Occupational differences in US Army suicide rates

BACKGROUND

Civilian suicide rates vary by occupation in ways related to occupational stress exposure. Comparable military research finds suicide rates elevated in combat arms occupations. However, no research has evaluated variation in this pattern by deployment history, the indicator of occupation stress widely considered responsible for the recent rise in the military suicide rate.

METHOD

The joint associations of Army occupation and deployment history in predicting suicides were analysed in an administrative dataset for the 729 337 male enlisted Regular Army soldiers in the US Army between 2004 and 2009.

RESULTS

There were 496 suicides over the study period (22.4/100 000 person-years). Only two occupational categories, both in combat arms, had significantly elevated suicide rates: infantrymen (37.2/100 000 person-years) and combat engineers (38.2/100 000 person-years). However, the suicide rates in these two categories were significantly lower when currently deployed (30.6/100 000 person-years) than never deployed or previously deployed (41.2-39.1/100 000 person-years), whereas the suicide rate of other soldiers was significantly higher when currently deployed and previously deployed (20.2-22.4/100 000 person-years) than never deployed (14.5/100 000 person-years), resulting in the adjusted suicide rate of infantrymen and combat engineers being most elevated when never deployed [odds ratio (OR) 2.9, 95% confidence interval (CI) 2.1-4.1], less so when previously deployed (OR 1.6, 95% CI 1.1-2.1), and not at all when currently deployed (OR 1.2, 95% CI 0.8-1.8). Adjustment for a differential 'healthy warrior effect' cannot explain this variation in the relative suicide rates of never-deployed infantrymen and combat engineers by deployment status.

CONCLUSIONS

Efforts are needed to elucidate the causal mechanisms underlying this interaction to guide preventive interventions for soldiers at high suicide risk.

Understanding the elevated suicide risk of female soldiers during deployments

BACKGROUND

The Army Study to Assess Risk and Resilience in Servicemembers (Army STARRS) has found that the proportional elevation in the US Army enlisted soldier suicide rate during deployment (compared with the never-deployed or previously deployed) is significantly higher among women than men, raising the possibility of gender differences in the adverse psychological effects of deployment.

METHOD

Person-month survival models based on a consolidated administrative database for active duty enlisted Regular Army soldiers in 2004-2009 (n = 975,057) were used to characterize the gender × deployment interaction predicting suicide. Four explanatory hypotheses were explored involving the proportion of females in each soldier's occupation, the proportion of same-gender soldiers in each soldier's unit, whether the soldier reported sexual assault victimization in the previous 12 months, and the soldier's pre-deployment history of treated mental/behavioral disorders.

RESULTS

The suicide rate of currently deployed women (14.0/100,000 person-years) was 3.1-3.5 times the rates of other (i.e. never-deployed/previously deployed) women. The suicide rate of currently deployed men (22.6/100,000 person-years) was 0.9-1.2 times the rates of other men. The adjusted (for time trends, sociodemographics, and Army career variables) female:male odds ratio comparing the suicide rates of currently deployed v. other women v. men was 2.8 (95% confidence interval 1.1-6.8), became 2.4 after excluding soldiers with Direct Combat Arms occupations, and remained elevated (in the range 1.9-2.8) after adjusting for the hypothesized explanatory variables.

CONCLUSIONS

These results are valuable in excluding otherwise plausible hypotheses for the elevated suicide rate of deployed women and point to the importance of expanding future research on the psychological challenges of deployment for women.

Sociodemographic and career history predictors of suicide mortality in the United States Army 2004-2009

BACKGROUND

The US Army suicide rate has increased sharply in recent years. Identifying significant predictors of Army suicides in Army and Department of Defense (DoD) administrative records might help focus prevention efforts and guide intervention content. Previous studies of administrative data, although documenting significant predictors, were based on limited samples and models. A career history perspective is used here to develop more textured models.

METHOD

The analysis was carried out as part of the Historical Administrative Data Study (HADS) of the Army Study to Assess Risk and Resilience in Servicemembers (Army STARRS). De-identified data were combined across numerous Army and DoD administrative data systems for all Regular Army soldiers on active duty in 2004-2009. Multivariate associations of sociodemographics and Army career variables with suicide were examined in subgroups defined by time in service, rank and deployment history.

RESULTS

Several novel results were found that could have intervention implications. The most notable of these were significantly elevated suicide rates (69.6-80.0 suicides per 100 000 person-years compared with 18.5 suicides per 100 000 person-years in the total Army) among enlisted soldiers deployed either during their first year of service or with less than expected (based on time in service) junior enlisted rank; a substantially greater rise in suicide among women than men during deployment; and a protective effect of marriage against suicide only during deployment.

CONCLUSIONS

A career history approach produces several actionable insights missed in less textured analyses of administrative data predictors. Expansion of analyses to a richer set of predictors might help refine understanding of intervention implications.

Can utility-weighted health-related quality-of-life estimates capture health effects of quality improvement for depression?

BACKGROUND

Utility methods that are responsive to changes in desirable outcomes are needed for cost-effectiveness (CE) analyses and to help in decisions about resource allocation.

OBJECTIVES

Evaluated is the responsiveness of different methods that assign utility weights to subsets of SF-36 items to average improvements in health resulting from quality improvement (QI) interventions for depression.

DESIGN

A group level, randomized, control trial in 46 primary care clinics in six managed care organizations. Clinics were randomized to one of two QI interventions or usual care.

SUBJECTS

One thousand one hundred thirty-six patients with current depressive symptoms and either 12-month, lifetime, or no depressive disorder identified through screening 27,332 consecutive patients.

MEASURES

Utility weighted SF-12 or SF-36 measures, probable depression, and physical and mental health-related quality of life scores.

RESULTS

Several utility-weighted measures showed increases in utility values for patients in one of the interventions, relative to usual care, that paralleled the improved health effects for depression and emotional well being. However, QALY gains were small. Directly elicited utility values showed a paradoxical result of lower utility during the first year of the study for intervention patients relative to controls.

CONCLUSIONS

The results raise concerns about the use of direct single-item utility measures or utility measures derived from generic health status measures in effectiveness studies for depression. Choice of measure may lead to different conclusions about the benefit and CE of treatment. Utility measures that capture the mental health and non-health outcomes associated with treatment for depression are needed.

Cost-effectiveness of practice-initiated quality improvement for depression: results of a randomized controlled trial

CONTEXT

Depression is a leading cause of disability worldwide, but treatment rates in primary care are low.

OBJECTIVE

To determine the cost-effectiveness from a societal perspective of 2 quality improvement (QI) interventions to improve treatment of depression in primary care and their effects on patient employment.

DESIGN

Group-level randomized controlled trial conducted June 1996 to July 1999.

SETTING

Forty-six primary care clinics in 6 community-based managed care organizations.

PARTICIPANTS

One hundred eighty-one primary care clinicians and 1356 patients with positive screening results for current depression.

INTERVENTIONS

Matched practices were randomly assigned to provide usual care (n = 443 patients) or to 1 of 2 QI interventions offering training to practice leaders and nurses, enhanced educational and assessment resources, and either nurses for medication follow-up (QI-meds; n = 424 patients) or trained local psychotherapists (QI-therapy; n = 489). Practices could flexibly implement the interventions, which did not assign type of treatment.

MAIN OUTCOME MEASURES

Total health care costs, costs per quality-adjusted life-year (QALY), days with depression burden, and employment over 24 months, compared between usual care and the 2 interventions.

RESULTS

Relative to usual care, average health care costs increased $419 (11%) in QI-meds (P =.35) and $485 (13%) in QI-therapy (P =.28); estimated costs per QALY gained were between $15 331 and $36 467 for QI-meds and $9478 and $21 478 for QI-therapy; and patients had 25 (P =.19) and 47 (P =.01) fewer days with depression burden and were employed 17.9 (P =.07) and 20.9 (P =.03) more days during the study period.

CONCLUSIONS

Societal cost-effectiveness of practice-initiated QI efforts for depression is comparable with that of accepted medical interventions. The intervention effects on employment may be of particular interest to employers and other stakeholders.

Improving primary care for depression in late life: the design of a multicenter randomized trial

BACKGROUND

Late life depression can be successfully treated with antidepressant medications or psychotherapy, but few depressed older adults receive effective treatment.

RESEARCH DESIGN

A randomized controlled trial of a disease management program for late life depression.

SUBJECTS

Approximately 1,750 older adults with major depression or dysthymia are recruited from seven national study sites.

INTERVENTION

Half of the subjects are randomly assigned to a collaborative care program where a depression clinical specialist supervised by a psychiatrist and a primary care expert supports the patient's regular primary care provider to treat depression. Intervention services are provided for 12 months using antidepressant medications and Problem Solving Treatment in Primary Care according to a stepped care protocol that varies intervention intensity according to clinical needs. The other half of the subjects are assigned to care as usual.

EVALUATION

Subjects are independently assessed at baseline, 3 months, 6 months, 12 months, 18 months, and 24 months. The evaluation assesses the incremental cost-effectiveness of the intervention compared with care as usual. Specific outcomes examined include care for depression, depressive symptoms, health-related quality of life, satisfaction with depression care, health care costs, patient time costs, market and nonmarket productivity, and household income.

CONCLUSIONS

The study blends methods from health services and clinical research in an effort to protect internal validity while maximizing the generalizability of results to diverse health care systems. We hope that this study will show the cost-effectiveness of a new model of care for late life depression that can be applied in a range of primary care settings.

Long-term effectiveness of disseminating quality improvement for depression in primary care

BACKGROUND

This article addresses whether dissemination of short-term quality improvement (QI) interventions for depression to primary care practices improves patients' clinical outcomes and health-related quality of life (HRQOL) over 2 years, relative to usual care (UC).

METHODS

The sample included 1299 patients with current depressive symptoms and 12-month, lifetime, or no depressive disorder from 46 primary care practices in 6 managed care organizations. Clinics were randomized to UC or 1 of 2 QI programs that included training local experts and nurse specialists to provide clinician and patient education, assessment, and treatment planning, plus either nurse care managers for medication follow-up (QI-meds) or access to trained psychotherapists (QI-therapy). Outcomes were assessed every 6 months for 2 years.

RESULTS

For most outcomes, differences between intervention and UC patients were not sustained for the full 2 years. However, QI-therapy reduced overall poor outcomes compared with UC by about 8 percentage points throughout 2 years, and by 10 percentage points compared with QI-meds at 24 months. Both interventions improved patients' clinical and role outcomes, relative to UC, over 12 months (eg, a 10-11 and 6-7 percentage point difference in probable depression at 6 and 12 months, respectively).

CONCLUSIONS

While most outcome improvements were not sustained over the full 2 study years, findings suggest that flexible dissemination of short-term, QI programs in managed primary care can improve patient outcomes well after program termination. Models that support integrated psychotherapy and medication-based treatment strategies in primary care have the potential for relatively long-term patient benefits.

Health plan choice and information about out-of-pocket costs: an experimental analysis

Many consumers are offered two or more employer-sponsored health insurance plans, and competition among health plans for subscribers is promoted as a mechanism for balancing health care costs and quality. Yet consumers may not receive the information necessary to make informed health plan choices. This study tests the effects on health plan choice of providing supplemental decision-support materials to inform consumers about expected health plan costs. Our main finding is that such information induces consumers to bear more risk, especially those in relatively good health. Thus our results suggest that working-age, privately insured consumers currently may be over-insuring for medical care.

Impact of disseminating quality improvement programs for depression in managed primary care: a randomized controlled trial

CONTEXT

Care of patients with depression in managed primary care settings often fails to meet guideline standards, but the long-term impact of quality improvement (QI) programs for depression care in such settings is unknown.

OBJECTIVE

To determine if QI programs in managed care practices for depressed primary care patients improve quality of care, health outcomes, and employment.

DESIGN

Randomized controlled trial initiated from June 1996 to March 1997.

SETTING

Forty-six primary care clinics in 6 US managed care organizations.

PARTICIPANTS

Of 27332 consecutively screened patients, 1356 with current depressive symptoms and either 12-month, lifetime, or no depressive disorder were enrolled.

INTERVENTIONS

Matched clinics were randomized to usual care (mailing of practice guidelines) or to 1 of 2 QI programs that involved institutional commitment to QI, training local experts and nurse specialists to provide clinician and patient education, identification of a pool of potentially depressed patients, and either nurses for medication follow-up or access to trained psychotherapists.

MAIN OUTCOME MEASURES

Process of care (use of antidepressant medication, mental health specialty counseling visits, medical visits for mental health problems, any medical visits), health outcomes (probable depression and health-related quality of life [HRQOL]), and employment at baseline and at 6- and 12-month follow-up.

RESULTS

Patients in QI (n = 913) and control (n = 443) clinics did not differ significantly at baseline in service use, HRQOL, or employment after nonresponse weighting. At 6 months, 50.9% of QI patients and 39.7% of controls had counseling or used antidepressant medication at an appropriate dosage (P<.001), with a similar pattern at 12 months (59.2% vs 50.1%; P = .006). There were no differences in probability of having any medical visit at any point (each P > or = .21). At 6 months, 47.5% of QI patients and 36.6% of controls had a medical visit for mental health problems (P = .001), and QI patients were more likely to see a mental health specialist at 6 months (39.8% vs 27.2%; P<.001) and at 12 months (29.1% vs 22.7%; P = .03). At 6 months, 39.9% of QI patients and 49.9% of controls still met criteria for probable depressive disorder (P = .001), with a similar pattern at 12 months (41.6% vs 51.2%; P = .005). Initially employed QI patients were more likely to be working at 12 months relative to controls (P = .05).

CONCLUSIONS

When these managed primary care practices implemented QI programs that improve opportunities for depression treatment without mandating it, quality of care, mental health outcomes, and retention of employment of depressed patients improved over a year, while medical visits did not increase overall.

Quality of care for primary care patients with depression in managed care

OBJECTIVE

To evaluate the process and quality of care for primary care patients with depression under managed care organizations.

METHOD

Surveys of 1204 outpatients with depression at the time of and after a visit to 1 of 181 primary care clinicians from 46 primary care clinics in 7 managed care organizations. Patients had depressive symptoms in the previous 30 days, with or without a 12-month depressive disorder by diagnostic interview. Process indicators were depression counseling, mental health referral, or psychotropic medication management at index visit and the use of appropriate antidepressant medication during the last 6 months.

RESULTS

Of patients with depressive disorder and recent symptoms, 29% to 43% reported a depression-specific process of care in the index visit, and 35% to 42% used antidepressant medication in appropriate dosages in the prior 6 months. Patients with depressive disorders rather than symptoms only and those with comorbid anxiety had higher rates of depression-specific processes and quality of care (P < .005). Recurrent depression, suicidal ideation, and alcohol abuse were not uniquely associated with such rates. Patients visiting for old problems or checkups received more depression-specific care than those with new problems or unscheduled visits. The 7 managed care organizations varied by a factor of 2-fold in rates of depression counseling and appropriate anti-depressant use.

CONCLUSIONS

Rates of process and quality of care for depression as reported by patients are moderate to low in managed primary care practices. Such rates are higher for patients with more severe forms of depression or with comorbid anxiety, but not for those with severe but "silent" symptoms like suicide ideation. Visit context factors, such as whether the visit is scheduled, affect rates of depression-specific care. Rates of care for depression are highly variable among managed care organizations, emphasizing the need for process monitoring and quality improvement for depression at the organizational level.

How expensive are unlimited substance abuse benefits under managed care?

Substance abuse (SA) care has been excluded from recent federal and state legislation mandating equal benefits for mental health and medical care ("parity"), largely because of cost concerns. This article studies how many patients are affected by SA coverage limits and the likely implications of limits on insurance payments, using 1996-97 claims from 25 managed care plans with unlimited SA benefits. Changing even stringent limits on annual SA benefits has a small absolute effect on overall insurance costs under managed care, even though a large percentage of SA patients are affected. Removing an annual limit of $10,000 per year on SA care is estimated to increase insurance payments by about 6 cents per member per year, removing a limit of $1,000 increases payments by about $3.40. As long as care is comprehensively managed, "parity" for SA in employer-sponsored health plans is not very costly.

Costs and utilization of substance abuse care in a privately insured population under managed care

OBJECTIVE

Cost and utilization patterns of substance abuse and mental health treatment under private, employer-sponsored, managed behavioral health care plans were examined.

METHODS

Data were from claims made in 1995 in 93 behavioral health care plans covering 617,133 members. Rates of use of mental health and substance abuse care were determined, as were payments by insurers and patients for the two types of care. Means were calculated per plan member and per user of either of these service types.

RESULTS

Approximately .3 percent of plan members used any substance abuse services; 5.2 percent used mental health services. However, among substance abuse patients, average costs were more than twice as high as average costs for mental health patients. For substance abuse treatment, the annual cost per user was $2,188, compared with $979 for users of mental health care. Annual per-member costs were $6.51 for substance abuse treatment and $50.08 for mental health care. Higher costs for substance abuse treatment reflected greater rates of use of both inpatient and intensive outpatient treatment. Overall, substance abuse costs represented 13 percent of insurance payments for behavioral health care and perhaps .4 percent of the cost of health insurance overall.

CONCLUSIONS

Substance abuse coverage accounts for a small fraction of insurance payments for behavioral health coverage and a very small fraction of insurance payments for both physical and behavioral health care.

A successful, preventive-oriented village health worker program in Hebron, the West Bank, 1985-1996

Village health rooms (VHRs) were established in villages with no on-site health facilities in the Hebron District of the West Bank, beginning in 1985. By 1991, the program served a total population of 40,000 in 49 VHRs and by the end of 1996 covered 69 villages in Hebron and 20 in other districts that were previously served by visiting vaccination teams and nearby clinics. The VHRs provide close contact with the population of mothers for well child and pregnancy care, health education and provide visiting doctor/nurse teams for backup services and supervision. Data on coverage, utilization, costs, and outcome measures are presented. The program is accepted and grows despite adverse social and political conditions.

Race, socioeconomic status, and health: accounting for race differences in health

This article uses the Asset and Health Dynamics Among the Oldest Old (AHEAD) study to examine the extent to which observed differences in the prevalence of chronic conditions and functional limitations between Black and White adults (aged 70+) in the United States can be attributed to differences in various aspects of socioeconomic status (SES) between these groups. We use linear and logistic regression techniques to model the relationships between health outcomes and SES. Our findings indicate that race differences in measurable socioeconomic characteristics indeed explain a substantial fraction, but in general not all, of Black/White differences in health status. While our findings do not suggest that low SES directly "causes" poor health, any more than being Black does so, they do suggest that research and policy intended to address the deficit in health status among Blacks (when compared to Whites) in the U.S. would be well-served to begin with the deficit in wealth, education, and other SES measures.

Do smokers understand the mortality effects of smoking? Evidence from the Health and Retirement Survey

OBJECTIVES

This study examined whether smokers recognize that smoking is likely to shorten their lives and, if so, whether they understand the magnitude of this effect.

METHODS

People's expectations about their chances of reaching age 75 were compared with epidemiological predictions from life tables for never, former, current light, and current heavy smokers. Data on expectations of reaching age 75 came from the Health and Retirement Survey, a national probability sample of adults aged 50 through 62 years. Predictions came from smoking-specific life tables constituted from the 1986 National Mortality Followback Survey and the 1985 and 1987 National Health Interview Surveys.

RESULTS

Among men and women, the survival expectations of never, former, and current light smokers were close to actual predictions. However, among current heavy smokers, expectations of reaching age 75 were nearly twice as high as actuarial predictions.

CONCLUSIONS

These findings suggest that at least heavy smokers significantly underestimate their risk of premature mortality.

Race differences in labor force attachment and disability status

We used the first wave of the Health and Retirement Survey to study the effect of health on the labor force activity of black and white men and women in their 50s. The evidence we present confirms the notion that health is an extremely important determinant of early labor force exit. Our estimates suggest that health differences between blacks and whites can account for most of the racial gap in labor force attachment for men. For women, when participation rates are comparable, our estimates imply that black women would be substantially more likely to work than white women were it not for the marked health differences. We also found for both men and women that poor health has a substantially larger effect on labor force behavior for blacks. The evidence suggests that these differences result from black/white differences in access to the resources necessary to retire.

Gender differences in nutritional status and feeding patterns among infants in the Gaza Strip

OBJECTIVES

This study examined gender variation in nutritional treatment and anthropometric status of infants in the Gaza Strip. Numerous studies have documented gender differences in health status in developing areas, generally finding boys to be at an advantage over girls. Social and economic characteristics in Gaza suggest that one might expect preferential treatment of boys there.

METHODS

The study used data on two samples of infants 0 to 18 months of age collected from five health centers in Gaza. A variety of different analytic methods were used to look for gender differences in feeding patterns, prevalence of malnutrition, and anthropometric status.

RESULTS

Although some differences in nutritional treatment and anthropometric outcome for infants of different socioeconomic status and between the earlier and later samples were found, no consistent gender differences were revealed.

CONCLUSIONS

The findings are consistent with several different explanations. First, expectations of finding gender differences may have been unfounded. Alternatively, such differences may have existed previously but have been eliminated through successful public health intervention, rising levels of education, and economic development.

Growth and nutrition patterns of infants associated with a nutrition education and supplementation programme in Gaza, 1987-92

Since 1986, the 28 government community health centres providing primary care in Gaza have paid special attention to growth monitoring, nutrition education, and routine vitamin and iron supplementation in infancy. In 1987-88, 1989 and 1992, respectively, the nursing staff in five of these centres monitored the growth and feeding patterns of 2222, 1899, and 1012 children aged up to 15 months. The growth measures of children aged up to 6 months were similar to standard growth charts, but subsequently deficiencies developed in the study children. There were no differences between the patterns for males and females. Infants from upper socioeconomic categories had growth patterns that were closest to the norm, but this was associated with feeding and supplementation differences. There was improvement in the growth and feeding patterns of the 1989 and 1990-92 birth cohorts compared with the 1987-88 group and with the standard. Feeding patterns showed high levels of compliance with nutrition guidance. Growth monitoring, staff and maternal education, and supplementation with vitamins and, especially, iron were associated with marked improvements in feeding patterns and the growth status of children aged 3-15 months.

A ten-year experience in control of poliomyelitis through a combination of live and killed vaccines in two developing areas

We describe a successful program of poliomyelitis control using a combination of killed and live polio vaccines over a 10-year period in two developing areas, the West Bank and Gaza, adjacent to a relatively developed country, Israel. During the 1970s, immunization using live trivalent oral polio vaccine (OPV) in these areas covered more than 90 percent of the infant population. Nevertheless, the incidence of paralytic polio continued to be high, with many cases occurring in fully or partially immunized persons. It was thought that this could be due to interference with OPV take by other enteroviruses present in the environment due to poor sanitary conditions in these areas. A new policy combining five doses of OPV with two doses of inactivated polio vaccine (IPV) was adopted and implemented in 1978. In the 10 years since then, immunization coverage of infants increased to an estimated 95 percent and paralytic poliomyelitis has been controlled, despite exposure to wild poliovirus from neighboring countries including an outbreak in Israel in 1988. This experience suggests that wide coverage using the combination of IPV and OPV is an effective vaccination policy that may make eradication of polio possible even in developing areas.

Early onset of disk degeneration and spondylosis in sand rats (Psammomys obesus)

The sand rat is a desert animal which feeds mainly on salt bush, a shrub with a high salt content in its leaves. Sand rats have been used for the study of renal function, and since they may develop diabetes if kept on a laboratory diet without a supplement of salt bush, they have been used for investigation of diabetes-related disorders as well. Older diabetic and non-diabetic sand rats are prone to develop severe degeneration of the intervertebral disks, disk herniation, and subsequent hyperostotic spondylosis. This report is concerned with the relation of these processes to aging. The vertebral columns of 25 sand rats which were fed a standard laboratory diet and a supplement of salt bush ad libitum were examined. The sand rats ranged from 12 to 18 months of age. The vertebral columns were dissected, prepared for microscopic examination, and the findings were compared with those obtained previously in sand rats from 1 1/2 to 2 1/2 years of age. Both disk degeneration and spondylosis were comparable in course and frequency to the changes found in the older sand rats. It was concluded that factors other than age are involved in the pathogenesis of disk degeneration in the sand rat.

Pseudomonas aeruginosa in rabbit fur

Skin lesions with peculiar bluish-green discolouration and wet, matted appearance of the fur, occurred sporadically in a small rabbitry. Pseudomonas aeruginosa was isolated from the skin lesion.

A strain of Pasteurella multocida associated with infections in rabbit colonies

Pasteurella multocida was isolated from 4 conventional rabbit colonies. Amongst 51 isolates, 48 (94%) belonged to a group of strains with similar morphological, cultural, biochemical and antigenic characteristics; they were named for convenience Lo strains and gave rise to local or ascending infections. All Lo strains were found to be a new serotype, but 8 of them had additional antigenic factors characteristic of known serotypes. The other 3 isolates (6%) were identified as serotype 3, known to have a wide host range: 2 strains were associated with septicaemia and haemotogenic spread, and 1 with snuffles. Diagnostic agglutinating antibodies were present in the sera of adult rabbits. Maternal antibodies were in the sera of adult rabbits. Maternal antibodies were in the sera of rabbits of 3 and 4 weeks old, but by the age of 8 weeks the titres had fallen to an undetectable level.

Spontaneous intussusception of the small intestine in guinea-pigs

A condition is described in guinea-pigs which manifested itself by intussusception of the small intestine in 49 out of 77 fatal cases. Proliferation of the bile ducts and centrilobular fatty degeneration of the liver cells found on histological examination induced us to suspect aflatoxicosis. Toxicological analysis of the lucerne hay fed to the animals corroborated this hypothesis. An organic phosphorous insecticide was also found in the hay.