Pakistan's national COVID-19 response: lessons from an emergent response to the pandemic.

Introduction: In 2020, Pakistan faced the formidable challenge of the COVID-19 pandemic with an existing yet disjointed healthcare infrastructure, that included by over 18,000 public and an estimated 75,000 private health facilities and some elements of an epidemic surveillance and response system. This descriptive study examines how Pakistan developed a COVID-19 response, driven by establishing a central coordination and decision-making mechanism to overcome these systemic challenges. Methods: The study is based on interviews and interactions of the many actors in the response by the authors, who also participated in nearly all proceedings of the National Command and Operation Centre (NCOC) and many of the National Coordination Committee (NCC). This information is supplemented by reviewing documents, reports, news items, media and social media, and journal articles. Results: The study highlights the critical role of political arrangement, where the NCC, comprising of ministers, bureaucrats, and military personnel, facilitated federal and provincial integration. The NCC found resources and set policy. Its direction was implemented by the NCOC, a top-down yet inclusive platform, integrated political, military, and civil society actors, to ensure cohesive decision-making and implementation. It provided technical guidance, harnessed data for strategic decisions and held implementers accountable. At its peak, the NCOC boasted nearly 300 personnel, including high-ranking military officers, a stark contrast to the limited staffing in most ministries. In addition, the response's success is attributed to the perception of COVID-19 as an existential threat, leading to unprecedented collaboration and decisive actions that were enforced authoritatively. Conclusion: Pakistan's experience offers valuable insights for proactive management of health emergencies in resource-limited settings. It underscores the necessity for inter-sectoral dialog and data-driven policy implementation, especially in the context of political economies where activity-driven governance often overshadows objective-driven policy execution. However, the lessons from the COVID-19 response, including a blueprint for future epidemic responses and lessons for use of data and evidence in developing country health systems, if not institutionalized, risk being lost in the post-pandemic era.

Model simplification and sensitivity analysis of chemical species for oxidation behavior in multi route complex chemical mechanism.

This study employs a Model Reduction Technique (MRT) to simplify the four-step catalytic carbon monoxide (CO) oxidation reaction. The C-matrix method identifies key elements, key/non key components, and key reactions, while the Intrinsic Low-Dimensional Manifold (ILDM) pinpoints a Slow-Invariant Manifold (SIM) important for understanding key species behavior. Sensitivity analysis can be considered for measuring the efficiency of the chemical species in detailed mechanism. This systematic approach contributes to optimizing and controlling complex reactions offering broad application potential. In addition to the mathematical proof, the validation of the given chemical model is rectified. The comparison between the slow invariant manifold of both reaction routes is reported and the computational based results performed in this study are obtained through MATLAB.

Mathematical and sensitivity analysis for chemical species in multistep dynamical system: A computational study.

This study presents a significant contribution to the field of chemical kinetics by providing a detailed analysis of a multi-step chemical kinetic process using ordinary differential equations (ODEs). The aim is to describe complex chemical processes' kinetics and the steady-state behavior of chemical species. The research employs reduction techniques to simplify the model by separating fast and slow processes based on their time scales, with a focus on a two-step reversible reaction mechanism. Special consideration is given to the phase flow of solution trajectories near equilibrium points, providing a clear depiction of system behavior. MATLAB simulations demonstrate the physical properties of observed data, while sensitivity analysis reveals parameters' impact on species behavior. Overall, this study enhances our understanding of chemical kinetics and offers insights into modeling complex reaction processes, with implications for various applications in chemistry and related fields.

Clinical presentation and outcome of enteric fever in adult patients with cancer: a perspective from Pakistan.

Introduction. Enteric fever is a significant health concern in endemic countries. While extensive research has been conducted to understand its presentation and outcomes in non-cancer patients, limited data exist on its impact on cancer patients. This descriptive study aims to investigate the clinical presentation and outcome in cancer patients. Methodology. This retrospective observational study analysed 90 adult cancer patients from a single centre in Pakistan from January 2017 to December 2022. Inclusion criteria involved documented blood culture infections with Salmonella typhi or paratyphi A, B, or C. We examined clinical presentation, laboratory parameters, antimicrobial resistance, complications, and outcomes. Additionally, we explored the effects of chemotherapy, comorbidities, type of malignancy, and patient age on complications and mortality. Results. Salmonella typhi was the most prevalent organism (72.2 %), followed by Salmonella paratyphi A (22.2 %) and B (5.5 %). Variably-resistant isolates constituted 51.5 %, multi-drug resistant (MDR) isolates accounted for 20 %, extensively drug-resistant (XDR) for 14.4 % and ESBL-producers for 15.5 %, of all enteric fever infections. Enteric fever-associated complications were observed in 21.1 % of cases. Chemotherapy in the preceding month did not affect mortality, nor did age, gender, or malignancy type. However, comorbidities were statistically significant for mortality (p-value 0.03). A total of 8.8 % of patients required ICU care, and the all-cause 30 day mortality rate was 13.3 % Conclusion. Enteric fever remains prevalent in our geographical region. Unlike non-typhoidal Salmonella (NTS), enteric fever does not behave differently in an immunocompromised population, including cancer patients.

Trends in typhoid fever during the COVID-19 pandemic in Pakistan.

INTRODUCTION: Pakistan has been experiencing an extensively drug-resistant (XDR) outbreak of typhoid for some years. We sought to evaluate how the COVID-19 pandemic impacted typhoid epidemiology in Pakistan, from the beginning of the pandemic in 2020 through the end of 2022, and the reduction of COVID-19 cases. METHODOLOGY: We compared national public COVID-19 data with retrospectively obtained patient data of confirmed S. Typhi isolates between January 2019 and December 2022 from Shaukat Khanum Memorial Cancer Hospital and Research Centre and the hospital's extended network of laboratory collection centers across Pakistan. RESULTS: We observed that during the early onset of the COVID-19 pandemic and COVID-19 peaks, typhoid positivity generally decreased. This suggests that restrictions and non-pharmaceutical interventions that limited social interactions and promoted good sanitation and hygiene practices had a positive secondary effect on typhoid. This led to an overall yearly decrease in typhoid positivity between 2019 to 2021. However, the percentage of S. Typhi cases isolated that were ceftriaxone-resistant continued to increase, suggesting the continued dominance of XDR typhoid in Pakistan. In 2022, with the alleviation of pandemic restrictions, we observed increased typhoid positivity and COVID-19 and typhoid positivity started to follow similar trends. CONCLUSIONS: Given the continued presence of COVID-19 along with XDR typhoid in Pakistan, it will be imperative to use differential testing to ensure that the epidemiology of each reported is accurate, the spread of each it contained, and that antibiotics are not misused. The use of approved vaccinations will lessen the burden of both diseases.

COVID-19 in Pakistan: A national analysis of five pandemic waves.

OBJECTIVES: The COVID-19 pandemic showed distinct waves where cases ebbed and flowed. While each country had slight, nuanced differences, lessons from each wave with country-specific details provides important lessons for prevention, understanding medical outcomes and the role of vaccines. This paper compares key characteristics from the five different COVID-19 waves in Pakistan. METHODS: Data was sourced from daily national situation reports (Sitreps) prepared by the National Emergency Operations Centre (NEOC) in Islamabad. We use specific criteria to define COVID-19 waves. The start of each COVID-19 wave is marked by the day of the lowest number of daily cases preceding a sustained increase, while the end is the day with the lowest number of cases following a 7-days decline, which should be lower than the 7 days following it. Key variables such as COVID-19 tests, cases, and deaths with their rates of change to the peak and then to the trough are used to draw descriptive comparisons. Additionally, a linear regression model estimates daily new COVID-19 deaths in Pakistan. RESULTS: Pakistan saw five distinct waves, each of which displayed the typical topology of a complete infectious disease epidemic. The time from wave-start to peak became progressively shorter, and from wave-peak to trough, progressively longer. Each wave appears to also be getting shorter, except for wave 4, which lasted longer than wave 3. A one percent increase in vaccinations decreased deaths by 0.38% (95% CI: -0.67, -0.08) in wave 5 and the association is statistically significant. CONCLUSION: Each wave displayed distinct characteristics that must be interpreted in the context of the level of response and the variant driving the epidemic. Key indicators suggest that COVID-19 preventive measures kept pace with the disease. Waves 1 and 2 were mainly about prevention and learning how to clinically manage patients. Vaccination started late during wave 3 and its impact on hospitalizations and deaths became visible in wave 5. The impact of highly virulent strains Alpha/B.1.1.7 and Delta/B.1.617.2 variants during wave 3 and milder but more infectious Omicron/B.1.1.529 during wave 5 are apparent.

Cancer incidence in Khyber Pakhtunkhwa, Pakistan, 2020.

BACKGROUND: To present the population-based cancer statistics for Khyber Pakhtunkhwa (KP), Pakistan, an incidence study was conducted at the Shaukat Khanum Memorial Cancer Hospital and Research Centre (SKMCH&RC) in Lahore, Pakistan, in 2023. METHODS: Records from various centres on new cancers diagnosed among residents of KP between January and December 2020 were gathered. Both active and passive methods of data collection were applied, and the information was saved in a central repository at SKMCH&RC. The incidence rates were computed by age group and sex and presented per 100,000 population. RESULTS: Among children (0-14 years), the Age-Standardised Incidence Rate (ASIR) was 4.0 in girls and 6.1 in boys, and haematologic malignancies were more prevalent; in adolescents (15-19 years), the ASIR was 7.7 in females, 9.4 in males, and bone tumours, haematologic malignancies, and neurological cancers were prominent; in adult females (> / = 20 years), the ASIR was 84.9, and cancers of the breast, digestive system, and reproductive organs were predominant; and adult males, the ASIR was 73.0, and cancers of the gastrointestinal tract, lip/oral cavity/pharynx, prostate, and Non-Hodgkin Lymphoma (NHL) were common. CONCLUSIONS: It is crucial to investigate the aetiology of these diseases at the community level because dietary elements, infectious diseases, and tobacco use all appear to be significant contributors. Prospective studies could play a key role in highlighting the factors linked to these diseases. Therefore, cancer registration must continue in conjunction with the exploration of risk factors.

A Scoping Review Of The Literature Of Research Ethics Committees And Ethics Review Framework In Pakistan: What We Know And What We Still Need To Learn.

OBJECTIVE: To map literature on research ethics committees, institutional review boards and ethics review framework in Pakistan to identify key insights during public health emergencies and normal times. Method: The systematic scoping review was conducted in April 2022, and comprised literature search on PubMed, World Health Organisation Global Index Medicus and Summons databases for articles published between January 2005 and February 2022. Information extracted included authors' names, year of publication, title, study methodology, and key insights under the heads of challenges and solutions. Due to data heterogeneity, key themes were identified and analysed. RESULTS: Of the 2,190 studies initially identified, 21(0.95%) were subjected to full-text review, and, from among them, 9(45%) were analysed in detail. There were 4 key insights identified: research ethics committees and institutional review boards in Pakistan remain unregulated as they are currently not registered or accredited by a competent national-level authority; most members of such committees are not formally trained to implement the mandate; internal and external pressures hinder independent decision-making of such committees; and other issues hindering the functionality and performance of research ethics committees and institutional review boards. CONCLUSIONS: Despite existing publications calling for urgent policy and regulatory reforms, there is a dearth of literature and minimal policy actions underlying the fact that ethics review remains a neglected area in Pakistan.

Genetic and antiretroviral drug resistance mutations analysis of reverse transcriptase and protease gene from Pakistani people living with HIV-1.

BACKGROUND: Antiretroviral therapy (ART) effectiveness is compromised by the emergence of HIV drug resistance mutations (DRM) and can lead to the failure of ART. Apart from intrinsic viral factors, non-compliance with drugs and/or the use of sub-optimum therapy can lead to the emergence of DRMs. In Pakistan HIV currently exists as a concentrated epidemic, however, ART coverage is very low, and drug adherence is poor. ART is selected assuming without baseline genotyping. Pakistan has recently seen a rise in treatment failures, but the country's actual burden of DRM is still unknown. In this study, we perform the genetic and drug resistance analysis of the pol gene from Pakistani HIV-positive ART-naïve and ART-experienced individuals. METHODS: In this study, HIV-1 pol was sequenced from 146 HIV-1 positive individuals, divided into ART-naïve (n = 37) and ART-experienced (n = 109). The sequences were also used to determine HIV-1 subtypes, the prevalence of DRM, and pol genetic variability. RESULTS: DRM analysis identified numerous DRMs against reverse transcriptase inhibitors in both ART-naïve and ART-experienced groups, including a few that are classified as rare. Additionally, the ART-experienced group showed mutations associated with resistance to protease inhibitors. Genetic analysis showed negative selection pressure in both groups, but a higher rate of evolution in the ART-naïve group. CONCLUSION: High prevalence of DRMs, especially against previous first-line treatment in ART- naïve and the accumulation of DRMs in ART-experienced groups is concerning and warrants that a more extensive DRM survey be carried out to inform first-line and second-line ART regimen recommendations.

COVID-19 vaccine hesitancy and attitudes in Pakistan: a cross-sectional phone survey of major urban cities.

BACKGROUND: COVID-19 mass vaccination is the only hopeful savior to curb the pandemic. Vaccine distribution to achieve herd immunity is hindered by hesitance and negative attitude of the public against COVID-19 vaccination. This study aims to evaluate the vaccine hesitancy and attitudes in major cities in Pakistan as well as their determinants. METHODS: A cross-sectional telephonic survey was conducted in June 2021 in major cities of Pakistan including Karachi, Lahore, Islamabad, Peshawar, and Gilgit, from unvaccinated urban population aged 18 years or older. Random Digit Dialing through multi-stage stratified random sampling was used to ensure representation of each target city and socio-economic classes. Questionnaire collected information on socio-demographics, COVID-19-related experiences, risk perception of infection, and receptivity of COVID-19 vaccination. Multivariate logistic regression analyses were performed to identify key determinants of vaccine hesitancy and acceptance. RESULTS: The prevalence of vaccinated population in this survey was 15%. Of the 2270 respondents, 65% respondents were willing to vaccinate, while only 19% were registered for vaccination. Factors significantly associated with vaccine willingness were older age (aOR: 6.48, 95% CI: 1.94-21.58), tertiary education (aOR: 2.02, 95% CI: 1.36, 3.01), being employed (aOR: 1.34, 95% CI: 1.01, 1.78), perceived risk of COVID-19 (aOR: 4.38, 95% CI: 2.70, 7.12), and higher compliance with standard operating procedures (aOR: 1.72, 95% CI: 1.26, 2.35). The most common vaccine hesitancy reasons were 'no need' (n = 284, 36%) and concerns with 'vaccine safety and side effects' (n = 251, 31%), while most reported vaccine motivation reasons were 'health safety' (n = 1029, 70%) and 'to end the pandemic' (n = 357, 24%). CONCLUSIONS: Although our study found 35% hesitancy rate of COVID-19 vaccine, there were noticeable demographic differences that suggest tailored communication strategy to address concerns held by most hesitant subpopulation. Use of mobile vaccination facilities particularly for less mobile and disadvantaged, and implementation and evaluation of social mobilization strategy should be considered to increase overall COVID-19 vaccination acceptance and coverage.

Identification of Multiple Variant Extensively Drug-Resistant Typhoid Infections across Pakistan.

Typhoid fever, caused by Salmonella enterica serovar Typhi (S. Typhi), is a life-threatening bacterial infection. Recently, an outbreak of a new sublineage of extensively drug resistant (XDR) S. Typhi emerged in Pakistan in the province of Sindh. This sublineage had both a composite multidrug resistance transposon integrated on the chromosome and an acquired IncY plasmid carrying the extended spectrum beta-lactamase, blaCTX-M-15, which conferred resistance to third-generation cephalosporins. We observed previously that XDR typhoid had spread beyond the originating southern Sindh Province. Thus, we sought to determine the genetic diversity of 58 ceftriaxone-resistant S. Typhi clinical isolates by whole genome sequencing collected across Pakistan from November 2018 to December 2020 to provide insights into the molecular epidemiology of the evolving outbreak. We identify multiple novel genomic integrations of the extended spectrum beta-lactamase gene into the chromosome in S. Typhi, revealing the existence of various XDR typhoid variants circulating in the country. Notably, the integration of the IncY plasmid bearing antibiotic resistance genes may allow for subsequent plasmid acquisition by these variants, potentially leading to further plasmid-borne multidrug resistance. Our results can inform containment initiatives, help track associated outcomes and international spread, and help determine how widespread the risk is.

Raising the contraceptive prevalence rate to 50% by 2025 in Pakistan: an analysis of number of users and service delivery channels.

BACKGROUND: Pakistan is the fifth most populous country in the world, with a population that is growing at 2.4% annually. Despite considerable political will, including a national commitment that was endorsed by the president to raise the contraceptive prevalence rate (CPR) to 50% by 2025, it has stagnated at around 30-35%. Much of the dialogue on raising CPR is hypothetical and revolves around percentage point change rather than an actual number of women that must be served. METHODS: The Demographic and Health Survey 2017-18 (DHS 2017-18) provides information about the channels through which users receive family planning (FP) services and disaggregates this information at the provincial level. Proportions of users from each of these channels were multiplied by the Pakistan Census-2017 populations to arrive at the number of users. These users were compared with the total FP users and the number of women that had used any FP service in the past 12 months. Linear estimations of population were applied to calculate population numbers in 2025. RESULTS: The national target of 50% CPR by 2025 translates to a population of 20.02 million users. Currently, 11.26 million married women of reproductive age (MWRA) use any method, 8.22 million use a modern method and 4.94 million received this service in the past 12 months. Of these, 2.7 million did so from social marketing outlets, 0.76 million from public sector outreach through lady health workers (LHWs), 0.55 million from private sector and 0.88 million from public sector facilities. However, arriving at the CPR target means expanding annual service delivery from 4.94 to 13.7 million users. Since social marketing and LHW outreach may have become saturated, only public and private health facilities are the likely channels for such an expansion. CONCLUSIONS: We demonstrate triangulation of the survey data with the census data as a simple policy analysis tool that can help decision-makers estimate the quantum of services they must provide. Such an analysis also allows an understanding of the utilization patterns of each of these channels. In Pakistan's context, underutilization of funds and existing facilities suggests that increased funding or more providers will likely not be helpful. The policy changes that will likely be most effective include adding outreach to support existing public and private sector facilities while ensuring that procurement of commodities is prioritized.

Four-Month High-Dose Rifampicin Regimens for Pulmonary Tuberculosis.

BACKGROUND: Shorter but effective tuberculosis treatment regimens would be of value to the tuberculosis treatment community. High-dose rifampicin has been associated with more rapid and secure lung sterilization and may enable shorter tuberculosis treatment regimens. METHODS: We randomly assigned adults who were given a diagnosis of rifampicin-susceptible pulmonary tuberculosis to a 6-month control regimen, a similar 4-month regimen of rifampicin at 1200 mg/d (study regimen 1 [SR1]), or a 4-month regimen of rifampicin at 1800 mg/d (study regimen 2 [SR2]). Sputum specimens were collected at regular intervals. The primary end point was a composite of treatment failure and relapse in participants who were sputum smear positive at baseline. The noninferiority margin was 8 percentage points. Using a sequence of ordered hypotheses, noninferiority of SR2 was tested first. RESULTS: Between January 2017 and December 2020, 672 patients were enrolled in six countries, including 191 in the control group, 192 in the SR1 group, and 195 in the SR2 group. Noninferiority was not shown. Favorable responses rates were 93, 90, and 87% in the control, SR1, and SR2 groups, respectively, for a country-adjusted absolute risk difference of 6.3 percentage points (90% confidence interval, 1.1 to 11.5) comparing SR2 with the control group. The proportions of participants experiencing a grade 3 or 4 adverse event were 4.0, 4.5, and 4.4% in the control, SR1, and SR2 groups, respectively. CONCLUSIONS: Four-month high-dose rifampicin regimens did not have dose-limiting toxicities or side effects but failed to meet noninferiority criteria compared with the standard 6-month control regimen for treatment of pulmonary tuberculosis. (Funded by the MRC/Wellcome Trust/DFID Joint Global Health Trials Scheme; ClinicalTrials.gov number, NCT02581527.)

Community engagement to increase vaccine uptake: Quasi-experimental evidence from Islamabad and Rawalpindi, Pakistan.

Developing countries have been facing difficulties in reaching out to low-income and underserved communities for COVID-19 vaccination coverage. The rapidity of vaccine development caused a mistrust among certain subgroups of the population, and hence innovative approaches were taken to reach out to such populations. Using a sample of 1760 respondents in five low-income, informal localities of Islamabad and Rawalpindi, Pakistan, we evaluated a set of interventions involving community engagement by addressing demand and access barriers. We used multi-level mixed effects models to estimate average treatment effects across treatment areas. We found that our interventions increased COVID-19 vaccine willingness in two treatment areas that are furthest from city centers by 7.6% and 6.6% respectively, while vaccine uptake increased in one of the treatment areas by 17.1%, compared to the control area. Our results suggest that personalized information campaigns such as community mobilization help to increase COVID-19 vaccine willingness. Increasing uptake however, requires improving access to the vaccination services. Both information and access may be different for various communities and therefore a "one-size-fits-all" approach may need to be better localized. Such underserved and marginalized communities are better served if vaccination efforts are contextualized.

The Case of the Young Male with a Longstanding History of Dyspeptic Symptoms: Peritoneal Tuberculosis.

Portal vein thrombosis associated with peritoneal tuberculosis is an uncommon manifestation of extrapulmonary tuberculosis. We report one such case of a 33-year-old male with a one-year history of dyspepsia, having been on proton pump inhibitors all this time with temporary relief. In view of ongoing symptoms, an endoscopy was done, which at first showed duodenal ulcer. On repeat endoscopy after an interval, there was evidence of mucosa-associated lymphoid tissue (MALT) lymphoma, which prompted a host of investigations in the patient. A positron emission tomography (PET) scan revealed extensive omento-peritoneal involvement along with a hypodense lesion in the liver with interval development of portal vein thrombosis on a CT scan of the abdomen. The biopsy of the hepatic lesion showed granulomatous inflammation. Faced with a diagnostic dilemma, finally, a laparoscopic biopsy was done, which confirmed the diagnosis of peritoneal TB with portal vein thrombosis. This case highlights the importance of keeping a high index of suspicion to include tuberculosis as a differential when presented with a case such as this and to conduct appropriate investigations to establish the correct diagnosis.

Connecting SiO4 in Silicate and Silicate Chain Networks to Compute Kulli Temperature Indices.

A topological index is a numerical parameter that is derived mathematically from a graph structure. In chemical graph theory, these indices are used to quantify the chemical properties of chemical compounds. We compute the first and second temperature, hyper temperature indices, the sum connectivity temperature index, the product connectivity temperature index, the reciprocal product connectivity temperature index and the F temperature index of a molecular graph silicate network and silicate chain network. Furthermore, a QSPR study of the key topological indices is provided, and it is demonstrated that these topological indices are substantially linked with the physicochemical features of COVID-19 medicines. This theoretical method to find the temperature indices may help chemists and others in the pharmaceutical industry forecast the properties of silicate networks and silicate chain networks before trying.

A Paradigmatic Approach to Find the Valency-Based K-Banhatti and Redefined Zagreb Entropy for Niobium Oxide and a Metal-Organic Framework.

Entropy is a thermodynamic function in chemistry that reflects the randomness and disorder of molecules in a particular system or process based on the number of alternative configurations accessible to them. Distance-based entropy is used to solve a variety of difficulties in biology, chemical graph theory, organic and inorganic chemistry, and other fields. In this article, the characterization of the crystal structure of niobium oxide and a metal-organic framework is investigated. We also use the information function to compute entropies by building these structures with degree-based indices including the K-Banhatti indices, the first redefined Zagreb index, the second redefined Zagreb index, the third redefined Zagreb index, and the atom-bond sum connectivity index.

Optimal control problem arising from COVID-19 transmission model with rapid-test.

The world health organization (WHO) has declared the Coronavirus (COVID-19) a pandemic. In light of this ongoing global issue, different health and safety measure has been recommended by the WHO to ensure the proactive, comprehensive, and coordinated steps to bring back the whole world into a normal situation. This is an infectious disease and can be modeled as a system of non-linear differential equations with reaction rates which consider the rapid-test as the intervention program. Therefore, we have developed the biologically feasible region, i.e., positively invariant for the model and boundedness solution of the system. Our system becomes well-posed mathematically and epidemiologically for sensitive analysis and our analytical result shows an occurrence of a forward bifurcation when the basic reproduction number is equal to unity. Further, the local sensitivities for each model state concerning the model parameters are computed using three different techniques: non-normalizations, half-normalizations, and full normalizations. The numerical approximations have been measured by using System Biology Toolbox (SBedit) with MATLAB, and the model is analyzed graphically. Our result on the sensitivity analysis shows a potential of rapid-test for the eradication program of COVID-19. Therefore, we continue our result by reconstructing our model as an optimal control problem. Our numerical simulation shows a time-dependent rapid test intervention succeeded in suppressing the spread of COVID-19 effectively with a low cost of the intervention. Finally, we forecast three COVID-19 incidence data from China, Italy, and Pakistan. Our result suggests that Italy already shows a decreasing trend of cases, while Pakistan is getting closer to the peak of COVID-19.

In vitro Analysis of Surface Roughness Produced by an Air Polishing Device and Conventional Root Planing on Cementum: A Profilometric Study.

Context: Tooth surface polishing is an integral part of periodontal therapy. Enamel and cementum show a smooth surface clinically after debridement with the naked eye, but numerous surface irregularities can be detected microscopically. Air polishing is safe and effective when used by trained professionals. Aims: The aim of the study is to evaluate and compare the surface roughness of cementum by using an air polishing device and conventional root planing with hand instruments. Materials and Methods: A total of 45 extracted teeth stored in saline were divided into three groups randomly - Group A (conventional root planing), Group B (hand instrumentation and air polishing), and Group C (air polishing alone) - with 15 samples each. Samples were evaluated for surface roughness by using profilometer. Six parameters were checked for surface roughness. Statistical Analysis Used: The data were collected, charted, and analyzed using one-way ANOVA with post hoc LSD method for pairwise comparisons. Results: Least amount of surface roughness was achieved with Group C when compared with Group A and Group B. These differences were statistical significant (P < 0.0001). Conclusions: Air polishing can effectively smoothen the root surface by removing surface irregularities which are produced hand/ultrasonic instruments. Profilometer can be effectively used to measure the surface roughness.