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1.
J Neurovirol ; 29(6): 706-712, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37902948

RESUMEN

The significance of Epstein-Barr virus (EBV) detection in the cerebrospinal spinal fluid (CSF) in people living with HIV (PLWH) is not entirely understood. The detection of EBV DNA may represent active central nervous system (CNS) infection, reactivation in the setting of another CNS pathogen or due to impaired immunity, or detection of quiescent virus. We screened 470 adult PLWH in Zambia with neurological symptoms for the presence of EBV DNA in the CSF. We performed quantitative EBV PCR on the CSF and blood. We then performed quantitative EBV DNA PCR on the blood of controls with documented HIV viral suppression without CNS symptoms. The prevalence of EBV DNA in the CSF of patients with CNS symptoms was 28.9% (136/470). EBV DNA positivity was associated with younger age, shorter duration of HIV diagnosis, lower CSF glucose levels, higher CSF protein and white blood cell levels, and a positive CSF Mycobacterium tuberculosis result. The median EBV DNA load was 8000 cps/mL in both the CSF and blood with a range of 2000-2,753,000 cps/mL in the CSF and 1000 to 1,871,000 cps/mL in the blood. Molecular screening of CSF for other possible causes of infection identified Mycobacterium tuberculosis in 30.1% and cytomegalovirus (CMV) in 10.5% of samples. EBV DNA load in the blood and CSF was not associated with mortality. Our results suggest that even though EBV DNA was commonly detected in the CSF of our population, it appears to have limited clinical significance regardless of EBV DNA load.


Asunto(s)
Infecciones del Sistema Nervioso Central , Infecciones por Virus de Epstein-Barr , Infecciones por VIH , Adulto , Humanos , Infecciones por Virus de Epstein-Barr/complicaciones , Infecciones por Virus de Epstein-Barr/diagnóstico , Herpesvirus Humano 4/genética , Zambia/epidemiología , ADN Viral , Infecciones del Sistema Nervioso Central/complicaciones , Sistema Nervioso Central , Infecciones por VIH/complicaciones , Infecciones por VIH/diagnóstico
2.
Ann Clin Microbiol Antimicrob ; 22(1): 25, 2023 Apr 13.
Artículo en Inglés | MEDLINE | ID: mdl-37055793

RESUMEN

BACKGROUND: Patients who develop severe illness due to COVID-19 are more likely to be admitted to hospital and acquire bacterial co-infections, therefore the WHO recommends empiric treatment with antibiotics. Few reports have addressed the impact of COVID-19 management on emergence of nosocomial antimicrobial resistance (AMR) in resource constrained settings. This study aimed to ascertain whether being admitted to a COVID-19 ward (with COVID-19 infection) compared to a non-COVID-19 ward (as a COVID-19 negative patient) was associated with a change in the prevalence of bacterial hospital acquired infection (HAI) species or resistance patterns, and whether there were differences in antimicrobial stewardship (AMS) and infection prevention and control (IPC) guidelines between COVID-19 and non-COVID-19 wards. The study was conducted in Sudan and Zambia, two resource constrained settings with differing country-wide responses to COVID-19. METHODS: Patients suspected of having hospital acquired infections were recruited from COVID-19 wards and non-COVID-19 wards. Bacteria were isolated from clinical samples using culture and molecular methods and species identified. Phenotypic and genotypic resistance patterns were determined by antibiotic disc diffusion and whole genome sequencing. Infection prevention and control guidelines were analysed for COVID-19 and non-COVID-19 wards to identify potential differences. RESULTS: 109 and 66 isolates were collected from Sudan and Zambia respectively. Phenotypic testing revealed significantly more multi-drug resistant isolates on COVID-19 wards in both countries (Sudan p = 0.0087, Zambia p = 0.0154). The total number of patients with hospital acquired infections (both susceptible and resistant) increased significantly on COVID-19 wards in Sudan, but the opposite was observed in Zambia (both p = ≤ 0.0001). Genotypic analysis showed significantly more ß-lactam genes per isolate on COVID-19 wards (Sudan p = 0.0192, Zambia p = ≤ 0.0001). CONCLUSIONS: Changes in hospital acquired infections and AMR patterns were seen in COVID-19 patients on COVID-19 wards compared to COVID-19 negative patients on non-COVID-19 wards in Sudan and Zambia. These are likely due to a potentially complex combination of causes, including patient factors, but differing emphases on infection prevention and control, and antimicrobial stewardship policies on COVID-19 wards were highlighted.


Asunto(s)
Infecciones Bacterianas , COVID-19 , Infección Hospitalaria , Humanos , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Prevalencia , Pandemias , COVID-19/epidemiología , Farmacorresistencia Bacteriana , Infecciones Bacterianas/microbiología , Hospitales , Infección Hospitalaria/microbiología
3.
BMC Microbiol ; 21(1): 136, 2021 05 04.
Artículo en Inglés | MEDLINE | ID: mdl-33947325

RESUMEN

BACKGROUND: Antimicrobial resistance (AMR) poses a complex threat to global health security and universal health coverage. Recently, nosocomial infections with carbapenemase-producing Gram-negative bacilli (GNB) is increasing worldwide. We report the molecular characterization and detection of genes associated with carbapenemase producing Gram negative bacteria isolated from hospitalized patients at Soba University Hospital (SUH) in Khartoum State, Sudan. RESULTS: Between October 2016 and February 2017, a total of 206 GNB clinical specimens were collected from hospitalized patients in SUH. Of 206 carbapenem resistance isolates, 171 (83 %) were confirmed as phenotypically resistant and 121 (58.7 %) isolates harboured one or more carbapenemase genes. New Delhi metallo-ß-lactamase (NDM) types were the most predominant genes, blaNDM 107(52 %), followed by blaIMP 7 (3.4 %), blaOXA-48 5(2.4 %) and blaVIM 2 (0.9 %). Co-resistance genes with NDM producing GNB were detected in 87 (81.3 %) of all blaNDM producing isolates. NDM-1 was the most frequent subtype observed in 75 (70 %) blaNDM producing isolates. The highest percentage of resistance was recorded in ampicillin (98 %), cephalexin (93.5 %) amoxicillin clavulanic acid (90 %), cefotaxime (89.7 %), ceftriaxone (88.4 %), ceftazidime (84.2 %), sulfamethoxazole-trimethoprim (78.4 %) and nitrofurantoin (75.2 %), aztreonam (66 %) and temocillin (64 %). A close correlation between phenotypic and carbapenemase genes detection in all GNB was observed. CONCLUSIONS: The frequency of carbapenemase producing bacilli was found to be high in SUH. NDM was found to be the most prevalent carbapenemase gene among clinical isolates. Close surveillance across all hospitals in Sudan is required. The relative distribution of carbapenemase genes among GNB in nosocomial infections in Africa needs to be defined.


Asunto(s)
Carbapenémicos/farmacología , Farmacorresistencia Bacteriana/genética , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Gramnegativas/genética , Infecciones por Bacterias Gramnegativas/microbiología , Proteínas Bacterianas/genética , Genes Bacterianos/genética , Bacterias Gramnegativas/aislamiento & purificación , Hospitales Universitarios , Humanos , Sudán , beta-Lactamasas/genética
4.
Can J Infect Dis Med Microbiol ; 2021: 7865405, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34093925

RESUMEN

Neisseria gonorrhoeae (N. gonorrhoeae, gonococci, or GC), the etiologic agent of gonorrhea, is a human-obligate bacterial pathogen. The GC surface contains pili that mediate the adherence to host cells. Studies have shown that GC pili, coded by pilin genes, undergo remarkable changes during human experimental gonorrhea, possibly generated by DNA phase variation during infection. The question that arises is whether the changes in pilins can alter the adherence capacity of N. gonorrhoeae to host cells. In this study, six variants initially isolated from male volunteers infected with one single clone of GC were examined for their adherence patterns with human Chang conjunctiva cells. In this study, we showed that the variants showed distinct adherence patterns to this cell line under light microscopy and scanning electron microscopy. Moreover, two reisolates showed higher adherence capacities than that of the input strain. The results provide an additional example as to how the pilus variation may play a role in the pathogenesis of N. gonorrhoeae.

5.
Emerg Infect Dis ; 26(4): 811-814, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-32187004

RESUMEN

We detected West Nile virus (WNV) nucleic acid in crocodiles (Crocodylus niloticus) in Zambia. Phylogenetically, the virus belonged to lineage 1a, which is predominant in the Northern Hemisphere. These data provide evidence that WNV is circulating in crocodiles in Africa and increases the risk for animal and human transmission.


Asunto(s)
Caimanes y Cocodrilos , Fiebre del Nilo Occidental , Virus del Nilo Occidental , Animales , Humanos , Fiebre del Nilo Occidental/epidemiología , Fiebre del Nilo Occidental/veterinaria , Virus del Nilo Occidental/genética , Zambia/epidemiología
6.
Infect Immun ; 87(1)2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30348825

RESUMEN

Yersinia pseudotuberculosis is a Gram-negative enteropathogen and causes gastrointestinal infections. It disseminates from gut to mesenteric lymph nodes (MLNs), spleen, and liver of infected humans and animals. Although the molecular mechanisms for dissemination and infection are unclear, many Gram-negative enteropathogens presumably invade the small intestine via Peyer's patches to initiate dissemination. In this study, we demonstrate that Y. pseudotuberculosis utilizes its lipopolysaccharide (LPS) core to interact with CD209 receptors, leading to invasion of human dendritic cells (DCs) and murine macrophages. These Y. pseudotuberculosis-CD209 interactions result in bacterial dissemination to MLNs, spleens, and livers of both wild-type and Peyer's patch-deficient mice. The blocking of the Y. pseudotuberculosis-CD209 interactions by expression of O-antigen and with oligosaccharides reduces infectivity. Based on the well-documented studies in which HIV-CD209 interaction leads to viral dissemination, we therefore propose an infection route for Y. pseudotuberculosis where this pathogen, after penetrating the intestinal mucosal membrane, hijacks the Y. pseudotuberculosis-CD209 interaction antigen-presenting cells to reach their target destinations, MLNs, spleens, and livers.


Asunto(s)
Moléculas de Adhesión Celular/metabolismo , Células Dendríticas/microbiología , Endocitosis , Interacciones Huésped-Patógeno , Lectinas Tipo C/metabolismo , Lipopolisacáridos/metabolismo , Macrófagos/microbiología , Receptores de Superficie Celular/metabolismo , Yersinia pseudotuberculosis/patogenicidad , Animales , Adhesión Bacteriana , Células Cultivadas , Modelos Animales de Enfermedad , Humanos , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Unión Proteica , Yersiniosis/microbiología , Yersiniosis/patología , Yersiniosis/fisiopatología
7.
Infect Immun ; 87(8)2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31085704

RESUMEN

Salmonella enterica serovar Typhimurium, a Gram-negative bacterium, can cause infectious diseases ranging from gastroenteritis to systemic dissemination and infection. However, the molecular mechanisms underlying this bacterial dissemination have yet to be elucidated. A study indicated that using the lipopolysaccharide (LPS) core as a ligand, S Typhimurium was able to bind human dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin (hCD209a), an HIV receptor that promotes viral dissemination by hijacking antigen-presenting cells (APCs). In this study, we showed that S Typhimurium interacted with CD209s, leading to the invasion of APCs and potentially the dissemination to regional lymph nodes, spleen, and liver in mice. Shielding of the exposed LPS core through the expression of O-antigen reduces dissemination and infection. Thus, we propose that similar to HIV, S Typhimurium may also utilize APCs via interactions with CD209s as a way to disseminate to the lymph nodes, spleen, and liver to initiate host infection.


Asunto(s)
Moléculas de Adhesión Celular/fisiología , Lectinas Tipo C/fisiología , Receptores de Superficie Celular/fisiología , Salmonella typhimurium/patogenicidad , Animales , Células Presentadoras de Antígenos/microbiología , Femenino , Interacciones Huésped-Patógeno , Humanos , Lipopolisacáridos/fisiología , Mananos/farmacología , Ratones , Ratones Endogámicos C57BL , Antígenos O/fisiología , Ganglios Linfáticos Agregados/fisiología , Fagocitosis , Células RAW 264.7
8.
J Med Virol ; 90(11): 1757-1764, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30011348

RESUMEN

BACKGROUND: Human herpesvirus 6B (HHV-6B) is the causative agent of Roseola infantum, and has also been suggested to play a role in the pathogenesis of febrile seizures in young children, a percentage of whom go on to develop febrile status epilepticus (FSE), but the existing data is conflicting and inconclusive. HHV-6A is a distinct species, rarely detected in most parts of the world, but prior studies suggest a higher prevalence in febrile African children. We describe a case-control study comparing the frequency of HHV-6A and/or HHV-6B infections in children with febrile seizures (including FSE) and a control group of febrile children without seizures. METHODS: We recruited children aged 6 to 60 months admitted with a febrile illness with (cases) or without (controls) seizures presenting within 48 hours of commencement of fever. Three milliliters of whole blood was centrifuged and plasma stored at -80°C for pooled screening for HHV-6B and HHV-6A by Taqman real-time polymerase chain reaction. RESULTS: 102 cases and 95 controls were recruited. The prevalence of HHV-6B DNA detection did not differ significantly between cases (5.8% (6/102)) and controls (10.5% (10/95)) but HHV-6B infection was associated with FSE (OR, 15; 95% CI, [1.99-120]; P= 0.009). HHV-6A was not detected. CONCLUSION: Prevalence of HHV-6B was similar among cases and controls. Within the FS group, HHV-6B infection was associated with FSE, suggesting HHV-6B infections could play a role in the pathogenesis of FSE.


Asunto(s)
Exantema Súbito/complicaciones , Exantema Súbito/patología , Herpesvirus Humano 6/aislamiento & purificación , Convulsiones Febriles/epidemiología , Estado Epiléptico/epidemiología , Estudios de Casos y Controles , Preescolar , Exantema Súbito/virología , Femenino , Herpesvirus Humano 6/genética , Hospitales , Humanos , Lactante , Masculino , Prevalencia , Reacción en Cadena en Tiempo Real de la Polimerasa , Zambia/epidemiología
9.
BMC Med ; 14: 99, 2016 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-27363601

RESUMEN

BACKGROUND: Autopsy studies are the gold standard for determining cause-of-death and can inform on improved diagnostic strategies and algorithms to improve patient care. We conducted a cross-sectional observational autopsy study to describe the burden of respiratory tract infections in inpatient children who died at the University Teaching Hospital in Lusaka, Zambia. METHODS: Gross pathology was recorded and lung tissue was analysed by histopathology and molecular diagnostics. Recruitment bias was estimated by comparing recruited and non-recruited cases. RESULTS: Of 121 children autopsied, 64 % were male, median age was 19 months (IQR, 12-45 months). HIV status was available for 97 children, of whom 34 % were HIV infected. Lung pathology was observed in 92 % of cases. Bacterial bronchopneumonia was the most common pathology (50 %) undiagnosed ante-mortem in 69 % of cases. Other pathologies included interstitial pneumonitis (17 %), tuberculosis (TB; 8 %), cytomegalovirus pneumonia (7 %) and pneumocystis Jirovecii pneumonia (5 %). Comorbidity between lung pathology and other communicable and non-communicable diseases was observed in 80 % of cases. Lung tissue from 70 % of TB cases was positive for Mycobacterium tuberculosis by molecular diagnostic tests. A total of 80 % of TB cases were comorbid with malnutrition and only 10 % of TB cases were on anti-TB therapy when they died. CONCLUSIONS: More proactive testing for bacterial pneumonia and TB in paediatric inpatient settings is needed.


Asunto(s)
Infecciones del Sistema Respiratorio/epidemiología , Infecciones del Sistema Respiratorio/microbiología , Autopsia , Niño , Trastornos de la Nutrición del Niño/epidemiología , Preescolar , Comorbilidad , Estudios Transversales , Femenino , Humanos , Lactante , Masculino , Zambia/epidemiología
10.
Clin Infect Dis ; 60(3): 423-31, 2015 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-25352585

RESUMEN

BACKGROUND: Betaherpesviruses are established causes of morbidity and mortality in immunosuppressed patient groups but have been little studied in sub-Saharan Africa, the epicenter of the human immunodeficiency virus (HIV) pandemic. In this region, primary infections with human cytomegalovirus (HCMV) and human herpesvirus type 6 (HHV-6) type 6 are endemic in infancy, but the clinical impact of these infections among pediatric inpatient groups is poorly characterized and assumptive, based largely on data from Western populations. METHODS: We used TaqMan polymerase chain reaction to screen sera from a group of 303 pediatric inpatients aged between 3 weeks and 2 years, at the University Teaching Hospital in Lusaka, Zambia. We report the prevalence of DNAemia and viral loads within this patient group, and evaluate possible clinical associations/risk factors for betaherpesvirus infections in these hospitalized children. RESULTS: We detected betaherpesvirus DNAemia in 59.1% (179/303) of children. HCMV was the most prevalent (41.3%), followed by HHV-6B (20.5%), HHV-7 (20.1%), and HHV-6A (0.3%). HIV infection (odds ratio [OR], 2.31; 95% confidence interval [CI], 1.37-3.90; P = .002), being underweight (OR, 1.82; 95% CI, 1.06-3.12; P = .03), and an admission diagnosis of suspected meningitis (OR, 5.72; 95% CI, 1.07-30.5; P = .041) were independently associated with an increased odds of HCMV DNAemia. Conversely, HHV-6B and HHV-7 DNAemia were not associated with HIV, underweight, or admission diagnosis. Median HCMV viral load was moderately but significantly higher in HIV-infected children. CONCLUSIONS: Highly prevalent HCMV DNAemia was independently associated with HIV infection and being underweight across all age groups, and was also associated with meningitis, with previously underappreciated implications for the health and development of African children.


Asunto(s)
Infecciones por Citomegalovirus/epidemiología , Citomegalovirus/aislamiento & purificación , Herpesvirus Humano 6/aislamiento & purificación , Herpesvirus Humano 7/aislamiento & purificación , Infecciones por Roseolovirus/epidemiología , Preescolar , Citomegalovirus/genética , Infecciones por Citomegalovirus/etiología , Infecciones por Citomegalovirus/virología , ADN Viral/sangre , Femenino , Infecciones por VIH/complicaciones , Herpesvirus Humano 6/genética , Herpesvirus Humano 7/genética , Hospitales de Enseñanza , Hospitales Universitarios , Humanos , Huésped Inmunocomprometido , Lactante , Recién Nacido , Masculino , Prevalencia , Derivación y Consulta , Factores de Riesgo , Infecciones por Roseolovirus/etiología , Infecciones por Roseolovirus/virología , Delgadez , Carga Viral , Zambia
11.
Clin Infect Dis ; 58(5): 728-35, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24265360

RESUMEN

BACKGROUND: Congenital cytomegalovirus (CMV) infection is the major infectious cause of birth defects and hearing loss globally. There is a growing recognition of the potential clinical impact of congenital CMV infections in high-seroprevalence settings. METHODS: A cross-sectional study of neonatal admissions at a large referral center in sub-Saharan Africa to determine the prevalence of both symptomatic and asymptomatic congenital CMV infection was performed. Real-time polymerase chain reaction was used to screen DNA-extracted sera, urine, and saliva, and an enzyme-linked immunosorbent assay was used to screen serum samples for anti-CMV immunoglobulin M. Multivariate binary logistic regression was used to identify risk factors associated with increased odds of congenital CMV infection. RESULTS: Congenital CMV was detected in 3.8% (15/395) of neonates. Among these infants, 6 of 15 (40%) presented with jaundice, 1 of whom also had petechiae. Congenital CMV infection was detected in 9 of 79 (11.4%; 95% confidence interval [CI], 6.1%-20.3%) neonates born to human immunodeficiency virus (HIV)-infected mothers, and both maternal HIV (odds ratio [OR], 6.661 [95% CI, 2.126-20.876], P = .001) and jaundice (OR, 5.701 [95% CI, 1.776-18.306], P = .003) were independently linked with significantly increased odds of congenital CMV infection. CONCLUSIONS: Congenital and early infant CMV infections may have important consequences for child health in sub-Saharan Africa and other high HIV and CMV seroprevalence populations globally.


Asunto(s)
Infecciones por Citomegalovirus/congénito , Infecciones por Citomegalovirus/epidemiología , Infecciones por VIH/complicaciones , Hospitalización , Complicaciones Infecciosas del Embarazo/epidemiología , África del Sur del Sahara , Anticuerpos Antivirales/sangre , Estudios Transversales , ADN Viral/análisis , Ensayo de Inmunoadsorción Enzimática , Femenino , Hospitalización/estadística & datos numéricos , Humanos , Inmunoglobulina M/sangre , Recién Nacido , Masculino , Embarazo , Prevalencia , Reacción en Cadena en Tiempo Real de la Polimerasa , Factores de Riesgo , Saliva/virología , Suero/virología , Centros de Atención Terciaria , Orina/virología
12.
Trop Med Int Health ; 18(9): 1134-1140, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23834035

RESUMEN

OBJECTIVES: In high-tuberculosis (TB)-endemic countries, comorbidity of pulmonary TB in hospitalised patients with non-communicable diseases is well documented. In this study, we evaluated the use of the Xpert(®) MTB/RIF assay for the detection of concomitant pulmonary TB in patients admitted to the University Teaching Hospital, Lusaka, Zambia, with a primary obstetric or gynaecological condition. METHODS: The Study population were inpatients admitted with a primary obstetric or gynaecological problem who had a concomitant cough and were able to expectorate a sputum sample. Sputum samples from 94 patients were analysed for the presence of Mycobacterium tuberculosis (M.tb) by standard smear microscopy, MGIT culture, MGIT drug-susceptibility testing (DST) and the Xpert(®) MTB/RIF assay. The sensitivity and specificity of the Xpert(®) MTB/RIF assay were evaluated against the culture gold standard. RESULTS: Twenty-six of 94 (27.7%) patients had culture-confirmed pulmonary TB. The Xpert(®) MTB/RIF assay had a sensitivity of 80.8% [95% CI: 60.0-92.7%]) compared against MGIT culture. The Xpert(®) MTB/RIF assay was more sensitive than sputum smear microscopy (21/26 (80.8%) vs. 13/26 (50.0%), P = 0.02) and detected an additional eight culture-confirmed cases. Culture DST analysis identified two monoresistant M.tb strains: one resistant to rifampicin (rifampicin sensitive by the Xpert(®) MTB/RIF assay) and one to ethambutol. HIV infection was linked with a 3-fold increase in risk of TB, accounting for 87.5% (21/24) of TB cases. 50% of cases presented as comorbidities with other communicable diseases (CDs) and non-communicable diseases (NCDs). CONCLUSIONS: As an alternative to sputum microscopy, the Xpert(®) MTB/RIF assay provides a sensitive, specific and rapid method for the diagnosis of pulmonary TB in obstetric or gynaecological inpatients. Pulmonary TB is an important cause of concomitant comorbidity to the obstetric or gynaecological condition necessitating admission. TB and HIV comorbidities with other communicable and non-communicable diseases were also common. More proactive screening for TB comorbidity is required in obstetric and gynaecological wards.


Asunto(s)
Pruebas de Sensibilidad Microbiana/métodos , Servicio de Ginecología y Obstetricia en Hospital/estadística & datos numéricos , Tuberculosis Resistente a Múltiples Medicamentos/diagnóstico , Tuberculosis Pulmonar/diagnóstico , Adulto , Técnicas Bacteriológicas/instrumentación , Técnicas Bacteriológicas/métodos , Comorbilidad , Femenino , Enfermedades de los Genitales Femeninos/diagnóstico , Enfermedades de los Genitales Femeninos/epidemiología , Infecciones por VIH/diagnóstico , Infecciones por VIH/epidemiología , Humanos , Pacientes Internos/estadística & datos numéricos , Pruebas de Sensibilidad Microbiana/instrumentación , Mycobacterium tuberculosis/aislamiento & purificación , Embarazo , Complicaciones Infecciosas del Embarazo/diagnóstico , Complicaciones Infecciosas del Embarazo/epidemiología , Estudios Prospectivos , Sensibilidad y Especificidad , Esputo/microbiología , Tuberculosis Resistente a Múltiples Medicamentos/epidemiología , Tuberculosis Pulmonar/epidemiología , Adulto Joven , Zambia/epidemiología
13.
Viruses ; 15(9)2023 09 08.
Artículo en Inglés | MEDLINE | ID: mdl-37766306

RESUMEN

The circulation of both West Nile Virus (WNV) and Chikungunya Virus (CHIKV) in humans and animals, coupled with a favorable tropical climate for mosquito proliferation in Zambia, call for the need for a better understanding of the ecological and epidemiological factors that govern their transmission dynamics in this region. This study aimed to examine the contribution of climatic variables to the distribution of Culex and Aedes mosquito species, which are potential vectors of CHIKV, WNV, and other arboviruses of public-health concern. Mosquitoes collected from Lusaka as well as from the Central and Southern provinces of Zambia were sorted by species within the Culex and Aedes genera, both of which have the potential to transmit viruses. The MaxEnt software was utilized to predict areas at risk of WNV and CHIKV based on the occurrence data on mosquitoes and environmental covariates. The model predictions show three distinct spatial hotspots, ranging from the high-probability regions to the medium- and low-probability regions. Regions along Lake Kariba, the Kafue River, and the Luangwa Rivers, as well as along the Mumbwa, Chibombo, Kapiri Mposhi, and Mpika districts were predicted to be suitable habitats for both species. The rainfall and temperature extremes were the most contributing variables in the predictive models.


Asunto(s)
Aedes , Fiebre Chikungunya , Virus Chikungunya , Culex , Virus del Nilo Occidental , Animales , Humanos , Fiebre Chikungunya/epidemiología , Zambia/epidemiología , Mosquitos Vectores , Ecosistema
14.
Clin Infect Dis ; 55(9): 1171-8, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22806590

RESUMEN

BACKGROUND. There were 1.45 million deaths from tuberculosis in 2011. A substantial proportion of active pulmonary tuberculosis cases in countries where tuberculosis, human immunodeficiency virus (HIV) infection, and AIDS are highly endemic remain undiagnosed because of the reliance on sputum-smear microscopy. This study evaluated the performance of the Xpert MTB/RIF assay at a tertiary care referral center in Zambia, a country where the burden of tuberculosis and HIV infection is high. METHODS. A total of 881 adult inpatients admitted to University Teaching Hospital in Lusaka who were able to produce sputum were enrolled and analyzed in the study, irrespective of admission diagnosis. Sputum specimens were analyzed by fluorescence smear microscopy, the Xpert MTB/RIF assay, mycobacterial growth indicator tube (MGIT) culture,and MGIT drug-susceptibility testing. The sensitivity and specificity of the Xpert MTB/RIF assay were evaluated using culture as the gold standard. RESULTS. Culture-confirmed tuberculosis was found in 201 of 881 patients (22.8%). The specificity of the Xpert MTB/RIF assay was 95.0% (95% confidence interval [CI], 92.4%­96.8%),and the sensitivity was 86.1% (95% CI, 80.3%­90.4%). In sputum smear­negative, culture-positive cases, the assay was 74.7% sensitive (95% CI, 64.6%­82.8%), identifying 71 additional tuberculosis cases that were not detected by smear microscopy.A total of 18 of 111 patients with tuberculosis who were tested (16.2%) had multidrug-resistant (MDR) tuberculosis.The sensitivity and specificity of the Xpert MTB/RIF assay for detecting culture-confirmed, rifampicin-resistant tuberculosis was 81.3% (95% CI, 53.7%­95.0%) and 97.5% (95% CI,90.4%­99.6%), respectively. CONCLUSIONS. The Xpert MTB/RIF assay performs better than smear microscopy in an inpatient setting in a country where tuberculosis and HIV infection are highly endemic. Assessment of its usefulness and cost-effectiveness for increased detection of tuberculosis cases missed by sputum smear and for concomitant screening for MDR tuberculosis among adult inpatients attending tertiary care referral centers in other countries with a high burden of tuberculosis and HIV infection is warranted [corrected].


Asunto(s)
Técnicas de Diagnóstico Molecular/métodos , Tuberculosis Resistente a Múltiples Medicamentos/diagnóstico , Tuberculosis Pulmonar/diagnóstico , Adulto , Femenino , Humanos , Masculino , Valor Predictivo de las Pruebas , Estudios Prospectivos , Sensibilidad y Especificidad , Centros de Atención Terciaria , Zambia
15.
Int J Infect Dis ; 115: 195-200, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34896266

RESUMEN

BACKGROUND: Cysticercosis is a World Health Organization designated neglected human zoonosis worldwide. Data on cardiac cysticercosis and its contribution to sudden and unexpected community deaths are scarce and require study. METHODS: A study was performed of cysticercosis-related deaths and other incidental cases of cysticercosis seen at forensic post-mortem examination over a period of 12 months, in individuals who died suddenly and unexpectedly in the community in Lusaka, Zambia. Whole-body post-mortem examinations were performed according to standard operating procedures for post-mortem examinations. Representative samples were obtained from all body organs and subjected to histopathological examination. Information was obtained on circumstances surrounding the death. Data were collated on patient demographics, history, co-morbidities, pathological gross and microscopic findings, and forensic autopsy cause(s) of death. The available literature on cardiac cysticercosis was also reviewed. RESULTS: Nine cases of cysticercosis were identified. Eight of the nine cases had cardiac cysticercosis. There was no prior history of cysticercosis before death. All were male, aged between 28 and 56 years, and from high population density and low socioeconomic communities. There was no community case clustering identified. CONCLUSIONS: Cardiac cysticercosis and neurocysticercosis are important incidental findings in sudden and unexpected deaths in the community and can easily be missed antemortem. More investment in forensic autopsy services is required to define the undiagnosed burden of deaths due to treatable communicable diseases.


Asunto(s)
Cisticercosis , Neurocisticercosis , Adulto , Autopsia , Cisticercosis/diagnóstico , Cisticercosis/epidemiología , Muerte Súbita , Humanos , Masculino , Persona de Mediana Edad , Neurocisticercosis/diagnóstico , Neurocisticercosis/epidemiología , Zambia/epidemiología
16.
Int J Infect Dis ; 120: 150-157, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35427785

RESUMEN

OBJECTIVES: To conduct a diagnostic validation study of SARS-CoV-2 diagnostic kits. METHODS: We compared SARS-CoV-2 diagnostic test results from 3 RT-PCR assays used by the Zambian government between November 2020 and February 2021 (Panther Fusion assay, Da An Gene's 2019-nCoV RNA kit and Maccura's PCR Kit) with the Altona RealStar RT-PCR kit which served as the gold standard. We also evaluated results from rapid antigen testing and whether comorbidities were linked with increased odds of infection. RESULTS: We recruited 244 participants, 61% (149/244) were positive by at least 1 PCR assay. Da An Gene, Maccura, and Panther Fusion assays had sensitivities of 0.0% (95% confidence interval [CI] 0%-41%), 27.1% (95% CI 15%-42%), and 76% (95% CI 65%-85%), respectively, but specificity was low (<85% for all 3 assays). HIV and TB were not associated with SARS-CoV-2, whereas female sex (OR 0.5 [0.3-0.9], p = 0.026) and chronic pulmonary disease (0.1 [0.0-0.8], p = 0.031) were associated with lower odds of SARS-CoV-2 infection. Of 44 samples, 84% sequenced were Beta variant. CONCLUSIONS: The RT-PCR assays evaluated did not meet WHO recommended minimum sensitivity of 80%. Local diagnostic validation studies should be embedded within preparedness plans for future outbreaks to improve the public health response.


Asunto(s)
COVID-19 , SARS-CoV-2 , COVID-19/diagnóstico , COVID-19/epidemiología , Femenino , Humanos , Factores de Riesgo , SARS-CoV-2/genética , Sensibilidad y Especificidad , Zambia/epidemiología
17.
Int J Infect Dis ; 124 Suppl 1: S41-S46, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35341998

RESUMEN

BACKGROUND: The unprecedented and ongoing COVID-19 pandemic has exposed weaknesses in African countries' health systems. The impact of shifted focus on COVID-19 for the past 2 years on routine health services, especially those for the epidemics of Tuberculosis, HIV/AIDS and Malaria, have been dramatic in both quantity and quality. METHODS: In this article, we reflect on the COVID-19 related disruptions on the Tuberculosis, HIV/AIDS and Malaria routine health services across Africa. RESULTS: The COVID-19 pandemic resulted in disruptions of routine health services and diversion of already limited available resources in sub-Saharan Africa. As a result, disease programs like TB, malaria and HIV have recorded gaps in prevention and treatment with the prospects of reversing gains made towards meeting global targets. The extent of the disruption is yet to be fully quantified at country level as most data available is from modelling estimates before and during the pandemic. CONCLUSIONS: Accurate country-level data is required to convince donors and governments to invest more into revamping these health services and help prepare for managing future pandemics without disruption of routine services. Increasing government expenditure on health is a critical part of Africa's economic policy. Strengthening health systems at various levels to overcome the negative impacts of COVID-19, and preparing for future epidemics will require strong visionary political leadership. Innovations in service delivery and technological adaptations are required as countries aim to limit disruptions to routine services.


Asunto(s)
Síndrome de Inmunodeficiencia Adquirida , COVID-19 , Infecciones por VIH , Malaria , Tuberculosis , Humanos , Pandemias/prevención & control , COVID-19/epidemiología , Infecciones por VIH/epidemiología , Infecciones por VIH/prevención & control , África del Sur del Sahara/epidemiología , Síndrome de Inmunodeficiencia Adquirida/epidemiología , Síndrome de Inmunodeficiencia Adquirida/prevención & control , Tuberculosis/epidemiología , Tuberculosis/prevención & control , Malaria/epidemiología , Malaria/prevención & control , Servicios de Salud
18.
Int J Infect Dis ; 124 Suppl 1: S75-S81, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35283296

RESUMEN

OBJECTIVES: Tuberculosis remains a global emergency. In Zambia only 55% of tuberculosis cases are diagnosed. We performed a study to determine incidental cases of tuberculosis seen at forensic autopsy of individuals who died suddenly and unexpectedly in the community in Lusaka, Zambia. METHODS: Whole-body autopsies were performed according to Standard Operating Procedures. Representative samples obtained from relevant organs were subjected to pathological examination. Information on circumstances surrounding the death was obtained. Data on patient demographics, gross and microscopic pathological findings, and cause(s) of death were analysed. RESULTS: Incidental tuberculosis was found in 52 cases (45 male, 7 female, age range 14-66) out of 4286 whole-body autopsies. 41/52 (80%) were aged 21-50 years. One was a 14-year old boy who died during a football match. 39/52 (75%) deaths were attributable specifically to tuberculosis only. Other deaths were due to acute alcohol intoxication(4), violence(7), ruptured ectopic pregnancy(1), bacterial meningitis (1). All the cases were from poor socio-economic backgrounds and lived in high-density areas of Lusaka. CONCLUSIONS: Incidental cases of active tuberculosis undiagnosed antemortem seen at forensic autopsy reflects major gaps in the national TB control programs. More investments into proactive screening, testing, treatment activities, and accurate data collection are required.


Asunto(s)
Tuberculosis , Embarazo , Masculino , Humanos , Femenino , Adolescente , Adulto Joven , Adulto , Persona de Mediana Edad , Anciano , Autopsia , Zambia/epidemiología
19.
Pathogens ; 11(11)2022 Nov 14.
Artículo en Inglés | MEDLINE | ID: mdl-36422597

RESUMEN

Transmission dynamics and the maintenance of mammarenaviruses in nature are poorly understood. Using metagenomic next-generation sequencing (mNGS) and RT-PCR, we investigated the presence of mammarenaviruses and co-infecting helminths in various tissues of 182 Mastomys natalensis rodents and 68 other small mammals in riverine and non-riverine habitats in Zambia. The Luna virus (LUAV) genome was the only mammarenavirus detected (7.7%; 14/182) from M. natalensis. Only one rodent from the non-riverine habitat was positive, while all six foetuses from one pregnant rodent carried LUAV. LUAV-specific mNGS reads were 24-fold higher in semen than in other tissues from males. Phylogenetically, the viruses were closely related to each other within the LUAV clade. Helminth infections were found in 11.5% (21/182) of M. natalensis. LUAV-helminth co-infections were observed in 50% (7/14) of virus-positive rodents. Juvenility (OR = 9.4; p = 0.018; 95% CI: 1.47-59.84), nematodes (OR = 15.5; p = 0.001; 95% CI: 3.11-76.70), cestodes (OR = 10.8; p = 0.025; 95% CI: 1.35-86.77), and being male (OR = 4.6; p = 0.036; 95% CI: 1.10-18.90) were associated with increased odds of LUAV RNA detection. The role of possible sexual and/or congenital transmission in the epidemiology of LUAV infections in rodents requires further study, along with the implications of possible helminth co-infection.

20.
Viruses ; 14(9)2022 08 24.
Artículo en Inglés | MEDLINE | ID: mdl-36146671

RESUMEN

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern (VOCs) have significantly impacted the global epidemiology of the pandemic. From December 2020 to April 2022, we conducted genomic surveillance of SARS-CoV-2 in the Southern Province of Zambia, a region that shares international borders with Botswana, Namibia, and Zimbabwe and is a major tourist destination. Genetic analysis of 40 SARS-CoV-2 whole genomes revealed the circulation of Alpha (B.1.1.7), Beta (B.1.351), Delta (AY.116), and multiple Omicron subvariants with the BA.1 subvariant being predominant. Whereas Beta, Delta, and Omicron variants were associated with the second, third, and fourth pandemic waves, respectively, the Alpha variant was not associated with any wave in the country. Phylogenetic analysis showed evidence of local transmission and possible multiple introductions of SARS-CoV-2 VOCs in Zambia from different European and African countries. Across the 40 genomes analysed, a total of 292 mutations were observed, including 182 missense mutations, 66 synonymous mutations, 23 deletions, 9 insertions, 1 stop codon, and 11 mutations in the non-coding region. This study stresses the need for the continued monitoring of SARS-CoV-2 circulation in Zambia, particularly in strategically positioned regions such as the Southern Province which could be at increased risk of introduction of novel VOCs.


Asunto(s)
COVID-19 , SARS-CoV-2 , COVID-19/epidemiología , Codón de Terminación , Genómica , Humanos , Mutación , Filogenia , SARS-CoV-2/genética , Zambia/epidemiología
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