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"Clements, Archie C. A."
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Economic burden of multidrug-resistant tuberculosis on patients and households: a global systematic review and meta-analysis
by
Clements, Archie C. A.
,
Wolde, Haileab Fekadu
,
Alene, Kefyalew Addis
in
692/308
,
692/308/174
,
692/699/255/1856
2023
Multidrug-resistant tuberculosis (MDR-TB) is a major health threat worldwide, causing a significant economic burden to patients and their families. Due to the longer duration of treatment and expensive second-line medicine, the economic burden of MDR-TB is assumed to be higher than drug-susceptible TB. However, the costs associated with MDR-TB are yet to be comprehensively quantified. We conducted this systematic review and meta-analysis to determine the global burden of catastrophic costs associated with MDR-TB on patients and their households. We systematically searched five databases (CINHAL, MEDLINE, Embase, Scopus, and Web of Science) from inception to 2 September 2022 for studies reporting catastrophic costs on patients and affected families of MDR-TB. The primary outcome of our study was the proportion of patients and households with catastrophic costs. Costs were considered catastrophic when a patient spends 20% or more of their annual household income on their MDR-TB diagnosis and care. The pooled proportion of catastrophic cost was determined using a random-effects meta-analysis. Publication bias was assessed using visualization of the funnel plots and the Egger regression test. Heterogeneity was assessed using I
2
, and sub-group analysis was conducted using study covariates as stratification variables. Finally, we used the Preferred Reporting Items for Reporting Systematic Review and Meta-Analysis-20 (PRISMA-20). The research protocol was registered in PROSPERO (CRD42021250909). Our search identified 6635 studies, of which 11 were included after the screening. MDR-TB patients incurred total costs ranging from $USD 650 to $USD 8266 during treatment. The mean direct cost and indirect cost incurred by MDR-TB patients were $USD 1936.25 (SD ± $USD 1897.03) and $USD 1200.35 (SD ± $USD 489.76), respectively. The overall burden of catastrophic cost among MDR-TB patients and households was 81.58% (95% Confidence Interval (CI) 74.13–89.04%). The catastrophic costs incurred by MDR-TB patients were significantly higher than previously reported for DS-TB patients. MDR-TB patients incurred more expenditure for direct costs than indirect costs. Social protection and financial support for patients and affected families are needed to mitigate the catastrophic economic consequences of MDR-TB.
Journal Article
A Mathematical Model of Chikungunya Dynamics and Control: The Major Epidemic on Réunion Island
by
Clements, Archie C. A.
,
Yakob, Laith
in
Adulticides
,
Alphavirus Infections - epidemiology
,
Alphavirus Infections - prevention & control
2013
Chikungunya is a re-emerging arboviral disease transmitted by Aedes spp. mosquitoes. Although principally endemic to Africa and Asia, recent outbreaks have occurred in Europe following introductions by returning travellers. A particularly large outbreak occurred on Réunion Island in 2006, the published data from which forms the basis of the current study. A simple, deterministic mathematical model of the transmission of the virus between humans and mosquitoes was constructed and parameterised with the up-to-date literature on infection biology. The model is fitted to the large Réunion epidemic, resulting in an estimate of 4.1 for the type reproduction number of chikungunya. Although simplistic, the model provided a close approximation of both the peak incidence of the outbreak and the final epidemic size. Sensitivity analysis using Monte Carlo simulation demonstrated the strong influence that both the latent period of infection in humans and the pre-patent period have on these two epidemiological outcomes. We show why separating these variables, which are epidemiologically distinct in chikungunya infections, is not only necessary for accurate model fitting but also important in informing control.
Journal Article
Internet-based surveillance systems for monitoring emerging infectious diseases
by
Clements, Archie C A
,
Milinovich, Gabriel J
,
Hu, Wenbiao
in
Behavior
,
Biological and medical sciences
,
Communicable Diseases, Emerging - epidemiology
2014
Emerging infectious diseases present a complex challenge to public health officials and governments; these challenges have been compounded by rapidly shifting patterns of human behaviour and globalisation. The increase in emerging infectious diseases has led to calls for new technologies and approaches for detection, tracking, reporting, and response. Internet-based surveillance systems offer a novel and developing means of monitoring conditions of public health concern, including emerging infectious diseases. We review studies that have exploited internet use and search trends to monitor two such diseases: influenza and dengue. Internet-based surveillance systems have good congruence with traditional surveillance approaches. Additionally, internet-based approaches are logistically and economically appealing. However, they do not have the capacity to replace traditional surveillance systems; they should not be viewed as an alternative, but rather an extension. Future research should focus on using data generated through internet-based surveillance and response systems to bolster the capacity of traditional surveillance systems for emerging infectious diseases.
Journal Article
Clinical predictors of severe dengue: a systematic review and meta-analysis
by
Gray, Darren J.
,
Clements, Archie C. A.
,
Furuya-Kanamori, Luis
in
Asthma
,
Bias
,
Chronic obstructive pulmonary disease
2021
Background
Severe dengue is a life-threatening complication; rapid identification of these cases, followed by adequate management is crucial to improve the clinical prognosis. Therefore, this study aimed to identify risk factors and predictors of severe dengue.
Methods
A literature search for studies reporting risk factors of severe dengue among individuals with dengue virus infection was conducted in PubMed, Scopus and Web of Science database from inception to December 31, 2020. Pooled odds ratios (
ORs
) for patients’ demographic characteristics, co-morbidities, and warning signs were estimated using an inverse variance heterogeneity model.
Results
We included 143 articles in the meta-analysis from a total of 13 090 articles retrieved from the literature search. The risk factors of severe dengue were: being a child [
OR
= 1.96; 95% confidence interval (
CI
): 1.22–3.13], secondary infection (
OR
= 3.23; 95%
CI
: 2.28–4.57), and patients with pre-existing diabetes (
OR
= 2.88; 95%
CI
: 1.72–4.81) and renal disease (
OR
= 4.54; 95%
CI
: 1.55–13.31). Warning signs strongly associated with severe disease were increased haematocrit with a concurrent decrease in platelet count (
OR
= 5.13; 95%
CI
: 1.61–16.34), abdominal pain (
OR
= 2.00; 95%
CI
: 1.49–2.68), lethargy (
OR
= 2.73; 95%
CI
: 1.05–7.10), vomiting (
OR
= 1.80; 95%
CI
: 1.43–2.26), hepatomegaly (
OR
= 5.92; 95%
CI
: 3.29–10.66), ascites (
OR
= 6.30; 95%
CI
: 3.75–10.60), pleural effusion (
OR
= 5.72; 95%
CI
: 3.24–10.10) and melena (
OR
= 4.05; 95%
CI
: 1.64–10.00).
Conclusions
Our meta-analysis identified children, secondary infection, diabetes and renal disease(s) as important predictors of severe dengue. Our finding also supports the predictive ability of the WHO warning signs to identify severe dengue. These findings are useful for clinicians to identify severe dengue for management and timely interventions.
Journal Article
Clinical features and outcomes of COVID-19 and dengue co-infection: a systematic review
by
Gray, Darren J.
,
Clements, Archie C. A.
,
Adhikary, Ripon K.
in
Adult
,
Care and treatment
,
Case reports
2021
Background
Dengue is the most common arboviral disease in the tropical and sub-tropical regions of the world. Like other regions, dengue-endemic areas have faced the additional public health and socio-economic impact of the ongoing coronavirus disease 2019 (COVID-19) pandemic. COVID-19 and dengue co-infections have been reported, with complicated patient management and care requirements. This review aimed to collate and synthesise current knowledge on the clinical features and outcomes of COVID-19 and dengue virus co-infection, a potentially important new dimension to be considered in public health management of the COVID-19 pandemic.
Methods
A systematic literature review was conducted using PubMed, Web of Science and Scopus databases from 1st January to 21st November 2020. The key search terms used were “dengue” and “coronavirus”. Descriptive analysis with graphical illustrations were used to present the clinical and laboratory parameters of the co-infection.
Results
Thirteen published papers and four news articles were included in the review. Most studies were case reports with a detailed description of the clinical and laboratory characteristics of the co-infection. All cases were in adults with the exception of a six-year old child. The common symptoms of co-infection were fever, dyspnea, headache, and cough. Common laboratory results included thrombocytopenia, lymphocytopenia, elevated transaminases, and leukopenia. Serious outcomes of co-infection included septic shock, acute respiratory disease syndrome and multi-organ failure, leading to death in some patients.
Conclusions
COVID-19 and dengue co-infection was associated with severe disease and fatal outcomes. The correct diagnosis and treatment of co-infection poses a substantial challenge due to the overlapping clinical and laboratory parameters. Therefore, confirmative diagnostic tests are necessary for accurate and timely diagnosis and patient management.
Journal Article
Spatial clustering of notified tuberculosis in Ethiopia: A nationwide study
by
Clements, Archie C. A.
,
Alene, Kefyalew Addis
in
Acquired immune deficiency syndrome
,
AIDS
,
Automobiles
2019
Tuberculosis (TB) remains a major health problem worldwide and in Ethiopia. This study aimed to investigate the spatial distributions of notified TB over the whole territory of Ethiopia and to quantify the role of health care access, environmental, socio-demographic, and behavioural factors associated with the clustering of TB.
A spatial analysis was conducted using national TB data reported between June 2016 and June 2017 in Ethiopia. Spatial clustering of TB was explored using Moran's I statistic and the local indicator of spatial autocorrelation (LISA). A multivariate Poisson regression model was developed with a conditional autoregressive (CAR) prior structure and with posterior parameters estimated using Bayesian Markov chain Monte Carlo (MCMC) simulation with Gibbs sampling to investigate the drivers of the clustering.
A total of 120,149 TB cases were reported from 745 districts in Ethiopia during the study period; 41,343 (34%) were bacteriologically confirmed new pulmonary TB and 33,997 (28%) were clinically diagnosed, new, smear-negative pulmonary TB patients. The nationwide annual incidence rate of notified TB was 112 per 100,000 population. The highest incidence was observed in three city administrative regions, namely Dire Dewa (348 cases per 100,000 population), Addis Ababa (262 per 100,000 population) and Harari (206 per 100,000 population), and the lowest incidence was observed in Somali region (51 per 100,000 population). High-high spatial clustering of notified TB was detected at Humera, Gog, and Surima district, and low-low clustering was detected in some districts located in the Somali region. Poor health care access (IRR = 0.78; 95%CI: 0.66, 0.90) and good knowledge about TB (IRR = 0.84; 95%CI: 0.73, 0.96) were negatively associated with the incidence of notified TB.
Substantial spatial clustering of notified TB was detected at region, zone and district level in Ethiopia. Health care access and knowledge about TB was associated with incidence of TB. This study may provide policy makers target hotspot areas, where national control programs could be implemented more efficiently for the prevention and control of TB, and to address potential under-reporting in poor access areas.
Journal Article
Co-distribution and co-infection of chikungunya and dengue viruses
by
Milinovich, Gabriel
,
Brasil, Patricia
,
Dunning, Rebecca
in
Africa - epidemiology
,
Asia, Southeastern - epidemiology
,
Care and treatment
2016
Background
Chikungunya and dengue infections are spatio-temporally related. The current review aims to determine the geographic limits of chikungunya, dengue and the principal mosquito vectors for both viruses and to synthesise current epidemiological understanding of their co-distribution.
Methods
Three biomedical databases (PubMed, Scopus and Web of Science) were searched from their inception until May 2015 for studies that reported concurrent detection of chikungunya and dengue viruses in the same patient. Additionally, data from WHO, CDC and Healthmap alerts were extracted to create up-to-date global distribution maps for both dengue and chikungunya.
Results
Evidence for chikungunya-dengue co-infection has been found in Angola, Gabon, India, Madagascar, Malaysia, Myanmar, Nigeria, Saint Martin, Singapore, Sri Lanka, Tanzania, Thailand and Yemen; these constitute only 13 out of the 98 countries/territories where both chikungunya and dengue epidemic/endemic transmission have been reported.
Conclusions
Understanding the true extent of chikungunya-dengue co-infection is hampered by current diagnosis largely based on their similar symptoms. Heightened awareness of chikungunya among the public and public health practitioners in the advent of the ongoing outbreak in the Americas can be expected to improve diagnostic rigour. Maps generated from the newly compiled lists of the geographic distribution of both pathogens and vectors represent the current geographical limits of chikungunya and dengue, as well as the countries/territories at risk of future incursion by both viruses. These describe regions of co-endemicity in which lab-based diagnosis of suspected cases is of higher priority.
Journal Article
Asymptomatic Clostridium difficile colonization: epidemiology and clinical implications
by
Foster, Niki F.
,
Paterson, David L.
,
Furuya-Kanamori, Luis
in
Analysis
,
Asymptomatic Infections
,
Bacterial Proteins - metabolism
2015
Background
The epidemiology of
Clostridium difficile
infection (CDI) has changed over the past decades with the emergence of highly virulent strains. The role of asymptomatic
C. difficile
colonization as part of the clinical spectrum of CDI is complex because many risk factors are common to both disease and asymptomatic states. In this article, we review the role of asymptomatic
C. difficile
colonization in the progression to symptomatic CDI, describe the epidemiology of asymptomatic
C. difficile
colonization, assess the effectiveness of screening and intensive infection control practices for patients at risk of asymptomatic
C. difficile
colonization, and discuss the implications for clinical practice.
Methods
A narrative review was performed in PubMed for articles published from January 1980 to February 2015 using search terms ‘Clostridium difficile’ and ‘colonization’ or ‘colonisation’ or ‘carriage’.
Results
There is no clear definition for asymptomatic CDI and the terms carriage and colonization are often used interchangeably. The prevalence of asymptomatic
C. difficile
colonization varies depending on a number of host, pathogen, and environmental factors; current estimates of asymptomatic colonization may be underestimated as stool culture is not practical in a clinical setting.
Conclusions
Asymptomatic
C. difficile
colonization presents challenging concepts in the overall picture of this disease and its management. Individuals who are colonized by the organism may acquire protection from progression to disease, however they also have the potential to contribute to transmission in healthcare settings.
Journal Article
Mapping facility-based tuberculosis preventive treatment provision in Ethiopia: a geospatial analysis
by
Clements, Archie C. A.
,
Gilmour, Beth
,
Wolde, Haileab Fekadu
in
Acquired immune deficiency syndrome
,
AIDS
,
Disease prevention
2026
Background
Tuberculosis (TB) remains a major public health challenge in Ethiopia, despite being a preventable disease. TB preventive treatment (TPT) is a critical intervention to prevent the progression from latent TB infection to active disease, particularly among household contacts of TB patients and people living with HIV due to weakened immunity. However, the initiation and completion rates of TPT at subnational and local levels have not been thoroughly investigated. This study aims to map facility-based TPT initiation and completion rates among household contacts of TB across Ethiopia.
Methods
We used national TB data from the Health Management Information System (HMIS) of the Ethiopian Ministry of Health. We included TPT initiation and completion data reported between July 2022 and June 2023. Demographic and geographic covariates were obtained from publicly available sources. In total, we used 1,132 geolocated data points for TPT initiation and 838 data points for TPT completion. Using Bayesian geostatistical analysis, we estimated TPT initiation and completion rates at a 5 × 5 km spatial resolution across Ethiopia. These high-resolution estimates were then aggregated to generate district-level estimates.
Results
A total of 208,508 contacts of index TB cases were screened for TB during the reporting period, of whom 169,890 were found negative for active TB. Among these, 31.50% were initiated on TPT. Additionally, 39,760 individuals had started TPT in the 12 months prior to the reporting period, and 87.0% of them successfully completed treatment. Both TPT initiation and treatment completion showed substantial local and subnational variations across Ethiopia. For instance, district-level TPT initiation ranged from 0.01% in Bora to 99.0% in Tiro Afeta districts of Oromia region. Distance to health facilities had a negative association with both TPT initiation (
β
= -0.06; 95% CrI: -0.10, -0.01) and TPT completion rate (
β
= -0.57; 95% CrI: -0.73, -0.42). Higher population density was negatively associated with TPT completion rate (
β
= -0.34; 95% CrI: -0.58, -0.10), while HIV/AIDS prevalence showed a positive association with TPT initiation (
β
= 0.24; 95% CrI: 0.18,0.30).
Conclusion
Our findings revealed marked geographic variations in TPT provision at local and district levels. This suggests that districts with low performing health facilities, may require targeted interventions to optimize TPT implementation and help reduce TB burden in Ethiopia.
Journal Article
Bayesian spatio-temporal analysis of dengue transmission in Lao PDR
2024
Dengue, a zoonotic viral disease transmitted by
Aedes
mosquitoes, poses a significant public health concern throughout the Lao People’s Democratic Republic (Lao PDR). This study aimed to describe spatial–temporal patterns and quantify the effects of environmental and climate variables on dengue transmission at the district level. The dengue data from 2015 to 2020 across 148 districts of Lao PDR were obtained from the Lao PDR National Center for Laboratory and Epidemiology (NCLE). The association between monthly dengue occurrences and environmental and climate variations was investigated using a multivariable Zero-inflated Poisson regression model developed in a Bayesian framework. The study analyzed a total of 72,471 dengue cases with an incidence rate of 174 per 100,000 population. Each year, incidence peaked from June to September and a large spike was observed in 2019. The Bayesian spatio-temporal model revealed a 9.1% decrease (95% credible interval [CrI] 8.9%, 9.2%) in dengue incidence for a 0.1 unit increase in monthly normalized difference vegetation index at a 1-month lag and a 5.7% decrease (95% CrI 5.3%, 6.2%) for a 1 cm increase in monthly precipitation at a 6-month lag. Conversely, dengue incidence increased by 43% (95% CrI 41%, 45%) for a 1 °C increase in monthly mean temperature at a 3-month lag. After accounting for covariates, the most significant high-risk spatial clusters were detected in the southern regions of Lao PDR. Probability analysis highlighted elevated trends in 45 districts, emphasizing the importance of targeted control strategies in high-risk areas. This research underscores the impact of climate and environmental factors on dengue transmission, emphasizing the need for proactive public health interventions tailored to specific contexts in Lao PDR.
Journal Article