Changing determinants of infant and child mortality: on the basis of the Korean experience, 1955-73

Data from the 1974 Korean National Fertility Survey were analyzed to learn more about the main determinants of infant and child mortality in the course of mortality decline and how they change. In the Korean survey, about 5000 eligible women were selected for the individual survey and the sample design aimed at a self-weighting nationally representative and probability sample. Preliminary analysis showed clear mortality differentials between different socioeconomic levels and between demographic subgroups in infant and child mortality during the period 1955-73 in Korea. To examine the net effect of each variable on mortality, the logit-linear model was used. A table shows the probability level of 4 variables -- maternal age, birth order, mother's education, and number of rooms used by household -- in Korea, when the effects of others were controlled. In the urban areas, only the socioeconomic factors were the main determinants of infant mortality on all the birth cohorts. Mother's education and number of rooms used strongly affected infant mortality in the 1955-59 and 1960-64 birth cohorts, but the effects became weaker in the 1965-69 and 1970-73 birth cohorts, and their statistical significance was reduced. In the rural areas, the effects of 3 variables -- the exception being number of rooms used -- on infant mortality were statistically significant. It is concluded that the main determinants of infant mortality in urban areas were socioeconomic factors. The main determinants of infant mortality in the rural areas were demographic in the earlier birth cohorts, but in the recent birth cohorts mother's education, a socioeconomic factor, became the main determinant while the effects of demographic variables became weaker and finally disappeared. The change in the determinants of child mortality appears to be the reverse of that for infant mortality. Prior to the introduction of the national development program, in the rural areas mother's education was the main determinant of child mortality (rural 1955-59 cohort), but with the socioeconomic development the determinants changed to give dominance to demographic factors (urban 1955-59) cohort and, in the recent period, even the effects of demographic factors on child mortality became weaker (urban 1960-69 cohort). When the differences in living status by maternal age were weaker and the competition among siblings less because of small family size, only the socioeconomic variables remained as main determinants affecting child mortality.     

Epidemiology of mortality related to Chagas' disease in Brazil, 1999-2007

Background

Chagas'' disease is an important neglected public health problem in many Latin American countries, but population-based epidemiological data are scarce. Here we present a nationwide analysis on Chagas-associated mortality, and risk factors for death from this disease.

Methodology/Principal Findings

We analyzed all death certificates of individuals who died between 1999 and 2007 in Brazil, based on the nationwide Mortality Information System (a total of 243 data sets with about 9 million entries). Chagas'' disease was mentioned in 53,930 (0.6%) of death certificates, with 44,537 (82.6%) as an underlying cause and 9,387 (17.4%) as an associated cause of death. Acute Chagas'' disease was responsible for 2.8% of deaths. The mean standardized mortality rate was 3.36/100.000 inhabitants/year. Nationwide standardized mortality rates reduced gradually, from 3.78 (1999) to 2.78 (2007) deaths/year per 100,000 inhabitants (−26.4%). Standardized mortality rates were highest in the Central-West region, ranging from 15.23 in 1999 to 9.46 in 2007 (−37.9%), with a significant negative linear trend (p = 0.001; R² = 82%). Proportional mortality considering multiple causes of death was 0.60%. The Central-West showed highest proportional mortality among regions (2.17%), with a significant linear negative trend, from 2.28% to 1.90% (−19.5%; p = 0.001; R² = 84%). There was a significant increase in the Northeast of 38.5% (p = 0.006; R² = 82%). Bivariable analysis on risk factors for death from Chagas'' disease showed highest relative risks (RR) in older age groups (RR: 10.03; 95% CI: 9.40–10.70; p<0.001) and those residing in the Central-West region (RR: 15.01; 95% CI: 3.90–16.22; p<0.001). In logistic regression analysis, age ≥30 years (adjusted OR: 10.81; 95% CI: 10.03–10.65; p<0.001) and residence in one of the three high risk states Minas Gerais, Goiás or the Federal District (adjusted OR: 5.12; 95% CI: 5.03–5.22, p<0.001) maintained important independent risk factors for death by Chagas'' disease.

Conclusions/Significance

This is the first nationwide population-based study on Chagas mortality in Brazil, considering multiple causes of death. Despite the decline of mortality associated with Chagas'' disease in Brazil, the disease remains a serious public health problem with marked regional differences.     

Unemployment and mortality among Finnish men, 1981-5.

OBJECTIVE--To ascertain whether, after controlling for several relevant background variables simultaneously, unemployment is related to mortality and to assess whether this relation is causal or whether unhealthy people are more likely to become unemployed. DESIGN--Prospective study of mortality in Finland during 1981-5 based on 1980 census data on 30-54 year old wage earner men and with particular attention to unemployment in the year before the census. SETTING--Research project at the University of Helsinki. SUBJECTS--All wage earner men in Finland aged 30-54 at the 1980 census. MAIN OUTCOME MEASURES--Causes of death during 1981-5 and duration of unemployment in the year before the census. Background variables controlled for were age, socioeconomic state, marital state, and health. The data were analysed by log linear regression models. RESULTS--During the study period 1981-5, which covered almost 2.7 million person years, there were 9810 deaths. After controlling for all background variables relative total mortality among unemployed versus employed men was 1.93 (95% confidence interval 1.82 to 2.05). The excess mortality was highest in accidental and violent causes of death (relative mortality 2.51; 95% confidence interval 2.28 to 2.76). For circulatory diseases the relative death rate was 1.54 (95% confidence interval 1.40 to 1.70), but among neoplasms only lung cancer was associated with excess mortality. Selection for unemployment based on age, socioeconomic state, and marital state was evident but no such selection was detected based on health. Effects of unemployment on mortality were more pronounced with increasing duration of unemployment. CONCLUSIONS--The relative excess mortality of unemployed men in Finland cannot fully be explained by demographic, social, and health variables preceding unemployment. Unemployment therefore seems to have an independent causal effect on male mortality. Further studies are needed to elucidate the mechanisms between unemployment and mortality.     

Socioeconomic Factors and All Cause and Cause-Specific Mortality among Older People in Latin America,India, and China: A Population-Based Cohort Study

Background

Even in low and middle income countries most deaths occur in older adults. In Europe, the effects of better education and home ownership upon mortality seem to persist into old age, but these effects may not generalise to LMICs. Reliable data on causes and determinants of mortality are lacking.

Methods and Findings

The vital status of 12,373 people aged 65 y and over was determined 3–5 y after baseline survey in sites in Latin America, India, and China. We report crude and standardised mortality rates, standardized mortality ratios comparing mortality experience with that in the United States, and estimated associations with socioeconomic factors using Cox''s proportional hazards regression. Cause-specific mortality fractions were estimated using the InterVA algorithm. Crude mortality rates varied from 27.3 to 70.0 per 1,000 person-years, a 3-fold variation persisting after standardisation for demographic and economic factors. Compared with the US, mortality was much higher in urban India and rural China, much lower in Peru, Venezuela, and urban Mexico, and similar in other sites. Mortality rates were higher among men, and increased with age. Adjusting for these effects, it was found that education, occupational attainment, assets, and pension receipt were all inversely associated with mortality, and food insecurity positively associated. Mutually adjusted, only education remained protective (pooled hazard ratio 0.93, 95% CI 0.89–0.98). Most deaths occurred at home, but, except in India, most individuals received medical attention during their final illness. Chronic diseases were the main causes of death, together with tuberculosis and liver disease, with stroke the leading cause in nearly all sites.

Conclusions

Education seems to have an important latent effect on mortality into late life. However, compositional differences in socioeconomic position do not explain differences in mortality between sites. Social protection for older people, and the effectiveness of health systems in preventing and treating chronic disease, may be as important as economic and human development. Please see later in the article for the Editors'' Summary     

Demographic and socioeconomic factors affecting infant mortality in Egypt

This paper analyses the relative importance of demographic and socioeconomic factors with respect to their role in reducing infant mortality in Egypt. Logit analyses of data from a nationally representative sample of Egyptian households, and for urban and rural households separately, indicate that demographic factors have more effect on infant mortality than socioeconomic factors. The results also show the need to improve housing in urban areas and sewerage systems in rural areas in order to reduce infant mortality. One of the most important policy conclusions, however, concerns the importance of providing a vigorous educational campaign to enlighten mothers and prospective mothers in both rural and urban areas on the positive effects of breast-feeding, longer birth intervals, and fewer children on the survival of infants.     

Heredity of joint diseases

Abstract

This research examines the infant mortality/socioeconomic status relationship in Toledo, Ohio, for the years centering around 19S0, 1960, and 1970 in order to depict variables that contributed most to infant mortality for each time period. Zero‐order correlation coefficients demonstrated that the relationship has widened mainly as a result of an increasing inverse neonatal/socioeconomic pattern which was due in part to a “cause‐period cross‐over effect” (exogenous causes of death were contributing to deaths in the neonatal period in 1970). Further examination suggested that the status variables through which the differentials were operating have shifted from one time period to another. In 1950, crowded housing conditions and unemployment were primarily responsible; in 1960, it was housing and income; and in 1970, marital instability and income predominated. This paper suggests that as new social phenomena emerge they quickly affect sensitive indicators of well‐being such as the infant mortality rate.     

Parental death in childhood and pathways to increased mortality across the life course in Stockholm,Sweden: A cohort study

BackgroundPrevious studies have shown that the experience of parental death during childhood is associated with increased mortality risk. However, few studies have examined potential pathways that may explain these findings. The aim of this study is to examine whether familial and behavioural factors during adolescence and socioeconomic disadvantages in early adulthood mediate the association between loss of a parent at age 0 to 12 and all-cause mortality by the age of 63.Methods and findingsA cohort study was conducted using data from the Stockholm Birth Cohort Multigenerational Study for 12,615 children born in 1953, with information covering 1953 to 2016. Familial and behavioural factors at age 13 to 19 included psychiatric and alcohol problems in the surviving parent, receipt of social assistance, and delinquent behaviour in the offspring. Socioeconomic disadvantage in early adulthood included educational attainment, occupational social class, and income at age 27 to 37. We used Cox proportional hazard regression models, combined with a multimediator analysis, to separate direct and indirect effects of parental death on all-cause mortality.Among the 12,582 offspring in the study (men 51%; women 49%), about 3% experienced the death of a parent in childhood. During follow-up from the age of 38 to 63, there were 935 deaths among offspring. Parental death was associated with an elevated risk of mortality after adjusting for demographic and household socioeconomic characteristics at birth (hazard ratio [HR]: 1.52 [95% confidence interval: 1.10 to 2.08, p-value = 0.010]). Delinquent behaviour in adolescence and income during early adulthood were the most influential mediators, and the indirect associations through these variables were HR 1.03 (1.00 to 1.06, 0.029) and HR 1.04 (1.01 to 1.07, 0.029), respectively. After accounting for these indirect paths, the direct path was attenuated to HR 1.35 (0.98 to 1.85, 0.066). The limitations of the study include that the associations may be partly due to genetic, social, and behavioural residual confounding, that statistical power was low in some of the subgroup analyses, and that there might be other relevant paths that were not investigated in the present study.ConclusionsOur findings from this cohort study suggest that childhood parental death is associated with increased mortality and that the association was mediated through a chain of disadvantages over the life course including delinquency in adolescence and lower income during early adulthood. Professionals working with bereaved children should take the higher mortality risk in bereaved offspring into account and consider its lifelong consequences. When planning and providing support to bereaved children, it may be particularly important to be aware of their increased susceptibility to delinquency and socioeconomic vulnerability that eventually lead to higher mortality.

In this cohort study, Ayako Hiyoshi and colleagues show associations between parental death in a child’s life and mortality risk later in that child’s life.     

Analysis of structure and causes of mortality of HIV-infected in Volga Federal District in 2005 - 2010

Among with morbidity and affection, mortality is an objective indicator of HIV-infection epidemic process intensity. Dynamics of mortality of HIV-infected in Volga Federal District (VFD) in 2005 - 2010, distribution of deceased by disease stage, period of start and coverage by antiretroviral therapy were studied based on approved statistical forms and additional collected data, the leading causes of death were revealed, comparative analysis with population of HIV-infected in penitentiary system institutions was performed. All-cause mortality was established to have dynamics of growth in HIV-infected population in VFD in 2005 - 2010, at the same time HIV-infection mortality has a certain tendency of stabilization after 2007 with subsequent decline in 2010, that apparently is related to wide use of combined antiretroviral therapy. HIV-infection mortality among HIV-infected in penitentiary system of the district is significantly higher than mortality in the general population of HIV-infected in VFD. The leading cause of death in HIV-infection is tuberculosis.     

Differential family formation in Great Britain

Levels of fertility and nuptiality in developed countries in recent years have shown substantial differences by time-period, country and social groups. The very major fluctuations in period fertility have naturally been the prime concern of analysts. Since family formation is a multi-faceted phenomenon, different covariates are likely to be important to the process at different points. The approach in this paper is deliberately eclectic an exploratory, but it does permit a reasonably unbiased comparison of the relative power of a number of covariates which have been considered important in sociological, economic and psychological explanations of demographic change. Differentials in variables concerned with the timing, number, and distribution of fertility by a wide range of socioeconomic, attitudinal, inherited and housing characteristics from the British Family Formation Survey are reported. Variables associated with the couple's housing history and the wife's employment career are becoming more strongly associated with demographic differentials among younger cohorts than traditionally based ones such as religion or region of residence. Cluster analysis techniques show which groups family formation variables are strongly associated with particular types of non-demographic ones, and a natural grouping of explanatory variables is derived. The implications of these conclusions for data collection in demographic surveys are discussed.     

The demographic and socioeconomic factors predictive for populations at high-risk for La Crosse virus infection in West Virginia

Although a large body of literature exists for the environmental risk factors for La Crosse virus (LACV) transmission, the demographic and socioeconomic risk factors for developing LACV infection have not been investigated. Therefore, this study investigated the demographic and socioeconomic risk factors for LACV infection in West Virginia from 2003 to 2007, using two forward stepwise discriminant analyses. The discriminant analyses were used to evaluate a number of demographic and socioeconomic factors for their ability to predict: 1) those census tracts with at least one reported case of LACV infection versus those census tracts with no reported cases of LACV infection and 2) to evaluate significantly high-risk clusters for LACV infection versus significantly low-risk clusters for LACV infection. In the first model, a high school education diploma or a general education diploma or less and a lower housing densitywere found to be predictive of those census tracts with at least one case of LACV infection. A high school or a general education diploma or less, lower housing density, and housing built in 1969 and earlier were all found to be predictive of those census tracts displaying high-risk clusters versus census tracts displaying low-risk clusters in the second model. The cluster discriminant analysis was found to be more predictive than the census tract discriminant analysis as indicated by the Eigenvalues, canonical correlation, and grouping accuracy. The results of this study indicate that socioeconomically disadvantaged populations are at the highest risk for LACV infection and should be a focus of LACV infection prevention efforts.     

Social and proximate determinants of sexual activity in rural Nigeria

This study analyses the social, physiological and motivational determinants of sexual activity for 644 married women in rural areas of Osun State, Nigeria. The data come from the Fertility Awareness and Pregnancy Avoidance study conducted in 1993-94. Sexual activity is measured by three continuous variables: weekly frequency of (1) total sexual activity, (2) coital-only sex and (3) both coital/non-coital sex. Analyses of variance were performed to test the difference in group means between the predictor variables and measures of sexual activity. Ordinary least squares regression analyses were then performed for the three dependent variables. Two models are used: the first contains only those variables associated with an individual's demographic, social and economic status, and the second adds predictor variables associated with motivational and physiological factors. Results show that while many socioeconomic variables by themselves are significantly associated with sexual activity measures, the addition of physiological and motivational variables weakens their effects and lessens their original statistical significance. Additionally, the socioeconomic and demographic factors associated with frequency of sexual activity are not necessarily the same ones significantly associated with coital-only or combined coital/non-coital sex. While other studies have tended to focus either on socioeconomic or physiological factors, the joint examination of both types of influences seems to indicate that the latter have more proximate effects on the frequency of both coital and non-coital sexual activity of married women in this population. Contraceptive protection is shown to be highly positively associated with all three of the sexual activity measures, empirically confirming the important relationship between contraception and both coital and non-coital forms of sexual activity.     

Determinants of child mortality in south-west Uganda.

Anthropometric and sociodemographic variables were taken from 4320 children in a baseline survey carried out in March-April 1988 in the district of Mbarara, south-west Uganda. After 12 months a follow-up survey assessed the mortality of the children during the preceding year. Lack of ownership of cattle, recent arrival in the village, using candles for lighting, being of birth order higher than 5 and having a father with less than 8 years of schooling were significantly associated with child mortality. The addition of mid-upper arm circumference significantly improved the logistic model of socioeconomic variables and mortality and did not diminish the predictive power of socioeconomic variables in relation to increased mortality. This suggests that nutritional status and specific socioeconomic factors are both, independently, important predictors of child mortality.     

Unemployment and mortality in Denmark, 1970-80.

Relative mortality in the period 1970-80 was studied among Danish men and women who were unemployed and employed on the day of the 1970 census. The study population consisted of the total labour force in the age range 20-64 on 9 November 1970--that is, about 2 million employed and 22,000 unemployed people. Relative mortality was analysed by a multiplicative hazard regression model (as a natural extension of the standardised mortality ratio) and a multiplicative regression model with extra-Poisson variation. A significantly increased death rate (40-50%) was found among the unemployed after adjusting for occupation, housing category, geographical region, and marital state. Analysis of five main causes of death showed increased mortality from all causes, but especially from suicide or accidents. In areas where the local unemployment rate was comparatively high the relative mortality among the unemployed was lower. The increased mortality among the unemployed was interpreted as a consequence of health related selection as well as increased susceptibility associated with the psychosocial stress of unemployment.     

Invasive Non-typhoidal Salmonella Infections in Asia: Clinical Observations,Disease Outcome and Dominant Serovars from an Infectious Disease Hospital in Vietnam

Invasive non-typhoidal Salmonella (iNTS) infections are now a well-described cause of morbidity and mortality in children and HIV-infected adults in sub-Saharan Africa. In contrast, the epidemiology and clinical manifestations of iNTS disease in Asia are not well documented. We retrospectively identified >100 cases of iNTS infections in an infectious disease hospital in Southern Vietnam between 2008 and 2013. Clinical records were accessed to evaluate demographic and clinical factors associated with iNTS infection and to identify risk factors associated with death. Multi-locus sequence typing and antimicrobial susceptibility testing was performed on all organisms. Of 102 iNTS patients, 71% were HIV-infected, >90% were adults, 71% were male and 33% reported intravenous drug use. Twenty-six/92 (28%) patients with a known outcome died; HIV infection was significantly associated with death (p = 0.039). S. Enteritidis (Sequence Types (ST)11) (48%, 43/89) and S. Typhimurium (ST19, 34 and 1544) (26%, 23/89) were the most commonly identified serovars; S. Typhimurium was significantly more common in HIV-infected individuals (p = 0.003). Isolates from HIV-infected patients were more likely to exhibit reduced susceptibility against trimethoprim-sulfamethoxazole than HIV-negative patients (p = 0.037). We conclude that iNTS disease is a severe infection in Vietnam with a high mortality rate. As in sub-Saharan Africa, HIV infection was a risk factor for death, with the majority of the burden in this population found in HIV-infected adult men.     

Reproductive and socioeconomic determinants of child survival: confounded, interactive, and age-dependent effects.

Studies of infant and child mortality have evolved to distinguish between two sets of explanatory variables-factors related to reproductive or maternal characteristics and socioeconomic factors, generally described as characteristics of the family or household. Almost all multivariate analyses include variables from each of these two sets, but there has been little consideration of the relationship between them. We examine how these two sets of variables jointly affect mortality. We test first for confounded effects by examining socioeconomic effects while excluding and then including reproductive variables in nested multivariate models. Next, we look for age-dependent effects among the explanatory variables and find that reproductive and socioeconomic factors affect mortality at differing ages of children. Finally, we examine interactive effects of the two sets of variables. We conclude that the higher mortality observed among the low status groups is not a result of greater concentration of poor reproductive patterns in those groups. Instead, higher status groups probably have more resources available for combating the negative effects of the same high-risk reproductive patterns.     

The effects of infant deaths on the risk of subsequent birth: a comparative analysis of DHS data from Ghana and Kenya

This paper examines the conditions under which there might be a strong or weak relationship between childhood mortality and fertility at the micro level. The premise is that as a society undergoes transition during which a conscious effort is made to space and limit birth, the effect associated with infant death on the risk of subsequent birth reduces. Using the 1998 DHS data from Ghana and Kenya, our multivariate hazard models show that women who have experienced infant deaths tend to have a higher risk of subsequent births than those without any infant deaths at all parities studied in both countries. In a comparative context, however, the magnitude of the effect associated with infant death was weaker in Kenya at all parities, corroborating the hypothesis that the effect indeed reduces in the course of transition. Besides infant deaths, other demographic, socioeconomic and sociocultural factors were also found to associate with the risk of births. The limitations and policy implications of the findings are discussed.     

Socioeconomic, demographic and environmental determinants of infant mortality in Nepal

The Nepal Fertility and Family Planning Survey of 1986 demonstrated that demographic variables, previous birth interval and survival of preceding child, still predominated as determinants of infant mortality, particularly in rural areas of Nepal. However, in urban Nepal, where the level of socioeconomic development is higher, an environmental variable, along with previous birth interval and survival of preceding child emerges as important in determining infant mortality. Separate policy measures for child survival prospects in rural and urban Nepal are suggested.     

Social epidemiology of chronic liver disease and cirrhosis mortality in the United States, 1935-1997: trends and differentials by ethnicity, socioeconomic status, and alcohol consumption

This study examines trends and ethnic and socioeconomic differentials in chronic liver disease and cirrhosis mortality in the United States. Age-adjusted death rates from the National Vital Statistics System were used to analyze race and sex-specific mortality trends from 1968 through 1997. Age-adjusted liver cirrhosis mortality and per capita alcohol consumption data from 1935 through 1996 were modeled using time-series regression. Moreover, the Cox hazards regression was applied to the National Longitudinal Mortality Study, 1979-1989, to examine socioeconomic differentials at the individual level, whereas multivariate ordinary least squares regression was used to model state-specific cirrhosis mortality from 1990 to 1992 as a function of socioeconomic variables and alcohol consumption at the ecological level. Chronic liver disease and cirrhosis continues to be an important cause of death in the United States, even after three decades of consistently declining mortality rates. For both men and women aged 25 years and older, significant mortality differentials were found by age, race/ethnicity, marital status, family income, and employment status. For men, marked differentials were also found by nativity, rural-urban residence, and education. Unemployment, minority concentration, and alcohol consumption were major predictors of state-specific cirrhosis mortality. Both time-series and cross-sectional data indicate a strong correlation between alcohol consumption and US cirrhosis mortality. Substantial ethnic and socioeconomic differences in cirrhosis mortality suggest the need for social and public health policies and interventions that target such high-risk groups as American Indians, Hispanic Americans, the socially isolated, and the poor.     

Determinants of infant and early childhood mortality in Cameroon: The role of socioeconomic factors,housing characteristics,and immunization status

Abstract

This study examines factors impinging on the survival of children in Cameroon using longitudinal data collected by the United Nations Demographic Training and Research Institute of Yaounde, Cameroon. It deals especially with the role of socioeconomic factors (mother's education, employment, marital status, ethnicity, and household income), housing characteristics (construction materials, power source, source of water supply, extent of crowding), and immunization status on infant and child mortality. Two‐state parametric and nonparametric hazards models for the risk of death at any time within the course of the study are used, with and without accounting for unmeasured heterogeneity. Overall, overcrowding has robust deleterious effects on infant and child survival. As regards the effects of socioeconomic variables, the robustness of the effects of household income and ethnic differentials are unchanged, even after controlling for unmeasured heterogeneity; the deleterious effects of marital status are also apparent, but these effects are largely explained by unmeasured covariates. The data also suggest that the protective effects of full immunization status are robust and not contaminated by confounding factors, at least in the first 16 months of life. These findings provide solid ground to support immunization programs and efforts as a means to reduce significantly infant and child mortality.     

Patterns of mortality in southern sea otters (Enhydra lutris nereis) from 1998-2001

Detailed postmortem examination of southern sea otters (Enhydra lutris nereis) found along the California (USA) coast has provided an exceptional opportunity to understand factors influencing survival in this threatened marine mammal species. In order to evaluate recent trends in causes of mortality, the demographic and geographic distribution of causes of death in freshly deceased beachcast sea otters necropsied from 1998-2001 were evaluated. Protozoal encephalitis, acanthocephalan-related disease, shark attack, and cardiac disease were identified as common causes of death in sea otters examined. While infection with acanthocephalan parasites was more likely to cause death in juvenile otters, Toxoplasma gondii encephalitis, shark attack, and cardiac disease were more common in prime-aged adult otters. Cardiac disease is a newly recognized cause of mortality in sea otters and T. gondii encephalitis was significantly associated with this condition. Otters with fatal shark bites were over three times more likely to have pre-existing T. gondii encephalitis suggesting that shark attack, which is a long-recognized source of mortality in otters, may be coupled with a recently recognized disease in otters. Spatial clusters of cause-specific mortality were detected for T. gondii encephalitis (in Estero Bay), acanthocephalan peritonitis (in southern Monterey Bay), and shark attack (from Santa Cruz to Point A?o Nuevo). Diseases caused by parasites, bacteria, or fungi and diseases without a specified etiology were the primary cause of death in 63.8% of otters examined. Parasitic disease alone caused death in 38.1% of otters examined. This pattern of mortality, observed predominantly in juvenile and prime-aged adult southern sea otters, has negative implications for the overall health and recovery of this population.