NTD and NCD Co-morbidities: The Example of Dengue Fever

Understanding The Mimicker: Epidemiological Pattern and Determinant of Melioidosis Mortality in Negeri Sembilan, Malaysia

BACKGROUND

Melioidosis, a tropical infectious disease caused by Burkholderia pseudomallei, is epidemic in most region in Southeast Asia with high case fatality. However, there is scanty information regarding the disease's epidemiological pattern, demographics, and underlying risk factors.

METHOD

This 5-year retrospective study of 185 confirmed cases which were taken from the Negeri Sembilan Melioidosis Registry between 2018 and 2022. We aim to describe the incidence, mortality rate, case fatality, relationship with meteorology, and factors that influence mortality in this central region of Peninsular Malaysia.

RESULTS

Incidence rate (IR) of melioidosis in Negeri Sembilan is varied at 1.9 to 5.1 with mean of 3.1 in 100,000 population per year. IR varied between districts in the state from zero to 22.01 in 100,000 population per year. Mortality rate were ranged from 0.17 to 0.74 cases with mean of 0.44 cases in 100,000 population per year. The case fatality rate of this state scattered from 8.70% to 16.67%. There were no significant linear associations between cases and deaths with monthly rainfall and humidity. The mean age of patients was 52.8 years, predominated with age around 41-60 years old. Males (77.8%) predominated, and the majority of cases were Malays (88.9%) and had exposed to soil related activities (74.6%). Mortality from melioidosis was more likely in Bumiputera and non-Malaysians (p<0.05). Patients who had at least one comorbidity were at a higher risk of death from melioidosis (p<0.05). Diabetes mellitus was found in 41.1% of all identified cases, making it a major underlying risk factor for both developing and dying from melioidosis (aOR:19.32, 95%CI:1.91-195.59, p<0.05). Hypertension and mortality status in melioidosis are also significantly correlated (aOR: 7.75, 95% CI: 2.26-26.61, p<0.05).

CONCLUSION

The epidemiological patterns of cases reported from Negeri Sembilan are consistent for the most part from previous studies in other states in Malaysia and global with regard to its incidence, case fatality, demographic and predisposing chronic diseases. Diabetes mellitus and hypertension were significantly linked to increased mortality among all determinants.

Chronically hypertensive transgenic mice expressing human AT1R haplotype-I exhibit increased susceptibility to Francisella tularensis

Age-related illnesses, including hypertension and accompanying metabolic disorders, compromise immunity and exacerbate infection-associated fatalities. Renin-angiotensin system (RAS) is the key mechanism that controls blood pressure. Upregulation of RAS through angiotensin receptor type 1 (AT1R), a G-protein coupled receptor, contributes to the pathophysiological consequences leading to vascular remodeling, hypertension, and end-organ damage. Genetic variations that increase the expression of human AT1R may cause the above pathological outcomes associated with hypertension. Previously we have shown that our chronically hypertensive transgenic (TG) mice containing the haplotype-I variant (Hap-I, hypertensive genotype) of human AT1R (hAT1R) gene are more prone to develop the metabolic syndrome-related disorders as compared to the TG mice containing the haplotype-II variant (Hap-II, normotensive genotype). Since aging and an increased risk of hypertension can impact multiple organ systems in a complex manner, including susceptibility to various infections, the current study investigated the susceptibility and potential effect of acute bacterial infection using a Gram-negative intracellular bacterial pathogen, Francisella tularensis in our hAT1R TG mice. Our results show that compared to Hap-II, F. tularensis-infected aged Hap-I TG mice have significantly higher mortality post-infection, higher bacterial load and lung pathology, elevated inflammatory cytokines and altered gene expression profile favoring hypertension and inflammation. Consistent with worsened phenotype in aged Hap-I mice post-Francisella infection, gene expression profiles from their lungs revealed significantly altered expression of more than 1,400 genes. Furthermore, bioinformatics analysis identified genes associated with RAS and IFN-γ pathways regulating blood pressure and inflammation. These studies demonstrate that haplotype-dependent over-expression of the hAT1R gene leads to enhanced susceptibility and lethality due to F. tularensis LVS infection, which gets aggravated in aged animals. Clinically, these findings will help in exploring the role of AT1R-induced hypertension and enhanced susceptibility to infection-related respiratory diseases.

Potential role of transthoracic echocardiography for screening LV systolic dysfunction in patients with a history of dengue infection. A cross-sectional and cohort study and review of the literature

Background

Dengue virus can affect the cardiovascular system and men may be at higher risk of severe complications than women. We hypothesized that clinical dengue virus (DENV) infection could induce myocardial alterations of the left ventricle (LV) and that these changes could be detected by transthoracic echocardiography.

Methodology/Principal findings

We examined individuals from Acre in the Amazon Basin of Brazil in 2020 as part of the Malaria Heart Study. By questionnaires we collected information on self-reported prior dengue infection. All individuals underwent transthoracic echocardiography, analysis of left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS). We included 521 persons (mean age 40±15 years, 39% men, 50% urban areas) of which 253 (49%) had a history of dengue infection. In multivariable models adjusted for clinical and sociodemographic data, a history of self-reported dengue was significantly associated with lower LVEF (β = -2.37, P < 0.01) and lower GLS (β = 1.08, P < 0.01) in men, whereas no significant associations were found in women (P > 0.05). In line with these findings, men with a history of dengue had higher rates of LV systolic dysfunction (LVEF < 50% = 20%; GLS < 16% = 17%) than those without a history of dengue (LVEF < 50% = 7%; GLS < 16% = 8%; P < 0.01 and 0.06, respectively).

Conclusions/Significance

The findings of this study suggest that a clinical infection by dengue virus could induce myocardial alterations, mainly in men and in the LV, which could be detected by conventional transthoracic echocardiography. Hence, these results highlight a potential role of echocardiography for screening LV dysfunction in participants with a history of dengue infection. Further larger studies are warranted to validate the findings of this study.

Myopericarditis - A catastrophic complication of dengue fever

Dengue is a mosquito-borne viral fever seen commonly in the urban areas of tropical and sub-tropical countries. The spectrum of this disease varies from a simple fever which can be managed with anti-pyretics to dengue shock syndrome, which requires urgent intensive care admission. Dengue shock syndrome can be a life-threatening condition. Dengue fever can progress to dengue shock and later to dengue shock syndrome if not managed with promptness. Apart from the spectrum of progression known to us, dengue fever can have a varied set of atypical presentations. These atypical presentations can be neurological, cardiac, or even gastro-intestinal. Cardiac complications, although rare, have been reported, such as various atrioventricular arrhythmias, myocarditis, pericarditis, and even myopericarditis. Here, we report a case of a 65-year-old male who presented to us with severe dyspnea and fever. Examination and investigations revealed dengue fever with myopericarditis.

Process evaluation of complex interventions in non-communicable and neglected tropical diseases in low- and middle-income countries: a scoping review

OBJECTIVES

The aim of this review is to map out the use of process evaluation (PE) in complex interventions that address non-communicable diseases (NCDs) and neglected tropical diseases (NTDs) to identify gaps in the design and conduct, as well as strengths, limitations and implications, of this type of research in low- and middle-income countries (LMICs).

DESIGN

Scoping review of PE studies of complex interventions implemented in LMICs. Six databases were searched focused on studies published since 2008.

DATA SOURCES

Embase, PubMed, EbscoHost, Web of Science (WOS), Virtual Health Library (VHL) Regional Portal and Global Index Medicus: Regional Indexes AIM (AFRO), LILACS (AMRO/PAHO), IMEMR (EMRO), IMSEAR (SEARO), WPRIM (WPRO) Global Index Regional Indexes, MEDLINE, SciELO.

ELIGIBILITY CRITERIA

Studies conducted in LMICs on PEs of randomised controlled trials (RCTs) and non-RCTs published between January 2008 and January 2020. Other criteria were studies of interventions for people at risk or having physical and mental NCDs, and/or NTDs, and/or their healthcare providers and/or others related to achieve better health for these two disease groups. Studies were excluded if they were not reported in English or Spanish or Portuguese or French, not peer-reviewed articles, not empirical research and not human research.

DATA EXTRACTION AND SYNTHESIS

Data extracted to be evaluated were: available evidence in the utilisation of PE in the areas of NCDs and NTDs, including frameworks and theories used; methods applied to conduct PEs; and in a subsample, the barriers and facilitators to implement complex interventions identified through the PE. Variables were extracted and categorised. The information was synthesised through quantitative analysis by reporting frequencies and percentages. Qualitative analysis was also performed to understand facilitators and barriers presented in these studies. The implications for PEs, and how the information from the PE was used by researchers or other stakeholders were also assessed in this approach.

RESULTS

303 studies were identified, 79% were for NCDs, 12% used the label 'PE', 27% described a theory or framework for the PE, and 42% used mixed methods to analyse their findings. Acceptability, barriers and facilitators to implement the interventions, experiences and perceptions, and feasibility were the outcomes most frequently evaluated as part of the PEs. Barriers and facilitators themes identified were contextual factors, health system factors, human resources, attitudes and policy factors.

CONCLUSIONS

PEs in NCDs and NTDs are used in LMICs with a wide variety of methods. This review identified many PEs that were not labelled by the authors as such, as well as a limited application of PE-related theories and frameworks, and heterogeneous reporting of this type of study.

Dengue and Chikungunya virus co-infection in major metropolitan cities of provinces of Punjab and Khyber Pakhtunkhwa: A multi-center study

Dengue has become endemic in Pakistan with annual recurrence. A sudden increase in the dengue cases was reported from Rawalpindi in 2016, while an outbreak occurred for the first time in Peshawar in 2017. Therefore, a multi-center study was carried out to determine the circulating dengue virus (DENV) serotypes and Chikungunya virus (CHIKV) co-infection in Lahore, Rawalpindi, and Peshawar cities in 2016–18. A hospital-based cross-sectional study was carried out in Lahore and Rawalpindi in 2016–18, while a community-based study was carried out in Peshawar in 2017. The study participants were tested for dengue NS1 antigen using an immunochromatographic device while anti-dengue IgM/IgG antibodies were detected by indirect ELISA. All NS1 positive samples were used for DENV serotyping using multiplex real-time PCR assay. Additionally, dengue samples were tested for CHIKV co-infection using IgM/IgG ELISA. A total of 6291 samples were collected among which 8.11% were NS1 positive while 2.5% were PCR positive. DENV-2 was the most common serotype (75.5%) detected, followed by DENV-1 in 16.1%, DENV-3 in 3.9% and DENV-4 in 0.7% while DENV-1 and DENV-4 concurrent infections were detected in 3.9% samples. DENV-1 was the predominant serotype (62.5%) detected from Lahore and Rawalpindi, while DENV-2 was the only serotype detected from Peshawar. Comorbidities resulted in a significant increase (p-value<0.001) in the duration of hospital stay of the patients. Type 2 diabetes mellitus substantially (p-value = 0.004) contributed to the severity of the disease. Among a total of 590 dengue positive samples, 11.8% were also positive for CHIKV co-infection. Co-circulation of multiple DENV serotypes and CHIKV infection in Pakistan is a worrisome situation demanding the urgent attention of the public health experts to strengthen vector surveillance.

Mosquitoes are responsible for the transmission of many different types of infectious pathogens and parasites to humans. Some of these pathogens include viruses like dengue and chikungunya viruses which cause diseases in humans. Dengue virus has four different types (1, 2, 3, and 4) present in nature. In this study, we detected all four dengue virus types in hospitalized patients in Lahore and Rawalpindi. While only dengue virus type-2 was detected from Peshawar city. The secondary infections with different dengue virus types than the previous one might result in a more severe form of the disease. Therefore, the population of Peshawar is at risk of developing a severe form of dengue fever in the future in case of infection from another dengue virus type. The data of hospitalized patients showed that other diseases in addition to dengue fever result in an increased hospital stay. Comorbidities like diabetes also increase the risk of developing a more severe form of dengue fever. Combined infections of both dengue and chikungunya viruses were detected from Lahore, Rawalpindi, and Peshawar. The transmission of dengue and chikungunya viruses and the co-circulation of multiple dengue virus types not only impose public health burden but also result in economic losses.

Process evaluation of complex interventions in chronic and neglected tropical diseases in low- and middle-income countries-a scoping review protocol

BACKGROUND

The use of process evaluations is a growing area of interest in research groups working on complex interventions. This methodology tries to understand how the intervention was implemented to inform policy and practice. A recent systematic review by Liu et al. on process evaluations of complex interventions addressing non-communicable diseases found few studies in low- and middle- income countries (LMIC) because it was restricted to randomized controlled trials, primary healthcare level and non-communicable diseases. Yet, LMICs face different barriers to implement interventions in comparison to high-income countries such as limited human resources, access to health care and skills of health workers to treat chronic conditions especially at primary health care level. Therefore, understanding the challenges of interventions for non-communicable diseases and neglected tropical diseases (diseases that affect poor populations and have chronic sequelae) will be important to improve how process evaluation is designed, conducted and used in research projects in LMICs. For these reasons, in comparison to the study of Liu et al., the current study will expand the search strategy to include different study designs, languages and settings.

OBJECTIVE

Map research using process evaluation in the areas of non-communicable diseases and neglected tropical diseases to inform the gaps in the design and conduct of this type of research in LMICs.

METHODS

Scoping review of process evaluation studies of randomized controlled trials (RCTs) and non-RCTs of complex interventions implemented in LMICs including participants with non-communicable diseases or neglected tropical diseases and their health care providers (physicians, nurses, technicians and others) related to achieve better health for all through reforms in universal coverage, public policy, service delivery and leadership. The aspects that will be evaluated are as follows: (i) available evidence of process evaluation in the areas of non-communicable diseases and neglected tropical diseases such as frameworks and theories, (ii) methods applied to conduct process evaluations and (iii) gaps between the design of the intervention and its implementation that were identified through the process evaluation. Studies published from January 2008. Exclusion criteria are as follows: not peer reviewed articles, not a report based on empirical research, not reported in English or Spanish or Portuguese or French, reviews and non-human research.

DISCUSSION

This scoping review will map the evidence of process evaluations conducted in LMICs. It will also identify the methods they used to collect and interpret data, how different theories and frameworks were used and lessons from the implementation of complex interventions. This information will allow researchers to conduct better process evaluations considering special characteristics from countries with limited human resources, scarce data available and limited access to health care.

Dynamic dengue haemorrhagic fever calculators as clinical decision support tools in adult dengue

BACKGROUND

The objective of this study was to develop multiple prediction tools that calculate the risk of developing dengue haemorrhagic fever.

METHODS

Training data consisted of 1771 individuals from 2006-2008 admitted with dengue fever whereby 304 developed dengue haemorrhagic fever during hospitalisation. Least absolute shrinkage and selection operator regression was used to construct three types of calculators, static admission calculators and dynamic calculators that predict the risk of developing dengue haemorrhagic fever for a subsequent day (DAily Risk Tomorrow [DART]) or for any future point after a specific day since fever onset (DAily Risk Ever [DARE]).

RESULTS

From 119 admission covariates, 35 were in at least one of the calculators, which reported area under the curve (AUC) values of at least 0.72. Addition of person-time data for DART improved AUC to 0.76. DARE calculators displayed a large increase in AUC to 0.79 past day 7 with the inclusion of a strong predictor, maximum temperature on day 6 since onset, indicative of a saddleback fever.

CONCLUSIONS

All calculators performed well when validated with 2005 data. Addition of daily variables further improved the accuracy. These calculators can be used in tandem to assess the risk of dengue haemorrhagic fever upon admission and updated daily to obtain more precise risk estimates.

The rise or fall of neglected tropical diseases in East Asia Pacific

While the East Asia Pacific (EAP) region has experienced tremendous economic growth and development, the resulting public health gains from reductions in its neglected tropical diseases (NTDs) have been less than expected due to opposing forces of urbanization, political instability, food insecurity, and climate change, together with co-morbidities with non-communicable diseases, including diabetes and hypertension. To be sure there's been progress towards the elimination of lymphatic filariasis and trachoma through mass drug administration, and there are opportunities to extend MDA to yaws and scabies, but for most of the other NTDs we'll require new biotechnologies. So far, EAP's major technology hubs in China, Japan, Malaysia, Singapore, South Korea, and Taiwan have mostly failed to shift their attention towards new innovations for the NTDs, including new drugs, diagnostics, and vaccines, and vector control. Unless this situation changes the EAP could be facing a new grim reality of unhealthy megacities beset by emerging arbovirus infections, widespread antimicrobial resistance, and urban helminth infections.

The double burden of diabetes and global infection in low and middle-income countries

Four out of five people in the world with diabetes now live in low- and middle-income countries (LMIC), and the incidence of diabetes is accelerating in poorer communities. Diabetes increases susceptibility to infection and worsens outcomes for some of the world’s major infectious diseases such as tuberculosis, melioidosis and dengue, but the relationship between diabetes and many neglected tropical diseases is yet to be accurately characterised. There is some evidence that chronic viral infections such as hepatitis B and HIV may predispose to the development of type 2 diabetes by chronic inflammatory and immunometabolic mechanisms. Helminth infections such as schistosomiasis may be protective against the development of diabetes, and this finding opens up new territory for discovery of novel therapeutics for the prevention and treatment of diabetes. A greater understanding of the impact of diabetes on risks and outcomes for infections causing significant diseases in LMIC is essential in order to develop vaccines and therapies for the growing number of people with diabetes at risk of infection, and to prioritise research agendas, public health interventions and policy. This review seeks to give an overview of the current international diabetes burden, the evidence for interactions between diabetes and infection, immune mechanisms for the interaction, and potential interventions to tackle the dual burden of diabetes and infection.

Digyaindoleacid A: 2-(1-(4-Hydroxyphenyl)-3-oxobut-1-en-2-yloxy)-3-(1H-indol-3-yl)propanoic Acid, a Novel Indole Alkaloid

Digyaindoleacid A (1) is one of the novel alkaloids produced by the Ghanaian Paenibacillus sp. DE2SH (GenBank Accession Number: MH091697) isolated from the mangrove rhizosphere soils of the Pterocarpus santalinoides tree growing in the wetlands of the Digya National Park, Brong Ahafo Region, Ghana. This compound was isolated on HPLC at tR ≈ 60 min and its structure determined by MS, 1D, and 2D-NMR data. When tested against Trypanosoma brucei subsp. brucei strain GUTat 3.1, 1 produced a half-maximal inhibitory concentration (IC50) 5.21 μM compared to the standard diminazene aceturate (IC50 = 1.86 μM). In the presence of normal mouse macrophages RAW 264.7, 1 displayed a higher selectivity towards T. brucei subsp. brucei (selectivity indices (SI) = 30.2) with low toxicity. This result is interesting given that the drug diminazene aceturate is considerably toxic and 1 is a natural product isolate. The structure of 1 incorporates the backbone of the amino acid tryptophan which is crucial in the metabolism of Trypanosoma brucei subsp. brucei strain GUTat 3.1. It is possible that 1, could interfere with the normal uptake and metabolism of tryptophan in the parasite. However, 1 (IC50 = 135.41 μM) produced weak antileishmanial activity when tested against Leishmania donovani (Laveran and Mesnil) Ross (D10).

Diabetes alters immune response patterns to acute melioidosis in humans

Diabetes mellitus (DM) is a serious global health problem currently affecting over 450 million people worldwide. Defining its interaction with major global infections is an international public health priority. Melioidosis is caused by Burkholderia pseudomallei, an exemplar pathogen for studying intracellular bacterial infection in the context of DM due to the 12‐fold increased risk in this group. We characterized immune correlates of survival in peripheral blood of acute melioidosis patients with and without DM and highlight different immune response patterns. We demonstrate the importance of circulating NK cells and show that CX3CR1 expression on lymphocytes is a novel correlate of survival from acute melioidosis. Furthermore, excessive serum levels of IL‐15 and IL‐18BP contribute to poor outcome independent of DM comorbidity. CD8⁺ T cells and granzyme B expression in NK cells are important for survival of non‐DM patients, whereas high antibody titers against B. pseudomallei and double‐negative T cells are linked to survival of DM patients. Recall responses support a role of γδ T‐cell‐derived IFN‐γ in the establishment of protective immunity in the DM group. Defining the hallmarks of protection in people with DM is crucial for the design of new therapies and vaccines targeting this rapidly expanding risk group.

Linking Tropical Infections to Hypertension: New Comorbid Disease Paradigms in Our Era of "Blue Marble Health"

See Article by Etyang et al.

Comorbidities increase in-hospital mortality in dengue patients in Brazil

Dengue remains an unmet public health burden. We determined risk factors for dengue in-hospital mortality in Brazil. Of 326,380 hospitalised dengue cases in 9-45-year-old individuals, there were 971 deaths. Risk of dying was 11-times higher in the presence of underlying common comorbidities (renal, infectious, pulmonary disease and diabetes), similar to the risk of dying from severe dengue and much higher with the combination. Ensuring access to integrated dengue preventative measures in individuals aged ≥ 9 years including those with comorbidities may help achieve the WHO objective of 50% reduction in mortality and 25% reduction in morbidity due to dengue by 2020.

[About 98 cases of dengue hospitalized in a private clinic of Ouagadougou: epidemiology, diagnostic and evolution]

Extremely widespread, the dengue is a reemerging infectious disease. In Burkina Faso, dengue is a reality that was little known. The aim of this study was to study epidemiology, diagnostic and outcomes of dengue patients in Ouagadougou. A retrospective study covered a period of two years, from 1 January 2013 to 31 December 2014 in a private clinic in Ouagadougou. Patients included in the study were hospitalized for fever and painful syndrome with a positive test to the dengue non-structural antigen 1 (NS1 Ag). Ninety-eight cases of dengue on 343 suspected cases were registered. The average age of patients was 35.9 years. The sex-ratio (M/F) was 1.18. According to the professional activity, there was a predominance of civil servants (35.7%). The pain syndrome was found in 93.9% of patients. Leukopenia (73.5%), neutropenia (56.1%) and severe thrombocytopenia (57.1%) were the predominant hematological disturbances. Of the patients, 18.4% had hemorrhagic dengue and 11.2%, a dengue shock syndrome. Four patients died. The use of non-steroidal antiinflammatory drugs was associated with the severity of the infection (p=0.04). Dengue fever occurs in our context and constitutes a risk of mortality. The diagnosis of dengue should be performed systematically in front of a painful and febrile syndrome. The vector control is the best way of prevention against dengue pending the development of a vaccine.