Individually optimal choices can be collectively disastrous in COVID-19 disease control.

BACKGROUND: The word 'pandemic' conjures dystopian images of bodies stacked in the streets and societies on the brink of collapse. Despite this frightening picture, denialism and noncompliance with public health measures are common in the historical record, for example during the 1918 Influenza pandemic or the 2015 Ebola epidemic. The unique characteristics of SARS-CoV-2-its high basic reproduction number (R0), time-limited natural immunity and considerable potential for asymptomatic spread-exacerbate the public health repercussions of noncompliance with interventions (such as vaccines and masks) to limit disease transmission. Our work explores the rationality and impact of noncompliance with measures aimed at limiting the spread of SARS-CoV-2. METHODS: In this work, we used game theory to explore when noncompliance confers a perceived benefit to individuals. We then used epidemiological modeling to predict the impact of noncompliance on control of SARS-CoV-2, demonstrating that the presence of a noncompliant subpopulation prevents suppression of disease spread. RESULTS: Our modeling demonstrates that noncompliance is a Nash equilibrium under a broad set of conditions and that the existence of a noncompliant population can result in extensive endemic disease in the long-term after a return to pre-pandemic social and economic activity. Endemic disease poses a threat for both compliant and noncompliant individuals; all community members are protected if complete suppression is achieved, which is only possible with a high degree of compliance. For interventions that are highly effective at preventing disease spread, however, the consequences of noncompliance are borne disproportionately by noncompliant individuals. CONCLUSIONS: In sum, our work demonstrates the limits of free-market approaches to compliance with disease control measures during a pandemic. The act of noncompliance with disease intervention measures creates a negative externality, rendering suppression of SARS-CoV-2 spread ineffective. Our work underscores the importance of developing effective strategies for prophylaxis through public health measures aimed at complete suppression and the need to focus on compliance at a population level.

Cigarette smoking and quit attempts among injection drug users in Tijuana, Mexico.

INTRODUCTION: Injection drug use and cigarette smoking are major global health concerns. Limited data exist regarding cigarette smoking behavior and quit attempts among injection drug users (IDUs) in low- and middle-income countries to inform the development of cigarette smoking interventions. We conducted a cross-sectional study to describe cigarette smoking behavior and quit attempts among IDUs in Tijuana, Mexico. METHODS: IDUs were recruited through community outreach and administered in-person interviews. Multivariable Poisson regression models were constructed to determine prevalence ratios (PRs) for quit attempts. RESULTS: Of the 670 participants interviewed, 601 (89.7%) were current smokers. Of these, median number of cigarettes smoked daily was 10; 190 (31.6%) contemplated quitting smoking in the next 6 months; 132 (22.0%) had previously quit for ≥1 year; and 124 (20.6%) had made a recent quit attempt (lasting ≥1 day during the previous 6 months). In multivariable analysis, recent quit attempts were positively associated with average monthly income (≥3,500 pesos [US$280] vs. <1,500 pesos [US$120]; PR = 2.30; 95% CI = 1.57-3.36), smoking marijuana (PR = 1.38; 95% CI = 1.01-2.90), and smoking heroin (PR = 1.85; 95% CI = 1.23-2.78), and they were negatively associated with number of cigarettes smoked daily (PR = 0.96; 95% CI = 0.94-0.98). CONCLUSIONS: One out of 5 IDUs attempted to quit cigarette smoking during the previous 6 months. Additional research is needed to improve the understanding of the association between drug use patterns and cigarette smoking quit attempts, including the higher rate of quit attempts observed among IDUs who smoke marijuana or heroin compared with IDUs who do not smoke these substances.

Prenatal alcohol exposure patterns and alcohol-related birth defects and growth deficiencies: a prospective study.

BACKGROUND: The physical features of fetal alcohol syndrome include smooth philtrum, thin vermillion border, short palpebral fissures, microcephaly, and growth deficiencies on weight and height. However, little is known about the specific quantities of alcohol exposure, pattern of drinking, timing of exposure, and magnitude of risk for each of these features. METHODS: Using data on 992 subjects collected prospectively in California between 1978 and 2005, we examined the patterns and timing of alcohol exposure in relation to these features. Structural features were assessed by a dysmorphologist who performed a blinded physical examination of all infants. Patterns of drinking were evaluated by drinks per day, number of binge episodes, and maximum number of drinks. Timing of exposure was evaluated 0 to 6 weeks postconception, 6 to 12 weeks postconception, first trimester, second trimester, and third trimester. RESULTS: Higher prenatal alcohol exposure in every pattern was significantly associated with the incidence of smooth philtrum but not with short palpebral fissures. The strongest associations were with timing of exposure in the second half of the first trimester (RR 1.25, 95% CI 1.14 to 1.36 for average number of drinks per day; RR 1.17, 95% CI 1.09 to 1.26 for maximum number of drinks in 1 episode). Similarly, thin vermillion border was most strongly associated with exposure in the second half of the first trimester. Findings with respect to timing of exposure were similar for microcephaly and reduced birth weight. However, reduced birth length was increased with exposure in any trimester. These associations were linear, and there was no evidence of a threshold. CONCLUSIONS: Reduced birth length and weight, microcephaly, smooth philtrum, and thin vermillion border are associated with specific gestational timing of prenatal alcohol exposure and are dose-related without evidence of a threshold. Women should continue to be advised to abstain from alcohol consumption from conception throughout pregnancy.

Patterns of prenatal alcohol exposure and associated non-characteristic minor structural malformations: a prospective study.

The characteristic facial features of the more severe end of Fetal Alcohol Spectrum Disorders (FASD) include smooth philtrum, thin vermillion of the upper lip, and short palpebral fissures. A systematic evaluation of a comprehensive list of minor structural defects in association with varying patterns of prenatal exposure to alcohol has not been performed. We examined the patterns and timing of prenatal alcohol exposure to minor structural malformations occurring in at least 5% of the sample. Patterns of drinking were evaluated by drinks per day, number of binge episodes, and maximum number of drinks. Timing of exposure was evaluated 0-6 weeks post-conception, 6-12 weeks post-conception, first trimester, second trimester, and third trimester. Naevus flammeus neonatorum is significantly associated with various patterns of drinking during the second half of the first trimester (RR 1.14, 95% CI 1.04, 1.24 for average number of drinks per day; RR 1.04, 95% CI 1.02, 1.07 for number of binge episodes; RR 1.08, 95% CI 1.01, 1.15 for maximum number of drinks in one episode) and similar for number of binge episodes in all categories of timing of exposure and in the second trimester for average number of drinks per day. Other minor malformations occurring in at least 5% of the sample were not found to be significantly associated with prenatal alcohol exposure. Expected minor malformations were not found to be significantly associated with prenatal alcohol exposure. Naevus flammeus neonatorum appears to be part of the spectrum of features associated with prenatal alcohol exposure.

Work and empowerment: women and agriculture in South India.

This article explores the implications of women's work in agriculture in Telangana, a region in the state of Andhra Pradesh, India. I suggest that higher capital costs for cultivators' post-liberalisation increased the pressure to contain wage costs in a region where women form the majority of the agricultural wage labour force. Under such conditions, when women perform both own-cultivation as well as agricultural wage work in the fields of others, they face pressure to restrict bargaining for higher wages, contributing to a widening gender wage gap. To the extent that wages shape intra-household bargaining power, the empowering effect of workforce participation for such women would thus be blunted. From available NSS data I provide some preliminary evidence in support of this argument.