Justesen; Robin Broadhead; Wendel Miley; David Waters; James J. Goedert; John D. Chiphangwi; Taha E. Taha; Paolo G. Miotti

Objective:To compare risk factors for infants whose cord blood was positive for HIV DNA with those who were cord blood-negative but found to be HIV DNA-positive in early infancy. Methods:In 1994, infants born to HIV-infected women were enrolled in a study in Blantyre, Malawi. Birth weight and transmission risk factors from cord blood-positive infants were compared with cord blood-negative/HIV-positive infants on their first postnatal visit (4–7 weeks of age). Testing for HIV DNA on cord and peripheral blood was performed by polymerase chain reaction. Results:Of 249 HIV-infected infants (overall transmission rate, 26%), 83 (33%) were cord blood-positive and 166 were initially cord blood-negative. The mean birth weight was 2.1% (59 g) lighter in cord blood-positive infants than initially cord blood-negative infants; initially cord blood-negative infants were 2.8% (80 g) lighter than uninfected infants born to HIV-infected women. There were no significant differences in the risk factors for infection between HIV-infected cord blood-positive and -negative infants; when transmission was increased, both HIV-infected cord blood-positive and -negative infants contributed to the increase in a similar proportion. Interpretation:It was concluded that umbilical cord blood positivity for HIV DNA did not identify a subset of in utero HIV-infected infants and suggested that HIV-infected cord blood-positive and -negative infants have similar timing and routes of HIV infection.

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Taha E. Taha

Johns Hopkins University

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Paolo G. Miotti

National Institutes of Health

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Robert J. Biggar

National Institutes of Health

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Richard D. Semba

Johns Hopkins University School of Medicine

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