A5083882942- COVID-19 epidemiological studies
- Viral Infections and Outbreaks Research
- Influenza Virus Research Studies
- Viral Infections and Vectors
- SARS-CoV-2 and COVID-19 Research
- Salmonella and Campylobacter epidemiology
- Respiratory viral infections research
- Vector-Borne Animal Diseases
- Animal Disease Management and Epidemiology
- SARS-CoV-2 detection and testing
- Vibrio bacteria research studies
- Aquaculture disease management and microbiota
- Child Nutrition and Water Access
- Viral gastroenteritis research and epidemiology
- Vaccine Coverage and Hesitancy
- Disaster Response and Management
- HIV/AIDS Impact and Responses
- Vector-borne infectious diseases
- Statistical Methods and Bayesian Inference
- Dental Education, Practice, Research
- Bacterial Infections and Vaccines
- Dermatologic Treatments and Research
- vaccines and immunoinformatics approaches
- Data-Driven Disease Surveillance
- Hepatitis Viruses Studies and Epidemiology
World Health Organization
2021-2024
Epworth Hospital
2022
World Health Organization Regional Office for Africa
2018
New South Wales Department of Health
2017
National Centre for Immunisation Research & Surveillance
2017
National Health Laboratory Service
2009-2015
National Institute for Communicable Diseases
2013-2015
University of Pretoria
2009-2013
University of California, Irvine
2013
Togolese Ministry of Health
2013
We present a global analysis of the spread recently emerged SARS-CoV-2 variants and estimate changes in effective reproduction numbers at country-specific level using sequence data from GISAID. Nearly all investigated countries demonstrated rapid replacement previously circulating lineages by World Health Organization-designated concern, with estimated transmissibility increases 29% (95% CI: 24-33), 25% 20-30), 38% 29-48) 97% 76-117), respectively, for B.1.1.7, B.1.351, P.1 B.1.617.2.
We provide an interim report on pandemic H1N1 influenza activity in South Africa, with a focus the epidemiology and factors associated deaths. Following importation of virus 14 July 2009, epidemic peak during week starting 3 August, incidence Africa has declined. A total 12,331 cases 91 deaths have been laboratory-confirmed as 12 October 2009. Age distribution risk groups were similar to those observed elsewhere. The median age patients who died (33.5 years) was significantly higher than...
On 31 December 2019, the Municipal Health Commission of Wuhan, China, reported a cluster atypical pneumonia cases. 5 January 2020, WHO publicly released Disease Outbreak News (DON) report, providing information about cases, implemented response interventions, and WHO’s risk assessment advice on public health social measures. Following 9 additional DON reports 209 daily situation reports, 17 August published first edition COVID-19 Weekly Epidemiological Update (WEU). 1 September 2023, 158th...
To determine the prevalence of invasive nontyphoid salmonellosis and typhoid fever in Malawi South Africa, we compared case frequency patient age distribution. Invasive showed a clear bimodal distribution; infection developed women at younger than men. Case for was lower salmonellosis.
School closure is a non-pharmaceutical intervention that was considered in many national pandemic plans developed prior to the start of influenza A(H1N1)pdm09 pandemic, and received considerable attention during event. Here, we retrospectively review compare local experiences with school closures several countries pandemic. Our intention not make systematic country experiences; rather, it present diversity provide examples from perspectives. Data were gathered following meeting, organized by...
During 2008, Rift Valley fever (RVF) virus re-emerged in South Africa as focal outbreaks several provinces.To investigate an outbreak affecting cattle farmers and farm workers, the staff students of a veterinary school, assess prevalence infection during outbreak, document clinical presentation cases, identify potential risk factors.We conducted cross-sectional serological survey exposed veterinarians farmers, who were examined to determine presence current or recent illness. Blood specimens...
Abstract Rift Valley fever (RVF) is an emerging zoonosis posing a public health threat to humans in Africa. During sporadic RVF outbreaks 2008–2009 and widespread epidemics 2010–2011, 302 laboratory-confirmed human infections, including 25 deaths (case-fatality rate, 8%) were identified. Incidence peaked late summer early autumn each year, which coincided with incidence rate patterns livestock. Most case-patients adults (median age 43 years), men (262; 87%), who worked farming, animal or...
Since 1995, measles vaccination at nine and 18 months has been routine in South Africa; however, coverage seldom reached >95%. We describe the epidemiology of laboratory-confirmed case-patients assess impact nationwide mass campaign during 2009 to 2011 outbreak Africa.Serum specimens collected from patients with suspected-measles were tested for measles-specific IgM antibodies using an enzyme-linked immunosorbent assay genotypes a subset determined. To estimate campaign, we compared...
Objectives: To describe trends in the age-specific incidence of serogroup B invasive meningococcal disease (IMD) Australia, 1999–2015. Design, setting, participants: Analysis February 2017 de-identified notification data from Australian National Notifiable Diseases Surveillance System all notifications IMD Australia with a recorded diagnosis date during Major outcomes: rates 1999–2015, by age, serogroup, Indigenous status, and region. Results: The (MenB) declined progressively 1.52 cases per...
Rift Valley fever (RVF) is a mosquito-borne viral zoonosis affecting domestic and wild ruminants, camels humans. Outbreaks of RVF are characterized by sudden onset abortions high mortality amongst ruminants. Humans develop disease ranging from mild flu-like illness to more severe complications including hemorrhagic syndrome, ocular neurological lesions death. During the outbreak in South Africa 2010/11, total 278 human cases were laboratory confirmed, 25 deaths. The role host inflammatory...
Background During the 2009 H1N1 pandemic (pH1N1), morbidity and mortality sparing was observed among elderly population; it hypothesized that this age group benefited from immunity to pH1N1 due cross-reactive antibodies generated prior infection with antigenically similar influenza viruses. Evidence serologic studies genetic similarities between historical viruses suggest incidence of cases should drop markedly in cohorts born disappearance 1957, namely those at least 52–53 years old 2009,...
Background. We documented the introduction of 2009 pandemic influenza A virus subtype H1N1 (A[H1N1]pdm09) into South Africa and describe its clinical presentation, epidemiology, transmissibility. Methods. conducted a prospective descriptive study first 100 laboratory-confirmed cases A(H1N1)pdm09 infections identified through active case finding surveillance. Infected patients attending clinicians were interviewed, close contacts followed up to investigate household transmission. Findings....
It is widely accepted that influenza transmission dynamics vary by age; however methods to quantify the reproductive number age group are limited. We introduce a simple method estimate modifying originally proposed Wallinga and Teunis using existing information on contact patterns between groups. additionally perform sensitivity analysis determine potential impact of differential healthcare seeking age. illustrate this data from 2009 H1N1 Influenza pandemic in Gauteng Province, South Africa....
Since the beginning of coronavirus disease 2019 (COVID-19) pandemic, numerous severe acute respiratory syndrome 2 (SARS-CoV-2) variants have emerged, some leading to large increases in infections, hospitalizations and deaths globally.The virus's impact on public health depends many factors, including emergence new viral their global spread.Consequently, early detection surveillance characterization clinical effects are vital for assessing risk.The unprecedented capacity genomic sequencing...
Estimates of parameters for disease transmission in large-scale infectious outbreaks are often obtained to represent large groups people, providing an average over a potentially very diverse area. For control measures be more effective, measure the heterogeneity is desirable. We propose novel extension network-based approach estimating reproductive number. With this we can incorporate spatial and/or demographic information through similarity matrix. apply 2009 Influenza pandemic South Africa...
Background/Objective Describing transmissibility parameters of past pandemics from diverse geographic sites remains critical to planning responses future outbreaks. We characterize the influenza A(H1N1)pdm09 (hereafter pH1N1) in South Africa during 2009 by estimating serial interval (SI), initial effective reproductive number (initial Rt) and temporal variation Rt. Methods make use data a central registry all pH1N1 laboratory-confirmed cases detected throughout Africa. Whenever date symptom...
The basic reproductive number (R₀) and the distribution of serial interval (SI) are often used to quantify transmission during an infectious disease outbreak. In this paper, we present estimates R₀ SI from 2003 SARS outbreak in Hong Kong Singapore, 2009 pandemic influenza A(H1N1) South Africa using methods that expand upon existing Bayesian framework. This expanded framework allows for incorporation additional information, such as contact tracing or household data, through prior...
Background: In developing countries, cholera often occurs in large-scale outbreaks and causes high burden of disease leads to death some cases. The purpose the study was describe characterise cases, also identify environmental health factors that contributed outbreak.Methods: A descriptive, retrospective conducted outbreak outbreak. preliminary assessment done by means Microsoft Excel 2003 thereafter followed statistical analysis database using Epi Info software. STATA 11 used for...