Is TNF alpha a mediator in the co-existence of malaria and type 2 diabetes in a malaria endemic population?

Malaria remains a disease of public health importance globally, especially in sub-Saharan Africa. Malaria deaths reduced globally steadily between 2000-2019, however there was a 10% increase in 2020 due to disruptions in medical service during the COVID-19 pandemic. Globally, about 96% of malaria deaths occurred in 29 countries; out of which, four countries (Nigeria, the Democratic Republic of the Congo, the Niger, and the United Republic of Tanzania) accounted for just over half of the malaria deaths. Nigeria leads the four countries with the highest malaria deaths (accounting for 31% globally). Parallelly, sub-Saharan Africa is faced with a rise in the incidence of Type 2 diabetes (T2D). Until recently, T2D was a disease of adulthood and old age. However, this is changing as T2D in children and adolescents is becoming an increasingly important public health problem. Nigeria has been reported to have the highest burden of diabetes in Africa with a prevalence of 5.77% in the country. Several studies conducted in the last decade investigating the interaction between malaria and T2D in developing countries have led to the emergence of the intra-uterine hypothesis. The hypothesis has arisen as a possible explanation for the rise of T2D in malaria endemic areas; malaria in pregnancy could lead to intra-uterine stress which could contribute to low birth weight and may be a potential cause of T2D later in life. Hence, previous, and continuous exposure to malaria infection leads to a higher risk of T2D. Current and emerging evidence suggests that an inflammation-mediated link exists between malaria and eventual T2D emergence. The inflammatory process thus, is an important link for the co-existence of malaria and T2D because these two diseases are inflammatory-related. A key feature of T2D is systemic inflammation, characterized by the upregulation of inflammatory cytokines such as tumor necrosis factor alpha (TNF-α) which leads to impaired insulin signaling. Malaria infection is an inflammatory disease in which TNF-α also plays a major role. TNF-α plays an important role in the pathogenesis and development of malaria and T2D. We therefore hypothesize that TNF-α is an important link in the increasing co-existence of T2D.

Two cases of COVID-19 presenting with severe malaria: a clinical challenge (case report).

The novel coronavirus (COVID-19) pandemic has stretched the medical resources of both developed and developing countries. The global focus on COVID-19 may lead to the neglect of other infectious diseases such as malaria which is still endemic in many African countries. Some similarities in malaria and COVID-19 disease presentations may also lead to late diagnosis of either disease which could complicate the effects. Here, we present two cases of a 6-year-old child and a 17-year-old female who presented to a primary care facility in Ghana with a clinical and microscopy-confirmed diagnosis of severe malaria complicated by thrombocytopenia. As their symptoms worsened with associated respiratory complications, nasopharyngeal samples were taken for real-time polymerase chain reaction (RT-PCR) and tested positive for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Clinicians, policymakers, and public health practitioners should be alert to the variety of presenting symptoms of COVID-19 and its similarity to malaria to mitigate the risk of mortality from either disease.

Case of myocarditis secondary to severe Plasmodium falciparum infection.

Malaria remains one of the most prevalent infectious diseases globally. Despite targets set out by the WHO in 2015, there has been a rise in the number of cases since 2019 as an indirect effect of the COVID-19 pandemic.Cardiac complications are very rarely witnessed with severe malaria. Of the cardiac sequelae, myocarditis is one of the most frequently observed with a handful of case reports in the literature. We report a case of a man in his 50s who developed myocarditis while being managed for severe Plasmodium falciparum malaria in an intensive care unit in the UK and review the literature relevant to this case. This is the second reported case of this condition in the UK.

Increased circulating myeloid-derived suppressor cells in vivax malaria and severe falciparum malaria.

BACKGROUND: Circulating myeloid-derived-suppressor-cells (MDSC) with immunosuppressive function are increased in human experimental Plasmodium falciparum infection, but have not been studied in clinical malaria. METHODS: Using flow-cytometry, circulating polymorphonuclear-MDSC were evaluated in cryopreserved samples from patients with uncomplicated Plasmodium vivax (n = 8) and uncomplicated (n = 4) and severe (n = 16) falciparum malaria from Papua, Indonesia. RESULTS: The absolute number of circulating polymorphonuclear-MDSC were significantly elevated in severe falciparum malaria patients compared to controls (n = 10). Polymorphonuclear-MDSC levels in uncomplicated vivax malaria were also elevated to levels comparable to that seen in severe falciparum malaria. CONCLUSION: Control of expansion of immunosuppressive MDSC may be important for development of effective immune responses in falciparum and vivax malaria.

Prolonged fever and exaggerated hypercoagulopathy in malaria vivax relapse and COVID-19 co-infection: a case report.

BACKGROUND: Coronavirus disease 2019 (COVID-19) often causes atypical clinical manifestations similar to other infectious diseases. In malaria-endemic areas, the pandemic situation will very likely result in co-infection of COVID-19 and malaria, although reports to date are still few. Meanwhile, this disease will be challenging to diagnose in areas with low malaria prevalence because the symptoms closely resemble COVID-19. CASE PRESENTATION: A 23-year-old male patient presented to the hospital with fever, anosmia, headache, and nausea 1 week before. He was diagnosed with COVID-19 and treated for approximately 10 days, then discharged to continue self-quarantine at home. 2 weeks later, he returned to the hospital with a fever raised intermittently every 2 days and marked by a chilling-fever-sweating cycle. A laboratory test for malaria and a nasopharyngeal swab for SARS CoV-2 PCR were conducted, confirming both diagnoses. The laboratory examination showed markedly elevated D-dimer. He was treated with dihydroartemisinin-piperaquine (DHP) 4 tablets per day for 3 days and primaquine 2 tablets per day for 14 days according to Indonesian National Anti-malarial Treatment Guidelines. After 6 days of treatment, the patient had no complaints, and the results of laboratory tests had improved. This report describes the key points in considering the differential diagnosis and prompt treatment of malaria infection during the pandemic of COVID-19 in an endemic country to prevent the worse clinical outcomes. COVID-19 and malaria may also cause a hypercoagulable state, so a co-infection of those diseases may impact the prognosis of the disease. CONCLUSION: This case report shows that considering the possibility of a co-infection in a COVID-19 patient who presents with fever can prevent delayed treatment that can worsen the disease outcome. Paying more attention to a history of travel to malaria-endemic areas, a history of previous malaria infection, and exploring anamnesis regarding the fever patterns in patients are important points in making a differential diagnosis of malaria infection during the COVID-19 pandemic.

Infectious disease-associated encephalopathies.

Infectious diseases may affect brain function and cause encephalopathy even when the pathogen does not directly infect the central nervous system, known as infectious disease-associated encephalopathy. The systemic inflammatory process may result in neuroinflammation, with glial cell activation and increased levels of cytokines, reduced neurotrophic factors, blood-brain barrier dysfunction, neurotransmitter metabolism imbalances, and neurotoxicity, and behavioral and cognitive impairments often occur in the late course. Even though infectious disease-associated encephalopathies may cause devastating neurologic and cognitive deficits, the concept of infectious disease-associated encephalopathies is still under-investigated; knowledge of the underlying mechanisms, which may be distinct from those of encephalopathies of non-infectious cause, is still limited. In this review, we focus on the pathophysiology of encephalopathies associated with peripheral (sepsis, malaria, influenza, and COVID-19), emerging therapeutic strategies, and the role of neuroinflammation.

Fever in the Returning Traveler.

BACKGROUND: It is predicted that approximately two billion tourist trips to foreign countries will be taken worldwide each year by 2030. Germany has long been among the most active countries in tourism. The frequency of illness among persons returning from developing and newly industrialized countries is 43-79%. The appropriate diagnosis of fever in returning travelers is a clinically important matter, as it can be a sign of a life-threatening illness. METHODS: This review is based on publications (2001-2022) retrieved by a selective search in PubMed for studies on the epidemiology, diagnosis, and treatment of febrile illnesses in returning travelers, or on specific tropical diseases. RESULTS: Diarrhea, fever, and skin changes are the most common manifestations of disease after travel to tropical and sub - tropical areas. The diagnostic evaluation should be performed in a series of steps, beginning with a precise travel history and the identification of specific risk factors. Among travelers returning from sub-Saharan Africa, Plasmodium falciparum malaria is the most common cause of fever on presentation to centers for infectious diseases and tropical medicine, affecting approximately 50 per 1000 travelers. Among persons returning from travel to Southeast Asia, dengue fever is the most common infectious disease, affecting 50-160 per 1000 travelers. Further potentially dangerous diseases include chikungunya and zika fever, typhoid and paratyphoid fever, amoebic liver abscess, visceral leishmaniasis (kala-azar), leptospirosis, and, very rarely, imported cases of viral hemorrhagic fever. COVID-19 and influenza are important differential diagnoses. CONCLUSION: The differential diagnosis can be narrowed by thorough history-taking with particular attention to the patient's travel route, combined with a good knowledge of the geographic spread and incubation times of the main tropical diseases. Algorithms help clinicians to focus the diagnostic work-up and select the appropriate further laboratory tests and diagnostic procedures.

Impact of COVID-19 and malaria coinfection on clinical outcomes: a retrospective cohort study.

OBJECTIVES: Despite the possibility of concurrent infection with COVID-19 and malaria, little is known about the clinical course of coinfected patients. We analysed the clinical outcomes of patients with concurrent COVID-19 and malaria infection. METHODS: We conducted a retrospective cohort study that assessed prospectively collected data of all patients who were admitted between May and December 2020 to the Universal COVID-19 treatment center (UCTC), Khartoum, Sudan. UCTC compiled demographic, clinical, laboratory (including testing for malaria), and outcome data in all patients with confirmed COVID-19 hospitalized at that clinic. The primary outcome was all-cause mortality during the hospital stay. We built proportional hazard Cox models with malaria status as the main exposure and stepwise adjustment for age, sex, cardiovascular comorbidities, diabetes, and hypertension. RESULTS: We included 591 patients with confirmed COVID-19 diagnosis who were also tested for malaria. Mean (SD) age was 58 (16.2) years, 446/591 (75.5%) were males. Malaria was diagnosed in 270/591 (45.7%) patients. Most malaria patients were infected by Plasmodium falciparum (140/270; 51.9%), while 121/270 (44.8%) were coinfected with Plasmodium falciparum and Plasmodium vivax. Median follow-up was 29 days. Crude mortality rates were 10.71 and 5.87 per 1000 person-days for patients with and without concurrent malaria, respectively. In the fully adjusted Cox model, patients with concurrent malaria and COVID-19 had a greater mortality risk (hazard ratio 1.43, 95% confidence interval 1.21-1.69). DISCUSSION: Coinfection with COVID-19 and malaria is associated with increased all-cause in-hospital mortality compared to monoinfection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Low incidence of COVID-19 case severity and mortality in Africa; Could malaria co-infection provide the missing link?

BACKGROUND: Despite reports of malaria and coronavirus diseases 2019 (COVID-19) co-infection, malaria-endemic regions have so far recorded fewer cases of COVID-19 and deaths from COVID-19, indicating a probable protection from the poor outcome of COVID-19 by malaria. On the contrary, other evidence suggests that malaria might contribute to the death caused by COVID-19. Hence, this paper reviewed existing evidence hypothesizing poor outcome or protection of COVID-19 patients when co-infected with malaria. METHODS: PRISMA guidelines for systematic review were employed in this study. Published articles from December 2019 to May 2021on COVID-19 and malaria co-infection and outcome were systematically searched in relevant and accessible databases following a pre-defined strategy. Studies involving human, in vivo animal studies, and in vitro studies were included. RESULTS: Twenty three (23) studies were included in the review out of the 3866 records identified in the selected scientific databases. Nine (9) papers reported on co-infection of COVID-19 and malaria. Five (5) papers provided information about synergism of malaria and COVID-19 poor prognosis, 2 papers reported on syndemic of COVID-19 and malaria intervention, and 7 studies indicated that malaria protects individuals from COVID-19. CONCLUSIONS: Low incidence of COVID-19 in malaria-endemic regions supports the hypothesis that COVID-19 poor prognosis is prevented by malaria. Although further studies are required to ascertain this hypothesis, cross-immunity and common immunodominant isotopes provide strong evidence to support this hypothesis. Also, increase in co-inhibitory receptors and atypical memory B cells indicate synergy between COVID-19 and malaria outcome, though, more studies are required to make a definite conclusion.

Current malaria infection, previous malaria exposure, and clinical profiles and outcomes of COVID-19 in a setting of high malaria transmission: an exploratory cohort study in Uganda.

BACKGROUND: The potential effects of SARS-CoV-2 and Plasmodium falciparum co-infection on host susceptibility and pathogenesis remain unknown. We aimed to establish the prevalence of malaria and describe the clinical characteristics of SARS-CoV-2 and P falciparum co-infection in a high-burden malaria setting. METHODS: This was an exploratory prospective, cohort study of patients with COVID-19 who were admitted to hospital in Uganda. Patients of all ages with a PCR-confirmed diagnosis of SARS-CoV-2 infection who had provided informed consent or assent were consecutively enrolled from treatment centres in eight hospitals across the country and followed up until discharge or death. Clinical assessments and blood sampling were done at admission for all patients. Malaria diagnosis in all patients was done by rapid diagnostic tests, microscopy, and molecular methods. Previous P falciparum exposure was determined with serological responses to a panel of P falciparum antigens assessed using a multiplex bead assay. Additional evaluations included complete blood count, markers of inflammation, and serum biochemistries. The main outcome was overall prevalence of malaria infection and malaria prevalence by age (including age categories of 0-20 years, 21-40 years, 41-60 years, and >60 years). The frequency of symptoms was compared between patients with COVID-19 with P falciparum infection versus those without P falciparum infection. The frequency of comorbidities and COVID-19 clinical severity and outcomes was compared between patients with low previous exposure to P falciparum versus those with high previous exposure to P falciparum. The effect of previous exposure to P falciparum on COVID-19 clinical severity and outcomes was also assessed among patients with and those without comorbidities. FINDINGS: Of 600 people with PCR-confirmed SARS-CoV-2 infection enrolled from April 15, to Oct 30, 2020, 597 (>99%) had complete information and were included in our analyses. The majority (502 [84%] of 597) were male individuals with a median age of 36 years (IQR 28-47). Overall prevalence of P falciparum infection was 12% (95% CI 9·4-14·6; 70 of 597 participants), with highest prevalence in the age groups of 0-20 years (22%, 8·7-44·8; five of 23 patients) and older than 60 years (20%, 10·2-34·1; nine of 46 patients). Confusion (four [6%] of 70 patients vs eight [2%] of 527 patients; p=0·040) and vomiting (four [6%] of 70 patients vs five [1%] of 527 patients; p=0·014] were more frequent among patients with P falciparum infection than those without. Patients with low versus those with high previous P falciparum exposure had a increased frequency of severe or critical COVID-19 clinical presentation (16 [30%] of 53 patients vs three [5%] of 56 patients; p=0·0010) and a higher burden of comorbidities, including diabetes (12 [23%] of 53 patients vs two [4%] of 56 patients; p=0·0010) and heart disease (seven [13%] of 53 patients vs zero [0%] of 56 patients; p=0·0030). Among patients with no comorbidities, those with low previous P falciparum exposure still had a higher proportion of cases of severe or critical COVID-19 than did those with high P falciparum exposure (six [18%] of 33 patients vs one [2%] of 49 patients; p=0·015). Multivariate analysis showed higher odds of unfavourable outcomes in patients who were older than 60 years (adjusted OR 8·7, 95% CI 1·0-75·5; p=0·049). INTERPRETATION: Although patients with COVID-19 with P falciparum co-infection had a higher frequency of confusion and vomiting, co-infection did not seem deleterious. The association between low previous malaria exposure and severe or critical COVID-19 and other adverse outcomes will require further study. These preliminary descriptive observations highlight the importance of understanding the potential clinical and therapeutic implications of overlapping co-infections. FUNDING: Malaria Consortium (USA).

Malaria, COVID-19 and angiotensin-converting enzyme 2: what does the available population data say?

The etiopathogenesis of COVID-19 and its differential geographic spread suggest some populations are apparently 'less affected' through many host-related factors that involve angiotensin-converting enzyme 2 (ACE2) protein, which is also the entry receptor for SARS-CoV-2. The role of ACE2 has been well studied in COVID-19 but not in the context of malaria and COVID-19. We have previously suggested how malaria might intersect with COVID-19 through ACE2 mutation and here we evaluate the currently available data that could provide a link between the two diseases. Based on the existing global and Indian data on malaria, COVID-19 and the suggested ACE2 mutation, the association could not be examined robustly, neither accepting nor refuting the suggested hypothesis. We strongly recommend targeted evaluation of this hypothesis through carefully designed robust molecular epidemiological studies.

The association between malaria prevalence and COVID-19 mortality.

BACKGROUND: The number of persons infected with COVID-19 continues to increase with deaths reported daily across the globe. High income countries such as the US, the UK, Italy and Belgium have reported high COVID-19 related deaths but low-and-middle-income countries have recorded fewer deaths despite having poor healthcare system. This study aimed to investigate the association between malaria prevalence and COVID-19 mortality. METHODS: An ecological study was conducted with data from 195 countries. Spearman's correlation was used to test the association between the population variables and COVID-19 mortality. Generalized linear model with Poisson distribution was used to determine the significant predictors of COVID-19 mortality. RESULTS: There was a significant positive correlation between median age, life expectancy, 65+ mortality and COVID-19 mortality while malaria prevalence, sex ratio and cardiovascular mortality were negatively correlated with COVID-19 mortality. Malaria prevalence, life expectancy and mortality rate were significant on multivariate regression analysis. CONCLUSION: The results of this study support the hypotheses that there are reduced COVID-19 deaths in malaria endemic countries, although the results need to be proved further by clinical trials.

Co-infection of COVID-19 and recurrent malaria.

In tropical countries, endemic diseases such as malaria can be challenging to distinguish from COVID-19 because of the similarities in presenting symptoms. Here we reported a case of a young soldier with fever and myalgia six days before admission, with non-productive cough, chills, nausea and vomiting, dizziness, and headache for two days. Previously, he had experienced four times of malaria infection. He had a history of positive non-falciparum malaria rapid diagnostic test (RDT) two days before admission. Significant findings were epigastric tenderness, splenomegaly, and severe thrombocytopenia of 36×103 cells / µL. A naso-oropharyngeal swab examination revealed a positive SARS-CoV-2 infection. Consequently, he was hospitalized for 12 days, successfully treated, and discharged without sequelae. Thus, in light of a pandemic, physicians need to raise the suspicion of concurrent COVID-19 infection with other tropical diseases, especially at-risk patients, because malaria and COVID-19 may share similar manifestations. Moreover, further ancillary testing, such as RDT, may be warranted.

Clinical characteristics of COVID-19 patients hospitalized at Clinique Ngaliema, a public hospital in Kinshasa, in the Democratic Republic of Congo: A retrospective cohort study.

OBJECTIVES: To describe the clinical characteristics of patients infected with SARS-CoV-2 at Clinique Ngaliema, a public hospital, in Kinshasa, in the Democratic Republic of Congo (DRC). METHODS: This retrospective study analyzed medical records including socio-demographics, past medical history, clinical manifestation, comorbidities, laboratory data, treatment and disease outcome of 160 hospitalized COVID-19 patients, with confirmed result of SARS-CoV-2 viral infection. RESULTS: The median age of patients was 54 years (IQR: 38-64), and there was no significant gender difference (51% of male). The most common comorbidities were hypertension (55 [34%]), diabetes (31 [19%]) and obesity (13 [8%]). Fever (93 [58%]), cough (92 [57%]), fatigue (87 [54%]), shortness of breath (72 [45%]) and myalgia (33 [21%]) were the most common symptoms, upon admission. Patients were categorized into mild (92 [57%]), moderate (19 [12%]) and severe (49 [31%]). Severe patients were older and were more likely to have comorbidities, compared to mild ones. The majority of patients (92% [147 of 160]) patients received hydroxychloroquine or chloroquine phosphate. Regression model revealed that older age, lower SpO2, higher heart rate and elevated AST at admission were all risk factors associated with in-hospital death. The prevalence of COVID-19 and malaria co-infection was 0.63% and 70 (44%) of all patients received antimalarial treatment before hospitalization. CONCLUSION: Our findings indicated that the epidemiological and clinical feature of COVID-19 patients in Kinshasa are broadly similar to previous reports from other settings. Older age, lower SpO2, tachycardia, and elevated AST could help to identify patients at higher risk of death at an early stage of the illness. Plasmodium spp co-infection was not common in hospitalized COVID-19 patients.

Preventing the re-establishment of malaria in Sri Lanka amidst the COVID-19 pandemic.

The COVID-19 pandemic has had a considerable impact on other health programmes in countries, including on malaria, and is currently under much discussion. As many countries are accelerating efforts to eliminate malaria or to prevent the re-establishment of malaria from recently eliminated countries, the COVID-19 pandemic has the potential to cause major interruptions to ongoing anti-malaria operations and risk jeopardizing the gains that have been made so far. Sri Lanka, having eliminated malaria in 2012, was certified by the World Health Organization as a malaria-free country in 2016 and now implements a rigorous programme to prevent its re-establishment owing to the high receptivity and vulnerability of the country to malaria. Sri Lanka has also dealt with the COVID-19 epidemic quite successfully limiting the cumulative number of infections and deaths through co-ordinated efforts between the health sector and other relevant sectors, namely the military, the Police Department, Departments of Airport and Aviation and Foreign Affairs, all of which have been deployed for the COVID-19 epidemic under the umbrella of a Presidential Task Force. The relevance of imported infections and the need for a multi-sectoral response are features common to both the control of the COVID-19 epidemic and the Prevention of Re-establishment (POR) programme for malaria. Sri Lanka's malaria POR programme has, therefore, creatively integrated its activities with those of the COVID-19 control programme. Through highly coordinated operations the return to the country of Sri Lankan nationals stranded overseas by the COVID-19 pandemic, many from malaria endemic countries, are being monitored for malaria as well as COVID-19 in an integrated case surveillance system under quarantine conditions, to the success of both programmes. Twenty-three imported malaria cases were detected from February to October through 2773 microscopic blood examinations performed for malaria in quarantine centres, this number being not much different to the incidence of imported malaria during the same period last year. This experience highlights the importance of integrated case surveillance and the need for a highly coordinated multi-sectoral approach in dealing with emerging new infections. It also suggests that synergies between the COVID-19 epidemic control programme and other health programmes may be found and developed to the advantage of both.

Implications of COVID-19 Pandemic on Evolution of Diabetes in Malaria-Endemic African Region.

The coronavirus disease 2019 (COVID-19) pandemic continues to cause havoc to many countries of the globe, with no end in sight, due to nonavailability of a given vaccine or treatment regimen. The pandemic has so far had a relatively limited impact on the African continent, which contributes more than 93% of global malaria burden. However, the limited burden of COVID-19 pandemic on the African region could have long-term implications on the health and wellbeing of affected inhabitants due to its malaria-endemic status. Malaria causes recurrent insulin resistance with episodes of infection at relatively low parasitaemia. Angiotensin-converting enzyme 2 (ACE2) which is widely distributed in the human body is implicated in the pathogenesis of malaria, type 2 diabetes mellitus (T2DM), and COVID-19. Use of ACE2 by the COVID-19 virus induces inflammation and oxidative stress, which can lead to insulin resistance. Although COVID-19 patients in malaria-endemic African region may not exhibit severe signs and symptoms of the disease, their risk of exhibiting heightened insulin resistance and possible future development of T2DM is high due to their prior exposure to malaria. African governments must double efforts at containing the continued spread of the virus without neglecting existing malarial control measures if the region is to avert the plausible long-term impact of the pandemic in terms of future development of T2DM.

The potential public health consequences of COVID-19 on malaria in Africa.

The burden of malaria is heavily concentrated in sub-Saharan Africa (SSA) where cases and deaths associated with COVID-19 are rising1. In response, countries are implementing societal measures aimed at curtailing transmission of SARS-CoV-22,3. Despite these measures, the COVID-19 epidemic could still result in millions of deaths as local health facilities become overwhelmed4. Advances in malaria control this century have been largely due to distribution of long-lasting insecticidal nets (LLINs)5, with many SSA countries having planned campaigns for 2020. In the present study, we use COVID-19 and malaria transmission models to estimate the impact of disruption of malaria prevention activities and other core health services under four different COVID-19 epidemic scenarios. If activities are halted, the malaria burden in 2020 could be more than double that of 2019. In Nigeria alone, reducing case management for 6 months and delaying LLIN campaigns could result in 81,000 (44,000-119,000) additional deaths. Mitigating these negative impacts is achievable, and LLIN distributions in particular should be prioritized alongside access to antimalarial treatments to prevent substantial malaria epidemics.