Assessing a syndemic: Gibraltar in the time of cholera.

More than a decade ago Singer (2009) described Gibraltar's experience with cholera and smallpox in 1865 as a syndemic. In this study, we provide a reassessment of that event and, consequently, propose a methodology to identify a syndemic at the population level. We propose that the concept of the harvesting effect from demographic studies on crisis mortality provides a useful framework for evaluating the presence of a syndemic. Our research begins by establishing a normative baseline mortality (BM) through life table analysis, where changes in life expectancy (LE) around BM can be used to show a distinctive pattern of significant decline and increase. Such was the case with the presence of both cholera and smallpox in the fall of 1865, when LE fell significantly to 19.64 years from the background LE of 32.88 years. A year later, this decline was followed by a significant increase in LE to 41.34 years. Excessive mortality followed by a fallow (healthy) period represents a signature feature of a syndemic driven by a short-term infectious disease epidemic. The presence of both cholera and smallpox in 1860 did not produce similar results, evidence which suggests that the presence of two infectious epidemics in an impoverished population was not sufficient to produce a syndemic. The presence of a protracted state of quarantine, with its concomitant social and economic consequences, was a driving force responsible for amplifying the disease burden in 1865, and elevating to a syndemic status. Multivariate Poisson regression revealed patio level limiting factors (such as, presence of a cistern, a well, a live-in servant, and a Jewish co-resident), as well as risk factors (such as, a smallpox death in the building; the presence of a foreign-born individual). From the two-phase assessment of the syndemic in Gibraltar, we developed a conceptual framework for identifying, contributing, driving, and limiting factors.

Surveillance Metrics of SARS-CoV-2 Transmission in Central Asia: Longitudinal Trend Analysis.

BACKGROUND: SARS-CoV-2, the virus that caused the global COVID-19 pandemic, has severely impacted Central Asia; in spring 2020, high numbers of cases and deaths were reported in this region. The second wave of the COVID-19 pandemic is currently breaching the borders of Central Asia. Public health surveillance is necessary to inform policy and guide leaders; however, existing surveillance explains past transmissions while obscuring shifts in the pandemic, increases in infection rates, and the persistence of the transmission of COVID-19. OBJECTIVE: The goal of this study is to provide enhanced surveillance metrics for SARS-CoV-2 transmission that account for weekly shifts in the pandemic, including speed, acceleration, jerk, and persistence, to better understand the risk of explosive growth in each country and which countries are managing the pandemic successfully. METHODS: Using a longitudinal trend analysis study design, we extracted 60 days of COVID-19-related data from public health registries. We used an empirical difference equation to measure the daily number of cases in the Central Asia region as a function of the prior number of cases, level of testing, and weekly shift variables based on a dynamic panel model that was estimated using the generalized method of moments approach by implementing the Arellano-Bond estimator in R. RESULTS: COVID-19 transmission rates were tracked for the weeks of September 30 to October 6 and October 7-13, 2020, in Central Asia. The region averaged 11,730 new cases per day for the first week and 14,514 for the second week. Infection rates increased across the region from 4.74 per 100,000 persons to 5.66. Russia and Turkey had the highest 7-day moving averages in the region, with 9836 and 1469, respectively, for the week of October 6 and 12,501 and 1603, respectively, for the week of October 13. Russia has the fourth highest speed in the region and continues to have positive acceleration, driving the negative trend for the entire region as the largest country by population. Armenia is experiencing explosive growth of COVID-19; its infection rate of 13.73 for the week of October 6 quickly jumped to 25.19, the highest in the region, the following week. The region overall is experiencing increases in its 7-day moving average of new cases, infection, rate, and speed, with continued positive acceleration and no sign of a reversal in sight. CONCLUSIONS: The rapidly evolving COVID-19 pandemic requires novel dynamic surveillance metrics in addition to static metrics to effectively analyze the pandemic trajectory and control spread. Policy makers need to know the magnitude of transmission rates, how quickly they are accelerating, and how previous cases are impacting current caseload due to a lag effect. These metrics applied to Central Asia suggest that the region is trending negatively, primarily due to minimal restrictions in Russia.

Approaches to the prevention of type 2 diabetes in Gibraltar.

The incidence of type 2 diabetes mellitus is rising worldwide, with the number of people with the condition expected to reach 552 million by 2030. This is largely due to changing demographics, ageing populations and a worldwide increase in obesity rates. This article explores diabetes in Gibraltar. The main focus is the incidence of type 2 diabetes, in the context of the characteristics of the adult population and how these relate to risk factors, such as obesity, smoking and genetics. Thereis a brief exploration of the history of Gibraltar and how its particular circumstances may account for an increased incidence of diabetes. Finally, the evolution of the local diabetes service and future developments are discussed, along with innovative approaches to diabetes prevention, which may be adapted for use in other communities.

Situating mortality: quantifying crisis points and periods of stability.

A wide range of stressors can cause a dramatic and sudden rise in the death rate in populations, typically resulting in what is referred to as crisis mortality. Here we present a method to standardize the assessment of identifying moments of crises. A modification of the mortality Z-score methodology which is combined with time series analysis was used to investigate mortality events over the course of nearly two centuries for two populations: Gibraltar and Malta. A benefit of this method is that it situates the yearly death rate within the prevailing mortality pattern, and by doing so allows the researcher to assess the relative impact of that event against the norm for the period under investigation. A series of threshold values were established to develop levels of mortality to distinguish moments of lower mortality than expected, background mortality, a crisis, and a catastrophe. Our findings suggested that within defined periods, a limited number of events constituted moments of excessive mortality in the range of a crisis or higher. These included epidemics (yellow fever and influenza in Gibraltar only, and cholera) and casualties associated with World War II. Episodes of lower than expected mortality were only detected (although not significant) in the 20th century in Malta, and at the micro level, the harvesting effect appears to have occurred following cholera epidemics in both locations and influenza in Gibraltar. The analysis demonstrates clearly that the impact of epidemics can be highly variable across time and populations.

The Jewish advantage and household security: life expectancy among 19th Century Sephardim of Gibraltar.

Using the historical population of Gibraltar to examine the pattern of mortality of Jews and Roman Catholics revealed that: (1) the Jews exhibited a significantly better health status as measured by life expectancy at birth (47.66 and 47.56 for Jewish males and females vs. 38.10 and 40.89 for Catholics males and females, respectively), (2) most of the disparity is found in the very young age categories and (3) the significantly lower rates of deaths could be attributed to the diarrheal and nutritional complex. Stage two of the research involved the linkage of deaths over a 7-year period relative to their household context as of 1878. Being Jewish, having a servant, having access to a water well in the tenement and residing in a tenement only with other Jews, were all factors that contributed to a higher life expectancy. Our explanation for the enhanced survivorship among the Jews is grounded in economics as well as in an established welfare system, in religious precepts and in secular knowledge of health. One of the more notable and hitherto unobserved findings is that Roman Catholics residing in the same tenements with Jews enjoyed a distinct health advantage. This suggests that a positive amplification effect arose from their co-residence with the Jews.

From the mouths of monkeys: detection of Mycobacterium tuberculosis complex DNA from buccal swabs of synanthropic macaques.

Although the Mycobacterium tuberculosis complex (MTBC) infects a third of all humans, little is known regarding the prevalence of mycobacterial infection in nonhuman primates (NHP). For more than a century, tuberculosis has been regarded as a serious infectious threat to NHP species. Advances in the detection of MTBC open new possibilities for investigating the effects of this poorly understood pathogen in diverse populations of NHP. Here, we report results of a cross-sectional study using well-described molecular methods to detect a nucleic acid sequence (IS6110) unique to the MTBC. Sample collection was focused on the oral cavity, the presumed route of transmission of MTBC. Buccal swabs were collected from 263 macaques representing 11 species in four Asian countries and Gibraltar. Contexts of contact with humans included free ranging, pets, performing monkeys, zoos, and monkey temples. Following DNA isolation from buccal swabs, the polymerase chain reaction (PCR) amplified IS6110 from 84 (31.9%) of the macaques. In general, prevalence of MTBC DNA was higher among NHP in countries where the World Health Organization reports higher prevalence of humans infected with MTBC. This is the first demonstration of MTBC DNA in the mouths of macaques. Further research is needed to establish the significance of this finding at both the individual and population levels. PCR of buccal samples holds promise as a method to elucidate the mycobacterial landscape among NHP, particularly macaques that thrive in areas of high human MTBC prevalence.

Brief communication: Rethinking the impact of the 1918 influenza pandemic on sex differentials in mortality.

This study will assess the general impact of the 1918 influenza on overall mortality and its impact on mortality attributable to pulmonary tuberculosis in a small-scale population. Using life table and decomposition methodologies, changes in mortality in Gibraltar used a scheme that identified a pre-epidemic period (1904-1917), the epidemic year (1918), and the post-epidemic period (1919-1927). Overall health in both sexes fell significantly in 1918 with a drop in life expectancy at birth, however, health quickly rebounded in the post-epidemic period. In the case of women, there was a significant increase in life expectancy at birth after the epidemic. The impact of influenza on the magnitude of sex differentials in the life expectancy at birth fell during epidemic year but returned to a level comparable to that of the pre-epidemic period. With respect to respiratory tuberculosis deaths, the immediate impact of influenza was restricted to only a significant increase in the rate among women (aged 15-54). In the post-epidemic period, tuberculosis mortality rates returned to the pre-epidemic state in both sexes. The findings from Gibraltar stand in contrast opposition to results reported for experience in the United States during the 1918 flu.

Measles outbreak in Gibraltar, August-October 2008--a preliminary report.

To date, 276 clinical diagnosed cases of measles have been notified in Gibraltar. The outbreak, which has been ongoing since August 2008 and affected almost 1% of the local population, unmasked errors in vaccination uptake assumptions and highlighted the need for improved data recording and research on disease transmission rates in small crowded populations.

Unique pattern of enzootic primate viruses in Gibraltar macaques.

Because Gibraltar's macaques (Macaca sylvanus) have frequent contact with humans, we assayed 79 macaques for antibodies to enzootic primate viruses. All macaques were seronegative for herpesvirus B, simian T-cell lymphotropic virus, simian retrovirus, simian immunodeficiency virus, and rhesus cytomegalovirus. Seroprevalence of simian foamy virus reached 88% among adult animals.

Pediculosis in Macaca sylvanus of Gibraltar.

Pedicinus spp. parasitize several species of nonhuman primates. This is the first published report confirming the presence of Pedicinus albidus (Rudow) infestation in the free-ranging macaques (Macaca sylvanus) of Gibraltar. The diagnosis of pediculosis was based upon finding adult lice on host animals.

The role of morbidity in the mortality decline of the nineteenth century: evidence from the military population at Gibraltar 1818-1899.

The causes of the nineteenth-century decline of mortality, characterized by lower mortality rates and increased longevity, have been the subject of debate among researchers for the past half-century. Because of a paucity of reliable data, little is understood about the role of morbidity, or illness episodes, in the mortality decline. This article introduces the results of a study that looks at the relationship of morbidity in the mortality decline during this portion of the epidemiological transition. The data are comprised of hospital admissions and deaths collected by the British army on the soldiers of the Gibraltar garrison from 1819 to 1899. Morbidity dropped during this period, but at a slower rate than mortality, and all categories of disease did not fall in concert; in some categories, morbidity rose as mortality dropped. Statistical modeling is used to analyze the categories of diseases that were most influential in the decline of mortality in this group. This research shows that there are discernible relationships between morbidity and mortality and that the two parameters are responding to different driving forces. Because changes within the military medical system may have had an effect on the relationship of the morbidity and mortality rates of the soldiers, surviving medical reports are used to reconstruct the medical care of the troops during the study period.

The prevalences of overweight and obesity in children aged 4 to 12 years in Gibraltar.

OBJECTIVE: To determine the prevalences of overweight and obesity in children aged 4 to 12 years, using the standard definitions proposed by the International Obesity Taskforce. DESIGN: Population prevalence cross-sectional survey involving measurement of height and weight. Data collection took place in 1998. SETTING: Schools in Gibraltar. SUBJECTS: In total 2994 children, aged 4-12 years, attending these schools (1540 boys, 1454 girls). RESULTS: Prevalence of overweight in boys was 19.7%, while obesity prevalence was 10.8%. For the girls, overweight prevalence was 21.4%, while obesity prevalence was 10.6%. There were no significant differences in the proportions of overweight or obesity between boys and girls. CONCLUSIONS: This was the first time that the prevalences of overweight and obesity have been estimated in children from Gibraltar. These data provide further information on prevalence rates of overweight and obesity, using defined cut-offs for comparison with data from other countries.

Tuberculosis mortality and recent childbirth: a retrospective case-control study of Gibraltarian women, 1874-1884.

Prior to the introduction of effective treatment for pulmonary tuberculosis, there was little consensus on the potential health risk of pregnancy among infected women. While, intuitively, pregnancy was viewed as a risk for tuberculosis disease and mortality, early studies could not establish such a link with any great certainty. Our case study combines the methods of family reconstitution and a case-control approach to explore the possibility that the physiological and social strains of recent childbirth and the early mothering of infants may have been risk factors in adult female tuberculosis mortality in late 19th-century Gibraltar. The study is based on 244 reproductive age women who died between 1874 and 1884; some 55% of these deaths were attributed to tuberculosis. The record linkage indicates that almost 12% of the women who died had given birth within the year preceding their death. Factoring in the effects of age at death, marital status, and religion, the logistic regression results indicate that recent childbirth did not increase the risk of tuberculosis mortality among these women.

A matter of privilege: infant mortality in the Garrison Town of Gibraltar, 1870-1899.

The British colony of Gibraltar offers an opportunity to compare the infant mortality rates of the civilian and military populations inhabiting a small-scale urban setting from 1870 to 1899. Both groups shared the same poor-quality housing, the same sanitary infrastructure, and the same environmental inseparability. Sufficient water supply, in particular, proved to be a daily struggle for the families living on the Rock. Privilege for the military meant that service families had preferential access to a pure water supply after the installation of a water-condensing plant as well as to a better quality supply of water and milk. The availability of these privileges to one group, and not the other, is associated with a marked decline in infant mortality in the second half of the study period.