Publications
108 results found
Haw DJ, Biggerstaff M, Prasad P, et al., 2023, Using real-time data to guide decision-making during an influenza pandemic: A modelling analysis., PLoS Comput Biol, Vol: 19
Influenza pandemics typically occur in multiple waves of infection, often associated with initial emergence of a novel virus, followed (in temperate regions) by a resurgence accompanying the onset of the annual influenza season. Here, we examined whether data collected from an initial pandemic wave could be informative, for the need to implement non-pharmaceutical measures in any resurgent wave. Drawing from the 2009 H1N1 pandemic in 10 states in the USA, we calibrated simple mathematical models of influenza transmission dynamics to data for laboratory confirmed hospitalisations during the initial 'spring' wave. We then projected pandemic outcomes (cumulative hospitalisations) during the fall wave, and compared these projections with data. Model results showed reasonable agreement for all states that reported a substantial number of cases in the spring wave. Using this model we propose a probabilistic decision framework that can be used to determine the need for preemptive measures such as postponing school openings, in advance of a fall wave. This work illustrates how model-based evidence synthesis, in real-time during an early pandemic wave, could be used to inform timely decisions for pandemic response.
Arinaminpathy N, Rade K, Kumar R, et al., 2023, The potential impact of vaccination on tuberculosis burden in India: A modelling analysis., Indian J Med Res, Vol: 157, Pages: 119-126, ISSN: 0971-5916
BACKGROUND & OBJECTIVES: Vaccination will play an important role in meeting the end tuberculosis (TB) goals. While certain vaccine candidates in advanced stages of clinical trials raise hope for the future availability of new tools, in the immediate term, there is also increasing interest in Bacille Calmette-Guérin revaccination among adults and adolescents as a potential strategy. Here, we sought to estimate the potential epidemiological impact of TB vaccination in India. METHODS: We developed a deterministic, age-structured, compartmental model of TB in India. Data from the recent national prevalence survey was used to inform epidemiological burden while also incorporating a vulnerable population who may be prioritized for vaccination, the latter consistent with the burden of undernutrition. Using this framework, the potential impact on incidence and mortality of a vaccine with 50 per cent efficacy was estimated, if rolled out in 2023 to cover 50 per cent of the unvaccinated each year. Simulated impacts were compared for disease- vs. infection-preventing vaccines, as well as when prioritizing vulnerable groups (those with undernutrition) rather than the general population. A sensitivity analyses were also conducted with respect to the duration, and efficacy, of vaccine immunity. RESULTS: When rolled out in the general population, an infection-preventing vaccine would avert 12 per cent (95% Bayesian credible intervals (Crl): 4.3-28%) of cumulative TB incidence between 2023 and 2030, while a disease-preventing vaccine would avert 29 per cent (95% Crl: 24-34%). Although the vulnerable population accounts for only around 16 per cent of India's population, prioritizing this group for vaccination would achieve almost half the impact of rollout in the general population, in the example of an infection-preventing vaccine. Sensitivity analysis also highlights the importance of the duration and efficacy of vaccine-induced immunity. INTERPRETATION & CONCLUSION
Baik Y, Cilloni L, Kendall E, et al., 2022, Symptom-based vs asymptomatic testing for controlling SARS-CoV-2 transmission in low- and middle-income countries: A modelling analysis., Epidemics, Vol: 41
BACKGROUND: Diagnostic testing plays a critical role in the global COVID-19 response. Polymerase chain reaction (PCR) tests are highly accurate, but in resource-limited settings, limited capacity has led to testing delays; whereas lateral flow assays (LFAs) offer opportunities for rapid and affordable testing. We examined the potential epidemiological impact of different strategies for LFA deployment. METHODS: We developed a deterministic compartmental model of SARS-CoV-2 transmission, parameterised to resemble a large Indian city. We assumed that PCR would be used to test symptomatic individuals presenting to outpatient settings for care. We examined how the second epidemic wave in India could have been mitigated by LFA deployment in its early stages by comparing two strategies: (i) community-based screening, using LFAs to test a proportion of the population, irrespective of symptoms (in addition to symptom-driven PCR), and (ii) symptom-driven outpatient testing, using LFAs to replace PCR. RESULTS: Model projections suggest that a stock of 25 million LFAs, used over a 600-day period in a city of 20 million people, would reduce the cumulative symptomatic incidence of COVID-19 by 0.44% if used for community-based screening, and by 13% if used to test symptomatic outpatients, relative to a no-LFA, PCR-only scenario. Sensitivity analysis suggests that outpatient testing would be more efficient in reducing transmission than community-based screening, when at least 5% of people with symptomatic COVID-19 seek care, and at least 10% of SARS-CoV-2 infections develop symptoms. Under both strategies, however, 2% of the population would be unnecessarily isolated. INTERPRETATION: In this emblematic setting, LFAs would reduce transmission most efficiently when used to test symptomatic individuals in outpatient settings. To avoid large numbers of unnecessary isolations, mass testing with LFAs should be considered as a screening tool, with follow-up confirmation. Future work shoul
Sahu S, Wandwalo E, Arinaminpathy N, 2022, Exploring the Impact of the COVID-19 Pandemic on Tuberculosis Care and Prevention, JOURNAL OF THE PEDIATRIC INFECTIOUS DISEASES SOCIETY, Vol: 11, Pages: S67-S71, ISSN: 2048-7193
Nsengiyumva NP, Campbell JR, Oxlade O, et al., 2022, Scaling up target regimens for tuberculosis preventive treatment in Brazil and South Africa: An analysis of costs and cost-effectiveness, PLOS MEDICINE, Vol: 19, ISSN: 1549-1277
Vesga J, Lienhardt C, Nsengimyumva P, et al., 2022, Prioritising attributes for tuberculosis preventive treatment regimens: a modelling analysis, BMC Medicine, Vol: 20, ISSN: 1741-7015
Background:Recent years have seen important improvements in available preventive treatment regimens for tuberculosis (TB), and research is ongoing to develop these further. To assist with the formulation of target product profiles for future regimens, we examined which regimen properties would be most influential in the epidemiological impact of preventive treatment.Methods:Following expert consultation, we identified 5 regimen properties relevant to the incidence-reducing impact of a future preventive treatment regimen: regimen duration, efficacy, ease-of-adherence (treatment completion rates in programmatic conditions), forgiveness to non-completion and the barrier to developing rifampicin resistance during treatment. For each regimen property, we elicited expert input for minimally acceptable and optimal (ideal-but-feasible) performance scenarios for future regimens. Using mathematical modelling, we then examined how each regimen property would influence the TB incidence reduction arising from full uptake of future regimens according to current WHO guidelines, in four countries: South Africa, Kenya, India and Brazil.Results:Of all regimen properties, efficacy is the single most important predictor of epidemiological impact, while ease-of-adherence plays an important secondary role. These results are qualitatively consistent across country settings; sensitivity analyses show that these results are also qualitatively robust to a range of model assumptions, including the mechanism of action of future preventive regimens.Conclusions:As preventive treatment regimens against TB continue to improve, understanding the key drivers of epidemiological impact can assist in guiding further development. By meeting these key targets, future preventive treatment regimens could play a critical role in global efforts to end TB.
Mandal S, Parchani K, Arinaminpathy N, et al., 2022, 'Imperfect but useful': pandemic response in the Global South can benefit from greater use of mathematical modelling, BMJ GLOBAL HEALTH, Vol: 7, ISSN: 2059-7908
- Author Web Link
- Cite
- Citations: 1
Arinaminpathy N, Saad-Roy CM, Yang Q, et al., 2022, A global system for the next generation of vaccines COVID-19 has shown that hurdles can be overcome, Science, Vol: 376, Pages: 462-464, ISSN: 0036-8075
Den Boon S, Lienhardt C, Zignol M, et al., 2022, WHO target product profiles for TB preventive treatment, INTERNATIONAL JOURNAL OF TUBERCULOSIS AND LUNG DISEASE, Vol: 26, Pages: 302-+, ISSN: 1027-3719
- Author Web Link
- Cite
- Citations: 4
Mandal S, Arinaminpathy N, Bhargava B, et al., 2021, Responsible travel to and within India during the COVID-19 pandemic, JOURNAL OF TRAVEL MEDICINE, Vol: 28, ISSN: 1195-1982
Kendall EA, Arinaminpathy N, Sacks JA, et al., 2021, Antigen-based Rapid Diagnostic Testing or Alternatives for Diagnosis of Symptomatic COVID-19 A Simulation-based Net Benefit Analysis, EPIDEMIOLOGY, Vol: 32, Pages: 811-819, ISSN: 1044-3983
- Author Web Link
- Cite
- Citations: 5
Silva S, Arinaminpathy N, Atu R, et al., 2021, Economic impact of tuberculosis mortality in 120 countries and the cost of not achieving the Sustainable Development Goals tuberculosis targets: a full-income analysis (vol 9, pg e1372, 2021), LANCET GLOBAL HEALTH, Vol: 9, Pages: E1507-E1507, ISSN: 2214-109X
Shrestha S, Kendall EA, Chang R, et al., 2021, Achieving a "step change" in the tuberculosis epidemic through comprehensive community-wide intervention: a model-based analysis, BMC MEDICINE, Vol: 19, ISSN: 1741-7015
- Author Web Link
- Cite
- Citations: 4
Arinaminpathy N, Nandi A, Shibu V, et al., 2021, Engaging with the private healthcare sector for the control of tuberculosis in India: Cost and cost-effectiveness, BMJ Global Health, Vol: 6, Pages: 1-10, ISSN: 2059-7908
BackgroundThe control of tuberculosis (TB) in India is complicated by the presence of a large, disorganised private sector where most patients first seek care. Following pilots in Mumbai and Patna (two major cities in India), an initiative known as the ‘Public Private Interface Agency’ (PPIA) is now being expanded across the country. We aimed to estimate the cost-effectiveness of scaling up PPIA operations, in line with India’s National Strategic Plan for TB control.MethodsFocusing on Mumbai and Patna, we collected cost data from implementing organisations in both cities and combined this data with models of TB transmission dynamics. Estimating the cost per DALY averted between 2014 (the start of PPIA scale-up) and 2025, we assessed cost-effectiveness using two willingness-to-pay approaches: a WHO-CHOICE threshold based on per-capita economic productivity, and a more stringent threshold incorporating opportunity costs in the health system.FindingsA PPIA scaled up to ultimately reach 50% of privately-treated TB patients in Mumbai and Patna would cost, respectively, USD 228 (95% C.I. 159 – 320) per DALY averted and USD 564 (95% C.I. 409 - 775) per DALY averted. In Mumbai, the PPIA would be cost-effective relative to all thresholds considered. In Patna, if focusing on adherence support, rather than on improved diagnosis, the PPIA would be cost-effective relative to all thresholds considered. These differences between sites arise from variations in the burden of drug resistance: amongst the services of a PPIA, improved diagnosis (including rapid tests with genotypic drug sensitivity testing) has greatest value in settings such as Mumbai, with a high burden of drug-resistant TB.ConclusionsTo accelerate decline in TB incidence, it is critical first to engage effectively with the private sector in India. Mechanisms such as the PPIA offer cost-effective ways of doing so, particularly when tailored to local settings.
Silva S, Arinaminpathy N, Atun R, et al., 2021, Economic impact of tuberculosis mortality in 120 countries and the cost of not achieving the Sustainable Development Goals tuberculosis targets: a full-income analysis, LANCET GLOBAL HEALTH, Vol: 9, Pages: E1372-E1379, ISSN: 2214-109X
- Author Web Link
- Cite
- Citations: 13
Arinaminpathy N, Das J, McCormick T, et al., 2021, Quantifying heterogeneity in SARS-CoV-2 transmission during the lockdown in India, Epidemics: the journal of infectious disease dynamics, Vol: 36, Pages: 1-7, ISSN: 1755-4365
The novel SARS-CoV-2 virus, as it manifested in India in April 2020, showed marked heterogeneity in its transmission. Here, we used data collected from contact tracing during the lockdown in response to the first wave of COVID-19 in Punjab, a major state in India, to quantify this heterogeneity, and to examine implications for transmission dynamics. We found evidence of heterogeneity acting at multiple levels: in the number of potentially infectious contacts per index case, and in the per-contact risk of infection. Incorporating these findings in simple mathematical models of disease transmission reveals that these heterogeneities act in combination to strongly influence transmission dynamics. Standard approaches, such as representing heterogeneity through secondary case distributions, could be biased by neglecting these underlying interactions between heterogeneities. We discuss implications for policy, and for more efficient contact tracing in resource-constrained settings such as India. Our results highlight how contact tracing, an important public health measure, can also provide important insights into epidemic spread and control.
Mandal S, Arinaminpathy N, Bhargava B, et al., 2021, Responsive and agile vaccination strategies against COVID-19 in India, LANCET GLOBAL HEALTH, Vol: 9, Pages: E1197-E1200, ISSN: 2214-109X
- Author Web Link
- Cite
- Citations: 8
Mandal S, Arinaminpathy N, Bhargava B, et al., 2021, Plausibility of a third wave of COVID-19 in India: A mathematical modelling based analysis., Indian J Med Res, Vol: 153, Pages: 522-532
BACKGROUND & OBJECTIVES: In the context of India's ongoing resurgence of COVID-19 (second wave since mid-February 2021, following the subsiding of the first wave in September 2020), there has been increasing speculation on the possibility of a future third wave of infection, posing a burden on the healthcare system. Using simple mathematical models of the transmission dynamics of SARS-CoV-2, this study examined the conditions under which a serious third wave could occur. METHODS: Using a deterministic, compartmental model of SARS-CoV-2 transmission, four potential mechanisms for a third wave were examined: (i) waning immunity restores previously exposed individuals to a susceptible state, (ii) emergence of a new viral variant that is capable of escaping immunity to previously circulating strains, (iii) emergence of a new viral variant that is more transmissible than the previously circulating strains, and (iv) release of current lockdowns affording fresh opportunities for transmission. RESULTS: Immune-mediated mechanisms (waning immunity, or viral evolution for immune escape) are unlikely to drive a severe third wave if acting on their own, unless such mechanisms lead to a complete loss of protection among those previously exposed. Likewise, a new, more transmissible variant would have to exceed a high threshold (R0>4.5) to cause a third wave on its own. However, plausible mechanisms for a third wave include: (i) a new variant that is more transmissible and at the same time capable of escaping prior immunity, and (ii) lockdowns that are highly effective in limiting transmission and subsequently released. In both cases, any third wave seems unlikely to be as severe as the second wave. Rapid scale-up of vaccination efforts could play an important role in mitigating these and future waves of the disease. INTERPRETATION & CONCLUSIONS: This study demonstrates plausible mechanisms by which a substantial third wave could occur, while also illustrating that it is
Mandal S, Arinaminpathy N, Bhargava B, et al., 2021, Plausibility of a third wave of COVID-19 in India: A mathematical modelling based analysis, INDIAN JOURNAL OF MEDICAL RESEARCH, Vol: 153, Pages: 522-+, ISSN: 0971-5916
- Author Web Link
- Cite
- Citations: 14
Ricks S, Kendall EA, Dowdy DW, et al., 2021, Quantifying the potential value of antigen-detection rapid diagnostic tests for COVID-19: a modelling analysis, BMC Medicine, Vol: 19, Pages: 1-13, ISSN: 1741-7015
BackgroundTesting plays a critical role in treatment and prevention responses to the COVID-19 pandemic. Compared to nucleic acid tests (NATs), antigen-detection rapid diagnostic tests (Ag-RDTs) can be more accessible, but typically have lower sensitivity and specificity. By quantifying these trade-offs, we aimed to inform decisions about when an Ag-RDT would offer greater public health value than reliance on NAT. MethodsFollowing an expert consultation, we selected two use cases for analysis: rapid identification of people with COVID-19 amongst patients admitted with respiratory symptoms in a ‘hospital’ setting; and early identification and isolation of people with mildly symptomatic COVID-19 in a ‘community’ setting. Using decision analysis, we evaluated the health system cost and health impact (deaths averted and infectious days isolated) of an Ag-RDT-led strategy, compared to a strategy based on NAT and clinical judgment. We adopted a broad range of values for ‘contextual’ parameters relevant to a range of settings, including the availability of NAT, the performance of clinical judgement, etc. We performed a multivariate sensitivity analysis to all of these parameters. ResultsIn a hospital setting, an Ag-RDT-led strategy would avert more deaths than a NAT-based strategy, and at lower cost per death averted, when the sensitivity of clinical judgement is less than 85%, and when NAT results are available in time to inform clinical decision-making for less than 90% of patients. The use of an Ag-RDT is robustly supported in community settings, where it would avert more transmission at lower cost than relying on NAT alone, under a wide range of assumptions. ConclusionsDespite their imperfect sensitivity and specificity, Ag-RDTs have the potential to be simultaneously more impactful, and have a lower cost per death and infectious person-days averted, than current approaches to COVID-19 diagnostic testing.
Mandal S, Das H, Deo S, et al., 2021, Combining serology with case-detection, to allow the easing of restrictions against SARS-CoV-2: a modelling-based study in India, Scientific Reports, Vol: 11, Pages: 1-9, ISSN: 2045-2322
India’s lockdown against SARS-CoV-2, if lifted without any other mitigations in place, could risk a second wave of infection. A test-and-isolate strategy, using PCR diagnostic tests, could help to minimise the impact of this second wave. Meanwhile, population-level serological surveillance can provide valuable insights into the level of immunity in the population. Using a mathematical model, consistent with an Indian megacity, we examined how seroprevalence data could guide a test-and-isolate strategy, for lifting a lockdown. For example, if seroprevalence is 20% of the population, we show that a testing strategy needs to identify symptomatic cases within 5 – 8 days of symptom onset, in order to prevent a resurgent wave from overwhelming hospital capacity in the city. This estimate is robust to uncertainty in the effectiveness of the lockdown, as well as in immune protection against reinfection. To set these results in their economic context, we estimate that the weekly cost of such a PCR-based testing programme would be less than 2.1% of the weekly economic loss due to the lockdown. Our results illustrate how PCR-based testing and serological surveillance can be combined to design evidence-based policies, for lifting lockdowns in Indian cities and elsewhere.
Fu H, Lewnard JA, Frost I, et al., 2021, Modelling the global burden of drug-resistant tuberculosis avertable by a post-exposure vaccine, Nature Communications, Vol: 12, Pages: 1-9, ISSN: 2041-1723
There have been notable advances in the development of vaccines against active tuberculosis (TB) disease for adults and adolescents. Using mathematical models, we seek to estimate the potential impact of a post-exposure TB vaccine, having 50% efficacy in reducing active disease, on global rifampicin-resistant (RR-) TB burden. In 30 countries that together accounted for 90% of global RR-TB incidence in 2018, a future TB vaccine could avert 10% (95% credible interval: 9.7–11%) of RR-TB cases and 7.3% (6.6–8.1%) of deaths over 2020–2035, with India, China, Indonesia, Pakistan, and the Russian Federation having the greatest contribution. This impact would increase to 14% (12–16%) and 31% (29–33%) respectively, when combined with improvements in RR-TB diagnosis and treatment relative to a scenario of no vaccine and no such improvements. A future TB vaccine could have important implications for the global control of RR-TB, especially if implemented alongside enhancements in management of drug resistance.
Mandal S, Arinaminpathy N, Bhargava B, et al., 2021, India's pragmatic vaccination strategy against COVID-19: a mathematical modelling-based analysis, BMJ OPEN, Vol: 11, ISSN: 2044-6055
- Author Web Link
- Cite
- Citations: 7
Ricks S, Denkinger CM, Schumacher SG, et al., 2020, The potential impact of urine-LAM diagnostics on tuberculosis incidence and mortality: a modelling analysis, PLoS Medicine, Vol: 17, ISSN: 1549-1277
BackgroundLateral flow urine lipoarabinomannan (LAM) tests could offer important new opportunities for the early detection of tuberculosis (TB). The currently licensed LAM test, Alere Determine TB LAM Ag (‘LF-LAM’), performs best in the sickest people living with HIV (PLHIV). However, the technology continues to improve, with newer LAM tests, such as Fujifilm SILVAMP TB LAM (‘SILVAMP-LAM’) showing improved sensitivity, including amongst HIV-negative patients. It is important to anticipate the epidemiological impact that current and future LAM tests may have on TB incidence and mortality.Methods and findingsConcentrating on South Africa, we examined the impact that widening LAM test eligibility would have on TB incidence and mortality. We developed a mathematical model of TB transmission to project the impact of LAM tests, distinguishing ‘current’ tests (with sensitivity consistent with LF-LAM), from hypothetical ‘future’ tests (having sensitivity consistent with SILVAMP-LAM). We modelled the impact of both tests, assuming full adoption of the 2019 WHO guidelines for the use of these tests amongst those receiving HIV care. We also simulated the hypothetical deployment of future LAM tests for all people presenting to care with TB symptoms, not restricted to PLHIV. Our model projects that 2,700,000 (95% credible interval [CrI] 2,000,000–3,600,000) and 420,000 (95% CrI 350,000–520,000) cumulative TB incident cases and deaths, respectively, would occur between 2020 and 2035 if the status quo is maintained. Relative to this comparator, current and future LAM tests would respectively avert 54 (95% CrI 33–86) and 90 (95% CrI 55–145) TB deaths amongst inpatients between 2020 and 2035, i.e., reductions of 5% (95% CrI 4%–6%) and 9% (95% CrI 7%–11%) in inpatient TB mortality. This impact in absolute deaths averted doubles if testing is expanded to include outpatients, yet remains <1% of count
Cilloni L, Arinaminpathy N, Stagg H, et al., 2020, Trade-offs between cost and accuracy in active case-finding for tuberculosis: a dynamic modelling analysis, PLoS Medicine, Vol: 17, Pages: 1-20, ISSN: 1549-1277
BackgroundActive case-finding (ACF) may be valuable in tuberculosis (TB) control, but questions remain about its optimum implementation in different settings. For example, smear microscopy misses up to half of TB cases, yet is cheap, and detects the most infectious TB cases. What, then, is the incremental value of using more sensitive and specific, yet more costly, tests such as Xpert MTB/RIF, in ACF in a high burden setting?Methods and FindingsWe constructed a dynamic transmission model of TB, calibrated to be consistent with an urban slum population in India. We applied this model to compare the potential cost and impact of two hypothetical approaches, following initial symptom screening: (i) ‘moderate accuracy’ testing employing a microscopy-like test (that is, lower cost but also lower accuracy) for bacteriological confirmation and (ii) ‘high accuracy’ testing employing an Xpert-like test (higher-cost but also higher accuracy, while also detecting rifampicin resistance).Results suggest that ACF using a moderate-accuracy test could in fact cost more overall than using a high-accuracy test. Under an illustrative budget of USD 20 million in a slum population of 2 million, high-accuracy testing would avert 1·14 (95% Bayesian credible intervals 0·75 – 1·99, with p = 0.28) cases relative to each case averted by moderate-accuracy testing. Test specificity is a key driver: high-accuracy testing would be significantly more impactful at the 5% significance level, as long as the high-accuracy test has specificity at least 3 percentage points greater than the moderate-accuracy test. Additional factors promoting the impact of a high-accuracy are that: its ability to detect rifampicin resistance can lead to long-term cost savings in second-line treatment; and its higher sensitivity contributes to the overall cases averted by ACF.Amongst limitations of this study, our cost model has a narrow focus on the commodity costs of tes
Cilloni L, Fu H, Vesga JF, et al., 2020, The potential impact of the COVID-19 pandemic on the tuberculosis epidemic a modelling analysis, EClinicalMedicine, Vol: 28, ISSN: 2589-5370
Background: Routine services for tuberculosis (TB) are being disrupted by stringent lockdowns against the novel SARS-CoV-2 virus. We sought to estimate the potential long-term epidemiological impact of such disruptions on TB burden in high-burden countries, and how this negative impact could be mitigated. Methods: We adapted mathematical models of TB transmission in three high-burden countries (India, Kenya and Ukraine) to incorporate lockdown-associated disruptions in the TB care cascade. The anticipated level of disruption reflected consensus from a rapid expert consultation. We modelled the impact of these disruptions on TB incidence and mortality over the next five years, and also considered potential interventions to curtail this impact. Findings: Even temporary disruptions can cause long-term increases in TB incidence and mortality. If lockdown-related disruptions cause a temporary 50% reduction in TB transmission, we estimated that a 3-month suspension of TB services, followed by 10 months to restore to normal, would cause, over the next 5 years, an additional 1⋅19 million TB cases (Crl 1⋅06-1⋅33) and 361,000 TB deaths (CrI 333-394 thousand) in India, 24,700 (16,100-44,700) TB cases and 12,500 deaths (8.8-17.8 thousand) in Kenya, and 4,350 (826-6,540) cases and 1,340 deaths (815-1,980) in Ukraine. The principal driver of these adverse impacts is the accumulation of undetected TB during a lockdown. We demonstrate how long term increases in TB burden could be averted in the short term through supplementary "catch-up" TB case detection and treatment, once restrictions are eased. Interpretation: Lockdown-related disruptions can cause long-lasting increases in TB burden, but these negative effects can be mitigated with rapid restoration of TB services, and targeted interventions that are implemented as soon as restrictions are lifted. Funding: USAID and Stop TB Partnership.
Reid MJA, Silva S, Arinaminpathy N, et al., 2020, Building a tuberculosis-free world while responding to the COVID-19 pandemic, LANCET, Vol: 396, Pages: 1312-1313, ISSN: 0140-6736
- Author Web Link
- Cite
- Citations: 10
Arinaminpathy N, Das J, McCormick TH, et al., 2020, Quantifying heterogeneity in SARS-CoV-2 transmission during the lockdown in India.
The novel SARS-CoV-2 virus shows marked heterogeneity in its transmission. Here, we used data collected from contact tracing during the lockdown in Punjab, a major state in India, to quantify this heterogeneity, and to examine implications for transmission dynamics. We found evidence of heterogeneity acting at multiple levels: in the number of potentially infectious contacts per index case, and in the per-contact risk of infection. Incorporating these findings in simple mathematical models of disease transmission reveals that these heterogeneities act in combination to strongly influence transmission dynamics. Standard approaches, such as representing heterogeneity through secondary case distributions, could be biased by neglecting these underlying interactions between heterogeneities. We discuss implications for policy, and for more efficient contact tracing in resource-constrained settings such as India. Our results highlight how contact tracing, an important public health measure, can also provide important insights into epidemic spread and control.
Hogan A, Jewell B, Sherrard-Smith E, et al., 2020, Potential impact of the COVID-19 pandemic on HIV, TB and malaria in low- and middle-income countries: a modelling study, The Lancet Global Health, Vol: 8, Pages: e1132-e1141, ISSN: 2214-109X
Background: COVID-19 has the potential to cause substantial disruptions to health services, including by cases overburdening the health system or response measures limiting usual programmatic activities. We aimed to quantify the extent to which disruptions in services for human immunodeficiency virus (HIV), tuberculosis (TB) and malaria in low- and middle-income countries with high burdens of those disease could lead to additional loss of life. Methods: We constructed plausible scenarios for the disruptions that could be incurred during the COVID-19 pandemic and used established transmission models for each disease to estimate the additional impact on health that could be caused in selected settings.Findings: In high burden settings, HIV-, TB- and malaria-related deaths over five years may increase by up to 10%, 20% and 36%, respectively, compared to if there were no COVID-19 pandemic. We estimate the greatest impact on HIV to be from interruption to antiretroviral therapy, which may occur during a period of high health system demand. For TB, we estimate the greatest impact is from reductions in timely diagnosis and treatment of new cases, which may result from any prolonged period of COVID-19 suppression interventions. We estimate that the greatest impact on malaria burden could come from interruption of planned net campaigns. These disruptions could lead to loss of life-years over five years that is of the same order of magnitude as the direct impact from COVID-19 in places with a high burden of malaria and large HIV/TB epidemics.Interpretation: Maintaining the most critical prevention activities and healthcare services for HIV, TB and malaria could significantly reduce the overall impact of the COVID-19 pandemic.Funding: Bill & Melinda Gates Foundation, The Wellcome Trust, DFID, MRC
Mandal S, Bhatia V, Sharma M, et al., 2020, The potential impact of preventive therapy against tuberculosis in the WHO South-East Asian Region: a modelling approach, BMC Medicine, Vol: 18, ISSN: 1741-7015
BackgroundThe prevention of tuberculosis (TB) is key for accelerating current, slow declines in TBburden. The 2018 World Health Organization (WHO) guidelines on eligibility forpreventive therapy to treat latent TB infection (LTBI) include: people living with humanimmunodeficiency virus (PLHIV), household contacts of TB patients including children,and those with clinical conditions including silicosis, dialysis, transplantation etc. andother country-specific groups. We aimed to estimate the potential impact of fullimplementation of these guidelines in the WHO South-East Asian (SEA) Region, whichbears the largest burden of TB and LTBI amongst the WHO Regions.MethodsWe developed mathematical models of TB transmission dynamics, calibratedindividually to each of the 11 countries in the Region. We modelled preventive therapyin the absence of other TB interventions. As an alternative comparator, reflectingongoing developments in TB control in the region, we also simulated improvements inthe treatment cascade for active TB, including private sector engagement andintensified case-finding. Relative to both scenarios, for each country in the region weprojected TB cases and deaths averted between 2020 and 2030, by full uptake ofpreventive therapy, defined as comprehensive coverage amongst eligible populationsas per WHO guidelines, and assuming outcomes consistent with clinical trials. We alsoperformed sensitivity analysis to illustrate impact under less-than-optimal conditions.ResultsAt the regional level, full uptake of preventive therapy amongst identified risk groupswould reduce annual incidence rates in 2030 by 8.30% (95% CrI 6.48 – 10.83) relativeto 2015, in the absence of any additional interventions. If implemented against abackdrop of improved TB treatment cascades, preventive therapy would achieve anincremental 6.93 percentage points (95% CrI 5.81 – 8.51) of reduction in annualincidence rates, compared to 2015. At the regional level, the numbers of individu
This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.