Last data update: Jun 24, 2024. (Total: 47078 publications since 2009)
Records 1-28 (of 28 Records) |
Query Trace: Maina S [original query] |
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P16 expression and recurrent cervical intraepithelial neoplasia after cryotherapy among women living with HIV
Maina D , Chung MH , Temmerman M , Moloo Z , Wawire J , Greene SA , Unger ER , Mugo N , Sakr S , Sayed S , McGrath CJ . Front Med (Lausanne) 2023 10 1277480 BACKGROUND: The expression of p16 protein, a surrogate marker for high-risk human papillomavirus (hrHPV), is associated with cervical dysplasia. We evaluated correlates of p16 expression at treatment for high-grade cervical lesions and its utility in predicting the recurrence of cervical intraepithelial lesions grade 2 or higher (CIN2+) following cryotherapy among women with HIV. METHODS: This is a subgroup analysis of women with HIV in Kenya with baseline cervical biopsy-confirmed CIN2+ who were randomized to receive cryotherapy and followed every six-months for two-years for biopsy-confirmed recurrence of CIN2+. P16 immunohistochemistry was performed on the baseline cervical biopsy with a positive result defined as strong abnormal nuclear expression in a continuous block segment of cells (at least 10-20 cells). RESULTS: Among the 200 women with CIN2+ randomized to cryotherapy, 160 (80%) had a baseline cervical biopsy specimen available, of whom 94 (59%) were p16-positive. p16 expression at baseline was associated with presence of any one of 14 hrHPV genotypes [Odds Ratio (OR) = 3.2; 95% Confidence Interval (CI), 1.03-9.78], multiple lifetime sexual partners (OR = 1.6; 95% CI, 1.03-2.54) and detectable plasma HIV viral load (>1,000 copies/mL; OR = 1.43; 95% CI, 1.01-2.03). Longer antiretroviral therapy duration (≥2 years) at baseline had lower odds of p16 expression (OR = 0.46; 95% CI, 0.24-0.87) than <2 years of antiretroviral therapy. Fifty-one women had CIN2+ recurrence over 2-years, of whom 33 (65%) were p16-positive at baseline. p16 was not associated with CIN2+ recurrence (Hazard Ratio = 1.35; 95% CI, 0.76-2.40). CONCLUSION: In this population of women with HIV and CIN2+, 41% of lesions were p16 negative and baseline p16 expression did not predict recurrence of cervical neoplasia during two-year follow up. |
Evaluation of post-introduction COVID-19 vaccine effectiveness: Summary of interim guidance of the World Health Organization.
Patel MK , Bergeri I , Bresee JS , Cowling BJ , Crowcroft NS , Fahmy K , Hirve S , Kang G , Katz MA , Lanata CF , L'Azou Jackson M , Joshi S , Lipsitch M , Mwenda JM , Nogareda F , Orenstein WA , Ortiz JR , Pebody R , Schrag SJ , Smith PG , Srikantiah P , Subissi L , Valenciano M , Vaughn DW , Verani JR , Wilder-Smith A , Feikin DR . Vaccine 2021 39 (30) 4013-4024 Phase 3 randomized-controlled trials have provided promising results of COVID-19 vaccine efficacy, ranging from 50 to 95% against symptomatic disease as the primary endpoints, resulting in emergency use authorization/listing for several vaccines. However, given the short duration of follow-up during the clinical trials, strict eligibility criteria, emerging variants of concern, and the changing epidemiology of the pandemic, many questions still remain unanswered regarding vaccine performance. Post-introduction vaccine effectiveness evaluations can help us to understand the vaccine's effect on reducing infection and disease when used in real-world conditions. They can also address important questions that were either not studied or were incompletely studied in the trials and that will inform evolving vaccine policy, including assessment of the duration of effectiveness; effectiveness in key subpopulations, such as the very old or immunocompromised; against severe disease and death due to COVID-19; against emerging SARS-CoV-2 variants of concern; and with different vaccination schedules, such as number of doses and varying dosing intervals. WHO convened an expert panel to develop interim best practice guidance for COVID-19 vaccine effectiveness evaluations. We present a summary of the interim guidance, including discussion of different study designs, priority outcomes to evaluate, potential biases, existing surveillance platforms that can be used, and recommendations for reporting results. |
Feasibility of the bag-mediated filtration system for environmental surveillance of poliovirus in Kenya
Zhou NA , Fagnant-Sperati CS , Komen E , Mwangi B , Mukubi J , Nyangao J , Hassan J , Chepkurui A , Maina C , van Zyl WB , Matsapola PN , Wolfaardt M , Ngwana FB , Jeffries-Miles S , Coulliette-Salmond A , Penaranda S , Shirai JH , Kossik AL , Beck NK , Wilmouth R , Boyle DS , Burns CC , Taylor MB , Borus P , Meschke JS . Food Environ Virol 2019 12 (1) 35-47 The bag-mediated filtration system (BMFS) was developed to facilitate poliovirus (PV) environmental surveillance, a supplement to acute flaccid paralysis surveillance in PV eradication efforts. From April to September 2015, environmental samples were collected from four sites in Nairobi, Kenya, and processed using two collection/concentration methodologies: BMFS (> 3 L filtered) and grab sample (1 L collected; 0.5 L concentrated) with two-phase separation. BMFS and two-phase samples were analyzed for PV by the standard World Health Organization poliovirus isolation algorithm followed by intratypic differentiation. BMFS samples were also analyzed by a cell culture independent real-time reverse transcription polymerase chain reaction (rRT-PCR) and an alternative cell culture method (integrated cell culture-rRT-PCR with PLC/PRF/5, L20B, and BGM cell lines). Sabin polioviruses were detected in a majority of samples using BMFS (37/42) and two-phase separation (32/42). There was statistically more frequent detection of Sabin-like PV type 3 in samples concentrated with BMFS (22/42) than by two-phase separation (14/42, p = 0.035), possibly due to greater effective volume assayed (870 mL vs. 150 mL). Despite this effective volume assayed, there was no statistical difference in Sabin-like PV type 1 and Sabin-like PV type 2 detection between these methods (9/42 vs. 8/42, p = 0.80 and 27/42 vs. 32/42, p = 0.18, respectively). This study demonstrated that BMFS can be used for PV environmental surveillance and established a feasible study design for future research. |
Determining the cause of death among children hospitalized with respiratory illness in Kenya: Protocol for Pediatric Respiratory Etiology Surveillance Study (PRESS)
Njuguna HN , Zaki SR , Roberts DJ , Fligner CL , Keating MK , Rogena E , Walong E , Gachii AK , Maleche-Obimbo E , Irimu G , Mathaiya J , Orata N , Lopokoiyit R , Maina J , Emukule GO , Onyango CO , Gikunju S , Owuor C , Kinuthia P , Bunei M , Fields B , Widdowson MA , Mott JA , Chaves SS . JMIR Res Protoc 2019 8 (1) e10854 BACKGROUND: In sub-Saharan Africa, where the burden of respiratory disease-related deaths is the highest, information on the cause of death remains inadequate because of poor access to health care and limited availability of diagnostic tools. Postmortem examination can aid in the ascertainment of causes of death. This manuscript describes the study protocol for the Pediatric Respiratory Etiology Surveillance Study (PRESS). OBJECTIVE: This study protocol aims to identify causes and etiologies associated with respiratory disease-related deaths among children (age 1-59 months) with respiratory illness admitted to the Kenyatta National Hospital (KNH), the largest public hospital in Kenya, through postmortem examination coupled with innovative approaches to laboratory investigation. METHODS: We prospectively followed children hospitalized with respiratory illness until the end of clinical care or death. In case of death, parents or guardians were offered grief counseling, and postmortem examination was offered. Lung tissue specimens were collected using minimally invasive tissue sampling and conventional autopsy where other tissues were collected. Tissues were tested using histopathology, immunohistochemistry, and multipathogen molecular-based assays to identify pathogens. For each case, clinical and laboratory data were reviewed by a team of pathologists, clinicians, laboratorians, and epidemiologists to assign a cause of and etiology associated with death. RESULTS: We have enrolled pediatric cases of respiratory illness hospitalized at the KNH at the time of this submission; of those, 14.8% (140/945) died while in the hospital. Both analysis and interpretation of laboratory results and writing up of findings are expected in 2019-2020. CONCLUSIONS: Postmortem studies can help identify major pathogens contributing to respiratory-associated deaths in children. This information is needed to develop evidence-based prevention and treatment policies that target important causes of pediatric respiratory mortality and assist with the prioritization of local resources. Furthermore, PRESS can provide insights into the interpretation of results using multipathogen testing platforms in resource-limited settings. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/10854. |
Kenya tuberculosis prevalence survey 2016: Challenges and opportunities of ending TB in Kenya
Enos M , Sitienei J , Ong'ang'o J , Mungai B , Kamene M , Wambugu J , Kipruto H , Manduku V , Mburu J , Nyaboke D , Ngari F , Omesa E , Omale N , Mwirigi N , Okallo G , Njoroge J , Githiomi M , Mwangi M , Kirathe D , Kiplimo R , Ndombi A , Odeny L , Mailu E , Kandie T , Maina M , Kasera K , Mulama B , Mugi B , Weyenga H . PLoS One 2018 13 (12) e0209098 BACKGROUND: We aimed to determine the prevalence of pulmonary TB amongst the adult population (>/=15 years) in 2016 in Kenya. METHOD: A nationwide cross-sectional survey where participants first underwent TB symptom screening and chest x-ray. Subsequently, participants who reported cough >2weeks and/or had a chest x-ray suggestive of TB, submitted sputum specimen for laboratory examination by smear microscopy, culture and Xpert MTB/RIF. RESULT: The survey identified 305 prevalent TB cases translating to a prevalence of 558 [95%CI 455-662] per 100,000 adult population. The highest disease burden was reported among people aged 25-34 years (716 [95% CI 526-906]), males (809 [(95% CI 656-962]) and those who live in urban areas (760 [95% CI 539-981]). Compared to the reported TB notification rate for Kenya in 2016, the prevalence to notification ratio was 2.5:1. The gap between the survey prevalence and notification rates was highest among males, age groups 25-34, and the older age group of 65 years and above. Only 48% of the of the survey prevalent cases reported cough >2weeks. In addition, only 59% of the identified cases had the four cardinal symptoms for TB (cough >/=2 weeks, fever, night sweat and weight loss. However, 88.2% had an abnormal chest x-ray suggestive of TB. The use of Xpert MTB/RIF identified 77.7% of the cases compared to smear microscopy's 46%. Twenty-one percent of the survey participants with respiratory symptoms reported to have sought prior health care at private clinics and chemists. Among the survey prevalent cases who reported TB related symptoms, 64.9% had not sought any health care prior to the survey. CONCLUSION: This survey established that TB prevalence in Kenya is higher than had been estimated, and about half of the those who fall ill with the disease each year are missed. |
Assessment of anthropometric data following investments to ensure quality: Kenya Demographic Health Surveys Case Study, 2008 to 2009 and 2014
Leidman E , Mwirigi LM , Maina-Gathigi L , Wamae A , Imbwaga AA , Bilukha OO . Food Nutr Bull 2018 39 (3) 379572118783181 BACKGROUND: Evidence-based nutrition programs depend on accurate estimates of malnutrition derived from data collected in population representative surveys. The feasibility of obtaining accurate anthropometric data as part of national, multisectoral surveys has been a debated issue. OBJECTIVES: The study aimed to evaluate changes in anthropometric data quality corresponding to investments by the Kenya Ministry of Health and nutrition sector partners for the 2014 Kenya Demographic Health Survey. METHODS: Anthropometric data collected during the 2008 to 2009 and 2014 Kenya surveys were reanalyzed to assess standard parameters of quality: standard deviation, skewness, and kurtosis of z-score values for 3 anthropometric indicators (weight for height, height for age, and weight for age), percentage of children with missing measurements and outlier values, digit preference, and heaping of age. RESULTS: A total of 9936 households were selected in 2008 to 2009, and 39 679 households were selected in 2014. Standard deviation of z-scores for all 3 indicators was smaller in 2014 than in 2008 to 2009. Applying original Demographic and Health Survey exclusion criteria, weight for height z-scores were 1.16 in 2014, 10.1% narrower than 2008 to 2009. The percentage of outlying values declined significantly from 2008 to 2009 to 2014 for both height for age and weight for height ( P < .001). Digit preference scores in 2014 improved for both weight ( P = .011) and height ( P < .001) suggesting less rounding of terminal digits. CONCLUSIONS: All tests of data quality suggest an improvement in 2014 relative to 2008 to 2009, despite the complexity implied by the larger sample. This improvement corresponds with efforts to enhance training and supervision of anthropometry, suggesting a positive effect of these enhancements. |
A 2015 outbreak of flea-borne rickettsiosis in San Gabriel Valley, Los Angeles County, California.
Nelson K , Maina AN , Brisco A , Foo C , Croker C , Ngo V , Civen R , Richards AL , Fujioka K , Wekesa JW . PLoS Negl Trop Dis 2018 12 (4) e0006385 Although flea-borne rickettsiosis is endemic in Los Angeles County, outbreaks are rare. In the spring of 2015 three human cases of flea-borne rickettsiosis among residents of a mobile home community (MHC) prompted an investigation. Fleas were ubiquitous in common areas due to presence of flea-infested opossums and overabundant outdoor cats and dogs. The MHC was summarily abated in June 2015, and within five months, flea control and removal of animals significantly reduced the flea population. Two additional epidemiologically-linked human cases of flea-borne rickettsiosis detected at the MHC were suspected to have occurred before control efforts began. Molecular testing of 106 individual and 85 pooled cat fleas, blood and ear tissue samples from three opossums and thirteen feral cats using PCR amplification and DNA sequencing detected rickettsial DNA in 18.8% of the fleas. Seventeen percent of these cat fleas tested positive for R. felis-specific DNA compared to under two (<2) percent for Candidatus R. senegalensis-specific DNA. In addition, serological testing of 13 cats using a group-specific IgG-ELISA detected antibodies against typhus group rickettsiae and spotted fever group rickettsiae in six (46.2%) and one (7.7%) cat, respectively. These results indicate that cats and their fleas may have played an active role in the epidemiology of the typhus group and/or spotted fever group rickettsial disease(s) in this outbreak. |
A comparison of Kenyan Biomphalaria pfeifferi and B. sudanica as vectors for Schistosoma mansoni, including a discussion of the need to better understand the effects of snail breeding systems on transmission
Mutuku M , Lu L , Otiato F , Mwangi IN , Kinuthia JM , Maina GM , Laidemitt MR , Lelo EA , Ochanda H , Loker ES , Mkoji GM . J Parasitol 2017 103 (6) 669-676 In Kenya, schistosomes infect an estimated 6 million people with >30 million people at risk of infection. We compared compatibility with, and ability to support and perpetuate, Schistosoma mansoni of Biomphalaria pfeifferi and Biomphalaria sudanica, 2 prominent freshwater snail species involved in schistosomiasis transmission in Kenya. Field-derived B. pfeifferi (from a stream in Mwea, central Kenya) and B. sudanica (from Nawa, Lake Victoria, in western Kenya) were exposed to S. mansoni miracidia isolated from fecal samples of naturally infected humans from Mwea or Nawa. Juvenile (<6 mm shell diameter), young adult (6-9 mm), and adult snails (>9 mm) were each exposed to a single miracidium. Schistosoma mansoni developed faster and consistently had higher infection rates (39.6-80.7%) in B. pfeifferi than in B. sudanica (2.4-21.5%), regardless of the source of S. mansoni or the size of the snails used. Schistosoma mansoni from Nawa produced higher infection rates in both B. pfeifferi and B. sudanica than did S. mansoni from Mwea. Mean daily cercariae production was greater for B. pfeifferi exposed to sympatric than allopatric S. mansoni (583-1,686 vs. 392-1,232), and mean daily cercariae production amongst B. sudanica were consistently low (50-590) with no significant differences between sympatric or allopatric combinations. Both non-miracidia exposed and miracidia-exposed B. pfeifferi had higher mortality rates than for B. sudanica, but mean survival time of shedding snails (9.3-13.7 weeks) did not differ significantly between the 2 snail species. A small proportion (1.5%) of the cercariae shedding B. pfeifferi survived up to 40 wk post-exposure. Biomphalaria pfeifferi was more likely to become infected and to shed more cercariae than B. sudanica, suggesting that the risk per individual snail of perpetuating transmission in Kenyan streams or lacustrine habitats may differ considerably. High infections rates exhibited by the preferential self-fertilizing B. pfeifferi relative to the out-crossing B. sudanica point out to the need to investigate further the role of host breeding systems in influencing transmission of schistosomiasis by snail hosts. |
Isolation and characterization of a novel Rickettsia species (Rickettsia asembonensis sp. nov.) obtained from cat fleas (Ctenocephalides felis)
Maina AN , Luce-Fedrow A , Omulo S , Hang J , Chan TC , Ade F , Jima DD , Ogola E , Ge H , Breiman RF , Njenga MK , Richards AL . Int J Syst Evol Microbiol 2016 66 (11) 4512-4517 A novel rickettsial agent, 'Candidatus Rickettsia asembonensis' strain NMRCiiT, was isolated from cat fleas, Ctenocephalides felis, from Kenya. Genotypic characterization of the new isolate based on sequence analysis of five rickettsial genes, rrs, gltA, ompA, ompB and sca4, indicated that this isolate clustered with Rickettsia felis URRWXCal2. The degree of nucleotide similarity demonstrated that isolate NMRCiiT belongs within the genus Rickettsia and fulfils the criteria for classification as a representative of a novel species. The name Rickettsia asembonensis sp. nov. is proposed, with NMRCiiT (=DSM 100172T=CDC CRIRC RAS001T=ATCC VR-1827T) as the type strain. |
Displaced populations due to humanitarian emergencies and its impact on global eradication and elimination of vaccine-preventable diseases
Lam E , Diaz M , Maina AG , Brennan M . Confl Health 2016 10 27 Populations affected by humanitarian emergencies may require unique strategies to ensure access to life-saving vaccines and attain sufficiently high population immunity to interrupt virus circulation. Vaccination strategies among displaced populations should not be an afterthought and must be part of the vaccine-preventable disease eradication and elimination initiatives from the start. |
Factors associated with adequate weekly reporting for disease surveillance data among health facilities in Nairobi County, Kenya, 2013
Mwatondo AJ , Ng'ang'a Z , Maina C , Makayotto L , Mwangi M , Njeru I , Arvelo W . Pan Afr Med J 2016 23 165 INTRODUCTION: Kenya adopted the Integrated Disease Surveillance and Response (IDSR) strategy in 1998 to strengthen disease surveillance and epidemic response. However, the goal of weekly surveillance reporting among health facilities has not been achieved. We conducted a cross-sectional study to determine the prevalence of adequate reporting and factors associated with IDSR reporting among health facilities in one Kenyan County. METHODS: Health facilities (public and private) were enrolled using stratified random sampling from 348 facilities prioritized for routine surveillance reporting. Adequately-reporting facilities were defined as those which submitted >10 weekly reports during a twelve-week period and a poor reporting facilities were those which submitted <10 weekly reports. Multivariate logistic regression with backward selection was used to identify risk factors associated with adequate reporting. RESULTS: From September 2 through November 30, 2013, we enrolled 175 health facilities; 130(74%) were private and 45(26%) were public. Of the 175 health facilities, 77 (44%) facilities classified as adequate reporting and 98 (56%) were reporting poorly. Multivariate analysis identified three factors to be independently associated with weekly adequate reporting: having weekly reporting forms at visit (AOR19, 95% CI: 6-65], having posters showing IDSR functions (AOR8, 95% CI: 2-12) and having a designated surveillance focal person (AOR7, 95% CI: 2-20). CONCLUSION: The majority of health facilities in Nairobi County were reporting poorly to IDSR and we recommend that the Ministry of Health provide all health facilities in Nairobi County with weekly reporting tools and offer specific trainings on IDSR which will help designate a focal surveillance person. |
Evidence of rickettsia and orientia infections among abattoir workers in Djibouti
Horton KC , Jiang J , Maina A , Dueger E , Zayed A , Ahmed AA , Pimentel G , Richards AL . Am J Trop Med Hyg 2016 95 (2) 462-5 Of 49 workers at a Djiboutian abattoir, eight (16%, 95% confidence interval [CI]: 9-29) were seropositive against spotted fever group rickettsiae (SFGR), two (4%, 95% CI: 1-14) against typhus group rickettsiae, and three (6%, 95% CI: 2-17) against orientiae. One worker (9%, 95% CI: 2-38) seroconverted against orientiae during the study period. This is the first evidence of orientiae exposure in the Horn of Africa. SFGR were also identified by polymerase chain reaction in 32 of 189 (11%, 95% CI: 8-15) tick pools from 26 of 72 (36%) cattle. Twenty-five (8%, 95% CI: 6-12) tick pools were positive for Rickettsia africae, the causative agent of African tick-bite fever. Health-care providers in Djibouti should be aware of the possibility of rickettsiae infections among patients, although further research is needed to determine the impact of these infections in the country. |
Notes from the field: hepatitis E outbreak among refugees from South Sudan - Gambella, Ethiopia, April 2014-January 2015
Browne LB , Menkir Z , Kahi V , Maina G , Asnakew S , Tubman M , Elyas HZ , Nigatu A , Dak D , Maung UA , Nakao JH , Bilukha O , Shahpar C . MMWR Morb Mortal Wkly Rep 2015 64 (19) 537 In early April 2014, two South Sudanese refugees in the Gambella region of western Ethiopia experienced acute onset of jaundice, accompanied by fever. One patient was a pregnant woman aged 24 years evaluated at a routine prenatal clinic visit in Leitchour refugee camp. The second patient was a malnourished boy aged 1 year who resided in Tierkidi refugee camp. The boy died despite hospitalization. During the last 2 weeks of May, four more cases of acute jaundice syndrome (AJS), defined as yellow discoloration of the eyes, were detected in Leitchuor. By mid-June, an additional 50 AJS cases were reported across three large camps in the region, Kule, Leitchuor, and Tierkidi, with 45 (90%) of these cases reported in Leitchuor. Sera collected from a convenience sample of 21 AJS cases were sent to Addis Ababa and Nairobi for real-time polymerase chain reaction testing; 12 (57%) were positive for hepatitis E virus (HEV) RNA. By January 2015, a total of 1,117 suspected cases of hepatitis E meeting the case definition of AJS were reported among refugees in camps across Gambella. |
Progressing beyond SLMTA: are internal audits and corrective action the key drivers of quality improvement?
Maina RN , Mengo DM , Mohamud AD , Ochieng SM , Milgo SK , Sexton CJ , Moyo S , Luman ET . Afr J Lab Med 2014 3 (2) 222 BACKGROUND: Kenya has implemented the Strengthening Laboratory Management Toward Accreditation (SLMTA) programme to facilitate quality improvement in medical laboratories and to support national accreditation goals. Continuous quality improvement after SLMTA completion is needed to ensure sustainability and continue progress toward accreditation. METHODS: Audits were conducted by qualified, independent auditors to assess the performance of five enrolled laboratories using the Stepwise Laboratory Quality Improvement Process Towards Accreditation (SLIPTA) checklist. End-of-programme (exit) and one year post-programme (surveillance) audits were compared for overall score, star level (from zero to five, based on scores) and scores for each of the 12 Quality System Essential (QSE) areas that make up the SLIPTA checklist. RESULTS: All laboratories improved from exit to surveillance audit (median improvement 38 percentage points, range 5-45 percentage points). Two laboratories improved from zero to one star, two improved from zero to three stars and one laboratory improved from three to four stars. The lowest median QSE scores at exit were: internal audit; corrective action; and occurrence management and process improvement (< 20%). Each of the 12 QSEs improved substantially at surveillance audit, with the greatest improvement in client management and customer service, internal audit and information management (> 50 percentage points). The two laboratories with the greatest overall improvement focused heavily on the internal audit and corrective action QSEs. CONCLUSION: Whilst all laboratories improved from exit to surveillance audit, those that focused on the internal audit and corrective action QSEs improved substantially more than those that did not; internal audits and corrective actions may have acted as catalysts, leading to improvements in other QSEs. Systematic identification of core areas and best practices to address them is a critical step toward strengthening public medical laboratories. |
High prevalence of Rickettsia africae variants in Amblyomma variegatum ticks from domestic mammals in rural western Kenya: implications for human health
Maina AN , Jiang J , Omulo SA , Cutler SJ , Ade F , Ogola E , Feikin DR , Njenga MK , Cleaveland S , Mpoke S , Ng'ang'a Z , Breiman RF , Knobel DL , Richards AL . Vector Borne Zoonotic Dis 2014 14 (10) 693-702 Tick-borne spotted fever group (SFG) rickettsioses are emerging human diseases caused by obligate intracellular Gram-negative bacteria of the genus Rickettsia. Despite being important causes of systemic febrile illnesses in travelers returning from sub-Saharan Africa, little is known about the reservoir hosts of these pathogens. We conducted surveys for rickettsiae in domestic animals and ticks in a rural setting in western Kenya. Of the 100 serum specimens tested from each species of domestic ruminant 43% of goats, 23% of sheep, and 1% of cattle had immunoglobulin G (IgG) antibodies to the SFG rickettsiae. None of these sera were positive for IgG against typhus group rickettsiae. We detected Rickettsia africae-genotype DNA in 92.6% of adult Amblyomma variegatum ticks collected from domestic ruminants, but found no evidence of the pathogen in blood specimens from cattle, goats, or sheep. Sequencing of a subset of 21 rickettsia-positive ticks revealed R. africae variants in 95.2% (20/21) of ticks tested. Our findings show a high prevalence of R. africae variants in A. variegatum ticks in western Kenya, which may represent a low disease risk for humans. This may provide a possible explanation for the lack of African tick-bite fever cases among febrile patients in Kenya. |
Cryptosporidiosis in HIV/AIDS patients in Kenya: clinical features, epidemiology, molecular characterization and antibody responses
Wanyiri JW , Kanyi H , Maina S , Wang DE , Steen A , Ngugi P , Kamau T , Waithera T , O'Connor R , Gachuhi K , Wamae CN , Mwamburi M , Ward HD . Am J Trop Med Hyg 2014 91 (2) 319-28 We investigated the epidemiological and clinical features of cryptosporidiosis, the molecular characteristics of infecting species and serum antibody responses to three Cryptosporidium-specific antigens in human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) patients in Kenya. Cryptosporidium was the most prevalent enteric pathogen and was identified in 56 of 164 (34%) of HIV/AIDS patients, including 25 of 70 (36%) with diarrhea and 31 of 94 (33%) without diarrhea. Diarrhea in patients exclusively infected with Cryptosporidium was significantly associated with the number of children per household, contact with animals, and water treatment. Cryptosporidium hominis was the most prevalent species and the most prevalent subtype family was Ib. Patients without diarrhea had significantly higher serum IgG levels to Chgp15, Chgp40 and Cp23, and higher fecal IgA levels to Chgp15 and Chgp40 than those with diarrhea suggesting that antibody responses to these antigens may be associated with protection from diarrhea and supporting further investigation of these antigens as vaccine candidates. |
Measles outbreak response among adolescent and adult Somali refugees displaced by famine in Kenya and Ethiopia, 2011
Navarro-Colorado C , Mahamud A , Burton A , Haskew C , Maina GK , Wagacha JB , Ahmed JA , Shetty S , Cookson S , Goodson JL , Schilperoord M , Spiegel P . J Infect Dis 2014 210 (12) 1863-70 BACKGROUND: The refugee complexes of Dadaab, Kenya, and Dollo-Ado, Ethiopia, experienced measles outbreaks during June-November 2011, following a large influx of refugees from Somalia. METHODS: Line-lists from health facilities were used to describe the outbreak in terms of age, sex, vaccination status, arrival date, attack rates (ARs), and case fatality ratios (CFRs) for each camp. Vaccination data and coverage surveys were reviewed. RESULTS: In Dadaab, 1370 measles cases and 32 deaths (CFR, 2.3%) were reported. A total of 821 cases (60.1%) were aged ≥15 years, 906 (82.1%) arrived to the camps in 2011, and 1027 (79.6%) were unvaccinated. Camp-specific ARs ranged from 212 to 506 cases per 100 000 people. In Dollo-Ado, 407 cases and 23 deaths (CFR, 5.7%) were reported. Adults aged ≥15 years represented 178 cases (43.7%) and 6 deaths (26.0%). Camp-specific ARs ranged from 21 to 1100 cases per 100 000 people. Immunization activities that were part of the outbreak responses initially targeted children aged 6 months to 14 years and were later expanded to include individuals up to 30 years of age. CONCLUSIONS: The target age group for outbreak response-associated immunization activities at the start of the outbreaks was inconsistent with the numbers of cases among unvaccinated adolescents and adults in the new population. In displacement of populations from areas affected by measles outbreaks, health authorities should consider vaccinating adults in routine and outbreak response activities. |
Notes from the field: malnutrition and elevated mortality among refugees from South Sudan - Ethiopia, June-July 2014
Andresen E , Bilukha OO , Menkir Z , Gayford M , Kavosa M , Wtsadik M , Maina G , Gose M , Nyagucha I , Shahpar C . MMWR Morb Mortal Wkly Rep 2014 63 (32) 700-1 As a result of armed civil conflict in South Sudan that started in mid-December of 2013, an estimated 1.1 million persons were internally displaced, and approximately 400,000 refugees fled South Sudan to neighboring countries (primarily to Ethiopia, Uganda, Sudan, and Kenya). Refugees from South Sudan arriving in Ethiopia are sheltered in three refugee camps located in Gambella region: Leitchuor, Kule, and Tierkidi. The camps were established during January-May 2014 and have estimated refugee populations of 47,000, 51,000, and 50,000, respectively. Reports from health clinics and humanitarian agencies providing assistance to refugees suggested poor nutritional status of arriving refugees and elevated mortality rates. To assess the nutritional status of refugee children aged 6-59 months and mortality rates (crude [all ages] and aged <5 years), the Administration for Refugee and Returnee Affairs (an Ethiopian government aid agency), the United Nations High Commissioner for Refugees, World Food Programme, and United Nations Children's Fund, in collaboration with CDC, conducted cross-sectional population-representative surveys in Leitchuor, Kule, and Tierkidi camps during June-July 2014. Anthropometric measurements in children were taken using standard procedures, and nutritional status was classified based on 2006 World Health Organization (WHO) growth standards. Hemoglobin was measured using HemoCue Hb 301. Anemia was diagnosed according to WHO thresholds. Retrospective mortality rates in Leitchuor and Kule were measured using a household census method. |
Populations at increased Risk for HIV infection in Kenya: results from a national population-based household survey, 2012
Githuka G , Hladik W , Mwalili S , Cherutich P , Muthui M , Gitonga J , Maina WK , Kim AA . J Acquir Immune Defic Syndr 2014 66 Suppl 1 S46-56 BACKGROUND: Populations with higher risks for HIV exposure contribute to the HIV epidemic in Kenya. We present data from the second Kenya AIDS Indicator Survey to estimate the size and HIV prevalence of populations with high-risk characteristics. METHODS: The Kenya AIDS Indicator Survey 2012 was a national survey of Kenyans aged 18 months to 64 years which linked demographic and behavioral information with HIV results. Data were weighted to account for sampling probability. This analysis was restricted to adults aged 18 years and older. RESULTS: Of 5088 men and 6745 women, 0.1% [95% confidence interval (CI): 0.03 to 0.14] were persons who inject drugs (PWID). Among men, 0.6% (CI: 0.3 to 0.8) had ever had sex with other men, and 3.1% (CI: 2.4 to 3.7) were males who had ever engaged in transactional sex work (MTSW). Among women, 1.9% (CI: 1.3 to 2.5) had ever had anal sex, and 4.1% (CI: 3.5 to 4.8) were women who had ever engaged in transactional sex work (FTSW). Among men, 17.6% (CI: 15.7 to 19.6) had been male clients of transactional sex workers (TSW). HIV prevalence was 0% among men who have sex with men, 6.3% (CI: 0 to 18.1) among persons who injected drugs, 7.1% (CI: 4.8 to 9.4) among male clients of TSW, 7.6% (CI: 1.8 to 13.4) among MTSW, 12.1% (CI: 7.1 to 17.1) among FTSW, and 12.1% (CI: 5.0 to 19.2) among females who ever had engaged in anal sex. CONCLUSIONS: Population-based data on high-risk populations can be used to set realistic targets for HIV prevention, care, and treatment for these groups. These data should inform priorities for high-risk populations in the upcoming Kenyan strategic plan on HIV/AIDS. |
Mother-to-child transmission of HIV in Kenya: results from a nationally representative study
Sirengo M , Muthoni L , Kellogg TA , Kim AA , Katana A , Mwanyumba S , Kimanga DO , Maina WK , Muraguri N , Elly B , Rutherford GW . J Acquir Immune Defic Syndr 2014 66 Suppl 1 S66-74 BACKGROUND: Kenya has an estimated 13,000 new infant HIV infections that occur annually. We measured the burden of HIV infection among women of childbearing age and assessed access to and coverage of key prevention of mother-to-child transmission interventions. METHODS: The second Kenya AIDS Indicator Survey was a nationally representative 2-stage cluster sample of households. We analyzed data from women aged 15-54 years who had delivered a newborn within the preceding 5 years and from whom we obtained samples for HIV testing. RESULTS: Of 3310 women who had ≥1 live birth in the preceding 5 years, 2862 (86.5%) consented to HIV testing in the survey, and 171 (6.1%) were found to be infected. Ninety-five percent received prenatal care, 93.1% were screened for HIV during prenatal care, and of those screened, 97.8% received their test results. Seventy-six women were known to be infected in their last pregnancy. Of these, 54 (72.3%) received antepartum antiretroviral prophylaxis, and 51 (69.1%) received intrapartum prophylaxis; 56 (75.3%) reported their newborns received postpartum prophylaxis. Of the 76 children born to these mothers, 63 (82.5%) were tested for HIV at the first immunization visit or thereafter, and 8 (15.1%) were HIV infected. CONCLUSIONS: We found a substantial burden of HIV in Kenyan women of childbearing age and a cumulative 5-year mother-to-child transmission rate of 15%. Although screening has improved over the past 5 years, fewer than three-quarters of infected pregnant women are receiving antiretroviral prophylaxis. Universal antiretroviral therapy for HIV-infected pregnant women will be essential in achieving Kenyan's target to eliminate mother-to-child transmission to <5% by 2015. |
The status of HIV testing and counseling in Kenya: results from a nationally representative population-based survey
Ng'ang'a A , Waruiru W , Ngare C , Ssempijja V , Gachuki T , Njoroge I , Oluoch P , Kimanga DO , Maina WK , Mpazanje R , Kim AA . J Acquir Immune Defic Syndr 2014 66 Suppl 1 S27-36 BACKGROUND: HIV testing and counseling (HTC) is essential for successful HIV prevention and treatment programs. The national target for HTC is 80% of the adult population in Kenya. Population-based data to measure progress towards this HTC target are needed to assess the country's changing needs for HIV prevention and treatment. METHODS: In 2012-2013, we conducted a national HIV survey among Kenyans aged 18 months to 64 years. Respondents aged 15-64 years were administered a questionnaire that collected information on demographics, HIV testing behavior, and self-reported HIV status. Blood samples were collected for HIV testing in a central laboratory. Participants were offered home-based testing and counseling to learn their HIV status in the home and point-of-care CD4 testing if they tested HIV-positive. RESULTS: Of 13,720 adults who were interviewed, 71.6% [95% confidence interval (CI): 70.2 to 73.1] had been tested for HIV. Among those, 56.1% (95% CI: 52.8 to 59.4) had been tested in the past year, 69.4% (95% CI: 68.0 to 70.8) had been tested more than once, and 37.2% (95% CI: 35.7 to 38.8) had been tested with a partner. Fifty-three percent (95% CI: 47.6 to 58.7) of HIV-infected persons were unaware of their infection. Overall 9874 (72.0%) of participants accepted home-based HIV testing and counseling; 4.1% (95% CI: 3.3 to 4.9) tested HIV-positive, and of those, 42.5% (95% CI 31.4 to 53.6) were in need of immediate treatment for their HIV infection but not receiving it. CONCLUSIONS: HIV testing rates have nearly reached the national target for HTC in Kenya. However, knowledge of HIV status among HIV-infected persons remains low. HTC needs to be expanded to reach more men and couples, and strategies are needed to increase repeat testing for persons at risk for HIV infection. |
Status of voluntary medical male circumcision in Kenya: findings from 2 nationally representative surveys in Kenya, 2007 and 2012
Galbraith JS , Ochieng A , Mwalili S , Emusu D , Mwandi Z , Kim AA , Rutherford G , Maina WK , Kimanga DO , Chesang K , Cherutich P . J Acquir Immune Defic Syndr 2014 66 Suppl 1 S37-45 BACKGROUND: The Kenyan Ministry of Health initiated a voluntary medical male circumcision (VMMC) program in 2008. We used data from 2 nationally representative surveys to estimate trends in the number, demographic characteristics, and sexual behaviors of recently circumcised and uncircumcised HIV-uninfected men in Kenya. METHODS: We compared the proportion of circumcised men between the first and second Kenya AIDS Indicator Survey (KAIS 2007 and KAIS 2012) to assess the progress of Kenya's VMMC program. We calculated the number of uncircumcised HIV-uninfected men. We conducted descriptive analyses and used multivariable methods to identify the variables independently associated with HIV-uninfected uncircumcised men aged 15-64 years in the VMMC priority region of Nyanza. RESULTS: The proportion of men who reported being circumcised increased significantly from 85.0% in 2007 to 91.2% in 2012. The proportions of circumcised men increased in all regions, with the highest increases of 18.1 and 9.0 percentage points in the VMMC priority regions of Nyanza and Nairobi, respectively. Half (52.5%) of HIV-uninfected and uncircumcised men had never been married, and 84.6% were not using condoms at all times with their last sexual partner. CONCLUSIONS: VMMC prevalence has increased across Kenya demonstrating the success of the national program. Despite this accomplishment, the Nyanza region remains below the target to circumcise 80% of all eligible men aged 15-49 years between 2009 and 2013. As new cohorts of young men enter into adolescence, consistent focus is needed. To ensure sustainability of the VMMC program, financial resources and coordinated planning must continue. |
Tuberculosis and HIV at the national level in Kenya: results from the second Kenya AIDS Indicator Survey
Mbithi A , Gichangi A , Kim AA , Katana A , Weyenga H , Williamson J , Robinson K , Oluoch T , Maina WK , Kellogg TA , De Cock KM . J Acquir Immune Defic Syndr 2014 66 Suppl 1 S106-15 BACKGROUND: Co-morbidity with tuberculosis and HIV is a common cause of mortality in sub-Saharan Africa. In the second Kenya AIDS Indicator Survey, we collected data on knowledge and experience of HIV and tuberculosis, as well as on access to and coverage of relevant treatment services and antiretroviral therapy (ART) in Kenya. METHODS: A national, population-based household survey was conducted from October 2012 to February 2013. Information was collected through household questionnaires, and blood samples were taken for HIV, CD4 cell counts, and HIV viral load testing at a central laboratory. RESULTS: Overall, 13,720 persons aged 15-64 years participated; 96.7% [95% confidence interval (CI): 96.3 to 97.1] had heard of tuberculosis, of whom 2.0% (95% CI: 1.7 to 2.2) reported having prior tuberculosis. Among those with laboratory-confirmed HIV infection, 11.6% (95% CI: 8.9 to 14.3) reported prior tuberculosis. The prevalence of laboratory-confirmed HIV infection in persons reporting prior tuberculosis was 33.2% (95% CI: 26.2 to 40.2) compared to 5.1% (95% CI: 4.5 to 5.8) in persons without prior tuberculosis. Among those in care, coverage of ART for treatment-eligible persons was 100% for those with prior tuberculosis and 88.6% (95% CI: 81.6 to 95.7) for those without. Among all HIV-infected persons, ART coverage among treatment-eligible persons was 86.9% (95% CI: 74.2 to 99.5) for persons with prior tuberculosis and 58.3% (95% CI: 47.6 to 69.0) for those without. CONCLUSIONS: Morbidity from tuberculosis and HIV remain major health challenges in Kenya. Tuberculosis is an important entry point for HIV diagnosis and treatment. Lack of knowledge of HIV serostatus is an obstacle to access to HIV services and timely ART for prevention of HIV transmission and HIV-associated disease, including tuberculosis. |
The Kenya AIDS indicator survey 2012: rationale, methods, description of participants, and response rates
Waruiru W , Kim AA , Kimanga DO , Ng'ang'a J , Schwarcz S , Kimondo L , Ng'ang'a A , Umuro M , Mwangi M , Ojwang JK , Maina WK . J Acquir Immune Defic Syndr 2014 66 Suppl 1 S3-s12 BACKGROUND: Cross-sectional population-based surveys are essential surveillance tools for tracking changes in HIV epidemics. In 2007, Kenya implemented the first AIDS Indicator Survey [Kenya AIDS Indicator Survey (KAIS) 2007], a nationally representative, population-based survey that collected demographic and behavioral data and blood specimens from individuals aged 15-64 years. Kenya's second AIDS Indicator Survey (KAIS 2012) was conducted to monitor changes in the epidemic, evaluate HIV prevention, care, and treatment initiatives, and plan for an efficient and effective response to the HIV epidemic. METHODS: KAIS 2012 was a cross-sectional 2-stage cluster sampling design, household-based HIV serologic survey that collected information on households as well as demographic and behavioral data from Kenyans aged 18 months to 64 years. Participants also provided blood samples for HIV serology and other related tests at the National HIV Reference Laboratory. RESULTS: Among 9300 households sampled, 9189 (98.8%) were eligible for the survey. Of the eligible households, 8035 (87.4%) completed household-level questionnaires. Of 16,383 eligible individuals aged 15-64 years and emancipated minors aged less than 15 years in these households, 13,720 (83.7%) completed interviews; 11,626 (84.7%) of the interviewees provided a blood specimen. Of 6302 eligible children aged 18 months to 14 years, 4340 (68.9%) provided a blood specimen. Of the 2094 eligible children aged 10-14 years, 1661 (79.3%) completed interviews. CONCLUSIONS: KAIS 2012 provided representative data to inform a strategic response to the HIV epidemic in the country. |
Kenya AIDS Indicator Surveys 2007 and 2012: implications for public health policies for HIV prevention and treatment
Maina WK , Kim AA , Rutherford GW , Harper M , K'Oyugi B O , Sharif S , Kichamu G , Muraguri NM , Akhwale W , De Cock KM . J Acquir Immune Defic Syndr 2014 66 Suppl 1 S130-7 AIDS Indicator Surveys are standardized surveillance tools used by countries with generalized HIV epidemics to provide, in a timely fashion, indicators for effective monitoring of HIV. Such data should guide responses to the HIV epidemic, meet program reporting requirements, and ensure comparability of findings across countries and over time. Kenya has conducted 2 AIDS Indicator Surveys, in 2007 (KAIS 2007) and 2012-2013 (KAIS 2012). These nationally representative surveys have provided essential epidemiologic, sociodemographic, behavioral, and biologic data on HIV and related indicators to evaluate the national HIV response and inform policies for prevention and treatment of the disease. We present a summary of findings from KAIS 2007 and KAIS 2012 and the impact that these data have had on changing HIV policies and practice. |
Engagement in HIV care among Kenyan adults and adolescents: results from a national population-based survey
Wafula R , Masyuko S , Ng'ang'a L , Kim AA , Gichangi A , Mukui I , Batuka J , Ngugi EW , Maina WK , Schwarcz S . J Acquir Immune Defic Syndr 2014 66 Suppl 1 S98-s105 BACKGROUND: Increasing access to care and treatment for HIV-infected persons is a goal in Kenya's response to the HIV epidemic. Using data from the second Kenya AIDS Indicator Survey (KAIS 2012), we describe coverage of services received among adults and adolescents who were enrolled in HIV care. METHODS: KAIS 2012 was a population-based survey that collected information from persons aged 15-64 years that included self-reported HIV status, and for persons reporting HIV infection, use of HIV care and antiretroviral therapy (ART). Blood specimens were collected and tested for HIV. HIV-positive specimens were tested for CD4 counts and viral load. RESULTS: Among 363 persons who reported HIV infection, 93.4% [95% confidence interval (CI): 87.2 to 99.6] had ever received HIV care. Among those receiving HIV care, 96.3% (95% CI: 94.1 to 98.4) were using cotrimoxazole prophylaxis, and 74.6% (95% CI: 69.0 to 80.2) were receiving ART. A lower proportion of persons in care and not on ART reported using cotrimoxazole (89.5%, 95% CI: 82.5 to 96.5 compared with 98.6%, 95% CI: 97.1 to 100) and had a CD4 count measurement done (72.9%, 95% CI: 64.0 to 81.9 compared with 90.0%, 95% CI: 82.8 to 97.3) than persons in care and on ART, respectively. Among persons in care and not on ART, 23.2% (95% CI: 6.8 to 39.7) had CD4 counts ≤350 cells per microliter. Viral suppression was observed in 75.3% (95% CI: 68.7 to 81.9) of persons on ART. CONCLUSIONS: Linkage and retention in care are high among persons with known HIV infection. However, improvements in care for the pre-ART population are needed. Viral suppression rates were comparable to developed settings. |
Coxiella burnetii in humans, domestic ruminants, and ticks in rural western Kenya
Knobel DL , Maina AN , Cutler SJ , Ogola E , Feikin DR , Junghae M , Halliday JE , Richards AL , Breiman RF , Cleaveland S , Njenga MK . Am J Trop Med Hyg 2013 88 (3) 513-518 We conducted serological surveys for Coxiella burnetii in archived sera from patients that visited a rural clinic in western Kenya from 2007 to 2008 and in cattle, sheep, and goats from the same area in 2009. We also conducted serological and polymerase chain reaction-based surveillance for the pathogen in 2009-2010, in human patients with acute lower respiratory illness, in ruminants following parturition, and in ticks collected from ruminants and domestic dogs. The IgG antibodies against C. burnetii were detected in 30.9% (N = 246) of archived patient sera and in 28.3% (N = 463) of cattle, 32.0% (N = 378) of goats, and 18.2% (N = 159) of sheep surveyed. Four of 135 (3%) patients with acute lower respiratory illness showed seroconversion to C. burnetii. The pathogen was detected by polymerase chain reaction in specimens collected from three of six small ruminants that gave birth within the preceding 24 hours, and in five of 10 pools (50%) of Haemaphysalis leachi ticks collected from domestic dogs. |
Rickettsia felis infection in febrile patients, western Kenya, 2007-2010
Maina AN , Knobel DL , Jiang J , Halliday J , Feikin DR , Cleaveland S , Ng'ang'a Z , Junghae M , Breiman RF , Richards AL , Njenga MK . Emerg Infect Dis 2012 18 (2) 328-31 To determine previous exposure and incidence of rickettsial infections in western Kenya during 2007-2010, we conducted hospital-based surveillance. Antibodies against rickettsiae were detected in 57.4% of previously collected serum samples. In a 2008-2010 prospective study, Rickettsia felis DNA was 2.2x more likely to be detected in febrile than in afebrile persons. |
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