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Dive into the research topics where Samuel Malamba is active.

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Featured researches published by Samuel Malamba.


The Lancet | 2004

Effect of co-trimoxazole prophylaxis on morbidity, mortality, CD4-cell count, and viral load in HIV infection in rural Uganda.

Jonathan Mermin; John Lule; John Paul Ekwaru; Samuel Malamba; Robert Downing; Ray Ransom; Frank Kaharuza; David H. Culver; Francis Kizito; Rebecca Bunnell; Aminah Kigozi; Damalie Nakanjako; Winnie Wafula; Robert Quick

BACKGROUND Prophylaxis with co-trimoxazole (trimethoprim-sulphamethoxazole) is recommended for people with HIV infection or AIDS but is rarely used in Africa. We assessed the effect of such prophylaxis on morbidity, mortality, CD4-cell count, and viral load among people with HIV infection living in rural Uganda, an area with high rates of bacterial resistance to co-trimoxazole. METHODS Between April, 2001, and March, 2003, we enrolled, and followed up with weekly home visits, 509 individuals with HIV-1 infection and their 1522 HIV-negative household members. After 5 months of follow-up, HIV-positive participants were offered daily co-trimoxazole prophylaxis (800 mg trimethoprim, 160 mg sulphamethoxazole) and followed up for a further 1.5 years. We assessed rates of malaria, diarrhoea, hospital admission, and death. FINDINGS Co-trimoxazole was well tolerated with rare (<2% per person-year) adverse reactions. Even though rates of resistance in diarrhoeal pathogens were high (76%), co-trimoxazole prophylaxis was associated with a 46% reduction in mortality (hazard ratio 0.54 [95% CI 0.35-0.84], p=0.006) and lower rates of malaria (multivariate incidence rate ratio 0.28 [0.19-0.40], p<0.0001), diarrhoea (0.65 [0.53-0.81], p<0.0001), and hospital admission (0.69 [0.48-0.98], p=0.04). The annual rate of decline in CD4-cell count was less during prophylaxis than before (77 vs 203 cells per microL, p<0.0001), and the annual rate of increase in viral load was lower (0.08 vs 0.90 log(10) copies per mL, p=0.01). INTERPRETATION Daily co-trimoxazole prophylaxis was associated with reduced morbidity and mortality and had beneficial effects on CD4-cell count and viral load. Co-trimoxazole prophylaxis is a readily available, effective intervention for people with HIV infection in Africa.


Aids and Behavior | 2006

Disclosure of HIV Status and Adherence to Daily Drug Regimens Among HIV-infected Children in Uganda

Winnie Bikaako-Kajura; Emmanuel Luyirika; David W. Purcell; Julia Downing; Frank Kaharuza; Jonathan Mermin; Samuel Malamba; Rebecca Bunnell

Pediatric adherence to daily drug regimens has not been widely assessed in Africa where majority of HIV infected children live. Using in-depth interviews of 42 HIV-infected children taking ART and/or cotrimoxazole prophylaxis, and 42 primary caregivers, at a comprehensive HIV/AIDS clinic in Uganda, we evaluated their adherence experiences for purposes of program improvement. Daily drug regimens provided by the pediatric clinic included cotrimoxazole prophylaxis as well as ART and cotrimoxazole combined. Complete disclosure of HIV status by caregivers to children and strong parental relationships were related to good adherence. Structural factors including poverty and stigma were barriers to adherence even for children who had had complete disclosure and a supportive relationship with a parent. To ensure adherence to life-extending medications, our findings underscore the need for providers to support caregivers to disclose, provide on-going support and maintain open communication with HIV-infected children taking cotrimoxazole prophylaxis and ART.


PLOS ONE | 2009

Reproductive Intentions and Outcomes among Women on Antiretroviral Therapy in Rural Uganda: A Prospective Cohort Study

Jaco Homsy; Rebecca Bunnell; David Moore; Rachel King; Samuel Malamba; Rose Nakityo; David V. Glidden; Jordan W. Tappero; Jonathan Mermin

Background Antiretroviral therapy (ART) may influence the biological, social and behavioral determinants of pregnancy in HIV-infected women. However, there are limited longitudinal data on the reproductive intentions and outcomes among women on ART in Africa. Methodology /Principal Findings Using a prospective cohort design, we analyzed trends in desire for children and predictors of pregnancy among a cohort of 733 HIV-infected women in rural Uganda who initiated ART between May 2003 and May 2004 and were followed up in their homes until June 2006. Women answered in-depth social and behavioral questionnaires administered every quarter in year 1 after initiating ART, and every 6 to 12 months thereafter. Use of family planning methods was assessed at 18 and 24 months after starting ART. We tested for non-constant pregnancy incidence by using a shape parameter test from the Weibull distribution. We modeled repeated measurements of all variables related to the womens desire for children over time using a generalized estimating equation (GEE) extension to the logistic regression model. Risk factors for pregnancy were examined using Cox proportional hazards model. 711 women eligible for the study were followed-up for a median time of 2.4 years after starting ART. During this time, less than 7% of women reported wanting more children at any time point yet 120 (16.9%) women experienced 140 pregnancies and pregnancy incidence increased from 3.46 per 100 women-years (WY) in the first quarter to 9.5 per 100 WY at 24 months (p<0.0001). This was paralleled by an increase in the proportion of women reporting sexual activity in the past 3 months, from 24.4% at baseline to 32.5% over 24 months of follow-up (p = 0.001). Only 14% of women used permanent or semi-permanent family planning methods by their second year on ART. In the multivariate model, younger age (HR = 2.71 per 10-year decrease, 95% CI: 2.95–3.78), having a BMI>18.5 (HR = 1.09, CI: 1.01–1.18) and not having used condoms consistently in the last 3 months (HR = 1.79, CI: 1.02–3.13) were independently associated with pregnancy. Conclusion/Significance Women on ART and their partners should be consistently counseled on the effects of ART in restoring fertility, and offered regularly free and comprehensive family planning services as part of their standard package of care.


Journal of Acquired Immune Deficiency Syndromes | 2010

Breastfeeding, mother-to-child HIV transmission, and mortality among infants born to HIV-Infected women on highly active antiretroviral therapy in rural Uganda.

Jaco Homsy; David Moore; Alex Barasa; Willi Were; Celina Likicho; Bernard Waiswa; Robert Downing; Samuel Malamba; Jordan W. Tappero; Jonathan Mermin

Background:Highly active antiretroviral therapy (HAART) drastically reduces mother-to-child transmission of HIV, but where breastfeeding is the only safe infant feeding option, HAART for the prevention of mother-to-child transmission needs to be evaluated in relation to both HIV transmission and infant mortality. Design and Methods:One hundred and two ≥18-year old women on HAART in rural Uganda who delivered one or more live infants between March 1, 2003 and January 1, 2007 were enrolled in a prospective study to assess HIV transmission and infant survival. All pregnant women were counseled to exclusively breastfeed for 3-6 months according to national guidelines at the time. Infants were followed-up for ≥7 months and were offered HIV polymerase chain reaction testing quarterly from 6 weeks of age until ≥6 weeks after complete weaning. Results:Of 118 infants born during follow-up, 109 (92%) were breastfed. Median durations of exclusive and total breastfeeding were 4 months (interquartile range 3-6) and 5 months (interquartile range 3-7), respectively. None of the infants tested HIV polymerase chain reaction positive over follow-up but 16 infants died without a definitive HIV status at a median age of 2.6 months. In total, 23 (19%) infants died during follow-up at a median age of 3.7 months; 15 (65%) of whom with severe diarrhea and/or vomiting in the week preceding their death. In multivariate analysis, there was a 6-fold greater risk of death among infants breastfed for less than 6 months independent of maternal CD4 count closest to delivery, maternal marital status or maternal death (adjusted hazard ratio = 6.19; 95% confidence interval 1.41-27.0, P = 0.015). Conclusions:In resource-constrained settings, HIV-infected pregnant women should be assessed for HAART eligibility and treated as needed without delay, and should be encouraged to breastfeed their infants for at least 6 months.


AIDS | 2005

Cotrimoxazole prophylaxis by HIV-infected persons in Uganda reduces morbidity and mortality among HIV-uninfected family members.

Jonathan Mermin; John Lule; John Paul Ekwaru; Robert Downing; Peter Hughes; Rebecca Bunnell; Samuel Malamba; Ray Ransom; Frank Kaharuza; Alex Coutinho; Aminah Kigozi; Robert Quick

Background:The effect of cotrimoxazole prophylaxis taken by persons with HIV on community health and antimicrobial resistance is unknown. Objective:To assess the effect of cotrimoxazole prophylaxis taken by persons with HIV on morbidity, mortality, and antimicrobial resistance of diarrheal pathogens infecting their HIV-negative family members. Design:Prospective cohort in rural Uganda. Methods:A total of 879 persons with HIV and 2771 HIV-negative family members received weekly home-visits. After 5 months, persons with HIV received daily cotrimoxazole prophylaxis and households were followed for an average of 17 additional months. Findings:During the study, 224 participants with HIV (25%) and 29 household members (1%) died. Mortality among HIV-negative family members < 10 years old was 63% less during the cotrimoxazole period than before [hazard ratio, 0.37; 95% confidence interval (CI), 0.14–0.95; P = 0.04]. Malaria among family members was less common during cotrimoxazole treatment [incidence rate ratio (IRR), 0.62; CI, 0.53–0.74; P < 0.0001], as were diarrhea (IRR, 0.59; CI, 0.45–0.76; P = 0.0001), and hospitalizations (IRR, 0.57; CI, 0.36–0.92; P = 0.02). Death of a parent with HIV was associated with a threefold increase in mortality among HIV-negative children < 10 years old (hazard ratio, 2.9; CI, 1.1–8.1; P = 0.04). Of 134 bacterial isolates from family members before cotrimoxazole treatment, 89 (66%) were resistant to cotrimoxazole; of 75 recovered during cotrimoxazole treatment, 54 (72%) were resistant (P = 0.41). Interpretation:Cotrimoxazole prophylaxis taken by persons with HIV was associated with decreased morbidity and mortality among family members. Antimicrobial resistance among diarrheal pathogens infecting family members did not increase. Concerns regarding the spread of bacterial resistance should not impede implementation of cotrimoxazole programs.


Journal of Acquired Immune Deficiency Syndromes | 2005

Long-term Experience Providing Antiretroviral Drugs in a Fee-for-service Hiv Clinic in Uganda: Evidence of Extended Virologic and Cd4+ Cell Count Responses

Charles Kabugo; Sylver Bahendeka; Raymond Mwebaze; Samuel Malamba; David Katuntu; Robert Downing; Jonathan Mermin; Paul J. Weidle

Objective:To describe the long-term experience of providing anti-retroviral (ARV) therapy, including CD4+ cell count and virologic response, at St. Francis Hospital, Nsambya, Uganda. Methods:The HIV clinic established in 1998 is a fee-for-service model where patients pay for ARVs. The care of patients who started ARVs from August 1, 1998 until October 31, 2000 was evaluated through December 31, 2002. Data were collected at the HIV clinic on standardized clinical forms. These patients had free CD4+ cell count and viral load testing performed at times determined by the physician. All persons who had ≥1 CD4+ cell count or viral load done ≥90 days after starting therapy were evaluated. Results:Three hundred twenty-one patients (49% women, 66% ARV naive, median age = 38 years, median CD4+ cell count = 79 cells/mm3, and median viral load = 249,489 copies/mL) attended the HIV clinic. Two hundred sixty-three (82%) patients returned at least once after the initial visit, of whom 54 (21%) had an interruption in therapy for >1 year. One hundred thirty-five patients were in care in 2002, 69 were known to have died (9 of whom died in 2002), and 68 were lost to follow-up. The probability of remaining alive and in care at 1 year was 0.56 (95% confidence interval [CI]: 0.50-0.61), 0.46 (95% CI: 0.41-0.51) at 2 years, 0.40 (95% CI: 0.34-0.45) at 3 years, and 0.35 (95% CI: 0.29-0.41) at 4 years. In an on-treatment analysis, the median CD4+ cell count increase during year 1 was +55 cells/mm3, +112 cells/mm3 during year 2, +142 cells/mm3 during year 3, and +131 cells/mm3 during year 4. The median log viral load change from baseline during year 1 was −1.4 copies/mL, −1.32 copies/mL during year 2, −1.9 copies/mL during year 3, and −1.51 copies/mL during year 4. Conclusions:This fee-for-service HIV clinic providing ARV treatment has successfully operated and managed patients for more than 4 years. Those who survived and remained on therapy derived long-term virologic and immunologic responses to ARV drugs in a manner similar to that observed in industrialized countries. Strategies to reduce the financial burden and other barriers to uninterrupted care as well as incentives to increase such practice models should be further explored in the African context.


Journal of Acquired Immune Deficiency Syndromes | 2007

The need for partner consent is a main reason for opting out of routine HIV testing for prevention of mother-to-child transmission in a rural Ugandan hospital.

Jaco Homsy; Rachel King; Samuel Malamba; Christine Opio; Julius N. Kalamya; Jonathan Mermin; Alice Okallanyi; John Obonyo

Across Africa in 2005 100000 women) can be expected to be infected with HIV. Thus as routine HCT becomes the standard entry point to PMTCT programs understanding the reasons why some women decline the service is increasingly important. (excerpt)


AIDS | 2003

Development of phenotypic and genotypic resistance to antiretroviral therapy in the UNAIDS HIV Drug Access Initiative--Uganda.

Paul J. Weidle; Robert Downing; Catherine Sozi; Raymond Mwebaze; Gideon Rukundo; Samuel Malamba; Richard Respess; Kurt Hertogs; Brendan A. Larder; Dorothy Ochola; Jonathan Mermin; Badara Samb; Eve M. Lackritz

ObjectiveWe describe phenotypic drug resistance, response to therapy, and genotypic mutations among HIV-infected patients in Uganda taking antiretroviral medications for ≥ 90 days who had a viral load ≥ 1000 copies/ml. MethodsHIV-1 group and subtype, virologic and immunologic responses to antiretroviral therapy, phenotypic resistance to antiretroviral drugs, and associated genotypic mutations among patients at three treatment centers in Uganda between June 1999 and August 2000 were assessed. Therapy was two nucleoside reverse transcriptase inhibitors (NRTIs) or highly active antiretroviral therapy (HAART). ResultsAll HIV identified was HIV-1, group M, subtypes A, C, and D. Sixty-one (65%) of 94 patients with a phenotypic resistance result had evidence of phenotypic resistance including resistance to a NRTI for 51 of 92 (55%) taking NRTIs, to a non-nucleoside reverse transcriptase inhibitor (NNRTI) for nine of 16 (56%) taking NNRTIs, and to a protease inhibitor (PI) for eight of 37 (22%) taking PIs. At the time of the first specimen with resistance, the median change from baseline viral load was −0.56 log copies/ml [interquartile range (IQR), −1.47 to +0.29] and CD4+ cell count was +35 × 106 cells/l (IQR, −18 to +87). Genotypic resistance mutations, matched with phenotypic resistance assay results and drug history, were generally consistent with those seen for HIV-1, group M, subtype B infections in industrialized countries. ConclusionInitial phenotypic resistance and corresponding genotypic mutations among patients treated in Uganda were similar to those with subtype B infections in North America and Europe. These data support policies that promote the use of HAART regimens against HIV-1, group M, non-B subtypes in a manner consistent with that used for subtype B infections.


Malaria Journal | 2007

The effect of HIV on morbidity and mortality in children with severe malarial anaemia

Samuel Malamba; Wolfgang Hladik; Arthur Reingold; Flora Banage; Willi McFarland; George W. Rutherford; Derrick Mimbe; Esau Nzaro; Robert Downing; Jonathan Mermin

BackgroundMalaria and HIV are common causes of mortality in sub-Saharan Africa. The effect of HIV infection on morbidity and mortality in children with severe malarial anaemia was assessed.MethodsChildren <5 years old were followed as part of a prospective cohort study to assess the transfusion-associated transmission of blood-borne pathogens at Mulago Hospital, Kampala, Uganda. All children were hospitalized with a diagnosis of severe malarial anaemia requiring blood transfusion. Survival to different time points post-transfusion was compared between HIV-infected and uninfected children. Generalized estimating equations were used to analyse repeated measurement outcomes of morbidity, adjusting for confounders.FindingsOf 847 children, 78 (9.2%) were HIV-infected. Median follow-up time was 162 days (inter-quartile range: 111, 169). HIV-infected children were more likely to die within 7 days (Hazard ratio [HR] = 2.86, 95% Confidence interval [CI] 1.30–6.29, P = 0.009) and within 28 days (HR = 3.70, 95% CI 1.91–7.17, P < 0.001) of an episode of severe malarial anaemia, and were more likely to die in the 6 months post-transfusion (HR = 5.70, 95% CI 3.54–9.16, P < 0.001) compared to HIV-uninfected children. HIV-infected children had more frequent re-admissions due to malaria within 28 days (Incidence rate ratio (IRR) = 3.74, 95% CI 1.41–9.90, P = 0.008) and within 6 months (IRR = 2.66, 95% CI 1.17 – 6.07, P = 0.02) post-transfusion than HIV-uninfected children.ConclusionHIV-infected children with severe malarial anaemia suffered higher all-cause mortality and malaria-related mortality than HIV-uninfected children. Children with HIV and malaria should receive aggressive treatment and further evaluation of their HIV disease, particularly with regard to cotrimoxazole prophylaxis and antiretroviral therapy.


American Journal of Tropical Medicine and Hygiene | 2010

Plasmodium falciparum Dihydrofolate Reductase and Dihyropteroate Synthase Mutations and the Use of Trimethoprim-Sulfamethoxazole Prophylaxis among Persons Infected with Human Immunodeficiency Virus

Samuel Malamba; Taylor Sandison; John Lule; Arthur Reingold; Jordan Walker; Grant Dorsey; Jonathan Mermin

A prospective cohort design was used to measure the association between daily cotrimoxazole-prophylaxis and infection with Plasmodium falciparum containing mutations associated with antifolate resistance among persons infected with human immunodeficiency virus (HIV) in Tororo and Busia District, in eastern Uganda. Of 149 cases of P. falciparum parasitemia diagnosed, 147 (99%) (smears from participants taking prophylaxis = 91 and smears from those not taking cotrimoxazole prophylaxis = 56) were successfully assessed for mutations in the dihydrofolate reductase (dhfr) and dihydropteroate synthase (dhps) mutations associated with antifolate resistance. Prevalences of the dhfr pure triple mutant (74% and 70%; P = 0.71), the dhps pure double mutant (95% and 88%; P = 0.21), and the dhfr/dhps pure quintuple mutant (73% and 64%; P = 0.36), were not significantly different between those taking and those not taking cotrimoxazole-prophylaxis, respectively. The overall prevalence of the pure quintuple mutant in this study was 69%, which is among the highest in Africa. Although resistance rates of P. falciparum to antifolate drugs are high, cotrimoxazole-prophylaxis in HIV-infected persons was not associated with a higher prevalence of mutations associated with antifolate resistance.

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Jonathan Mermin

Centers for Disease Control and Prevention

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Robert Downing

University of Pennsylvania

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John Lule

Centers for Disease Control and Prevention

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Rebecca Bunnell

Centers for Disease Control and Prevention

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Aminah Kigozi

Centers for Disease Control and Prevention

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Jaco Homsy

University of California

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Ray Ransom

Centers for Disease Control and Prevention

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Robert Quick

Centers for Disease Control and Prevention

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