Last data update: May 13, 2024. (Total: 46773 publications since 2009)
Records 1-10 (of 10 Records) |
Query Trace: Chege W[original query] |
---|
Detection of Anopheles stephensi mosquitoes by molecular surveillance, Kenya
Ochomo EO , Milanoi S , Abong'o B , Onyango B , Muchoki M , Omoke D , Olanga E , Njoroge L , Juma EO , Otieno JD , Matoke-Muhia D , Kamau L , Rafferty C , Gimnig JE , Shieshia M , Wacira D , Mwangangi J , Maia M , Chege C , Omar A , Rono MK , Abel L , O'Meara WP , Obala A , Mbogo C , Kariuki L . Emerg Infect Dis 2023 29 (12) 2498-2508 The Anopheles stephensi mosquito is an invasive malaria vector recently reported in Djibouti, Ethiopia, Sudan, Somalia, Nigeria, and Ghana. The World Health Organization has called on countries in Africa to increase surveillance efforts to detect and report this vector and institute appropriate and effective control mechanisms. In Kenya, the Division of National Malaria Program conducted entomological surveillance in counties at risk for An. stephensi mosquito invasion. In addition, the Kenya Medical Research Institute conducted molecular surveillance of all sampled Anopheles mosquitoes from other studies to identify An. stephensi mosquitoes. We report the detection and confirmation of An. stephensi mosquitoes in Marsabit and Turkana Counties by using endpoint PCR and morphological and sequence identification. We demonstrate the urgent need for intensified entomological surveillance in all areas at risk for An. stephensi mosquito invasion, to clarify its occurrence and distribution and develop tailored approaches to prevent further spread. |
The epidemiology of HIV population viral load in twelve sub-Saharan African countries
Hladik W , Stupp P , McCracken SD , Justman J , Ndongmo C , Shang J , Dokubo EK , Gummerson E , Koui I , Bodika S , Lobognon R , Brou H , Ryan C , Brown K , Nuwagaba-Biribonwoha H , Kingwara L , Young P , Bronson M , Chege D , Malewo O , Mengistu Y , Koen F , Jahn A , Auld A , Jonnalagadda S , Radin E , Hamunime N , Williams DB , Kayirangwa E , Mugisha V , Mdodo R , Delgado S , Kirungi W , Nelson L , West C , Biraro S , Dzekedzeke K , Barradas D , Mugurungi O , Balachandra S , Kilmarx PH , Musuka G , Patel H , Parekh B , Sleeman K , Domaoal RA , Rutherford G , Motsoane T , Bissek AZ , Farahani M , Voetsch AC . PLoS One 2023 18 (6) e0275560 BACKGROUND: We examined the epidemiology and transmission potential of HIV population viral load (VL) in 12 sub-Saharan African countries. METHODS: We analyzed data from Population-based HIV Impact Assessments (PHIAs), large national household-based surveys conducted between 2015 and 2019 in Cameroon, Cote d'Ivoire, Eswatini, Kenya, Lesotho, Malawi, Namibia, Rwanda, Tanzania, Uganda, Zambia, and Zimbabwe. Blood-based biomarkers included HIV serology, recency of HIV infection, and VL. We estimated the number of people living with HIV (PLHIV) with suppressed viral load (<1,000 HIV-1 RNA copies/mL) and with unsuppressed viral load (viremic), the prevalence of unsuppressed HIV (population viremia), sex-specific HIV transmission ratios (number female incident HIV-1 infections/number unsuppressed male PLHIV per 100 persons-years [PY] and vice versa) and examined correlations between a variety of VL metrics and incident HIV. Country sample sizes ranged from 10,016 (Eswatini) to 30,637 (Rwanda); estimates were weighted and restricted to participants 15 years and older. RESULTS: The proportion of female PLHIV with viral suppression was higher than that among males in all countries, however, the number of unsuppressed females outnumbered that of unsuppressed males in all countries due to higher overall female HIV prevalence, with ratios ranging from 1.08 to 2.10 (median: 1.43). The spatial distribution of HIV seroprevalence, viremia prevalence, and number of unsuppressed adults often differed substantially within the same countries. The 1% and 5% of PLHIV with the highest VL on average accounted for 34% and 66%, respectively, of countries' total VL. HIV transmission ratios varied widely across countries and were higher for male-to-female (range: 2.3-28.3/100 PY) than for female-to-male transmission (range: 1.5-10.6/100 PY). In all countries mean log10 VL among unsuppressed males was higher than that among females. Correlations between VL measures and incident HIV varied, were weaker for VL metrics among females compared to males and were strongest for the number of unsuppressed PLHIV per 100 HIV-negative adults (R2 = 0.92). CONCLUSIONS: Despite higher proportions of viral suppression, female unsuppressed PLHIV outnumbered males in all countries examined. Unsuppressed male PLHIV have consistently higher VL and a higher risk of transmitting HIV than females. Just 5% of PLHIV account for almost two-thirds of countries' total VL. Population-level VL metrics help monitor the epidemic and highlight key programmatic gaps in these African countries. |
HIV incidence, recent HIV infection, and associated factors, Kenya, 2007-2018
Young PW , Musingila P , Kingwara L , Voetsch D , Zielinski-Gutierrez E , Bulterys M , Kim AA , Bronson MA , Parekh B , Dobbs T , Patel H , Reid G , Achia T , Keter A , Mwalili S , Ogollah FM , Ondondo R , Longwe H , Chege D , Bowen N , Umuro M , Ngugi C , Justman J , Cherutich P , De Cock KM . AIDS Res Hum Retroviruses 2022 39 (2) 57-67 BACKGROUND: Nationally-representative surveys provide an opportunity to assess trends in recent HIV infection based on assays for recent HIV infection. METHODS: We assessed HIV incidence in Kenya in 2018 and trends in recent HIV infection among adolescents and adults in Kenya using nationally representative household surveys conducted in 2007, 2012 and 2018. To assess trends, we defined a recent HIV infection testing algorithm (RITA) that classified as recently infected (<12 months) those HIV-positive participants that were recent on the HIV-1 limiting antigen (LAg)-avidity assay without evidence of antiretroviral use. We assessed factors associated with recent and long-term (≥12 months) HIV infection versus no infection using a multinomial logit model while accounting for complex survey design. FINDINGS: Of 1,523 HIV-positive participants in 2018, 11 were classified as recent. Annual HIV incidence was 0.14% in 2018 (95% confidence interval [CI] 0.057-0.23), representing 35,900 (95% CI 16,300-55,600) new infections per year in Kenya among persons aged 15-64 years. The percentage of HIV infections that were determined to be recent was similar in 2007 and 2012 but fell significantly from 2012 to 2018 (adjusted odds ratio [aOR]=0.31, p<0.001). Compared to no HIV infection, being aged 25-34 versus 35-64 years (aOR=4.2, 95% CI 1.4-13), having more lifetime sex partners (aOR=5.2, 95% CI 1.6-17 for 2-3 partners and aOR=8.6, 95% CI 2.8-26 for ≥4 partners versus 0-1 partners), and never having tested for HIV (aOR=4.1, 95% CI 1.5-11) were independently associated with recent HIV infection. INTERPRETATION: Though HIV remains a public health priority in Kenya, HIV incidence estimates and trends in recent HIV infection support a significant decrease in new HIV infections from 2012 to 2018, a period of rapid expansion in HIV diagnosis, prevention, and treatment. |
Association of schistosomiasis and HIV infections: a systematic review and meta-analysis
Patel P , Rose CE , Kjetland EF , Downs JA , Mbabazi PS , Sabin K , Chege W , Watts DH , Secor WE . Int J Infect Dis 2020 102 544-553 BACKGROUND: Female genital schistosomiasis (FGS) affects up to 56 million women in sub-Saharan Africa and may increase risk of HIV infection. METHODS: To assess the association of schistosomiasis with HIV infection, we examined peer-reviewed literature published until December 31, 2018 and generated a pooled estimate for the odds ratio using Bayesian random effects models. RESULTS: Of the 364 abstracts identified, 26 were included in the summary. Eight reported odds ratios of the association between schistosomiasis and HIV; one reported a transmission hazard ratio (HR) of 1·8 (95% confidence interval [CI]: 1·2-2·6) among women and 1·4 (95% CI: 1·0-1·9) among men; 11 described the prevalence of schistosomiasis among HIV-positive persons (range, 1·5%-36·6%); and six reported the prevalence of HIV among persons with schistosomiasis (range, 5·8%-57·3%). Six studies were selected for quantitative analysis. The pooled estimate for the odds ratio of HIV among persons with schistosomiasis was 2·3 (95% CI: 1·2-4·3). CONCLUSIONS: We found a significant association of schistosomiasis with HIV. However, we could not generate a specific summary estimate for FGS. We provide a research agenda to determine the effect of FGS on HIV infection. WHO's policy on mass drug administration for schistosomiasis may prevent HIV. |
The feasibility of recruiting and retaining men who have sex with men and transgender women in a multinational prospective HIV prevention research cohort study in sub-Saharan Africa (HPTN 075)
Sandfort TG , LHamilton E , Marais A , Guo X , Sugarman J , Chen YQ , Cummings V , Dadabhai S , Dominguez K , Panchia R , Schnabel D , Zulu F , Reynolds D , Radebe O , Mbeda C , Kamba D , Kanyemba B , Ogendo A , Stirratt M , Chege W , Lucas J , Fawzy M , McKinstry LA , Eshleman SH . J Int AIDS Soc 2020 23 Suppl 6 e25600 INTRODUCTION: Men who have sex with men (MSM) and transgender women (TGW) in sub-Saharan Africa (SSA) are profoundly affected by HIV with high HIV prevalence and incidence. This population also faces strong social stigma and legal barriers, potentially impeding participation in research. To date, few multi-country longitudinal HIV research studies with MSM/TGW have been conducted in SSA. Primary objective of the HIV Prevention Trials Network (HPTN) 075 study was to assess feasibility of recruiting and retaining a multinational prospective cohort of MSM/TGW in SSA for HIV prevention research. METHODS: HPTN 075, conducted from 2015 to 2017, was designed to enroll 400 MSM/TGW at four sites in SSA (100 per site: Kisumu, Kenya; Blantyre, Malawi; Cape Town, South Africa; and Soweto, South Africa). The number of HIV-positive persons was capped at 20 per site; HIV-positive persons already in care were excluded from participation. The one-year study included five biobehavioural assessments. Community-based input and risk mitigation protocols were included in study design and conduct. RESULTS: Of 624 persons screened, 401 were enrolled. One in five participants was classified as transgender. Main reasons for ineligibility included: (a) being HIV positive after the cap was reached (29.6%); (b) not reporting anal intercourse with a man in the preceding three months (20.6%); and (c) being HIV positive and already in care (17.5%). Five (1.2%) participants died during the study (unrelated to study participation). 92.9% of the eligible participants (368/396) completed the final study visit and 86.1% participated in all visits. The main, overlapping reasons for early termination included being (a) unable to adhere to the visit schedule, predominantly because of relocation (46.4%), and (b) unable to contact the participant (32.1%). Participants reported strong motivation to participate and few participation barriers. Four participants reported social harms (loss of confidentiality and sexual harassment by study staff) that were successfully addressed. CONCLUSIONS: HPTN 075 successfully enrolled a multinational sample of MSM/TGW in SSA in a prospective HIV prevention research study with a high retention rate and few documented social harms. This supports the feasibility of conducting large-scale research trials in this population to address its urgent, unmet HIV prevention needs. |
Healthcare-related stigma among men who have sex with men and transgender women in sub-Saharan Africa participating in HIV Prevention Trials Network (HPTN) 075 study
Mbeda C , Ogendo A , Lando R , Schnabel D , Gust DA , Guo X , Akelo V , Dominguez K , Panchia R , Mbilizi Y , Chen Y , Chege W . AIDS Care 2020 32 (8) 1-9 ABSTRACT The inability to access health services when needed is a critical barrier to HIV prevention, treatment and care among men who have sex with men (MSM) and transgender women (TGW). Using data collected in HPTN 075, we explored factors associated with any experienced healthcare-related stigma. HPTN 075 was a cohort study to assess the feasibility of recruiting and retaining MSM and TGW in clinical trials in sub-Saharan Africa. Of 401 MSM and TGW enrolled at four sites (Kisumu, Kenya; Blantyre, Malawi; Cape Town, Soweto, South Africa) 397 contributed to the analysis (79.9% cis-gender and 20.1% TGW). Of these, (45.3%; 180/397) reported one or more of healthcare-related stigma experiences. Most frequently reported experiences included fear to seek healthcare services (36.3%) and avoiding seeking such services because of the discovery of MSM status (29.2%). Few men and TGW (2.5%) reported having been denied health services because of having sex with men. In multivariable analysis, more participants in Soweto [adjusted odds ratio (AOR) = 2.60] and fewer participants in Blantyre (AOR = 0.27) reported any healthcare-related stigma experiences, in comparison to participants in Kisumu. MSM and TGW that did not have a supportive gay community to rely on were more likely to report any healthcare-related stigma experiences (AOR = 1.46), whereas MSM and TGW who reported high social support and who never had engaged in transactional sex were less likely to report such experiences (AOR = 0.76 and AOR = 0.43, respectively). Our results suggest that encouraging support groups for MSM and TGW as well as training and sensitizing healthcare staff, and the general community, on MSM and TGW health issues and cultural competence may reduce stigma, improve access to healthcare, which could ultimately reduce HIV transmission. |
A digital microfluidic system for serological immunoassays in remote settings
Ng AHC , Fobel R , Fobel C , Lamanna J , Rackus DG , Summers A , Dixon C , Dryden MDM , Lam C , Ho M , Mufti NS , Lee V , Asri MAM , Sykes EA , Chamberlain MD , Joseph R , Ope M , Scobie HM , Knipes A , Rota PA , Marano N , Chege PM , Njuguna M , Nzunza R , Kisangau N , Kiogora J , Karuingi M , Burton JW , Borus P , Lam E , Wheeler AR . Sci Transl Med 2018 10 (438) Serosurveys are useful for assessing population susceptibility to vaccine-preventable disease outbreaks. Although at-risk populations in remote areas could benefit from this type of information, they face several logistical barriers to implementation, such as lack of access to centralized laboratories, cold storage, and transport of samples. We describe a potential solution: a compact and portable, field-deployable, point-of-care system relying on digital microfluidics that can rapidly test a small volume of capillary blood for disease-specific antibodies. This system uses inexpensive, inkjet-printed digital microfluidic cartridges together with an integrated instrument to perform enzyme-linked immunosorbent assays (ELISAs). We performed a field validation of the system's analytical performance at Kakuma refugee camp, a remote setting in northwestern Kenya, where we tested children aged 9 to 59 months and caregivers for measles and rubella immunoglobulin G (IgG). The IgG assays were determined to have sensitivities of 86% [95% confidence interval (CI), 79 to 91% (measles)] and 81% [95% CI, 73 to 88% (rubella)] and specificities of 80% [95% CI, 49 to 94% (measles)] and 91% [95% CI, 76 to 97% (rubella)] (measles, n = 140; rubella, n = 135) compared with reference tests (measles IgG and rubella IgG ELISAs from Siemens Enzygnost) conducted in a centralized laboratory. These results demonstrate a potential role for this point-of-care system in global serological surveillance, particularly in remote areas with limited access to centralized laboratories. |
Delivery of an Ebola virus-positive stillborn infant in a rural community health center, Sierra Leone, January 2015
Bower H , Grass JE , Veltus E , Brault A , Campbell S , Basile AJ , Wang D , Paddock CD , Erickson BR , Salzer JS , Belser J , Chege E , Seneca D , Saffa G , Stroeher U , Decroo T , Caleo GM . Am J Trop Med Hyg 2015 94 (2) 417-9 We report the case of an Ebola virus (EBOV) RNA-negative pregnant woman who delivered an EBOV RNA-positive stillborn infant at a community health center in rural Sierra Leone, 1 month after the mother's last possible exposure. The mother was later found to be immunoglobulins M and G positive indicating previous infection. The apparent absence of Ebola symptoms and not recognizing that the woman had previous contact with an Ebola patient led health workers performing the delivery to wear only minimal personal protection, potentially exposing them to a high risk of EBOV infection. This case emphasizes the importance of screening for epidemiological risk factors as well as classic and atypical symptoms of Ebola when caring for pregnant women, even once they have passed the typical time frame for exposure and incubation expected in nonpregnant adults. It also illustrates the need for health-care workers to use appropriate personal protection equipment when caring for pregnant women in an Ebola setting. |
Evaluation of syndromic management of sexually transmitted infections within the Kisumu Incidence Cohort Study
Otieno FO , Ndivo R , Oswago S , Ondiek J , Pals S , McLellan-Lemal E , Chen RT , Chege W , Gray KM . Int J STD AIDS 2014 25 (12) 851-9 BACKGROUND: While laboratory aetiological diagnosis is considered the gold standard for diagnosis and management of sexually transmitted infections, syndromic management has been presented as a simplified and affordable approach for sexually transmitted infection management in limited resource settings. METHODS: Sexually transmitted infection signs and symptoms were collected using staff-administered computer-assisted personal interview and audio computer-assisted self-interview. Participants underwent a medical examination and laboratory testing for common sexually transmitted infections. The performance of syndromic management was assessed on the agreement between interviewing methods as well as accurate diagnosis. RESULTS: We screened 846 participants, of whom 88 (10.4%) received syndromic sexually transmitted infection diagnosis while 272 (32.2%) received an aetiological diagnosis. Agreement between syndromic and aetiological diagnoses was very poor (overall kappa = 0.09). The most prevalent sexually transmitted infection was herpes simplex virus type 2 and the percentage of persons with any sexually transmitted infection was higher among women (48.6%) than men (15.6%, p < 0.0001). Agreement between audio computer-assisted self-interview and computer-assisted personal interview interviewing methods for syndromic diagnosis of sexually transmitted infections ranged from poor to good. CONCLUSION: Our findings suggest that syndromic management of sexually transmitted infections is not a sufficient tool for sexually transmitted infection diagnosis in this setting; development and improvement of sexually transmitted infection diagnostic capabilities through laboratory confirmation is needed in resource-limited settings. |
Baseline findings of an HIV incidence cohort study to prepare for future HIV prevention clinical trials in Kisumu, Kenya
Chege W , Pals SL , McLellan-Lemal E , Shinde S , Nyambura M , Otieno FO , Gust DA , Chen RT , Thomas T . J Infect Dev Ctries 2012 6 (12) 870-80 INTRODUCTION: In an analysis of baseline findings of an HIV incidence cohort study, an assessment was made of HIV prevalence among persons presenting for enrollment and any differences in demographic characteristics between persons not enrolled compared to those enrolled. We also described and compared HIV risk behaviors in males and females enrolled in the study. METHODOLOGY: A computer-assisted survey was administered to collect baseline demographic and HIV risk data from 1,277 men and women aged 18-34 years. Testing for HIV and other sexually transmitted infections (STI) was conducted. Out of 1,277 persons prescreened for eligibility, 625 were enrolled. RESULTS: HIV prevalence of all persons who completed screening was 14.8% (females: 21.1%; males: 8.1%). The odds of being enrolled in the study were higher for persons 18-24 years compared to those 30-34 years of age [adjusted odds ratio (AOR)=2.18, CI=1.13, 4.21] and males compared to females [AOR=2.07, CI=1.43, 2.99]. Among those enrolled in the study, the most prevalent HIV risk behaviors were unprotected sex (49%), alcohol use (45%), and transactional sex (30%) in the last three months. Compared to females, a significantly greater proportion of males reported using any alcohol or recreational drug in the last three months, a history of oral sex, sex with partner other than a spouse or main partner, ever having a blood transfusion, ever being treated for an STI, and having knowledge of their last HIV test result. CONCLUSION: The Kisumu Field Station successfully recruited individuals with HIV risk characteristics for the HIV incidence cohort study. |
- Page last reviewed:Feb 1, 2024
- Page last updated:May 13, 2024
- Content source:
- Powered by CDC PHGKB Infrastructure