Search

Your search keyword '"Uyoga, Sophie"' showing total 206 results
Start Over Author "Uyoga, Sophie" Language english
206 results on '"Uyoga, Sophie"'

1. Factors affecting haemoglobin dynamics in African children with acute uncomplicated Plasmodium falciparum malaria treated with single low-dose primaquine or placebo

Author

Onyamboko, Marie A., Olupot-Olupot, Peter, Were, Winifred, Namayanja, Cate, Onyas, Peter, Titin, Harriet, Baseke, Joy, Muhindo, Rita, Kayembe, Daddy K., Ndjowo, Pauline O., Basara, Benjamin B., Okalebo, Charles B., Williams, Thomas N., Uyoga, Sophie, Taya, Chiraporn, Bamisaiye, Adeola, Fanello, Caterina, Maitland, Kathryn, Day, Nicholas P. J., Taylor, Walter R. J., and Mukaka, Mavuto

Published
2023
Full Text
View/download PDF

2. Pharmacokinetics of single low dose primaquine in Ugandan and Congolese children with falciparum malaria

Author

Mukaka, Mavuto, Onyamboko, Marie A., Olupot-Olupot, Peter, Peerawaranun, Pimnara, Suwannasin, Kanokon, Pagornrat, Watcharee, Kouhathong, Jindarat, Madmanee, Wanassanan, Were, Winifred, Namayanja, Cate, Onyas, Peter, Titin, Harriet, Baseke, Joy, Muhindo, Rita, Kayembe, Daddy K., Ndjowo, Pauline O., Basara, Benjamin B., Bongo, Georgette S., Okalebo, Charles B., Abongo, Grace, Uyoga, Sophie, Williams, Thomas N., Taya, Chiraporn, Dhorda, Mehul, Dondorp, Arjen M., Waithira, Naomi, Imwong, Mallika, Maitland, Kathryn, Fanello, Caterina, Day, Nicholas P.J., Tarning, Joel, White, Nicholas J., and Taylor, Walter R.J.

Published
2023
Full Text
View/download PDF

3. Whole blood versus red cell concentrates for children with severe anaemia: a secondary analysis of the Transfusion and Treatment of African Children (TRACT) trial

Author

Maitland, Kathryn, Walker, Sarah A, George, Elizabeth C, Williams, Thomas N, Gibb, Diana M, Mpoya, Ayub, Frost, Gary, Walsh, Kevin, Olupot-Olupot, Peter, Nteziyaremye, Julius, Namayanja, Cate, Ssenyondo, Tonny, Passi, George, Muhindo, Rita, Masifa, George, Adong, Ruth, Okalebo, Charles B, Atimango, Emmanuela, Thembo, Nobert, Odong, George, Kiluli, Godfrey, Kapsindet, Job, Kiguli, Sarah, Opoka, Robert O, Kayaga, Julianne, Nabawanuka, Eva, Kadama, Eva, Mukisa, Cynthia Williams, Engoru, Charles, Alaroker, Florence, Nakuya, Margaret, Amorut, Denis, Olupot, Moses, Onyas, Pius, Ariimi, Margaret, Itipe, Melda, Atim, Mary G, Abeno, Mary, Okwi, Steven, Kulume, Mary G, Among, Grace, Achipa, Dorreen E, Uyoga, Sophie, Macharia, Alex, Mellewa, Machpherson, Chagaluka, George, Kennedy, Neil, Kumwenda, Felistas, Sochera, Tiferanji Fatch, Malenga, Albert, Chimalizeni, Yamikani FG, Gushu, Benard, Phiri, Tusekile, Chesale, Amisa, Mitole, Ndaona, Chokani, Ellida, Munthali, Annie, Hensbroek, Michael Boele von, South, Annabelle, Thomason, Margaret J, Baptiste, David, Connon, Roisin, MacCabe, Leanne, Ali, Abdul, Khamis, Kibibi, Madoola, Macreen, Abongo, Grace, Bates, Imelda, Urban, Britta, Heydermann, Robert, Kyomuhendo, Flavia, Nakalanzi, Sarah, Chabuka, John, Mkandawire, Nkhafwire, Fitzgerald, Felicity, Evans, Jennifer A, Molyneux, Elizabeth, Lubega, Irene, Crawley, Jane, Kazembe, Peter, Murphy, Mike, Peto, Tim, Todd, Jim, Mirembe, Grace, Musoka, Philipa, Tenu, Filemoni, M'baya, Bridon, Kyeyune Byabazair, Dorothy, Mbanya, Dora, and Walker, A Sarah

Published
2022
Full Text
View/download PDF

4. Comparative performance of WANTAI ELISA for total immunoglobulin to receptor binding protein and an ELISA for IgG to spike protein in detecting SARS-CoV-2 antibodies in Kenyan populations

Author

Nyagwange, James, Kutima, Bernadette, Mwai, Kennedy, Karanja, Henry K., Gitonga, John N., Mugo, Daisy, Uyoga, Sophie, Tuju, James, Ochola-Oyier, Lynette I., Ndungu, Francis, Bejon, Philip, Agweyu, Ambrose, Adetifa, Ifedayo M.O., Scott, J.Anthony G., and Warimwe, George M.

Published
2022
Full Text
View/download PDF

6. Temporal trends of SARS-CoV-2 seroprevalence during the first wave of the COVID-19 epidemic in Kenya

Author

Adetifa, Ifedayo M. O., Uyoga, Sophie, Gitonga, John N., Mugo, Daisy, Otiende, Mark, Nyagwange, James, Karanja, Henry K., Tuju, James, Wanjiku, Perpetual, Aman, Rashid, Mwangangi, Mercy, Amoth, Patrick, Kasera, Kadondi, Ng’ang’a, Wangari, Rombo, Charles, Yegon, Christine, Kithi, Khamisi, Odhiambo, Elizabeth, Rotich, Thomas, Orgut, Irene, Kihara, Sammy, Bottomley, Christian, Kagucia, Eunice W., Gallagher, Katherine E., Etyang, Anthony, Voller, Shirine, Lambe, Teresa, Wright, Daniel, Barasa, Edwine, Tsofa, Benjamin, Bejon, Philip, Ochola-Oyier, Lynette I., Agweyu, Ambrose, Scott, J. Anthony G., and Warimwe, George M.

Published
2021
Full Text
View/download PDF

7. Co-trimoxazole or multivitamin multimineral supplement for post-discharge outcomes after severe anaemia in African children: a randomised controlled trial

Author

Maitland, Kathryn, Olupot-Olupot, Peter, Kiguli, Sarah, Chagaluka, George, Alaroker, Florence, Opoka, Robert O, Mpoya, Ayub, Walsh, Kevin, Engoru, Charles, Nteziyaremye, Julius, Mallewa, Machpherson, Kennedy, Neil, Nakuya, Margaret, Namayanja, Cate, Kayaga, Julianne, Nabawanuka, Eva, Sennyondo, Tonny, Aromut, Denis, Kumwenda, Felistas, Musika, Cynthia Williams, Thomason, Margaret J, Bates, Imelda, von Hensbroek, Michael Boele, Evans, Jennifer A, Uyoga, Sophie, Williams, Thomas N, Frost, Gary, George, Elizabeth C, Gibb, Diana M, and Walker, A Sarah

Published
2019
Full Text
View/download PDF

9. Human candidate gene polymorphisms and risk of severe malaria in children in Kilifi, Kenya: a case-control association study

Author

Abathina, Amadou, Abubakar, Ismaela, Achidi, Eric, Agbenyega, Tsiri, Aiyegbo, Mohammed, Akoto, Alex, Allen, Angela, Allen, Stephen, Amenga-Etego, Lucas, Amodu, Folakemi, Amodu, Olukemi, Anchang-Kimbi, Judith, Ansah, Nana, Ansah, Patrick, Ansong, Daniel, Antwi, Sampson, Anyorigiya, Thomas, Apinjoh, Tobias, Asafo-Agyei, Emmanuel, Asoala, Victor, Atuguba, Frank, Auburn, Sarah, Bah, Abdou, Bamba, Kariatou, Bancone, Germana, Band, Gavin, Barnwell, David, Barry, Abdoulaye, Bauni, Evasius, Besingi, Richard, Bojang, Kalifa, Bougouma, Edith, Bull, Susan, Busby, George, Camara, Abdoulie, Camara, Landing, Campino, Susana, Carter, Richard, Carucci, Dan, Casals-Pascual, Climent, Ceesay, Ndey, Ceesay, Pa, Chau, Tran, Chuong, Ly, Clark, Taane, Clarke, Geraldine, Cole-Ceesay, Ramou, Conway, David, Cook, Katharine, Cook, Olivia, Cornelius, Victoria, Corran, Patrick, Correa, Simon, Cox, Sharon, Craik, Rachel, Danso, Bakary, Davis, Timothy, Day, Nicholas, Deloukas, Panos, Dembele, Awa, deVries, Jantina, Dewasurendra, Rajika, Diakite, Mahamadou, Diarra, Elizabeth, Dibba, Yaya, Diss, Andrea, Djimdé, Abdoulaye, Dolo, Amagana, Doumbo, Ogobara, Doyle, Alan, Drakeley, Chris, Drury, Eleanor, Duffy, Patrick, Dunstan, Sarah, Ebonyi, Augustine, Elhassan, Ahmed, Elhassan, Ibrahim, Elzein, Abier, Enimil, Anthony, Esangbedo, Pamela, Evans, Jennifer, Evans, Julie, Farrar, Jeremy, Fernando, Deepika, Fitzpatrick, Kathryn, Fullah, Janet, Garcia, Jacob, Ghansah, Anita, Gottleib, Michael, Green, Angie, Hart, Lee, Hennsman, Meike, Hien, Tran, Hieu, Nguyen, Hilton, Eliza, Hodgson, Abraham, Horstmann, Rolf, Hubbart, Christina, Hughes, Catherine, Hussein, Ayman, Hutton, Robert, Ibrahim, Muntaser, Ishengoma, Deus, Jaiteh, Jula, Jallow, Mariatou, Jallow, Muminatou, Jammeh, Kebba, Jasseh, Momodou, Jeffreys, Anna, Jobarteh, Amie, Johnson, Kimberly, Joseph, Sarah, Jyothi, Dushyanth, Kachala, David, Kamuya, Dorcas, Kanyi, Haddy, Karunajeewa, Harin, Karunaweera, Nadira, Keita, Momodou, Kerasidou, Angeliki, Khan, Aja, Kivinen, Katja, Kokwaro, Gilbert, Konate, Amadou, Konate, Salimata, Koram, Kwadwo, Kwiatkowski, Dominic, Laman, Moses, Le, Si, Leffler, Ellen, Lemnge, Martha, Lin, Enmoore, Ly, Alioune, Macharia, Alexander, MacInnis, Bronwyn, Mai, Nguyen, Makani, Julie, Malangone, Cinzia, Mangano, Valentina, Manjurano, Alphaxard, Manneh, Lamin, Manning, Laurens, Manske, Magnus, Marsh, Kevin, Marsh, Vicki, Maslen, Gareth, Maxwell, Caroline, Mbunwe, Eric, McCreight, Marilyn, Mead, Daniel, Mendy, Alieu, Mendy, Anthony, Mensah, Nathan, Michon, Pascal, Miles, Alistair, Miotto, Olivo, Modiano, David, Mohamed, Hiba, Molloy, Sile, Molyneux, Malcolm, Molyneux, Sassy, Moore, Mike, Moyes, Catherine, Mtei, Frank, Mtove, George, Mueller, Ivo, Mugri, Regina, Munthali, Annie, Mutabingwa, Theonest, Nadjm, Behzad, Ndi, Andre, Ndila, Carolyne, Newton, Charles, Niangaly, Amadou, Njie, Haddy, Njie, Jalimory, Njie, Madi, Njie, Malick, Njie, Sophie, Njiragoma, Labes, Nkrumah, Francis, Ntunthama, Neema, Nyika, Aceme, Nyirongo, Vysaul, O'Brien, John, Obu, Herbert, Oduro, Abraham, Ofori, Alex, Olaniyan, Subulade, Olaosebikan, Rasaq, Oluoch, Tom, Omotade, Olayemi, Oni, Olajumoke, Onykwelu, Emmanuel, Opi, Daniel, Orimadegun, Adebola, O'Riordan, Sean, Ouedraogo, Issa, Oyola, Samuel, Parker, Michael, Pearson, Richard, Pensulo, Paul, Peshu, Norbert, Phiri, Ajib, Phu, Nguyen, Pinder, Margaret, Pirinen, Matti, Plowe, Chris, Potter, Claire, Poudiougou, Belco, Puijalon, Odile, Quyen, Nguyen, Ragoussis, Ioannis, Ragoussis, Jiannis, Rasheed, Oba, Reeder, John, Reyburn, Hugh, Riley, Eleanor, Risley, Paul, Rockett, Kirk, Rodford, Joanne, Rogers, Jane, Rogers, William, Rowlands, Kate, Ruano-Rubio, Valentín, Sabally-Ceesay, Kumba, Sadiq, Abubacar, Saidy-Khan, Momodou, Saine, Horeja, Sakuntabhai, Anavaj, Sall, Abdourahmane, Sambian, David, Sambou, Idrissa, SanJoaquin, Miguel, Sepúlveda, Nuno, Shah, Shivang, Shelton, Jennifer, Siba, Peter, Silva, Nilupa, Simmons, Cameron, Simpore, Jaques, Singhasivanon, Pratap, Sinh, Dinh, Sirima, Sodiomon, Sirugo, Giorgio, Sisay-Joof, Fatoumatta, Sissoko, Sibiry, Small, Kerrin, Somaskantharajah, Elilan, Spencer, Chris, Stalker, Jim, Stevens, Marryat, Suriyaphol, Prapat, Sylverken, Justice, Taal, Bintou, Tall, Adama, Taylor, Terrie, Teo, Yik, Thai, Cao, Thera, Mahamadou, Titanji, Vincent, Toure, Ousmane, Troye-Blomberg, Marita, Usen, Stanley, Uyoga, Sophie, Vanderwal, Aaron, Wangai, Hannah, Watson, Renee, Williams, Thomas, Wilson, Michael, Wrigley, Rebecca, Yafi, Clarisse, Yamoah, Lawrence, Ndila, Carolyne M, Macharia, Alexander W, Nyutu, Gideon, Ojal, John, Shebe, Mohammed, Awuondo, Kennedy O, Mturi, Neema, Tsofa, Benjamin, Clark, Taane G, Kariuki, Silvia, Mackinnon, Margaret, Maitland, Kathryn, Kwiatkowski, Dominic P, Rockett, Kirk A, and Williams, Thomas N

Published
2018
Full Text
View/download PDF

15. Non-O ABO blood group genotypes differ in their associations with Plasmodium falciparum rosetting and severe malaria.

Author

Opi, D. Herbert, Ndila, Carolyne M., Uyoga, Sophie, Macharia, Alex W., Fennell, Clare, Ochola, Lucy B., Nyutu, Gideon, Siddondo, Bethseba R., Ojal, John, Shebe, Mohammed, Awuondo, Kennedy O., Mturi, Neema, Peshu, Norbert, Tsofa, Benjamin, Band, Gavin, Maitland, Kathryn, Kwiatkowski, Dominic P., Rockett, Kirk A., Williams, Thomas N., and Rowe, J. Alexandra

Subjects
ABO blood group system, BLOOD groups, BLOOD group antigens, MALARIA, PLASMODIUM falciparum, GENOTYPES, ERYTHROCYTES
Abstract

Blood group O is associated with protection against severe malaria and reduced size and stability of P. falciparum-host red blood cell (RBC) rosettes compared to non-O blood groups. Whether the non-O blood groups encoded by the specific ABO genotypes AO, BO, AA, BB and AB differ in their associations with severe malaria and rosetting is unknown. The A and B antigens are host RBC receptors for rosetting, hence we hypothesized that the higher levels of A and/or B antigen on RBCs from AA, BB and AB genotypes compared to AO/BO genotypes could lead to larger rosettes, increased microvascular obstruction and higher risk of malaria pathology. We used a case-control study of Kenyan children and in vitro adhesion assays to test the hypothesis that "double dose" non-O genotypes (AA, BB, AB) are associated with increased risk of severe malaria and larger rosettes than "single dose" heterozygotes (AO, BO). In the case-control study, compared to OO, the double dose genotypes consistently had higher odds ratios (OR) for severe malaria than single dose genotypes, with AB (OR 1.93) and AO (OR 1.27) showing most marked difference (p = 0.02, Wald test). In vitro experiments with blood group A-preferring P. falciparum parasites showed that significantly larger rosettes were formed with AA and AB host RBCs compared to OO, whereas AO and BO genotypes rosettes were indistinguishable from OO. Overall, the data show that ABO genotype influences P. falciparum rosetting and support the hypothesis that double dose non-O genotypes confer a greater risk of severe malaria than AO/BO heterozygosity. Author summary: The most common human blood group, ABO, affects susceptibility to multiple diseases including malaria, whereby the non-O blood groups A, B and AB are associated with an increased risk of severe malaria in comparison to blood group O. This may occur because red blood cell (RBC) surface-expressed non-O blood group antigens mediate binding to P. falciparum-infected RBCs to form clumps known as rosettes, that occlude microvasculature circulation and cause severe malaria pathology. Nevertheless, to date, these conclusions have largely been based on ABO blood groups determined by serological antibody typing. Genetic classification into AO, AA, BO, BB, AB and OO offers a finer and more specific classification of ABO blood groups, but associations with severe malaria and rosetting based on this method have not been described previously. In a case-control study of >5000 Kenyan children, we show that the "double dose" non-O genotypes AA, BB and AB are associated with an increased risk to severe malaria compared to the "single dose" non-O genotypes AO and BO, and that this is most significant for AB versus AO. In in vitro experiments, double dose non-O genotypes formed larger rosettes compared to single dose non-O genotypes, providing a potential explanation for their increased severe malaria risk. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

19. The clinical epidemiology of sickle cell anemia In Africa

Author

Macharia, Alex W., Mochamah, George, Uyoga, Sophie, Ndila, Carolyne M., Nyutu, Gideon, Makale, Johnstone, Tendwa, Metrine, Nyatichi, Emily, Ojal, John, Shebe, Mohammed, Awuondo, Kennedy O., Mturi, Neema, Peshu, Norbert, Tsofa, Benjamin, Scott, J. Anthony G., Maitland, Kathryn, and Williams, Thomas N.

Published
2018
Full Text
View/download PDF

21. High false discovery rate of the Architect anti‐HCV screening test in blood donors in Uganda and evaluation of an algorithm for confirmatory testing.

Author

Lucey, Olivia, Acana, Susan, Olupot‐Olupot, Peter, Muhindo, Rita, Ayikobua, Ronald, Uyoga, Sophie, Kyeyune‐Byabazaire, Dorothy, Cooke, Graham, and Maitland, Kathryn

Subjects
FALSE discovery rate, DONOR blood supply, BLOOD testing, BLOOD donors, BLOOD banks
Abstract

Background and Objectives: Adequate supplies of donor blood remain a major challenge in sub‐Saharan Africa. This is exacerbated by a lack of confirmatory testing for transfusion‐transmitted infections by blood transfusion services (BTS), leading to significant blood disposal owing to putatively high seroprevalence rates amongst Ugandan blood donors. We aimed to ascertain the false discovery rate of the Architect anti‐hepatitis C virus (HCV) screening assay and categorize screen‐reactive samples into three groups: presumed false positive, active and past infection, and develop an algorithm for confirmatory testing. Materials and Methods: A total of 470 screen‐reactive HCV blood donations were retested using the Architect anti‐HCV assay, an alternative antibody test (SD Biosensor) and a core antigen (cAg) test. signal‐to cut‐off (S/CO) ratios and pre‐analytical factors (centrifugation speed, haemolysis check, time between collection and testing) were recorded. Based on the S/CO ratio evaluation, we propose a testing algorithm to guide supplemental tests. Results: The false discovery rate of the Architect anti‐HCV assay was 0.84 as 395/470 (84%) screen‐reactive samples had no evidence of HCV infection (SD Biosensor and cAg negative) (presumed false positive), 38/470 (8.1%) were antigenaemic, and 32/470 (6.8%) had evidence of past infection. The median S/CO ratios of the presumed false‐positive and active infection samples were 1.8 and 17.3, respectively. The positive predictive value of HCV positivity in samples with ratios above 12 was 91.8%. On retesting, 104/470 (22.1%) samples became negative. Conclusion: The Architect anti‐HCV assay has a very high false discovery rate in Ugandan BTSs, leading to excessive blood disposal. Pre‐analytical factors likely contribute to this. An introduction of confirmatory testing using an algorithm based on S/CO ratio evaluation could limit unnecessary blood wastage and donor deferral. [ABSTRACT FROM AUTHOR]

Published
2022
Full Text
View/download PDF

23. Incidence and predictors of hospital readmission in children presenting with severe anaemia in Uganda and Malawi: a secondary analysis of TRACT trial data

Author

Connon, Roisin, George, Elizabeth C., Olupot-Olupot, Peter, Kiguli, Sarah, Chagaluka, George, Alaroker, Florence, Opoka, Robert O., Mpoya, Ayub, Walsh, Kevin, Engoru, Charles, Nteziyaremye, Julius, Mallewa, Macpherson, Kennedy, Neil, Nakuya, Margaret, Namayanja, Cate, Nabawanuka, Eva, Sennyondo, Tonny, Amorut, Denis, Williams Musika, C., Bates, Imelda, Boele van Hensbroek, M., Evans, Jennifer A., Uyoga, Sophie, Williams, Thomas N., Frost, Gary, Gibb, Diana M., Maitland, Kathryn, Walker, A. Sarah, Kiguli, S., Opoka, R. O., Nabawanuka, E., Kayaga, J., Kadama, E., Mbwali, I., Nuwabaine, L., Nakikwaku, R., Nsubuga, J., Mpande, K., Adoo, R., Ouma, O., Adia, N. K., Olupot-Olupot, P., Nteziyaremye, J., Namanyanga, C., Passi, G., Sennyondo, T., Adong, R., Okalebo, C. B., Atimango, E., Mwamula, S., Kapsindet, J., Muhindo, G. Kiluli R., Thembo, G. Masifa N., Odong, G., Engoru, C., Aloroker, F., Nakuya, M., Amorut, D., Ariima, M., Itipe, M., Atim, M. G., Abeno, M., Amede, B., Olupot, M., Okwi, S., Kulume, M. G., Among, G., Onyas, P., Achipa, E. D., Maitland, K., Mpoya, A., Maitha, P., Uyoga, S., Williams, T. N., Macharia, A., Mallewa, M., Chagaluka, G., Chimalizeni, Y., Kennedy, N., Kumwenda, F., Nkosi, E., Sochera, T., Malenga, A., Gushu, B., Phiri, T., Chisale, A., Mitole, N., Chokani, E., Munthali, A., Frost, G., Walsheto, K., Gibb, D. M., George, E. C., Thomason, M., Baptiste, D., McCabe, L., Walker, A. S., Ali, A., Khamis, K., Madula, M., Abongo, G., Heydermann, R., Bates, I., Urban, B., Kyomuhendo, F., Nakalanzi, S., Chabuka, J., Mkandawire, N., Evans, J. A., Fitzgerald, F., Molyneux, E., Murphy, I. Lubega M., Kazembe, P., Crawley, J., Peto, T., Musoke, P., Todd, J., Mirembe, G., and Tenu, F.

Subjects
wh_155, ws_300, wa_395, wa_320
Abstract

Background: Severe anaemia (haemoglobin < 6 g/dL) is a leading cause of recurrent hospitalisation in African children. We investigated predictors of readmission in children hospitalised with severe anaemia in the TRACT trial (ISRCTN84086586) in order to identify potential future interventions.\ud Methods: Secondary analyses of the trial examined 3894 children from Uganda and Malawi surviving a hospital episode of severe anaemia. Predictors of all-cause readmission within 180 days of discharge were identified using multivariable regression with death as a competing risk. Groups of children with similar characteristics were identified using hierarchical clustering.\ud Results: Of the 3894 survivors 682 (18%) were readmitted; 403 (10%) had ≥2 re-admissions over 180 days. Three main causes of readmission were identified: severe anaemia (n = 456), malaria (n = 252) and haemoglobinuria/dark urine syndrome (n = 165). Overall, factors increasing risk of readmission included HIV-infection (hazard ratio 2.48\ud (95% CI 1.63–3.78), p < 0.001); ≥2 hospital admissions in the preceding 12 months (1.44(1.19–1.74), p < 0.001); history of transfusion (1.48(1.13–1.93), p = 0.005); and missing ≥1 trial medication dose (proxy for care quality) (1.43 (1.21–1.69), p < 0.001). Children with uncomplicated severe anaemia (Hb 4-6 g/dL and no severity features),\ud who never received a transfusion (per trial protocol) during the initial admission had a substantially lower risk of readmission (0.67(0.47–0.96), p = 0.04). Malaria (among children with no prior history of transfusion) (0.60(0.47–0.76), p < 0.001); younger-age (1.07 (1.03–1.10) per 1 year younger, p < 0.001) and known sickle cell disease (0.62(0.46–0.82), p = 0.001) also decreased risk of readmission. For anaemia re-admissions, gross splenomegaly and enlarged spleen increased risk by 1.73(1.23–2.44) and 1.46(1.18–1.82) respectively compared to no splenomegaly.\ud Clustering identified four groups of children with readmission rates from 14 to 20%. The cluster with the highest readmission rate was characterised by very low haemoglobin (mean 3.6 g/dL). Sickle Cell Disease (SCD) predominated in two clusters associated with chronic repeated admissions or severe, acute presentations in largely undiagnosed SCD. The final cluster had high rates of malaria (78%), severity signs and very low platelet count, consistent with acute severe\ud malaria.\ud Conclusions: Younger age, HIV infection and history of previous hospital admissions predicted increased risk of readmission. However, no obvious clinical factors for intervention were identified. As missing medication doses was highly predictive, attention to care related factors may be important.\ud Trial registration: ISRCTN ISRCTN84086586.\ud Keywords: Severe anaemia, Readmission

Published
2021

24. Anti-Severe Acute Respiratory Syndrome Coronavirus 2 Immunoglobulin G Antibody Seroprevalence Among Truck Drivers and Assistants in Kenya

Author

Kagucia, E Wangeci, Gitonga, John N, Kalu, Catherine, Ochomo, Eric, Ochieng, Benard, Kuya, Nickline, Karani, Angela, Nyagwange, James, Karia, Boniface, Mugo, Daisy, Karanja, Henry K, Tuju, James, Mutiso, Agnes, Maroko, Hosea, Okubi, Lucy, Maitha, Eric, Ajuck, Hossan, Mukabi, David, Moracha, Wycliffe, Bulimu, David, Andanje, Nelson, Aman, Rashid, Mwangangi, Mercy, Amoth, Patrick, Kasera, Kadondi, Ng'ang'a, Wangari, Nyaguara, Amek, Voller, Shirine, Otiende, Mark, Bottomley, Christian, Agoti, Charles N, Ochola-Oyier, Lynette I, Adetifa, Ifedayo MO, Etyang, Anthony O, Gallagher, Katherine E, Uyoga, Sophie, Barasa, Edwine, Bejon, Philip, Tsofa, Benjamin, Agweyu, Ambrose, Warimwe, George M, Scott, J Anthony G, and Magarini Sub-County TDA SARS-CoV-2 Serosurveillance Team, The Bu

Subjects
viruses, virus diseases, human activities
Abstract

In October 2020, anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunoglobulin G seroprevalence among truck drivers and their assistants (TDA) in Kenya was 42.3%, higher than among healthcare workers and blood donors. Truck drivers and their assistants transport essential supplies during the coronavirus disease 2019 pandemic, placing them at increased risk of being infected and of transmitting SARS-CoV-2 over a wide geographical area.

Published
2021

25. Point‐of‐care haemoglobin testing in African hospitals: a neglected essential diagnostic test

Author

Uyoga, Sophie, George, Elizabeth C., Bates, Imelda, Olupot‐Olupot, Peter, Chimalizeni, Yami, Molyneux, Elizabeth M., and Maitland, Kathryn

Subjects
wh_100, wh_155, ws_300, wa_395, wh_190
Abstract

Summary: Owing to the rapid turnaround time in the assessment of haemoglobin level by point‐of‐care tests (POC Hb), these have grown in popularity and scope in large parts of the world. However, whilst POC testing for malaria and HIV remains has been integrated into patient management in Africa, the use of POC haemoglobin testing remains neglected by health services. The main users of transfusions (paediatric, maternity and trauma services) present largely as emergencies. Ward‐based POC Hb could result in more rapid and accurate diagnosis of anaemia, contributing to saving of lives and at the same time reduce unnecessary transfusions which deplete the limited supplies of donated blood in Africa. Severe anaemia requiring transfusion is a major cause of paediatric admission in Africa. At a dissemination meeting to discuss the results of a large phase III paediatric transfusion trial and steps to implementation of the findings participants strongly recommended that one of the most pressing actions required was to prioritise the use of POC haemoglobin testing. This would facilitate implementation of the new transfusion algorithm, developed at the meeting, which refines patient management including blood transfusions. We present the rationale for the strongly recommended prioritisation of POC Hb, using paediatric transfusion as an exemplar.

Published
2021

26. A novel locus of resistance to severe malaria in a region of ancient balancing selection

Author

Band, Gavin, Rockett, Kirk A., Spencer, Chris C.A., Kwiatkowski, Dominic P., Le, Quang Si, Clarke, Geraldine M., Kivinen, Katja, Leffler, Ellen M., Cornelius, Victoria, Conway, David J., Williams, Thomas N., Taylor, Terrie, Bojang, Kalifa A., Doumbo, Ogobara, Thera, Mahamadou A., Modiano, David, Sirima, Sodiomon B., Wilson, Michael D., Koram, Kwadwo A., Agbenyega, Tsiri, Achidi, Eric, Marsh, Kevin, Reyburn, Hugh, Drakeley, Chris, Riley, Eleanor, Molyneux, Malcolm, Jallow, Muminatou, Pinder, Margaret, Toure, Ousmane B., Konate, Salimata, Sissoko, Sibiri, Bougouma, Edith C., Mangano, Valentina D., Amenga-Etego, Lucas N., Ghansah, Anita K., Hodgson, Abraham V.O., Ansong, Daniel, Enimil, Anthony, Evans, Jennifer, Apinjoh, Tobias O., Macharia, Alexander, Ndila, Carolyne M., Newton, Charles, Peshu, Norbert, Uyoga, Sophie, Manjurano, Alphaxard, Kachala, David, Nyirongo, Vysaul, Mead, Daniel, Drury, Eleanor, Auburn, Sarah, Campino, Susana G., MacInnis, Bronwyn, Stalker, Jim, Gray, Emma, Hubbart, Christina, Jeffreys, Anna E., Rowlands, Kate, Mendy, Alieu, Craik, Rachel, Fitzpatrick, Kathryn, Molloy, Sile, Hart, Lee, Hutton, Robert, Kerasidou, Angeliki, and Johnson, Kimberly J.

Published
2015
Full Text
View/download PDF

28. Sero-surveillance for IgG to SARS-CoV-2 at antenatal care clinics in three Kenyan referral hospitals: Repeated cross-sectional surveys 2020–21.

Author

Lucinde, Ruth K., Mugo, Daisy, Bottomley, Christian, Karani, Angela, Gardiner, Elizabeth, Aziza, Rabia, Gitonga, John N., Karanja, Henry, Nyagwange, James, Tuju, James, Wanjiku, Perpetual, Nzomo, Edward, Kamuri, Evans, Thuranira, Kaugiria, Agunda, Sarah, Nyutu, Gideon, Etyang, Anthony O., Adetifa, Ifedayo M. O., Kagucia, Eunice, and Uyoga, Sophie

Subjects
WOMEN'S hospitals, PRENATAL care, SARS-CoV-2, IMMUNOGLOBULIN G, HERD immunity, HOSPITALS
Abstract

Introduction: The high proportion of SARS-CoV-2 infections that have remained undetected presents a challenge to tracking the progress of the pandemic and estimating the extent of population immunity. Methods: We used residual blood samples from women attending antenatal care services at three hospitals in Kenya between August 2020 and October 2021and a validated IgG ELISA for SARS-Cov-2 spike protein and adjusted the results for assay sensitivity and specificity. We fitted a two-component mixture model as an alternative to the threshold analysis to estimate of the proportion of individuals with past SARS-CoV-2 infection. Results: We estimated seroprevalence in 2,981 women; 706 in Nairobi, 567 in Busia and 1,708 in Kilifi. By October 2021, 13% of participants were vaccinated (at least one dose) in Nairobi, 2% in Busia. Adjusted seroprevalence rose in all sites; from 50% (95%CI 42–58) in August 2020, to 85% (95%CI 78–92) in October 2021 in Nairobi; from 31% (95%CI 25–37) in May 2021 to 71% (95%CI 64–77) in October 2021 in Busia; and from 1% (95% CI 0–3) in September 2020 to 63% (95% CI 56–69) in October 2021 in Kilifi. Mixture modelling, suggests adjusted cross-sectional prevalence estimates are underestimates; seroprevalence in October 2021 could be 74% in Busia and 72% in Kilifi. Conclusions: There has been substantial, unobserved transmission of SARS-CoV-2 in Nairobi, Busia and Kilifi Counties. Due to the length of time since the beginning of the pandemic, repeated cross-sectional surveys are now difficult to interpret without the use of models to account for antibody waning. [ABSTRACT FROM AUTHOR]

Published
2022
Full Text
View/download PDF

29. BIRC6 modifies risk of invasive bacterial infection in Kenyan children.

Author

Gilchrist, James J., Kariuki, Silvia N., Watson, James A., Band, Gavin, Uyoga, Sophie, Ndila, Carolyne M., Mturi, Neema, Mwarumba, Salim, Mohammed, Shebe, Mosobo, Moses, Alasoo, Kaur, Rockett, Kirk A., Mentzer, Alexander J., Kwiatkowski, Dominic P., Hill, Adrian V. S., Maitland, Kathryn, Scott, J. Anthony G., and Williams, Thomas N.

Published
2022
Full Text
View/download PDF

32. Improving the diagnosis of severe malaria in African children using platelet counts and plasma PfHRP2 concentrations.

Author

Watson, James A., Uyoga, Sophie, Wanjiku, Perpetual, Makale, Johnstone, Nyutu, Gideon M., Mturi, Neema, George, Elizabeth C., Woodrow, Charles J., Day, Nicholas P. J., Bejon, Philip, Opoka, Robert O., Dondorp, Arjen M., John, Chandy C., Maitland, Kathryn, Williams, Thomas N., and White, Nicholas J.

Subjects
MALARIA, SICKLE cell trait, SICKLE cell anemia, AFRICANS, BACTERIAL diseases, CHILD patients, PLATELET count
Abstract

Severe malaria caused by Plasmodium falciparum is difficult to diagnose accurately in children in high-transmission settings. Using data from 2649 pediatric and adult patients enrolled in four studies of severe illness in three countries (Bangladesh, Kenya, and Uganda), we fitted Bayesian latent class models using two diagnostic markers: the platelet count and the plasma concentration of P. falciparum histidine-rich protein 2 (PfHRP2). In severely ill patients with clinical features consistent with severe malaria, the combination of a platelet count of ≤150,000/μl and a plasma PfHRP2 concentration of ≥1000 ng/ml had an estimated sensitivity of 74% and specificity of 93% in identifying severe falciparum malaria. Compared with misdiagnosed children, pediatric patients with true severe malaria had higher parasite densities, lower hematocrits, lower rates of invasive bacterial disease, and a lower prevalence of both sickle cell trait and sickle cell anemia. We estimate that one-third of the children enrolled into clinical studies of severe malaria in high-transmission settings in Africa had another cause of their severe illness. Severe malaria insights: Diagnosis of children with severe malaria caused by infection with Plasmodium falciparum has been difficult in high-transmission settings because of the high coincidence of malaria with other febrile illnesses. Watson et al. analyzed data from >2000 severely ill children and adults in low-transmission (Bangladesh) and high-transmission (Kenya and Uganda) settings. By fitting Bayesian latent class models using a combination of platelet counts and plasma concentrations of P. falciparum histidine-rich protein 2 (PfHRP2), they estimated that detection of ≤150,000 platelets/μl and a plasma PfHRP2 concentration of ≥1000 ng/ml had a sensitivity of about 74% and a specificity of about 93% in identifying severe malaria. These findings revealed that a proportion of children enrolled in several malaria clinical studies in high-transmission settings have severe febrile illness caused by other types of pathogens. [ABSTRACT FROM AUTHOR]

Published
2022
Full Text
View/download PDF

34. A predictive algorithm for identifying children with sickle cell anemia among children admitted to hospital with severe anemia in Africa.

Author

Olupot‐Olupot, Peter, Connon, Roisin, Kiguli, Sarah, Opoka, Robert O., Alaroker, Florence, Uyoga, Sophie, Nakuya, Margret, Okiror, William, Nteziyaremye, Julius, Ssenyondo, Tonny, Nabawanuka, Eva, Kayaga, Juliana, Williams Mukisa, Cynthia, Amorut, Denis, Muhindo, Rita, Frost, Gary, Walsh, Kevin, Macharia, Alexander W., Gibb, Diana M., and Walker, A. Sarah

Published
2022
Full Text
View/download PDF

35. Revealing the extent of the COVID-19 pandemic in Kenya based on serological and PCR-test data

Author

Ojal, John, Brand, Samuel PC, Were, Vincent, Okiro, Emelda A, Kombe, Ivy K, Mburu, Caroline, Aziza, Rabia, Ogero, Morris, Agweyu, Ambrose, Warimwe, George M, Uyoga, Sophie, Adetifa, Ifedayo MO, Scott, J Anthony G, Otieno, Edward, Ochola-Oyier, Lynette I, Agoti, Charles N, Kasera, Kadondi, Amoth, Patrick, Mwangangi, Mercy, Aman, Rashid, Ng’ang’a, Wangari, Tsofa, Benjamin, Bejon, Philip, Barasa, Edwine, Keeling, Matt J, and Nokes, D James

Abstract

Policy makers in Africa need robust estimates of the current and future spread of SARS-CoV-2. Data suitable for this purpose are scant. We used national surveillance PCR test, serological survey and mobility data to develop and fit a county-specific transmission model for Kenya. We estimate that the SARS-CoV-2 pandemic peaked before the end of July 2020 in the major urban counties, with 34 - 41% of residents infected, and will peak elsewhere in the country within 2-3 months. Despite this penetration, reported severe cases and deaths are low. Our analysis suggests the COVID-19 disease burden in Kenya may be far less than initially feared. A similar scenario across sub-Saharan Africa would have implications for balancing the consequences of restrictions with those of COVID-19.

Published
2020

36. Risk of pneumococcal bacteremia in Kenyan children with glucose-6-phosphate dehydrogenase deficiency

Author

Gilchrist, James J, Uyoga, Sophie, Pirinen, Matti, Rautanen, Anna, Mwarumba, Salim, Njuguna, Patricia, Mturi, Neema, Kenyan Bacteraemia Study Group, Hill, Adrian VS, Scott, J Anthony G, and Williams, Thomas N

Subjects
hemic and lymphatic diseases, parasitic diseases
Abstract

BACKGROUND: Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common enzyme deficiency state in humans. The clinical phenotype is variable and includes asymptomatic individuals, episodic hemolysis induced by oxidative stress, and chronic hemolysis. G6PD deficiency is common in malaria-endemic regions, an observation hypothesized to be due to balancing selection at the G6PD locus driven by malaria. G6PD deficiency increases risk of severe malarial anemia, a key determinant of invasive bacterial disease in malaria-endemic settings. The pneumococcus is a leading cause of invasive bacterial infection and death in African children. The effect of G6PD deficiency on risk of pneumococcal disease is undefined. We hypothesized that G6PD deficiency increases pneumococcal disease risk and that this effect is dependent upon malaria. METHODS: We performed a genetic case-control study of pneumococcal bacteremia in Kenyan children stratified across a period of falling malaria transmission between 1998 and 2010. RESULTS: Four hundred twenty-nine Kenyan children with pneumococcal bacteremia and 2677 control children were included in the study. Among control children, G6PD deficiency, secondary to the rs1050828 G>A mutation, was common, with 11.2% (n = 301 of 2677) being hemi- or homozygotes and 33.3% (n = 442 of 1329) of girls being heterozygotes. We found that G6PD deficiency increased the risk of pneumococcal bacteremia, but only during a period of high malaria transmission (P = 0.014; OR 2.33, 95% CI 1.19-4.57). We estimate that the population attributable fraction of G6PD deficiency on risk of pneumococcal bacteremia in areas under high malaria transmission is 0.129. CONCLUSIONS: Our data demonstrate that G6PD deficiency increases risk of pneumococcal bacteremia in a manner dependent on malaria. At the population level, the impact of G6PD deficiency on invasive pneumococcal disease risk in malaria-endemic regions is substantial. Our study highlights the infection-associated morbidity and mortality conferred by G6PD deficiency in malaria-endemic settings and adds to our understanding of the potential indirect health benefits of improved malaria control.

Published
2020

37. The effect of [[alpha].sup.+]-thalassaemia on the incidence of malaria and other diseases in children living on the coast of Kenya

Author

Wambua, Sammy, Mwangi, Tabitha W., Kortok, Moses, Uyoga, Sophie M., Macharia, Alex W., Mwacharo, Jedidah K., Weatherall, David J., Snow, Robert W., Marsh, Kevin, and Williams, Thomas N.

Subjects
Thalassemia -- Case studies, Thalassemia -- Physiological aspects, Malaria -- Physiological aspects, Malaria -- Genetic aspects, Children -- Diseases
Abstract

ABSTRACT Background The [alpha]-thalassaemias are the commonest genetic disorders of humans. It is generally believed that this high frequency reflects selection through a survival advantage against death from malaria; nevertheless, [...]

Published
2006

39. COVID-19 transmission dynamics underlying epidemic waves in Kenya.

Author

Brand, Samuel P. C., Ojal, John, Aziza, Rabia, Were, Vincent, Okiro, Emelda A., Kombe, Ivy K., Mburu, Caroline, Ogero, Morris, Agweyu, Ambrose, Warimwe, George M., Nyagwange, James, Karanja, Henry, Gitonga, John N., Mugo, Daisy, Uyoga, Sophie, Adetifa, Ifedayo M. O., Scott, J. Anthony G., Murunga, Nickson, Otiende, Mark, and Ochola-Oyier, Lynette I.

Published
2021
Full Text
View/download PDF

42. Plasma Plasmodium falciparum Histidine-rich Protein 2 Concentrations in Children With Malaria Infections of Differing Severity in Kilifi, Kenya.

Author

Uyoga, Sophie, Wanjiku, Perpetual, Rop, Jesse C, Makale, Johnstone, Macharia, Alexander W, Nyutu, Gideon M, Shebe, Mohammed, Awuondo, Kennedy A, Mturi, Neema, Woodrow, Charles J, Dondorp, Arjen M, Maitland, Kathryn, and Williams, Thomas N

Subjects
*PROTOZOA, *PROTEINS, *HISTIDINE, *PARASITEMIA, *CONFIDENCE intervals, *BLOOD plasma, *MALARIA, *SEVERITY of illness index, *RISK assessment, *MIXED infections, *DESCRIPTIVE statistics, *BACTERIAL diseases, *ANTIGENS, *CHILDREN
Abstract

Background Most previous studies support a direct link between total parasite load and the clinical severity of Plasmodium falciparum malaria infections. Methods We estimated P. falciparum parasite loads in 3 groups of children with malaria infections of differing severity: (1) children with World Health Organization–defined severe malaria (n = 1544), (2) children admitted with malaria but without features of severity (n = 200), and (3) children in the community with asymptomatic parasitemia (n = 33). Results Peripheral parasitemias were highest in those with uncomplicated malaria (geometric mean [GM] parasite count, 111 064/μL; 95% confidence interval, CI, 86 798–141 819/μL), almost 3 times higher than in those with severe malaria (39 588/μL; 34 990–44 791/μL) and >100 times higher than in those with asymptomatic malaria (1092/μL; 523–2280/μL). However, the GM P. falciparum histidine-rich protein 2 (Pf HRP2) values (95% CI) increased with severity, being 7 (4–12) ng/mL in asymptomatic malaria, 843 (655–1084) ng/mL in uncomplicated malaria, and 1369 (1244–1506) ng/mL in severe malaria. Pf HRP2 concentrations were markedly lower in the subgroup of patients with severe malaria and concomitant invasive bacterial infections of blood or cerebrospinal fluid (GM concentration, 312 ng/mL; 95% CI, 175–557 ng/mL; P <.001) than in those without such infections (1439 ng/mL; 1307–1584; P <.001). Conclusions The clinical severity of malaria infections related strongly to the total burden of P. falciparum parasites. A quantitative test for plasma concentrations of Pf HRP2 could be useful in identifying children at the greatest clinical risk and identifying critically ill children in whom malaria is not the primary cause. [ABSTRACT FROM AUTHOR]

Published
2021
Full Text
View/download PDF

43. Improving statistical power in severe malaria genetic association studies by augmenting phenotypic precision.

Author

Watson, James A., Ndila, Carolyne M., Uyoga, Sophie, Macharia, Alexander, Nyutu, Gideon, Mohammed, Shebe, Ngetsa, Caroline, Mturi, Neema, Peshu, Norbert, Tsofa, Benjamin, Rockett, Kirk, Leopold, Stije, Kingston, Hugh, George, Elizabeth C., Maitland, Kathryn, Day, Nicholas P. J., Dondorp, Arjen M., Bejon, Philip, Williams, Thomas, and Holmes, Chris C.

Published
2021
Full Text
View/download PDF

44. Transfusion management of severe anaemia in African children: a consensus algorithm.

Author

Maitland, Kathryn, Kiguli, Sarah, Olupot‐Olupot, Peter, Opoka, Robert O., Chimalizeni, Yami, Alaroker, Florence, Uyoga, Sophie, Kyeyune‐Byabazaire, Dorothy, M'baya, Bridon, Bates, Imelda, Williams, Thomas N., Munube, Deogratias, Mbanya, Dora, Molyneux, Elizabeth M., South, Annabelle, Walker, A. Sarah, Gibb, Diana M., George, Elizabeth C., Bongomin, Bodo, and Nabawanuka, Eva

Subjects
AFRICANS, SICKLE cell anemia, ANEMIA, MEDICAL personnel, ANEMIA treatment, FETOFETAL transfusion
Abstract

Summary: The phase III Transfusion and Treatment of severe anaemia in African Children Trial (TRACT) found that conservative management of uncomplicated severe anaemia [haemoglobin (Hb) 40–60 g/l] was safe, and that transfusion volume (20 vs. 30 ml/kg whole blood equivalent) for children with severe anaemia (Hb <60 g/l) had strong but opposing effects on mortality, depending on fever status (>37·5°C). In 2020 a stakeholder meeting of paediatric and blood transfusion groups from Africa reviewed the results and additional analyses. Among all 3196 children receiving an initial transfusion there was no evidence that nutritional status, presence of shock, malaria parasite burden or sickle cell disease status influenced outcomes or modified the interaction with fever status on volume required. Fever status at the time of ordering blood was a reliable determinant of volume required for optimal outcome. Elevated heart and respiratory rates normalised irrespective of transfusion volume and without diuretics. By consensus, a transfusion management algorithm was developed, incorporating three additional measurements of Hb post‐admission, alongside clinical monitoring. The proposed algorithm should help clinicians safely implement findings from TRACT. Further research should assess its implementation in routine clinical practice. [ABSTRACT FROM AUTHOR]

Published
2021
Full Text
View/download PDF

45. Human candidate gene polymorphisms and risk of severe malaria in children in Kilifi, Kenya: a case-control association study

Author

Ndila, Carolyne M, Uyoga, Sophie, Macharia, Alexander W, Nyutu, Gideon, Peshu, Norbert, Ojal, John, Shebe, Mohammed, Awuondo, Kennedy O, Mturi, Neema, Tsofa, Benjamin, Sepúlveda, Nuno, Clark, Taane G, Band, Gavin, Clarke, Geraldine, Rowlands, Kate, Hubbart, Christina, Jeffreys, Anna, Kariuki, Silvia, Marsh, Kevin, Mackinnon, Margaret, Maitland, Kathryn, Kwiatkowski, Dominic P, Rockett, Kirk A, Williams, Thomas N, Abathina, Amadou, Abubakar, Ismaela, Achidi, Eric, Agbenyega, Tsiri, Aiyegbo, Mohammed, Akoto, Alex, Allen, Angela, Allen, Stephen, Amenga-Etego, Lucas, Amodu, Folakemi, Amodu, Olukemi, Anchang-Kimbi, Judith, Ansah, Nana, Ansah, Patrick, Ansong, Daniel, Antwi, Sampson, Anyorigiya, Thomas, Apinjoh, Tobias, Asafo-Agyei, Emmanuel, Asoala, Victor, Atuguba, Frank, Auburn, Sarah, Bah, Abdou, Bamba, Kariatou, Bancone, Germana, Barnwell, David, Barry, Abdoulaye, Bauni, Evasius, Besingi, Richard, Bojang, Kalifa, Bougouma, Edith, Bull, Susan, Busby, George, Camara, Abdoulie, Camara, Landing, Campino, Susana, Carter, Richard, Carucci, Dan, Casals-Pascual, Climent, Ceesay, Ndey, Ceesay, Pa, Chau, Tran, Chuong, Ly, Clark, Taane, Cole-Ceesay, Ramou, Conway, David, Cook, Katharine, Cook, Olivia, Cornelius, Victoria, Corran, Patrick, Correa, Simon, Cox, Sharon, Craik, Rachel, Danso, Bakary, Davis, Timothy, Day, Nicholas, Deloukas, Panos, Dembele, Awa, Devries, Jantina, Dewasurendra, Rajika, Diakite, Mahamadou, Diarra, Elizabeth, Dibba, Yaya, Diss, Andrea, Djimdé, Abdoulaye, Dolo, Amagana, Doumbo, Ogobara, Doyle, Alan, Drakeley, Chris, Drury, Eleanor, Duffy, Patrick, Dunstan, Sarah, Ebonyi, Augustine, Elhassan, Ahmed, Elhassan, Ibrahim, Elzein, Abier, Enimil, Anthony, Esangbedo, Pamela, Evans, Jennifer, Evans, Julie, Farrar, Jeremy, Fernando, Deepika, Fitzpatrick, Kathryn, Fullah, Janet, Garcia, Jacob, Ghansah, Anita, Gottleib, Michael, Green, Angie, Hart, Lee, Hennsman, Meike, Hien, Tran, Hieu, Nguyen, Hilton, Eliza, Hodgson, Abraham, Horstmann, Rolf, Hughes, Catherine, Hussein, Ayman, Hutton, Robert, Ibrahim, Muntaser, Ishengoma, Deus, Jaiteh, Jula, Jallow, Mariatou, Jallow, Muminatou, Jammeh, Kebba, Jasseh, Momodou, Jobarteh, Amie, Johnson, Kimberly, Joseph, Sarah, Jyothi, Dushyanth, Kachala, David, Kamuya, Dorcas, Kanyi, Haddy, Karunajeewa, Harin, Karunaweera, Nadira, Keita, Momodou, Kerasidou, Angeliki, Khan, Aja, Kivinen, Katja, Kokwaro, Gilbert, Konate, Amadou, Konate, Salimata, Koram, Kwadwo, Kwiatkowski, Dominic, Laman, Moses, Si, Le, Leffler, Ellen, Lemnge, Martha, Lin, Enmoore, Alioune, Ly, Macharia, Alexander, Macinnis, Bronwyn, Mai, Nguyen, Makani, Julie, Malangone, Cinzia, Mangano, Valentina, Manjurano, Alphaxard, Manneh, Lamin, Manning, Laurens, Manske, Magnus, Marsh, Vicki, Maslen, Gareth, Maxwell, Caroline, Mbunwe, Eric, Mccreight, Marilyn, Mead, Daniel, Mendy, Alieu, Mendy, Anthony, Mensah, Nathan, Michon, Pascal, Miles, Alistair, Miotto, Olivo, Modiano, David, Mohamed, Hiba, Molloy, Sile, Molyneux, Malcolm, Molyneux, Sassy, Moore, Mike, Moyes, Catherine, Mtei, Frank, Mtove, George, Mueller, Ivo, Mugri, Regina, Munthali, Annie, Mutabingwa, Theonest, Nadjm, Behzad, Ndi, Andre, Ndila, Carolyne, Newton, Charles, Niangaly, Amadou, Njie, Haddy, Njie, Jalimory, Njie, Madi, Njie, Malick, Njie, Sophie, Njiragoma, Labes, Nkrumah, Francis, Ntunthama, Neema, Nyika, Aceme, Nyirongo, Vysaul, O'Brien, John, Obu, Herbert, Oduro, Abraham, Ofori, Alex, Olaniyan, Subulade, Olaosebikan, Rasaq, Oluoch, Tom, Omotade, Olayemi, Oni, Olajumoke, Onykwelu, Emmanuel, Opi, Daniel, Orimadegun, Adebola, O'Riordan, Sean, Ouedraogo, Issa, Oyola, Samuel, Parker, Michael, Pearson, Richard, Pensulo, Paul, Phiri, Ajib, Phu, Nguyen, Pinder, Margaret, Pirinen, Matti, Plowe, Chris, Potter, Claire, Poudiougou, Belco, Puijalon, Odile, Quyen, Nguyen, Ragoussis, Ioannis, Ragoussis, Jiannis, Rasheed, Oba, Reeder, John, Reyburn, Hugh, Riley, Eleanor, Risley, Paul, Rockett, Kirk, Rodford, Joanne, Rogers, Jane, Rogers, William, Ruano-Rubio, Valentín, Sabally-Ceesay, Kumba, Sadiq, Abubacar, Saidy-Khan, Momodou, Saine, Horeja, Sakuntabhai, Anavaj, Sall, Abdourahmane, Sambian, David, Sambou, Idrissa, Sanjoaquin, Miguel, Shah, Shivang, Shelton, Jennifer, Siba, Peter, Silva, Nilupa, Simmons, Cameron, Simpore, Jaques, Singhasivanon, Pratap, Sinh, Dinh, Sirima, Sodiomon, Sirugo, Giorgio, Sisay-Joof, Fatoumatta, Sissoko, Sibiry, Small, Kerrin, Somaskantharajah, Elilan, Spencer, Chris, Stalker, Jim, Stevens, Marryat, Suriyaphol, Prapat, Sylverken, Justice, Taal, Bintou, Tall, Adama, Taylor, Terrie, Teo, Yik, Thai, Cao, Thera, Mahamadou, Titanji, Vincent, Toure, Ousmane, Troye-Blomberg, Marita, Usen, Stanley, Vanderwal, Aaron, Wangai, Hannah, Watson, Renee, Williams, Thomas, Wilson, Michael, Wrigley, Rebecca, Yafi, Clarisse, Yamoah, Lawrence, The Wellcome Trust Centre for Human Genetics [Oxford], University of Oxford, London School of Hygiene and Tropical Medicine (LSHTM), The Wellcome Trust Sanger Institute [Cambridge], St Mary's Hospital, Imperial College, TNW and MM are funded through awards from the Wellcome Trust (grants 091758 and 202800 [to TNW] and grant 088634 [to MM]) and DPK and TGC receive support from the Medical Research Council (grant G19/9 [to DPK] and grants MR/K000551/1, MR/M01360X/1, MR/N010469/1, and MC_PC_15103 [to TGC]). The research leading to these results received funding from the European Community's Seventh Framework Programme (FP7/2007-2013, under grant agreement 242095) and from the Medical Research Council (grant G0600718). MalariaGEN is supported by the Wellcome Trust (WT077383/Z/05/Z) and by the Foundation for the National Institutes of Health (grant 566) as part of the Bill & Melinda Gates' Grand Challenges in Global Health Initiative. The Resource Centre for Genomic Epidemiology of Malaria is supported by the Wellcome Trust (grant 090770/Z/09/Z). Support was also provided by the Medical Research Council (grant G0600718). The Wellcome Trust also provides core awards to the Wellcome Trust Centre for Human Genetics (grant 090532/Z/09/Z) and to the Wellcome Trust Sanger Institute (grant 098051). This work forms part of a larger collaboration with the MalariaGEN Consortium, whose members are listed at http://www.malariagen.net/projects/host/consortium-members. This paper is published with permission from the Director of the Kenya Medical Research Institute (KEMRI)., MalariaGEN Consortium (Anavaj Sakuntabhai), and European Project: 242095,EC:FP7:HEALTH,FP7-HEALTH-2009-single-stage,EVIMALAR(2009)

Subjects
Case-Control Studies, Child, Child, Preschool, Female, Gene Frequency, Genetic Predisposition to Disease, Humans, Kenya, Malaria, Male, Polymorphism, Genetic, Hematology, macromolecular substances, [SDV.BIBS]Life Sciences [q-bio]/Quantitative Methods [q-bio.QM], Article, Genetic, [SDV.GEN.GH]Life Sciences [q-bio]/Genetics/Human genetics, parasitic diseases, [SDV.MP.PAR]Life Sciences [q-bio]/Microbiology and Parasitology/Parasitology, [SDV.SPEE]Life Sciences [q-bio]/Santé publique et épidémiologie, Polymorphism, Preschool
Abstract

Summary Background Human genetic factors are important determinants of malaria risk. We investigated associations between multiple candidate polymorphisms—many related to the structure or function of red blood cells—and risk for severe Plasmodium falciparum malaria and its specific phenotypes, including cerebral malaria, severe malaria anaemia, and respiratory distress. Methods We did a case-control study in Kilifi County, Kenya. We recruited as cases children presenting with severe malaria to the high-dependency ward of Kilifi County Hospital. We included as controls infants born in the local community between Aug 1, 2006, and Sept 30, 2010, who were part of a genetics study. We tested for associations between a range of candidate malaria-protective genes and risk for severe malaria and its specific phenotypes. We used a permutation approach to account for multiple comparisons between polymorphisms and severe malaria. We judged p values less than 0·005 significant for the primary analysis of the association between candidate genes and severe malaria. Findings Between June 11, 1995, and June 12, 2008, 2244 children with severe malaria were recruited to the study, and 3949 infants were included as controls. Overall, 263 (12%) of 2244 children with severe malaria died in hospital, including 196 (16%) of 1233 with cerebral malaria. We investigated 121 polymorphisms in 70 candidate severe malaria-associated genes. We found significant associations between risk for severe malaria overall and polymorphisms in 15 genes or locations, of which most were related to red blood cells: ABO, ATP2B4, ARL14, CD40LG, FREM3, INPP4B, G6PD, HBA (both HBA1 and HBA2), HBB, IL10, LPHN2 (also known as ADGRL2), LOC727982, RPS6KL1, CAND1, and GNAS. Combined, these genetic associations accounted for 5·2% of the variance in risk for developing severe malaria among individuals in the general population. We confirmed established associations between severe malaria and sickle-cell trait (odds ratio [OR] 0·15, 95% CI 0·11–0·20; p=2·61 × 10−58), blood group O (0·74, 0·66–0·82; p=6·26 × 10−8), and –α3·7-thalassaemia (0·83, 0·76–0·90; p=2·06 × 10−6). We also found strong associations between overall risk of severe malaria and polymorphisms in both ATP2B4 (OR 0·76, 95% CI 0·63–0·92; p=0·001) and FREM3 (0·64, 0·53–0·79; p=3·18 × 10−14). The association with FREM3 could be accounted for by linkage disequilibrium with a complex structural mutation within the glycophorin gene region (comprising GYPA, GYPB, and GYPE) that encodes for the rare Dantu blood group antigen. Heterozygosity for Dantu was associated with risk for severe malaria (OR 0·57, 95% CI 0·49–0·68; p=3·22 × 10−11), as was homozygosity (0·26, 0·11–0·62; p=0·002). Interpretation Both ATP2B4 and the Dantu blood group antigen are associated with the structure and function of red blood cells. ATP2B4 codes for plasma membrane calcium-transporting ATPase 4 (the major calcium pump on red blood cells) and the glycophorins are ligands for parasites to invade red blood cells. Future work should aim at uncovering the mechanisms by which these polymorphisms can result in severe malaria protection and investigate the implications of these associations for wider health. Funding Wellcome Trust, UK Medical Research Council, European Union, and Foundation for the National Institutes of Health as part of the Bill & Melinda Gates Grand Challenges in Global Health Initiative.

Published
2018

46. Seroprevalence of anti–SARS-CoV-2 IgG antibodies in Kenyan blood donors.

Author

Uyoga, Sophie, Adetifa, Ifedayo M. O., Karanja, Henry K., Nyagwange, James, Tuju, James, Wanjiku, Perpetual, Aman, Rashid, Mwangangi, Mercy, Amoth, Patrick, Kasera, Kadondi, Ng’ang’a, Wangari, Rombo, Charles, Yegon, Christine, Kithi, Khamisi, Odhiambo, Elizabeth, Rotich, Thomas, Orgut, Irene, Kihara, Sammy, Otiende, Mark, and Bottomley, Christian

Subjects
*BLOOD donors, *SARS-CoV-2, *SEROPREVALENCE, *IMMUNOGLOBULIN G
Abstract

The spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Africa is poorly described. The first case of SARS-CoV-2 in Kenya was reported on 12 March 2020, and an overwhelming number of cases and deaths were expected, but by 31 July 2020, there were only 20,636 cases and 341 deaths. However, the extent of SARS-CoV-2 exposure in the community remains unknown. We determined the prevalence of anti–SARS-CoV-2 immunoglobulin G among blood donors in Kenya in April–June 2020. Crude seroprevalence was 5.6% (174 of 3098). Population-weighted, testperformance-adjusted national seroprevalence was 4.3% (95% confidence interval, 2.9 to 5.8%) and was highest in urban counties Mombasa (8.0%), Nairobi (7.3%), and Kisumu (5.5%). SARS-CoV-2 exposure is more extensive than indicated by case-based surveillance, and these results will help guide the pandemic response in Kenya and across Africa. [ABSTRACT FROM AUTHOR]

Published
2021
Full Text
View/download PDF

47. β‐Thalassemia pathogenic variants in a cohort of children from the East African coast.

Author

Macharia, Alexander W., Mochamah, George, Uyoga, Sophie, Ndila, Carolyne M., Nyutu, Gideon, Tendwa, Metrine, Nyatichi, Emily, Makale, Johnstone, Ware, Russell E., and Williams, Thomas N.

Subjects
CHILD care, GENE frequency, FETAL hemoglobin, COASTS, HEMOGLOBINS, COHORT analysis
Abstract

Background: β‐Thalassemia is rare in sub‐Saharan Africa. Previous studies have suggested that it is limited to specific parts of West Africa. Based on hemoglobin A2 (HbA2) concentrations measured by HPLC, we recently speculated that β‐thalassemia might also be present on the East African coast of Kenya. Here, we follow this up using molecular methods. Methods: We used raised hemoglobin A2 (HbA2) values (> 4.0% of total Hb) to target all HbAA members of a cohort study in Kilifi, Kenya, for HBB sequencing for β‐thalassemia (n = 99) together with a sample of HbAA subjects with lower HbA2 levels. Because HbA2 values are artifactually raised in subjects carrying sickle hemoglobin (HbS) we sequenced all participants with an HPLC pattern showing HbS without HbA (n = 116) and a sample with a pattern showing both HbA and HbS. Results: Overall, we identified 83 carriers of four separate β‐thalassemia pathogenic variants: three β0‐thalassemia [CD22 (GAA→TAA), initiation codon (ATG→ACG), and IVS1‐3ʹ end del 25bp] and one β+‐thalassemia pathogenic variants (IVS‐I‐110 (G→A)). We estimated the minimum allele frequency of all variants combined within the study population at 0.3%. Conclusions: β‐Thalassemia is present in Kilifi, Kenya, an observation that has implications for the diagnosis and clinical care of children from the East Africa region. [ABSTRACT FROM AUTHOR]

Published
2020
Full Text
View/download PDF

48. Prevalence of SARS-CoV-2 Antibodies From a National Serosurveillance of Kenyan Blood Donors, January-March 2021.

Author

Uyoga, Sophie, Adetifa, Ifedayo M. O., Otiende, Mark, Yegon, Christine, Agweyu, Ambrose, Warimwe, George M., and Scott, J. Anthony G.

Subjects
*VIRAL antibodies, *IMMUNOGLOBULINS, *CORONAVIRUSES, *BLOOD donors, *PUBLIC health
Abstract

This study examines the prevalence of SARS-CoV-2 antibodies among blood donors aged 16 to 64 years in Kenya from January to March 2021. [ABSTRACT FROM AUTHOR]

Published
2021
Full Text
View/download PDF

49. Polymorphism in a lincRNA Associates with a Doubled Risk of Pneumococcal Bacteremia in Kenyan Children

Author

Kenyan Bacteraemia Study Group, Wellcome Trust Case Control Consortium 2 (WTCCC2), Rautanen, Anna, Pirinen, Matti, Mills, Tara C, Rockett, Kirk A, Strange, Amy, Ndungu, Anne W, Naranbhai, Vivek, Gilchrist, James J, Bellenguez, Céline, Freeman, Colin, Band, Gavin, Bumpstead, Suzannah J, Edkins, Sarah, Giannoulatou, Eleni, Gray, Emma, Dronov, Serge, Hunt, Sarah E, Langford, Cordelia, Pearson, Richard D, Su, Zhan, Vukcevic, Damjan, Macharia, Alex W, Uyoga, Sophie, Ndila, Carolyne, Mturi, Neema, Njuguna, Patricia, Mohammed, Shebe, Berkley, James A, Mwangi, Isaiah, Mwarumba, Salim, Kitsao, Barnes S, Lowe, Brett S, Morpeth, Susan C, Khandwalla, Iqbal, Kilifi Bacteraemia Surveillance Group, Blackwell, Jenefer M, Bramon, Elvira, Brown, Matthew A, Casas, Juan P, Corvin, Aiden, Duncanson, Audrey, Jankowski, Janusz, Markus, Hugh S, Mathew, Christopher G, Palmer, Colin NA, Plomin, Robert, Sawcer, Stephen J, Trembath, Richard C, Viswanathan, Ananth C, Wood, Nicholas W, Deloukas, Panos, Peltonen, Leena, Williams, Thomas N, Scott, J Anthony G, Chapman, Stephen J, Donnelly, Peter, Hill, Adrian VS, Spencer, Chris CA, Markus, Hugh [0000-0002-9794-5996], Sawcer, Stephen [0000-0001-7685-0974], and Apollo - University of Cambridge Repository

Subjects
Polymorphism, Genetic, Adolescent, Infant, Newborn, Infant, Bacteremia, Pneumonia, Pneumococcal, Kenya, Streptococcus pneumoniae, Risk Factors, Case-Control Studies, Child, Preschool, parasitic diseases, Humans, RNA, Long Noncoding, Child, Genome-Wide Association Study
Abstract

Bacteremia (bacterial bloodstream infection) is a major cause of illness and death in sub-Saharan Africa but little is known about the role of human genetics in susceptibility. We conducted a genome-wide association study of bacteremia susceptibility in more than 5,000 Kenyan children as part of the Wellcome Trust Case Control Consortium 2 (WTCCC2). Both the blood-culture-proven bacteremia case subjects and healthy infants as controls were recruited from Kilifi, on the east coast of Kenya. Streptococcus pneumoniae is the most common cause of bacteremia in Kilifi and was thus the focus of this study. We identified an association between polymorphisms in a long intergenic non-coding RNA (lincRNA) gene (AC011288.2) and pneumococcal bacteremia and replicated the results in the same population (p combined = 1.69 × 10(-9); OR = 2.47, 95% CI = 1.84-3.31). The susceptibility allele is African specific, derived rather than ancestral, and occurs at low frequency (2.7% in control subjects and 6.4% in case subjects). Our further studies showed AC011288.2 expression only in neutrophils, a cell type that is known to play a major role in pneumococcal clearance. Identification of this novel association will further focus research on the role of lincRNAs in human infectious disease.

Published
2016

50. Transfusion and Treatment of severe anaemia in African children (TRACT): a study protocol for a randomised controlled trial

Author

Mpoya, Ayub, Kiguli, Sarah, Olupot-Olupot, Peter, Opoka, Robert O., Engoru, Charles, Mallewa, Macpherson, Chimalizeni, Yami, Kennedy, Neil, Kyeyune, Dorothy, Wabwire, Benjamin, M’baya, Bridon, Bates, Imelda, Urban, Britta, von Hensbroek, Michael Boele, Heyderman, Robert, Thomason, Margaret J., Uyoga, Sophie, Williams, Thomas N., Gibb, Diana M., George, Elizabeth C., Walker, A. Sarah, Maitland, Kathryn, Global Health, and Paediatric Infectious Diseases / Rheumatology / Immunology

Subjects
Malawi, Time Factors, Health Status, Medicine (miscellaneous), Nutritional Status, Anaemia, Severity of Illness Index, Drug Administration Schedule, wb_356, Study Protocol, Hemoglobins, Patient Admission, SDG 3 - Good Health and Well-being, Clinical Protocols, Recurrence, Risk Factors, Sepsis, Infant Mortality, Trimethoprim, Sulfamethoxazole Drug Combination, Humans, Pharmacology (medical), Blood Transfusion, Uganda, Micronutrients, Hospital Mortality, Child, Children, Antibiotic prophylaxis, Anthelmintics, wh_155, Transfusion, Age Factors, Infant, Transfusion Reaction, Anemia, Vitamins, Haemoglobinopathies, Malaria, ws_300, ws_366, Treatment Outcome, Research Design, Child, Preschool, Africa, Child Mortality, Dietary Supplements, Emergency medicine, Biomarkers
Abstract

Background\ud In sub-Saharan Africa, where infectious diseases and nutritional deficiencies are common, severe anaemia is a common cause of paediatric hospital admission, yet the evidence to support current treatment recommendations is limited. To avert overuse of blood products, the World Health Organisation advocates a conservative transfusion policy and recommends iron, folate and anti-helminthics at discharge. Outcomes are unsatisfactory with high rates of in-hospital mortality (9–10 %), 6-month mortality and relapse (6 %). A definitive trial to establish best transfusion and treatment strategies to prevent both early and delayed mortality and relapse is warranted.\ud \ud Methods/Design\ud TRACT is a multicentre randomised controlled trial of 3954 children aged 2 months to 12 years admitted to hospital with severe anaemia (haemoglobin

Published
2015

Catalog

Books, media, physical & digital resources
See catalog results