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1.
Clin Infect Dis ; 76(76 Suppl1): S77-S86, 2023 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-37074433

RESUMO

BACKGROUND: To address knowledge gaps regarding diarrheagenic Escherichia coli (DEC) in Africa, we assessed the clinical and epidemiological features of enteroaggregative E. coli (EAEC), enteropathogenic E. coli (EPEC), and Shiga toxin-producing E. coli (STEC) positive children with moderate-to-severe diarrhea (MSD) in Mali, The Gambia, and Kenya. METHODS: Between May 2015 and July 2018, children aged 0-59 months with medically attended MSD and matched controls without diarrhea were enrolled. Stools were tested conventionally using culture and multiplex polymerase chain reaction (PCR), and by quantitative PCR (qPCR). We assessed DEC detection by site, age, clinical characteristics, and enteric coinfection. RESULTS: Among 4840 children with MSD and 6213 matched controls enrolled, 4836 cases and 1 control per case were tested using qPCR. Of the DEC detected with TAC, 61.1% were EAEC, 25.3% atypical EPEC (aEPEC), 22.4% typical EPEC (tEPEC), and 7.2% STEC. Detection was higher in controls than in MSD cases for EAEC (63.9% vs 58.3%, P < .01), aEPEC (27.3% vs 23.3%, P < .01), and STEC (9.3% vs 5.1%, P < .01). EAEC and tEPEC were more frequent in children aged <23 months, aEPEC was similar across age strata, and STEC increased with age. No association between nutritional status at follow-up and DEC pathotypes was found. DEC coinfection with Shigella/enteroinvasive E. coli was more common among cases (P < .01). CONCLUSIONS: No significant association was detected between EAEC, tEPEC, aEPEC, or STEC and MSD using either conventional assay or TAC. Genomic analysis may provide a better definition of the virulence factors associated with diarrheal disease.


Assuntos
Coinfecção , Escherichia coli Enteropatogênica , Infecções por Escherichia coli , Escherichia coli Shiga Toxigênica , Criança , Humanos , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/diagnóstico , Escherichia coli Shiga Toxigênica/genética , Coinfecção/epidemiologia , Diarreia/epidemiologia , Diarreia/diagnóstico , Escherichia coli Enteropatogênica/genética , Quênia
2.
J Infect Dis ; 225(12): 2097-2105, 2022 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-32777041

RESUMO

BACKGROUND: Respiratory syncytial virus (RSV) is an important cause of respiratory illness worldwide; however, burden data on mother-infant pairs remain sparse in sub-Saharan Africa, where human immunodeficiency virus (HIV) is prevalent. We evaluated the impact of maternal HIV infection on the burden of RSV among mothers and their infants in western Kenya. METHODS: We enrolled pregnant women (≤20 weeks' gestation) and followed them and their newborns weekly for up to 3-6 months postpartum, to document cases of acute respiratory illness (ARI). Nasal/oropharyngeal swabs were collected and tested for RSV using polymerase chain reaction. Analyses were stratified by maternal HIV status and incidence was computed per 1000 person-months. RESULTS: Compared to RSV-negative ARI cases, RSV-positive cases were associated with cough, apnea, and hospitalization among infants. RSV incidence per 1000 person-months among mothers was 4.0 (95% confidence interval [CI], 3.2-4.4), and was twice that among the HIV-infected mothers (8.4 [95% CI, 5.7-12.0]) compared to the HIV-uninfected mothers (3.1 [95% CI, 2.3-4.0]). Among infants, incidence per 1000 person-months was 15.4 (95% CI, 12.5-18.8); incidence did not differ by HIV exposure or prematurity. CONCLUSIONS: HIV infection may increase the risk of RSV illness among pregnant women. Future maternal RSV vaccines may have added benefit in areas with high HIV prevalence.


Assuntos
Infecções por HIV , Infecções por Vírus Respiratório Sincicial , Vírus Sincicial Respiratório Humano , Feminino , Infecções por HIV/complicações , Infecções por HIV/epidemiologia , Hospitalização , Humanos , Lactente , Recém-Nascido , Quênia/epidemiologia , Gravidez , Gestantes
3.
Emerg Infect Dis ; 28(13): S34-S41, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36502419

RESUMO

Existing acute febrile illness (AFI) surveillance systems can be leveraged to identify and characterize emerging pathogens, such as SARS-CoV-2, which causes COVID-19. The US Centers for Disease Control and Prevention collaborated with ministries of health and implementing partners in Belize, Ethiopia, Kenya, Liberia, and Peru to adapt AFI surveillance systems to generate COVID-19 response information. Staff at sentinel sites collected epidemiologic data from persons meeting AFI criteria and specimens for SARS-CoV-2 testing. A total of 5,501 patients with AFI were enrolled during March 2020-October 2021; >69% underwent SARS-CoV-2 testing. Percentage positivity for SARS-CoV-2 ranged from 4% (87/2,151, Kenya) to 19% (22/115, Ethiopia). We show SARS-CoV-2 testing was successfully integrated into AFI surveillance in 5 low- to middle-income countries to detect COVID-19 within AFI care-seeking populations. AFI surveillance systems can be used to build capacity to detect and respond to both emerging and endemic infectious disease threats.


Assuntos
COVID-19 , Doenças Transmissíveis , Estados Unidos , Humanos , COVID-19/epidemiologia , SARS-CoV-2 , Teste para COVID-19 , Febre/epidemiologia
4.
J Infect Dis ; 219(7): 1049-1057, 2019 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-30576538

RESUMO

We report on infection patterns in 5 households (78 participants) delineating the natural history of human rhinovirus (HRV). Nasopharyngeal collections were obtained every 3-4 days irrespective of symptoms, over a 6-month period, with molecular screening for HRV and typing by sequencing VP4/VP2 junction. Overall, 311/3468 (8.9%) collections were HRV positive: 256 were classified into 3 species: 104 (40.6%) HRV-A; 14 (5.5%) HRV-B, and 138 (53.9%) HRV-C. Twenty-six known HRV types (13 HRV-A, 3 HRV-B, and 10 HRV-C) were identified (A75, C1, and C35 being most frequent). We observed continuous invasion and temporal clustering of HRV types in households (range 5-13 over 6 months). Intrahousehold transmission was independent of clinical status but influenced by age. Most (89.0%) of HRV infection episodes were limited to <14 days. Individual repeat infections were frequent (range 1-7 over 6 months), decreasing with age, and almost invariably heterotypic, indicative of lasting type-specific immunity and low cross-type protection.


Assuntos
Resfriado Comum/transmissão , Nasofaringe/virologia , Infecções por Picornaviridae/transmissão , Rhinovirus/classificação , Rhinovirus/isolamento & purificação , Adolescente , Adulto , Fatores Etários , Criança , Pré-Escolar , Resfriado Comum/epidemiologia , Características da Família , Humanos , Lactente , Quênia/epidemiologia , Infecções por Picornaviridae/epidemiologia , Estudos Prospectivos , Reação em Cadeia da Polimerase em Tempo Real , Recidiva , Fatores de Tempo , Adulto Jovem
5.
BMC Public Health ; 19(Suppl 3): 465, 2019 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-32326940

RESUMO

More than 75% of emerging infectious diseases are zoonotic in origin and a transdisciplinary, multi-sectoral One Health approach is a key strategy for their effective prevention and control. In 2004, US Centers for Disease Control and Prevention office in Kenya (CDC Kenya) established the Global Disease Detection Division of which one core component was to support, with other partners, the One Health approach to public health science. After catalytic events such as the global expansion of highly pathogenic H5N1 and the 2006 East African multi-country outbreaks of Rift Valley Fever, CDC Kenya supported key Kenya government institutions including the Ministry of Health and the Ministry of Agriculture, Livestock, and Fisheries to establish a framework for multi-sectoral collaboration at national and county level and a coordination office referred to as the Zoonotic Disease Unit (ZDU). The ZDU has provided Kenya with an institutional framework to highlight the public health importance of endemic and epidemic zoonoses including RVF, rabies, brucellosis, Middle East Respiratory Syndrome Coronavirus, anthrax and other emerging issues such as anti-microbial resistance through capacity building programs, surveillance, workforce development, research, coordinated investigation and outbreak response. This has led to improved outbreak response, and generated data (including discovery of new pathogens) that has informed disease control programs to reduce burden of and enhance preparedness for endemic and epidemic zoonotic diseases, thereby enhancing global health security. Since 2014, the Global Health Security Agenda implemented through CDC Kenya and other partners in the country has provided additional impetus to maintain this effort and Kenya's achievement now serves as a model for other countries in the region.Significant gaps remain in implementation of the One Health approach at subnational administrative levels; there are sustainability concerns, competing priorities and funding deficiencies.


Assuntos
Doenças Transmissíveis Emergentes/prevenção & controle , Surtos de Doenças/prevenção & controle , Saúde Única/estatística & dados numéricos , Saúde Pública/métodos , Zoonoses/prevenção & controle , Animais , Epidemias/prevenção & controle , Humanos , Quênia/epidemiologia , Avaliação de Programas e Projetos de Saúde
6.
BMC Public Health ; 19(1): 1317, 2019 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-31638946

RESUMO

BACKGROUND: Adolescent girls in sub-Saharan Africa are disproportionally vulnerable to sexual and reproductive health (SRH) harms. In western Kenya, where unprotected transactional sex is common, young females face higher rates of school dropout, often due to pregnancy, and sexually transmitted infections (STIs), including HIV. Staying in school has shown to protect girls against early marriage, teen pregnancy, and HIV infection. This study evaluates the impact of menstrual cups and cash transfer interventions on a composite of deleterious outcomes (HIV, HSV-2, and school dropout) when given to secondary schoolgirls in western Kenya, with the aim to inform evidence-based policy to improve girls' health, school equity, and life-chances. METHODS: Single site, 4-arm, cluster randomised controlled superiority trial. Secondary schools are the unit of randomisation, with schoolgirls as the unit of measurement. Schools will be randomised into one of four intervention arms using a 1:1:1:1 ratio and block randomisation: (1) menstrual cup arm; (2) cash transfer arm, (3) cups and cash combined intervention arm, or (4) control arm. National and county agreement, and school level consent will be obtained prior to recruitment of schools, with parent consent and girls' assent obtained for participant enrolment. Participants will be trained on safe use of interventions, with all arms receiving puberty and hygiene education. Annually, the state of latrines, water availability, water treatment, handwashing units and soap in schools will be measured. The primary endpoint is a composite of incident HIV, HSV-2, and all-cause school dropout, after 3 years follow-up. School dropout will be monitored each term via school registers and confirmed through home visits. HIV and HSV-2 incident infections and risk factors will be measured at baseline, mid-line and end-line. Intention to treat analysis will be conducted among all enrolled participants. Focus group discussions will provide contextual information on uptake of interventions. Monitoring for safety will occur throughout. DISCUSSION: If proved safe and effective, the interventions offer a potential contribution toward girls' schooling, health, and equity in low- and middle-income countries. TRIAL REGISTRATION: ClinicalTrials.gov NCT03051789 , 15th February 2017.


Assuntos
Redução do Dano , Produtos de Higiene Menstrual , Assistência Pública , Evasão Escolar/estatística & dados numéricos , Adolescente , Feminino , Infecções por HIV/epidemiologia , Infecções por HIV/prevenção & controle , Herpes Genital/epidemiologia , Herpes Genital/prevenção & controle , Humanos , Quênia/epidemiologia , Projetos de Pesquisa
7.
J Clin Microbiol ; 55(7): 2035-2044, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28404679

RESUMO

Infections of the central nervous system (CNS) are often acute, with significant morbidity and mortality. Routine diagnosis of such infections is limited in developing countries and requires modern equipment in advanced laboratories that may be unavailable to a number of patients in sub-Saharan Africa. We developed a TaqMan array card (TAC) that detects multiple pathogens simultaneously from cerebrospinal fluid. The 21-pathogen CNS multiple-pathogen TAC (CNS-TAC) assay includes two parasites (Balamuthia mandrillaris and Acanthamoeba), six bacterial pathogens (Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis, Mycoplasma pneumoniae, Mycobacterium tuberculosis, and Bartonella), and 13 viruses (parechovirus, dengue virus, Nipah virus, varicella-zoster virus, mumps virus, measles virus, lyssavirus, herpes simplex viruses 1 and 2, Epstein-Barr virus, enterovirus, cytomegalovirus, and chikungunya virus). The card also includes human RNase P as a nucleic acid extraction control and an internal manufacturer control, GAPDH (glyceraldehyde-3-phosphate dehydrogenase). This CNS-TAC assay can test up to eight samples for all 21 agents within 2.5 h following nucleic acid extraction. The assay was validated for linearity, limit of detection, sensitivity, and specificity by using either live viruses (dengue, mumps, and measles viruses) or nucleic acid material (Nipah and chikungunya viruses). Of 120 samples tested by individual real-time PCR, 35 were positive for eight different targets, whereas the CNS-TAC assay detected 37 positive samples across nine different targets. The CNS-TAC assays showed 85.6% sensitivity and 96.7% specificity. Therefore, the CNS-TAC assay may be useful for outbreak investigation and surveillance of suspected neurological disease.


Assuntos
Infecções do Sistema Nervoso Central/diagnóstico , Técnicas Microbiológicas/métodos , Técnicas de Diagnóstico Molecular/métodos , Adolescente , Adulto , África Subsaariana , Idoso , Idoso de 80 Anos ou mais , Amebozoários/isolamento & purificação , Bactérias/isolamento & purificação , Infecções do Sistema Nervoso Central/microbiologia , Infecções do Sistema Nervoso Central/parasitologia , Infecções do Sistema Nervoso Central/virologia , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Padrões de Referência , Sensibilidade e Especificidade , Vírus/isolamento & purificação , Adulto Jovem
8.
BMC Infect Dis ; 17(1): 591, 2017 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-28841843

RESUMO

BACKGROUND: Respiratory diseases cause substantial morbidity and mortality worldwide, with sub-Saharan Africa bearing the greatest burden. Identifying etiologies of respiratory disease is important to inform cost effective treatment, prevention and control strategies. Testing for all of the different pathogens that are potentially associated with respiratory illnesses is challenging. We piloted the use of a multi-pathogen respiratory Taqman Array Cards (TAC) to identify pathogens in respiratory samples collected from non-fatal and fatal cases and their matched asymptomatic controls. METHODS: This is a case control study comparing viral and bacterial pathogens detected among non-fatal and fatal cases to those detected among age and time matched asymptomatic controls. We used McNemar's test to compare proportions of pathogens detected among cases (non-fatal and fatal) to their matched asymptomatic controls. We used Mann-Whitney test to compare the distribution of median Cycle threshold (Ct) values among non-fatal and fatal cases to their corresponding asymptomatic controls. RESULTS: There were 72 fatal and 72 non-fatal cases matched to 72 controls. We identified at least one pathogen in 109/144 (76%) cases and 59/72 (82%) controls. For most pathogens, the median Ct values were lower among cases (fatal and non-fatal) compared to asymptomatic controls. CONCLUSIONS: Similar rates of pathogen detection among cases and controls make interpretation of results challenging. Ct-values might be helpful in interpreting clinical relevance of detected pathogens using multi-pathogen diagnostic tools.


Assuntos
Infecções Respiratórias/microbiologia , Infecções Respiratórias/virologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Criança , Pré-Escolar , Hospitalização/estatística & dados numéricos , Humanos , Lactente , Quênia/epidemiologia , Pessoa de Meia-Idade , Nasofaringe/microbiologia , Projetos Piloto , Kit de Reagentes para Diagnóstico , Infecções Respiratórias/mortalidade , Adulto Jovem
9.
J Infect Dis ; 214(suppl 3): S169-S176, 2016 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-27333914

RESUMO

West Africa experienced the first epidemic of Ebola virus infection, with by far the greatest number of cases in Guinea, Sierra Leone, and Liberia. The unprecedented epidemic triggered an unparalleled response, including the deployment of multiple Ebola treatment units and mobile/field diagnostic laboratories. The National Institute of Allergy and Infectious Diseases and the Centers for Disease Control and Prevention deployed a joint laboratory to Monrovia, Liberia, in August 2014 to support the newly founded Ebola treatment unit at the Eternal Love Winning Africa (ELWA) campus. The laboratory operated initially out of a tent structure but quickly moved into a fixed-wall building owing to severe weather conditions, the need for increased security, and the high sample volume. Until May 2015, when the laboratory closed, the site handled close to 6000 clinical specimens for Ebola virus diagnosis and supported the medical staff in case patient management. Laboratory operation and safety, as well as Ebola virus diagnostic assays, are described and discussed; in addition, lessons learned for future deployments are reviewed.


Assuntos
Serviços de Laboratório Clínico/organização & administração , Ebolavirus/isolamento & purificação , Epidemias/prevenção & controle , Doença pelo Vírus Ebola/epidemiologia , África Ocidental/epidemiologia , Centers for Disease Control and Prevention, U.S. , Feminino , Guiné/epidemiologia , Doença pelo Vírus Ebola/diagnóstico , Doença pelo Vírus Ebola/transmissão , Doença pelo Vírus Ebola/virologia , Humanos , Cooperação Internacional , Libéria/epidemiologia , Masculino , National Institute of Allergy and Infectious Diseases (U.S.) , Segurança , Serra Leoa/epidemiologia , Estados Unidos
10.
Clin Infect Dis ; 63(8): 1026-33, 2016 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-27531847

RESUMO

BACKGROUND: The ongoing Ebola outbreak in West Africa has resulted in 28 646 suspected, probable, and confirmed Ebola virus infections. Nevertheless, malaria remains a large public health burden in the region affected by the outbreak. A joint Centers for Disease Control and Prevention/National Institutes of Health diagnostic laboratory was established in Monrovia, Liberia, in August 2014, to provide laboratory diagnostics for Ebola virus. METHODS: All blood samples from suspected Ebola virus-infected patients admitted to the Médecins Sans Frontières ELWA3 Ebola treatment unit in Monrovia were tested by quantitative real-time polymerase chain reaction for the presence of Ebola virus and Plasmodium species RNA. Clinical outcome in laboratory-confirmed Ebola virus-infected patients was analyzed as a function of age, sex, Ebola viremia, and Plasmodium species parasitemia. RESULTS: The case fatality rate of 1182 patients with laboratory-confirmed Ebola virus infections was 52%. The probability of surviving decreased with increasing age and decreased with increasing Ebola viral load. Ebola virus-infected patients were 20% more likely to survive when Plasmodium species parasitemia was detected, even after controlling for Ebola viral load and age; those with the highest levels of parasitemia had a survival rate of 83%. This effect was independent of treatment with antimalarials, as this was provided to all patients. Moreover, treatment with antimalarials did not affect survival in the Ebola virus mouse model. CONCLUSIONS: Plasmodium species parasitemia is associated with an increase in the probability of surviving Ebola virus infection. More research is needed to understand the molecular mechanism underlying this remarkable phenomenon and translate it into treatment options for Ebola virus infection.


Assuntos
Coinfecção , Ebolavirus , Doença pelo Vírus Ebola/complicações , Doença pelo Vírus Ebola/mortalidade , Malária/complicações , Malária/parasitologia , Parasitemia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Criança , Pré-Escolar , Modelos Animais de Doenças , Ebolavirus/genética , Feminino , Doença pelo Vírus Ebola/diagnóstico , Doença pelo Vírus Ebola/epidemiologia , Humanos , Lactente , Recém-Nascido , Malária/diagnóstico , Malária/epidemiologia , Masculino , Camundongos , Pessoa de Meia-Idade , Carga Parasitária , Plasmodium/genética , Taxa de Sobrevida , Carga Viral , Adulto Jovem
11.
J Clin Microbiol ; 54(1): 49-58, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26491176

RESUMO

Acute febrile illness (AFI) is associated with substantial morbidity and mortality worldwide, yet an etiologic agent is often not identified. Convalescent-phase serology is impractical, blood culture is slow, and many pathogens are fastidious or impossible to cultivate. We developed a real-time PCR-based TaqMan array card (TAC) that can test six to eight samples within 2.5 h from sample to results and can simultaneously detect 26 AFI-associated organisms, including 15 viruses (chikungunya, Crimean-Congo hemorrhagic fever [CCHF] virus, dengue, Ebola virus, Bundibugyo virus, Sudan virus, hantaviruses [Hantaan and Seoul], hepatitis E, Marburg, Nipah virus, o'nyong-nyong virus, Rift Valley fever virus, West Nile virus, and yellow fever virus), 8 bacteria (Bartonella spp., Brucella spp., Coxiella burnetii, Leptospira spp., Rickettsia spp., Salmonella enterica and Salmonella enterica serovar Typhi, and Yersinia pestis), and 3 protozoa (Leishmania spp., Plasmodium spp., and Trypanosoma brucei). Two extrinsic controls (phocine herpesvirus 1 and bacteriophage MS2) were included to ensure extraction and amplification efficiency. Analytical validation was performed on spiked specimens for linearity, intra-assay precision, interassay precision, limit of detection, and specificity. The performance of the card on clinical specimens was evaluated with 1,050 blood samples by comparison to the individual real-time PCR assays, and the TAC exhibited an overall 88% (278/315; 95% confidence interval [CI], 84% to 92%) sensitivity and a 99% (5,261/5,326, 98% to 99%) specificity. This TaqMan array card can be used in field settings as a rapid screen for outbreak investigation or for the surveillance of pathogens, including Ebola virus.


Assuntos
Doenças Transmissíveis/diagnóstico , Doenças Transmissíveis/epidemiologia , Surtos de Doenças , Febre de Causa Desconhecida/diagnóstico , Febre de Causa Desconhecida/epidemiologia , Técnicas de Diagnóstico Molecular/métodos , Reação em Cadeia da Polimerase em Tempo Real/métodos , Adulto , Monitoramento Epidemiológico , Humanos , Técnicas de Diagnóstico Molecular/normas , Reação em Cadeia da Polimerase em Tempo Real/normas , Padrões de Referência , Sensibilidade e Especificidade , Fatores de Tempo
12.
Clin Infect Dis ; 61 Suppl 4: S302-9, 2015 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-26449945

RESUMO

BACKGROUND: Invasive infections with nontyphoidal Salmonella (NTS) lead to bacteremia in children and adults and are an important cause of illness in Africa; however, few data on the burden of NTS bacteremia are available. We sought to determine the burden of invasive NTS disease in a rural and urban setting in Kenya. METHODS: We conducted the study in a population-based surveillance platform in a rural setting in western Kenya (Lwak), and an informal urban settlement in Nairobi (Kibera) from 2009 to 2014. We obtained blood culture specimens from participants presenting with acute lower respiratory tract illness or acute febrile illness to a designated outpatient facility in each site, or any hospital admission for a potentially infectious cause (rural site only). Incidence was calculated using a defined catchment population and adjusting for specimen collection and healthcare-seeking practices. RESULTS: A total of 12 683 and 9524 blood cultures were analyzed from Lwak and Kibera, respectively. Of these, 428 (3.4%) and 533 (5.6%) grew a pathogen; among those, 208 (48.6%) and 70 (13.1%) were positive for NTS in Lwak and Kibera, respectively. Overall, the adjusted incidence of invasive NTS disease was higher in Lwak (839.4 per 100,000 person-years of observation [PYO]) than in Kibera (202.5 per 100,000 PYO). The highest adjusted incidences were observed in children <5 years of age (Lwak 3914.3 per 100,000 PYO and Kibera 997.9 per 100,000 PYO). The highest adjusted annual incidence was 1927.3 per 100,000 PYO (in 2010) in Lwak and 220.5 per 100,000 PYO (in 2011) in Kibera; the lowest incidences were 303.3 and 62.5 per 100,000 PYO, respectively (in 2012). In both sites, invasive NTS disease incidence generally declined over the study period. CONCLUSIONS: We observed an extremely high burden of invasive NTS disease in a rural area of Kenya and a lesser, but still substantial, burden in an urban slum. Although the incidences in both sites declined during the study period, invasive NTS infections remain an important cause of morbidity in these settings, particularly among children <5 years old.


Assuntos
Infecções por Salmonella/epidemiologia , Salmonella enterica/isolamento & purificação , Adolescente , Adulto , Fatores Etários , Criança , Pré-Escolar , Efeitos Psicossociais da Doença , Monitoramento Epidemiológico , Feminino , Humanos , Incidência , Lactente , Quênia/epidemiologia , Masculino , Estudos Retrospectivos , População Rural , Infecções por Salmonella/sangue , Infecções por Salmonella/microbiologia , Infecções por Salmonella/mortalidade , Salmonella enterica/classificação , Salmonella enterica/genética , Fatores de Tempo , População Urbana
13.
J Infect Dis ; 206(10): 1532-41, 2012 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-22966119

RESUMO

BACKGROUND: Respiratory syncytial virus (RSV) reinfects individuals repeatedly. The extent to which this is a consequence of RSV antigenic diversity is unclear. METHODS: Six-hundred thirty-five children from rural Kenya were closely monitored for RSV infection from birth through 3 consecutive RSV epidemics. RSV infections were identified by immunofluorescence testing of nasal washing samples collected during acute respiratory illnesses, typed into group A and B, and sequenced in the attachment (G) protein. A positive sample separated from a previous positive by ≥14 days was defined as a reinfection a priori. RESULTS: Phylogenetic analysis was undertaken for 325 (80%) of 409 identified infections, including 53 (64%) of 83 reinfections. Heterologous group reinfections were observed in 28 episodes, and homologous group reinfections were observed in 25 episodes; 10 involved homologous genotypes, 5 showed no amino acid changes, and 3 were separated by 21-24 days and were potentially persistent infections. The temporal distribution of genotypes among reinfections did not differ from that of single infections. CONCLUSIONS: The vast majority of infection and reinfection pairs differed by group, genotype, or G amino acid sequence (ie, comprised distinct viruses). The extent to which this is a consequence of immune memory of infection history or prevalent diversity remains unclear.


Assuntos
Infecções por Vírus Respiratório Sincicial/virologia , Vírus Sinciciais Respiratórios/genética , Criança , Análise por Conglomerados , Estudos de Coortes , Epidemias , Variação Genética , Genótipo , Humanos , Quênia/epidemiologia , Funções Verossimilhança , Dados de Sequência Molecular , Filogenia , Prevalência , RNA Viral/química , Recidiva , Infecções por Vírus Respiratório Sincicial/epidemiologia , Vírus Sinciciais Respiratórios/classificação , População Rural
14.
J Infect Dis ; 206 Suppl 1: S61-7, 2012 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-23169974

RESUMO

BACKGROUND: Influenza data gaps in sub-Saharan Africa include incidence, case fatality, seasonal patterns, and associations with prevalent disorders. METHODS: Nasopharyngeal samples from children aged <12 years who were admitted to Kilifi District Hospital during 2007-2010 with severe or very severe pneumonia and resided in the local demographic surveillance system were screened for influenza A, B, and C viruses by molecular methods. Outpatient children provided comparative data. RESULTS: Of 2002 admissions, influenza A virus infection was diagnosed in 3.5% (71), influenza B virus infection, in 0.9% (19); and influenza C virus infection, in 0.8% (11 of 1404 tested). Four patients with influenza died. Among outpatients, 13 of 331 (3.9%) with acute respiratory infection and 1 of 196 without acute respiratory infection were influenza positive. The annual incidence of severe or very severe pneumonia, of influenza (any type), and of influenza A, was 1321, 60, and 43 cases per 100,000 <5 years of age, respectively. Peak occurrence was in quarters 3-4 each year, and approximately 50% of cases involved infants: temporal association with bacteremia was absent. Hypoxia was more frequent among pneumonia cases involving influenza (odds ratio, 1.78; 95% confidence interval, 1.04-1.96). Influenza A virus subtypes were seasonal H3N2 (57%), seasonal H1N1 (12%), and 2009 pandemic H1N1 (7%). CONCLUSIONS: The burden of influenza was small during 2007-2010 in this pediatric hospital in Kenya. Influenza A virus subtype H3N2 predominated, and 2009 pandemic influenza A virus subtype H1N1 had little impact.


Assuntos
Gammainfluenzavirus/isolamento & purificação , Vírus da Influenza A/isolamento & purificação , Vírus da Influenza B/isolamento & purificação , Influenza Humana/epidemiologia , Influenza Humana/virologia , Pneumonia Viral/epidemiologia , Pneumonia Viral/virologia , Criança , Pré-Escolar , Feminino , Hospitalização , Hospitais de Distrito , Humanos , Lactente , Recém-Nascido , Quênia/epidemiologia , Masculino , Nasofaringe/virologia , Prevalência
15.
Clin Infect Dis ; 54 Suppl 2: S190-9, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22403235

RESUMO

BACKGROUND: Pneumonia is the leading cause of childhood death in the developing world. Higher-quality etiological data are required to reduce this mortality burden. METHODS: We conducted a case-control study of pneumonia etiology among children aged 1-59 months in rural Kenya. Case patients were hospitalized with World Health Organization-defined severe pneumonia (SP) or very severe pneumonia (VSP); controls were outpatient children without pneumonia. We collected blood for culture, induced sputum for culture and multiplex polymerase chain reaction (PCR), and obtained oropharyngeal swab specimens for multiplex PCR from case patients, and serum for serology and nasopharyngeal swab specimens for multiplex PCR from case patients and controls. RESULTS: Of 984 eligible case patients, 810 (84%) were enrolled in the study; 232 (29%) had VSP. Blood cultures were positive in 52 of 749 case patients (7%). A predominant potential pathogen was identified in sputum culture in 70 of 417 case patients (17%). A respiratory virus was detected by PCR from nasopharyngeal swab specimens in 486 of 805 case patients (60%) and 172 of 369 controls (47%). Only respiratory syncytial virus (RSV) showed a statistically significant association between virus detection in the nasopharynx and pneumonia hospitalization (odds ratio, 12.5; 95% confidence interval, 3.1-51.5). Among 257 case patients in whom all specimens (excluding serum specimens) were collected, bacteria were identified in 24 (9%), viruses in 137 (53%), mixed viral and bacterial infection in 39 (15%), and no pathogen in 57 (22%); bacterial causes outnumbered viral causes when the results of the case-control analysis were considered. CONCLUSIONS: A potential etiology was detected in >75% of children admitted with SP or VSP. Except for RSV, the case-control analysis did not detect an association between viral detection in the nasopharynx and hospitalization for pneumonia.


Assuntos
Criança Hospitalizada/estatística & dados numéricos , Pneumonia/etiologia , Vírus Sinciciais Respiratórios/isolamento & purificação , Bactérias/isolamento & purificação , Bactérias/patogenicidade , Infecções Bacterianas/diagnóstico , Infecções Bacterianas/epidemiologia , Infecções Bacterianas/microbiologia , Sangue/microbiologia , Sangue/virologia , Estudos de Casos e Controles , Pré-Escolar , Técnicas de Cultura , Feminino , Humanos , Lactente , Quênia/epidemiologia , Masculino , Reação em Cadeia da Polimerase Multiplex , Nasofaringe/microbiologia , Nasofaringe/virologia , Razão de Chances , Orofaringe/microbiologia , Orofaringe/virologia , Pneumonia/epidemiologia , Pneumonia/microbiologia , Pneumonia/virologia , Infecções por Vírus Respiratório Sincicial/diagnóstico , Infecções por Vírus Respiratório Sincicial/epidemiologia , Infecções por Vírus Respiratório Sincicial/virologia , Vírus Sinciciais Respiratórios/patogenicidade , População Rural/estatística & dados numéricos , Testes Sorológicos , Manejo de Espécimes , Escarro/microbiologia , Escarro/virologia
16.
J Med Virol ; 84(5): 823-31, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22431032

RESUMO

This study reports pediatric surveillance over 3 years for human rhinovirus (HRV) at the District Hospital of Kilifi, coastal Kenya. Nasopharyngeal samples were collected from children presenting at outpatient clinic with no signs of acute respiratory infection, or with signs of upper respiratory tract infection, and from children admitted to the hospital with lower respiratory tract infection. Samples were screened by real-time reverse transcriptase polymerase chain reaction (real-time RT-PCR) and classified further to species by nucleotide sequencing of the VP4/VP2 junction. Of 441 HRV positives by real-time RT-PCR, 332 were classified to species, with 47% (155) being HRV-A, 5% (18) HRV-B, and 48% (159) HRV-C. There was no clear seasonal pattern of occurrence for any species. The species were present in similar proportions in the inpatient and outpatient sample sets, and no significant association between species distribution and the severity of lower respiratory tract infection in the inpatients could be determined. HRV sequence analysis revealed multiple but separate clusters in circulation particularly for HRV-A and HRV-C. Most HRV-C clusters were distinct from reference sequences downloaded from GenBank. In contrast, most HRV-A and HRV-B sequences clustered with either known serotypes or strains from elsewhere within Africa and other regions of the world. This first molecular epidemiological study of HRV in the region defines species distribution in accord with reports from elsewhere in the world, shows considerable strain diversity and does not identify an association between any species and disease severity.


Assuntos
Epidemiologia Molecular , Infecções por Picornaviridae/epidemiologia , Infecções Respiratórias/epidemiologia , Rhinovirus/genética , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Quênia/epidemiologia , Masculino , Nasofaringe/virologia , Filogenia , Infecções por Picornaviridae/fisiopatologia , Infecções por Picornaviridae/virologia , Infecções Respiratórias/fisiopatologia , Infecções Respiratórias/virologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Rhinovirus/classificação , Rhinovirus/isolamento & purificação , Estações do Ano , Análise de Sequência de DNA , Especificidade da Espécie
17.
PLOS Glob Public Health ; 2(9): e0000951, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36962806

RESUMO

We investigated the first 152 laboratory-confirmed SARS-CoV-2 cases (125 primary and 27 secondary) and their 248 close contacts in Kisumu County, Kenya. Conducted June 10-October 8, 2020, this study included interviews and sample collection at enrolment and 14-21 days later. Median age was 35 years (IQR 28-44); 69.0% reported COVID-19 related symptoms, most commonly cough (60.0%), headache (55.2%), fever (53.3%) and loss of taste or smell (43.8%). One in five were hospitalized, 34.4% >25 years of age had at least one comorbidity, and all deaths had comorbidities. Adults ≥25 years with a comorbidity were 3.15 (95% CI 1.37-7.26) times more likely to have been hospitalized or died than participants without a comorbidity. Infectious comorbidities included HIV, tuberculosis, and malaria, but no current cases of influenza, respiratory syncytial virus, dengue fever, leptospirosis or chikungunya were identified. Thirteen (10.4%) of the 125 primary infections transmitted COVID-19 to 27 close contacts, 158 (63.7%) of whom resided or worked within the same household. Thirty-one percent (4 of 13) of those who transmitted COVID-19 to secondary cases were health care workers; no known secondary transmissions occurred between health care workers. This rapid assessment early in the course of the COVID-19 pandemic identified some context-specific characteristics which conflicted with the national line-listing of cases, and which have been substantiated in the year since. These included over two-thirds of cases reporting the development of symptoms during the two weeks after diagnosis, compared to the 7% of cases reported nationally; over half of cases reporting headaches, and nearly half of all cases reporting loss of taste and smell, none of which were reported at the time by the World Health Organization to be common symptoms. This study highlights the importance of rapid in-depth assessments of outbreaks in understanding the local epidemiology and response measures required.

18.
J Clin Microbiol ; 49(6): 2318-20, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21490188

RESUMO

Paired nasopharyngeal and oropharyngeal swabs collected from 533 children hospitalized with lower respiratory tract infection were assessed by multiplex reverse transcription-PCR. Oropharyngeal swabs increased the number of viral infections detected by 15%, compared to collection of a nasopharyngeal swab alone. This advantage was most pronounced for detection of influenza, parainfluenza, and adenovirus.


Assuntos
Orofaringe/virologia , Infecções Respiratórias/diagnóstico , Infecções Respiratórias/virologia , Manejo de Espécimes/métodos , Viroses/diagnóstico , Viroses/virologia , Vírus/isolamento & purificação , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Nasofaringe/virologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Sensibilidade e Especificidade , Virologia/métodos
19.
PLoS Negl Trop Dis ; 15(2): e0009049, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33524052

RESUMO

BACKGROUND: Brucellosis occurs globally with highly variable incidence in humans from very low in North America and Western Europe to high in the Middle East and Asia. There are few data in Sub-Saharan Africa. This study estimated the incidence of human brucellosis in a pastoralist community in Kenya. METHODS: Between February 2015 and January 2016, we enrolled persons living in randomly selected households in Kajiado County. Free health care was offered at three facilities in the study area. Those who met the study clinical case definition completed a standardized questionnaire on demographics, clinical history and presentation. A blood sample was collected and tested by Rose Bengal test (RBT), then later tested at the Kenya Medical Research Institute laboratory for Brucella IgG and IgM by ELISA. Those who tested positive by both RBT and ELISA (IgG or IgM antibodies) were classified as confirmed while those that only tested positive for IgG or IgM antibodies were classified as probable. Further, sera were tested by polymerase chain reaction using a TaqMan Array Card (TAC) for a panel of pathogens causing AFI including Brucella spp. Annual incidence of brucellosis was calculated as the number of confirmed cases in one year/total number in the study population. RESULTS: We enrolled a cohort of 4746 persons in 804 households. Over half (52.3%) were males and the median age was 18 years (Interquartile range (IQR) 9 months- 32 years). A total of 236 patients were enrolled at three health facilities; 64% were females and the median age was 40.5 years (IQR 28-53 years). Thirty-nine (16.5%) were positive for Brucella antibodies by IgG ELISA, 5/236 (2.1%) by IgM ELISA and 4/236 (1.7%) by RBT. Ten percent (22/217) were positive by TAC. We confirmed four (1.7%) brucellosis cases giving an annual incidence of 84/100,000 persons/year (95% CI 82, 87). The incidence did not significantly vary by gender, age and location of residence. CONCLUSION: We report a high incidence of brucellosis in humans among members of this pastoralist community. Brucellosis was the most common cause of febrile illness in this community.


Assuntos
Brucella/imunologia , Brucelose/diagnóstico , Brucelose/epidemiologia , Testes Sorológicos/métodos , Adolescente , Adulto , Anticorpos Antibacterianos/sangue , Criança , Pré-Escolar , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Lactente , Quênia/epidemiologia , Masculino , Reação em Cadeia da Polimerase , População Rural , Inquéritos e Questionários , Adulto Jovem
20.
Pediatr Infect Dis J ; 40(8): 715-722, 2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-33967229

RESUMO

BACKGROUND: In resource-limited settings, acute respiratory infections continue to be the leading cause of death in young children. We conducted postmortem investigations in children <5 years hospitalized with a clinical diagnosis of respiratory disease at Kenya's largest referral hospital. METHODS: We collected respiratory and other tissues postmortem to examine pathologic processes using histology, molecular and immunohistochemistry assays. Nasopharyngeal, trachea, bronchi and lung specimens were tested using 21-target respiratory pathogen real-time reverse transcription polymerase chain reaction assays deployed on Taqman Array Cards. Expert panels reviewed all findings to determine causes of death and associated pathogens. RESULTS: From 2014 to 2015, we investigated 64 pediatric deaths (median age 7 months). Pneumonia was determined as cause of death in 70% (42/52) of cases where death was associated with an infectious disease process. The main etiologies of pneumonia deaths were respiratory syncytial virus (RSV) (n = 7, 19%), Pneumocystis jirovecii (n = 7, 19%), influenza A (n = 5, 14%) and Streptococcus pneumoniae (n = 5, 14%)-10% of cases had multi-pathogen involvement. Among the other 10 deaths associated with a nonpneumonia infectious process, 4 did not have an etiology assigned, the others were associated with miliary tuberculosis (2), cerebral thrombosis due to HIV (1), Enterobacteriaceae (1), rotavirus (1), and 1 case of respiratory infection with severe hypokalemia associated with RSV. CONCLUSIONS: In spite of well-established vaccination programs in Kenya, some deaths were still vaccine preventable. Accelerated development of RSV monoclonal antibodies and vaccines, introduction of seasonal influenza vaccination, and maintenance or improved uptake of existing vaccines can contribute to further reductions in childhood mortality.


Assuntos
Criança Hospitalizada , Pneumonia/epidemiologia , Pneumonia/microbiologia , Pneumonia/mortalidade , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/microbiologia , Infecções Respiratórias/mortalidade , Autopsia , Causas de Morte , Pré-Escolar , Diagnóstico , Feminino , Humanos , Lactente , Quênia/epidemiologia , Masculino
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