Outreach Training and Supportive Supervision for Quality Malaria Service Delivery: A Qualitative Evaluation in 11 Sub-Saharan African Countries.

Quality improvement of malaria services aims to ensure that more patients receive accurate diagnosis, appropriate treatment, and referral. The Outreach Training and Supportive Supervision Plus (OTSS+) approach seeks to improve health facility readiness and provider competency through onsite supportive supervision, troubleshooting, and on-the-job training. As part of a multicomponent evaluation, qualitative research was conducted to understand the value of the OTSS+ approach for malaria quality improvement. Semistructured key informant interviews, focus group discussions, and structured health facility-based interviews were used to gather stakeholder perspectives at subnational, national, and global levels. Data were collected globally and in 11 countries implementing OTSS+; in-depth data collection was done in four: Cameroon, Ghana, Niger, and Zambia. Study sites and participants were selected purposively. Verbatim transcripts were analyzed thematically, following the Framework approach. A total of 262 participants were included in the analysis; 98 (37.4%) were supervisees, 99 (37.8%) were supervisors, and 65 (24.8%) were other stakeholders. The OTSS+ approach was perceived to improve provider knowledge and skills in malaria service delivery and to improve data and supply management indirectly. Improvements were attributed to a combination of factors. Participants valued the relevance, adaptation, and digitization of supervision checklists; the quality and amount of contact with problem-solving supervisors; and the joint identification of problems and solutions, and development of action plans. Opportunities for improvement were digitized checklist refinement, assurance of a sufficient pool of supervisors, prioritization of health facilities, action plan dissemination and follow-up, and data review and use. The OTSS+ approach was perceived to be a useful quality improvement approach for malaria services.

Effectiveness of buffered and non-buffered local anaesthetic in inferior alveolar nerve block: a randomised study.

The objective of this study was to compare the effectiveness of buffered and non-buffered local anaesthetic (LA) following inferior alveolar nerve block (IANB). This study was conducted at Usmanu Danfodiyo University Teaching Hospital Sokoto from June 2020 to January 2021. Subjects were randomised into Groups A and B. Group A received 2 ml of freshly prepared 2% lignocaine with 1:100,000 adrenaline buffered with 0.18 ml of 8.4% sodium bicarbonate solution while those in Group B received non-buffered 2% lignocaine with 1:100,000 adrenaline LA solutions. The onset of action of the LA was assessed by subjective and objective methods, while pain at the injection site was assessed using a numerical rating scale. Data obtained were analysed using statistical package for social sciences (IBM SPSS) version 21. The mean (SD) ages for Groups A and B were 37.4 (14.9) and 40.1 (14.4) years, respectively. The mean (SD) onset times of the LA by subjective testing were 126 (31.7) and 201 (66.8) seconds for Groups A and B, respectively. Similarly, the mean (SD) onset times of the local anaesthesia by objective testing for Groups A and B were 186 (41.0) and 287 (85.0) seconds, respectively, and both were significant (p<0.001). Pain at the injection site assessed objectively and subjectively were also statistically different (p<0.001). The findings of this study suggest that buffered LA is more effective than non-buffered LA of the same composition when used for IANB particularly concerning a significantly faster rate of onset and less pain at the injection site.

Status epilepticus no convulsivo como manifestación inicial en una familia con arteriopatía autosómica dominante cerebral con infartos subcorticales y leucoencefalopatía (CADASIL) / Non-convulsive status epilepticus as the initial manifestation in a family with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL)

La arteriopatía autosómica dominante cerebral con infartos subcorticales y leucoencefalopatía es una enfermedad autosómica dominante de pequeños vasos causada por mutaciones del gen NOTCH3. Típicamente se presenta con migraña, eventos isquémicos cerebrales recurrentes y trastornos cognitivos. Las crisis epilépticas son inusuales como manifestación inicial, pero aún más infrecuente es su presentación como status epilepticus no convulsivo1. Se presenta una serie familiar de 3 casos con esta arteriopatía, entre los cuales 2 de ellos tuvieron status epilepticus como manifestación de la enfermedad. (AU)

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an autosomal dominant small-vessel disease caused by mutations of the NOTCH3 gene. It typically presents with migraine, recurrent brain ischaemia, and cognitive disorders. Seizures rarely present as the initial manifestation, with non-convulsive status epilepticus being even less frequent. We present a series of 3 related patients with this arteriopathy, 2 of whom presented status epilepticus as a manifestation of the disease. (AU)

Capture, Release, and Identification of Newly Synthesized Proteins for Improved Profiling of Functional Translatomes.

New protein synthesis is regulated both at the level of mRNA transcription and translation. RNA-Seq is effective at measuring levels of mRNA expression, but techniques to monitor mRNA translation are much more limited. Previously, we reported results from O-propargyl-puromycin (OPP) labeling of proteins undergoing active translation in a 2-h time frame, followed by biotinylation using click chemistry, affinity purification, and on-bead digestion to identify nascent proteins by mass spectrometry (OPP-ID). As with any on-bead digestion protocol, the problem of nonspecific binders complicated the rigorous categorization of nascent proteins by OPP-ID. Here, we incorporate a chemically cleavable linker, Dde biotin-azide, into the protocol (OPP-IDCL) to provide specific release of modified proteins from the streptavidin beads. Following capture, the Dde moiety is readily cleaved with 2% hydrazine, releasing nascent polypeptides bearing OPP plus a residual C3H8N4 tag. When results are compared side by side with the original OPP-ID method, change to a cleavable linker led to a dramatic reduction in the number of background proteins detected in controls and a concomitant increase in the number of proteins that could be characterized as newly synthesized. We evaluated the method's ability to detect nascent proteins at various submilligram protein input levels and showed that, when starting with only 100 µg of protein, ∼1500 nascent proteins could be identified with low background. Upon treatment of K562 cells with MLN128, a potent inhibitor of the mammalian target of rapamycin, prior to OPP treatment, we identified 1915 nascent proteins, the majority of which were downregulated upon inhibitor treatment. Repressed proteins with log2 FC <-1 revealed a complex network of functionally interacting proteins, with the largest cluster associated with translational initiation. Overall, incorporation of the Dde biotin-azide cleavable linker into our protocol has increased the depth and accuracy of profiling of nascent protein networks.

Efficacy and safety of transcranial magnetic stimulation for treating major depressive disorder: An umbrella review and re-analysis of published meta-analyses of randomised controlled trials.

OBJECTIVES: We re-analysed data from published meta-analyses testing the effects of Transcranial Magnetic Stimulation (TMS) on Major Depressive Disorder (MDD) in adults. We applied up-to-date meta-analytic techniques for handling heterogeneity including the random-effects Hartung-Knapp-Sidik-Jonkman method and estimated 95% prediction intervals. Heterogeneity practices in published meta-analyses were assessed as a secondary aim. STUDY DESIGN AND SETTING: We performed systematic searches of systematic reviews with meta-analyses that included randomised controlled trials assessing the efficacy, tolerability, and side effects of TMS on MDD. We performed risk of bias assessment using A MeaSurement Tool to Assess Reviews (AMSTAR) 2 and re-analysed meta-analyses involving 10 or more primary studies. RESULTS: We included 29 systematic reviews and re-analysed 15 meta-analyses. Authors of all meta-analyses interpreted findings to suggest TMS is safe and effective for MDD. Our re-analysis showed that in 14 out of 15 meta-analyses, the 95% prediction intervals included the null and captured values in the opposite effect direction. We also detected presence of small-study effects in some meta-analyses and 24 out of 25 systematic reviews received an AMSTAR 2 rating classed as critically low. CONCLUSION: Authors of all included meta-analyses interpreted findings to suggest TMS is safe and effective for MDD despite lack of comprehensive investigation of heterogeneity. Our re-analysis revealed the direction and magnitude of treatment effects vary widely across different settings. We also found high risk of bias in the majority of included systematic reviews and presence of small-study effects in some meta-analyses. Because of these reasons, we argue TMS for MDD may not be as effective and potentially less tolerated in some populations than current evidence suggests.

Case fatality and factors associated with Maternal mortality in patients with eclampsia: A retrospective review of 761 cases in a tertiary institution in Nigeria.

To determine the case fatality and factors associated with maternal mortality in patients with eclampsia in UMTH, we conducted a retrospective review of 761 consecutive cases of eclampsia managed UMTH, Nigeria, from 2005 to 2020. Case fatality was 7.6%, most being unbooked primigravidae with no formal education. Common causes of death identified were aspiration, cerebrovascular accident, and haemorrhage. Admission delayed >10 hours was found to be independently associated with maternal death, and Caesarean delivery.

Non-convulsive status epilepticus as the initial manifestation in a family with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL).

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an autosomal dominant small-vessel disease caused by mutations of the NOTCH3 gene. It typically presents with migraine, recurrent brain ischaemia, and cognitive disorders. Seizures rarely present as the initial manifestation, with non-convulsive status epilepticus being even less frequent. We present a series of 3 related patients with this arteriopathy, 2 of whom presented status epilepticus as a manifestation of the disease.

The benefit of dynamic neutrophil-lymphocyte ratio and systemic immune-inflammation index in predicting survival in patients undergoing hemiarthroplasty.

OBJECTIVE: We aimed at investigating the relationship between the values of neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), systemic immune-inflammation index (SII) in the preoperative and postoperative periods in patients who underwent hemiarthroplasty. PATIENTS AND METHODS: The medical records of patients aged >65 years who underwent hemiarthroplasty due to hip fracture in our institution between January 2017 and December 2020 were examined. Dynamic Neutrophil-to-lymphocyte ratio (dNLR), platelet-to-lymphocyte ratio (dPLR), and systemic immune-inflammation index (dSII) were calculated using biomarker data (neutrophil, lymphocyte, and platelet counts) obtained at admission and on postoperative day 2 and 5. RESULTS: A total of 176 individuals (119 females, 57 males) were included in the study. The PLR on postoperative day 2, and NLR and SII measurement on postoperative day 2 and 5 in patients were found to have significant predictive value in 1-year mortality rates. A 1-year increase in age was associated with a 4.9% increased risk of death at 1-year follow-up (p=0.006). A 1-unit increase in NLR on postoperative day 5 was associated with a 4.3% increased risk of death at 1-year follow-up (p=0.004). CONCLUSIONS: The present study shows that our model for predicting the absolute mortality risk in patients can be improved by evaluating dSII, dPLR, and dNLR in the preoperative period and postoperative day 2 and 5. However, it cannot be said that the model has a discriminatory ability to exactly predict postoperative mortality. Nevertheless, these parameters may aid in the development of early therapeutic intervention to improve patient outcomes.

Bone mineral density (BMD) and neutrophil-lymphocyte ratio (NLR), monocyte-lymphocyte ratio (MLR), and platelet-lymphocyte ratio (PLR) in childhood thyroid diseases.

OBJECTIVE: This study aimed at investigating the laboratory parameters related to the pathogenesis of bone loss, including bone mineral density (BMD), neutrophil-lymphocyte ratio (NLR), monocyte-lymphocyte ratio (MLR), and platelet-lymphocyte ratio (PLR) in children with thyroid disease and healthy controls. PATIENTS AND METHODS: Children and adolescents with hypothyroidism (n=63) and hyperthyroidism (n=30) as well as 32 age- and sex-matched healthy controls were included in the study. Auxological data, BMD, hemogram parameters, the levels of thyroid hormone, thyroid stimulating hormone (TSH), thyroid autoantibodies, parathyroid hormone, 25-hydroxy vitamin D, alkaline phosphatase, calcium, and phosphorus were analyzed. RESULTS: The mean age of the patients was 12.12±2.7 years (range: 8-17). BMD Z-scores were within the normal range in all the patients and healthy controls. The BMD Z-scores were significantly higher in patients with hyperthyroidism than those in the control group and in patients with hypothyroidism. No significant difference was observed between the control and hypothyroid groups in terms of the BMD Z-scores. A correlation was observed between the BMD Z-scores and NLR, MLR, PLR, and free T4 levels. In patients with hypothyroidism, the BMD Z-scores were significantly positively correlated with the NLR, MLR, PLR, and the TSH level. In the control group, there was a moderate positive correlation between the BMD Z-scores and NLR. In the hyperthyroid group, there were no significant correlations between the BMD Z-scores and other variables. CONCLUSIONS: The study data suggest that in children and adolescents with thyroid disease, the relationship between the BMD Z-scores and NLR, MLR, and PLR at the initial diagnosis in the hypothyroidism group was different from that in their healthy peers.

Bone mineral density and complete blood count ratios in children and adolescents with obesity.

OBJECTIVE: Monocyte-to-lymphocyte ratio (MLR), platelet-to-lymphocyte ratio (PLR), neutrophil-to-lymphocyte ratio (NLR), monocyte-to-high-density lipoprotein ratio (MHR), and mean platelet volume (MPV) are considered novel inflammatory markers. In this study, we aimed to investigate the relationship between bone mineral density (BMD) Z score and blood cell composition in children and adolescents with obesity and to create a suitable index for the diagnosis of obesity-associated osteoporosis. PATIENTS AND METHODS: We included 148 children, comprising 112 children with obesity (obese group) and 36 sex- and age-matched healthy children (normal weight) (control group). Patient details acquired from medical records were used to measure blood count levels; BMD, using dual-energy X-ray absorptiometry; and BMD Z-scores, using race and sex specific curves. RESULTS: Mean BMD Z score in the obese and normal weight group was within the normal limits and significantly higher in the obese group. The BMD Z score showed a significant relationship with MLR and PLR. Patient BMD Z-scores were negatively correlated with MLR and PLR in the obese group and positively correlated in the control group. In addition, a positive correlation was found between BMD Z score and NLR in the control group. CONCLUSIONS: Our study outcomes show that there may be a relationship between bone mass and inflammation expressed as PLR and MLR in obese children and adolescents. PLR and MLR, which are common indicators of morbidity and mortality in many chronic inflammatory diseases, may also be useful for evaluating bone status in children with obesity. However, further research on the subject is warranted.

The use of video job-aids to improve the quality of seasonal malaria chemoprevention delivery.

Mobile phones are increasingly used in community health programmes, but the use of video job-aids that can be displayed on smart phones has not been widely exploited. We investigated the use of video job-aids to support the delivery of seasonal malaria chemoprevention (SMC) in countries in West and Central Africa. The study was prompted by the need for training tools that could be used in a socially distanced manner during the COVID-19 pandemic. Animated videos were developed in English, French, Portuguese, Fula and Hausa, illustrating key steps for administering SMC safely, including wearing masks, washing hands, and social distancing. Through a consultative process with the national malaria programmes of countries using SMC, successive versions of the script and videos were reviewed to ensure accurate and relevant content. Online workshops were held with programme managers to plan how to use the videos in SMC staff training and supervision, and the use of the videos was evaluated in Guinea through focus groups and in-depth interviews with drug distributors and other staff involved in SMC delivery and through direct observations of SMC administration. Programme managers found the videos useful as they reinforce messages, can be viewed at any time and repeatedly, and when used during training sessions, provide a focus of discussion and support for trainers and help retain messages. Managers requested that local specificities of SMC delivery in their setting be included in tailored versions of the video for their country, and videos were required to be narrated in a variety of local languages. In Guinea, SMC drug distributors found the video covered the all the essential steps and found the video easy to understand. However, not all key messages were followed as some of the safety measures, social distancing and wearing masks, were perceived by some as creating mistrust amongst communities. Video job-aids can potentially provide an efficient means of reaching large numbers of drug distributors with guidance for safe and effective distribution of SMC. Not all distributors use android phones, but SMC programmes are increasingly providing drug distributors with android devices to track delivery, and personal ownership of smartphones in sub-Saharan Africa is growing. The use of video job-aids for community health workers to improve the quality delivery of SMC, or of other primary health care interventions, should be more widely evaluated.

A critical appraisal of impact of compounding factors in limb salvage decision making in combat extremity vascular trauma.

OBJECTIVE: For more than half a century, surgeons who managed vascular injuries were guided by a 6-hour maximum ischaemic time dogma in their decision to proceed with vascular reconstruction or not. Contemporary large animal survival model experiments aimed at redefining the critical ischaemic time threshold concluded this to be less than 5 hours. Our clinical experience from recent combat vascular trauma contradicts this dogma with limb salvage following vascular reconstruction with an average ischaemic time of 6 hours. METHODS: During an 8-month period of the Sri Lankan Civil War, all patients with penetrating extremity vascular injuries were prospectively recorded by a single surgeon and retrospectively analysed. A total of 76 arterial injuries was analysed for demography, injury anatomy and physiology, treatment and outcomes. Subsequent statistical analysis was performed to evaluate the impact of independent variables to include; injury anatomy, concomitant venous, skeletal trauma, shock at presentation and time delay from injury to reconstruction. RESULTS: In this study, the 76 extremity arterial injuries had a median ischaemic time of 290 (IQR 225-375) min. Segmental arterial injury (p=0.02), skeletal trauma (p=0.05) and fasciotomy (p=0.03) were found to have a stronger correlation to subsequent amputation than ischaemic time. CONCLUSIONS: Multiple factors affect limb viability following compromised distal circulation and our data show a trend towards various subsets of limbs that are more vulnerable due to inherent or acquired paucity of collateral circulation. Early identification and prioritisation of these limbs could achieve functional limb salvage if recognised. Further prospective research should look into the clinical, biochemical and morphological markers to facilitate selection and prioritisation of limb revascularisation.

D-carvone induced ROS mediated apoptotic cell death in human leukemic cell lines (Molt-4).

The immature lymphoid cells with chromosomal structural and numerical abnormalities cause the acute lymphoblastic leukemia (ALL). This hematologic disorder constitutes about 25% of cancer prognosis among children and adolescents. D-Carvone, a monocyclic monoterpene obtained from the essential oils extracted from plants is reported to possess the various biological activities. The present study was aimed to investigate the anticancer potential of D-Carvone against the human leukemic Molt-4 cells. The cytotoxicity of DCarvone was analyzed by MTT assay. The level of lipid peroxidation and antioxidants were determined. The intracellular ROS, MMP and apoptosis were demonstrated by fluorescent staining techniques. The MTT assay revealed that the D-Carvone treatment suppressed the viability of Molt-4 cells and the IC50 was determined at 20 µM/ml. The D-Carvone treatment was increased the oxidative stress and reduced the level of antioxidants in the Molt-4 cell lines. The increased intracellular ROS, apoptotic cell death, and diminished MMP was noted in the D-Carvone treatment. In the Molt-4 cells, D-carvone induced the apoptosis in a time and dose dependent manner by the activation of caspases-8, -9 and -3. Thus, data provide insights for the clinical application of D-Carvone in the treatment of blood cancer Molt-4 cells. Our study suggests the therapeutic potential D-Carvone for the treatment of leukemia in future.

Fucoxanthin induced apoptotic cell death in oral squamous carcinoma (KB) cells.

Fucoxanthin (Fx) is an active compound commonly found in the many types of seaweed with numerous biological activities. The main goal of this investigation is to explore the effect of Fx against the cell proliferation, apoptotic induction and oxidative stress in the oral squamous (KB) cell line. Cytotoxicity of Fx was determined by MTT assay. The intracellular ROS production, mitochondrial membrane potential (MMP) and apoptosis induction in KB cells were examined through DCFH-DA, Rhodamine-123 and DAPI, and dual staining techniques. Effect of Fx on the antioxidant enzymes and lipid peroxidation in the KB cells was studied through the standard procedures. Fx treated KB cells showed morphological changes and reduced cell survival, which is exhibited by the cytotoxic activity of 50 µM/ml (IC50) Fx against the KB cells. The Fx treatment considerably induced the apoptotosis cells (EB/AO) and decreased the MMP (Rh-123) in KB cells. Further, it was pointed out that there was an increased lipid peroxidation (LPO) with decreased antioxidants (CAT, SOD and GSH). These results concluded that Fx has the cytotoxic effect against KB cells and has the potential to induce the apoptosis via increased oxidative stress. Hence, the Fx can be a promising agent for the treatment of oral cancer and it may lead to the development of cancer therapeutics.

A data driven change-point epidemic model for assessing the impact of large gathering and subsequent movement control order on COVID-19 spread in Malaysia.

The second wave of COVID-19 in Malaysia is largely attributed to a four-day mass gathering held in Sri Petaling from February 27, 2020, which contributed to an exponential rise of COVID-19 cases in the country. Starting from March 18, 2020, the Malaysian government introduced four consecutive phases of a Movement Control Order (MCO) to stem the spread of COVID-19. The MCO was implemented through various non-pharmaceutical interventions (NPIs). The reported number of cases reached its peak by the first week of April and then started to reduce, hence proving the effectiveness of the MCO. To gain a quantitative understanding of the effect of MCO on the dynamics of COVID-19, this paper develops a class of mathematical models to capture the disease spread before and after MCO implementation in Malaysia. A heterogeneous variant of the Susceptible-Exposed-Infected-Recovered (SEIR) model is developed with additional compartments for asymptomatic transmission. Further, a change-point is incorporated to model disease dynamics before and after intervention which is inferred based on data. Related statistical analyses for inference are developed in a Bayesian framework and are able to provide quantitative assessments of (1) the impact of the Sri Petaling gathering, and (2) the extent of decreasing transmission during the MCO period. The analysis here also quantitatively demonstrates how quickly transmission rates fall under effective NPI implementation within a short time period. The models and methodology used provided important insights into the nature of local transmissions to decision makers in the Ministry of Health, Malaysia.

Splenic infarction complicated with abscess after pelvic trauma as the first presentation of patent foramen ovale - A case report.

Hypercoagulability after trauma is a known entity. Following significant trauma, most guidelines advise anticoagulation treatment for venous thromboembolism (VTE) prophylaxis. VTE following minor trauma convoyed with arterial or systemic embolization dictate the need to search for uncommon source of thromboembolic complications. This is a report of an unusual case of pulmonary and systemic emboli complicated by splenic abscess following minor trauma in a patient with Diabetes Mellitus as the first presentation of patent foramen ovale (PFO).

3D TOF-PET image reconstruction using total variation regularization.

In this paper we introduce a semi-analytic algorithm for 3-dimensional image reconstruction for positron emission tomography (PET). The method consists of the back-projection of the acquired data into the most likely image voxel according to time-of-flight (TOF) information, followed by the filtering step in the image space using an iterative optimization algorithm with a total variation (TV) regularization. TV regularization in image space is more computationally efficient than usual iterative optimization methods for PET reconstruction with full system matrix that use TV regularization. The efficiency comes from the one-time TOF back-projection step that might also be described as a reformatting of the acquired data. An important aspect of our work concerns the evaluation of the filter operator of the linear transform mapping an original radioactive tracer distribution into the TOF back-projected image. We obtain concise, closed-form analytical formula for the filter operator. The proposed method is validated with the Monte Carlo simulations of the NEMA IEC phantom using a one-layer, 50 cm-long cylindrical device called Jagiellonian PET scanner. The results show a better image quality compared with the reference TOF maximum likelihood expectation maximization algorithm.

Transmembrane Polar Relay Drives the Allosteric Regulation for ABCG5/G8 Sterol Transporter.

The heterodimeric ATP-binding cassette (ABC) sterol transporter, ABCG5/G8, is responsible for the biliary and transintestinal secretion of cholesterol and dietary plant sterols. Missense mutations of ABCG5/G8 can cause sitosterolemia, a loss-of-function disorder characterized by plant sterol accumulation and premature atherosclerosis. A new molecular framework was recently established by a crystal structure of human ABCG5/G8 and reveals a network of polar and charged amino acids in the core of the transmembrane domains, namely, a polar relay. In this study, we utilize genetic variants to dissect the mechanistic role of this transmembrane polar relay in controlling ABCG5/G8 function. We demonstrated a sterol-coupled ATPase activity of ABCG5/G8 by cholesteryl hemisuccinate (CHS), a relatively water-soluble cholesterol memetic, and characterized CHS-coupled ATPase activity of three loss-of-function missense variants, R543S, E146Q, and A540F, which are respectively within, in contact with, and distant from the polar relay. The results established an in vitro phenotype of the loss-of-function and missense mutations of ABCG5/G8, showing significantly impaired ATPase activity and loss of energy sufficient to weaken the signal transmission from the transmembrane domains. Our data provide a biochemical evidence underlying the importance of the polar relay and its network in regulating the catalytic activity of ABCG5/G8 sterol transporter.

A Data Driven Change-point Epidemic Model for Assessing the Impact of Large Gathering and Subsequent Movement Control Order on COVID-19 Spread in Malaysia

The second wave of COVID-19 in Malaysia is largely attributed to a mass gathering held in Sri Petaling between February 27, 2020 and March 1, 2020, which contributed to an exponential rise of COVID-19 cases in the country. Starting March 18, 2020, the Malaysian government introduced four consecutive phases of a Movement Control Order (MCO) to stem the spread of COVID-19. The MCO was implemented through various non-pharmaceutical interventions (NPIs). The reported number of cases reached its peak by the first week of April and then started to reduce, hence proving the effectiveness of the MCO. To gain a quantitative understanding of the effect of MCO on the dynamics of COVID-19, this paper develops a class of mathematical models to capture the disease spread before and after MCO implementation in Malaysia. A heterogeneous variant of the Susceptible-Exposed-Infected-Recovered (SEIR) model is developed with additional compartments for asymptomatic transmission. Further, a change-point is incorporated to model the before and after disease dynamics, and is inferred based on data. Related statistical analyses for inference are developed in a Bayesian framework and are able to provide quantitative assessments of (1) the impact of the Sri Petaling gathering, and (2) the extent of decreasing transmission during the MCO period. The analysis here also quantitatively demonstrates how quickly transmission rates fall under effective NPI implemention within a short time period.