In Antarctica, scientists track a dangerous bird flu

Despite apparently minimal seabird deaths, grave concern for the next breeding season.

Clinical Herpes Zoster in Antarctica as a Model for Spaceflight

INTRODUCTION

Antarctica is a useful analog for spaceflight, as both environments are remote, isolated, and with limited resources. While previous studies have demonstrated increased asymptomatic viral shedding in both the Antarctic and spaceflight environments, clinical manifestations of reactivated viral disease have been less frequently identified. We sought to identify the incidence of clinical herpes zoster from viral reactivation in the Antarctic winter-over population.

METHODS

Medical records from the 2014 winter season were reviewed for the incidence of zoster in U.S. Antarctic personnel and then compared to the age-matched U.S.

POPULATION

RESULTS

Five cases of clinical herpes zoster occurred in the Antarctic Station population of 204 persons, for an incidence of 33.3 per 1000 person-years vs. 3.2 per 1000 person-years in the general population. Four cases were in persons under age 40, yielding an incidence of 106.7 per 1000 person-years in persons ages 30-39 compared to an incidence of 2.0 per 1000 person-years in the same U.S. age group.

DISCUSSION

Immune suppression due to the stressful Antarctic environment may have contributed to the increased incidence of herpes zoster in U.S. Antarctic personnel during the winter of 2014. Working and living in isolated, confined, and extreme environments can cause immune suppression, reactivating latent viruses and increasing viral shedding and symptomatic disease. Such changes have been observed in other austere environments, including spaceflight, suggesting that clinical manifestations of viral reactivation may be seen in future spaceflight.Reyes DP, Brinley AA, Blue RS, Gruschkus SK, Allen AT, Parazynski SE. Clinical herpes zoster in Antarctica as a model for spaceflight. Aerosp Med Hum Perform. 2017; 88(8):784-788.

Brucella antibody seroprevalence in Antarctic seals (Arctocephalus gazella, Leptonychotes weddellii and Mirounga leonina)

Brucellosis is a worldwide infectious zoonotic disease caused by Gram-negative bacteria of the genus Brucella, and Brucella infections in marine mammals were first reported in 1994. A serosurvey investigating the presence of anti-Brucella antibodies in 3 Antarctic pinniped species was undertaken with a protein A/G indirect enzyme-linked immunosorbent assay (iELISA) and the Rose Bengal test (RBT). Serum samples from 33 Weddell seals Leptonychotes weddelli were analysed, and antibodies were detected in 8 individuals (24.2%) with the iELISA and in 21 (65.6%) with the RBT. We tested 48 southern elephant seal Mirounga leonina sera and detected antibodies in 2 animals (4.7%) with both the iELISA and the RBT. None of the 21 Antarctic fur seals Arctocephalus gazella was found positive. This is the first report of anti-Brucella antibodies in southern elephant seals. The potential impact of Brucella infection in pinnipeds in Antarctica is not known, but Brucella spp. are known to cause abortion in terrestrial species and cetaceans. Our findings suggest that Brucella infection in pinnipeds is present in the Antarctic, but to date B. pinnipedialis has not been isolated from any Antarctic pinniped species, leaving the confirmation of infection pending.

Pathogen reduction requirements for direct potable reuse in Antarctica: evaluating human health risks in small communities

Small, remote communities often have limited access to energy and water. Direct potable reuse of treated wastewater has recently gained attention as a potential solution for water-stressed regions, but requires further evaluation specific to small communities. The required pathogen reduction needed for safe implementation of direct potable reuse of treated sewage is an important consideration but these are typically quantified for larger communities and cities. A quantitative microbial risk assessment (QMRA) was conducted, using norovirus, giardia and Campylobacter as reference pathogens, to determine the level of treatment required to meet the tolerable annual disease burden of 10(-6) DALYs per person per year, using Davis Station in Antarctica as an example of a small remote community. Two scenarios were compared: published municipal sewage pathogen loads and estimated pathogen loads during a gastroenteritis outbreak. For the municipal sewage scenario, estimated required log10 reductions were 6.9, 8.0 and 7.4 for norovirus, giardia and Campylobacter respectively, while for the outbreak scenario the values were 12.1, 10.4 and 12.3 (95th percentiles). Pathogen concentrations are higher under outbreak conditions as a function of the relatively greater degree of contact between community members in a small population, compared with interactions in a large city, resulting in a higher proportion of the population being at risk of infection and illness. While the estimates of outbreak conditions may overestimate sewage concentration to some degree, the results suggest that additional treatment barriers would be required to achieve regulatory compliance for safe drinking water in small communities.

Parasitic infection by larval helminths in Antarctic fishes: pathological changes and impact on the host body condition index

We examined pathological changes and relationship between body condition index (BCI) and parasitic infection in 5 species of fish, including 42 icefish Chionodraco hamatus (Channichtyidae), 2 dragonfish Cygnodraco mawsoni (Bathydraconidae), 30 emerald rock cod Trematomus bernacchii, 46 striped rock cod T. hansoni and 9 dusty rock cod T. newnesi (Nototheniidae) from the Ross Sea, Antarctica. All parasites were identified by a combination of morphology and mtDNA cytochrome-oxidase-2 sequence (mtDNA cox2) analysis, except Contracaecum osculatum s.l., for which only the latter was used. Five larval taxa were associated with pathological changes including 2 sibling species (D and E) of the C. osculatum species complex and 3 cestodes including plerocercoids of a diphyllobothridean, and 2 tetraphyllidean forms including cercoids with monolocular and bilocular bothridia. The most heavily infected hosts were C. hamatus and C. mawsoni, with C. hamatus most often infected by C. osculatum sp. D and sp. E and diphyllobothrideans, while C. mawsoni was most often infected with tetraphyllidean forms. Histologically, all fish showed varying severity of chronic inflammation associated with larval forms of helminths. Diphyllobothrideans and C. osculatum spp. were located in gastric muscularis or liver and were associated with necrosis and mild to marked fibrosis. Moderate multifocal rectal mucosal chronic inflammation was associated with attached tetraphyllidean scolices. C. hamatus showed a strong negative correlation between BCI and parasite burden.

Frostbites in circumpolar areas

Circumpolar areas are associated with prolonged cold exposure where wind, precipitation, and darkness further aggravate the environmental conditions and the associated risks. Despite the climate warming, cold climatic conditions will prevail in circumpolar areas and contribute to adverse health effects. Frostbite is a freezing injury where localized damage affects the skin and other tissues. It occurs during occupational or leisure-time activities and is common in the general population among men and women of various ages. Industries of the circumpolar areas where frostbite occurs frequently include transportation, mining, oil, and gas industry, construction, agriculture, and military operations. Cold injuries may also occur during leisure-time activities involving substantial cold exposure, such as mountaineering, skiing, and snowmobiling. Accidental situations (occupational, leisure time) often contribute to adverse cooling and cold injuries. Several environmental (temperature, wind, wetness, cold objects, and altitude) and individual (behavior, health, and physiology) predisposing factors are connected with frostbite injuries. Vulnerable populations include those having a chronic disease (cardiovascular, diabetes, and depression), children and the elderly, or homeless people. Frostbite results in sequelae causing different types of discomfort and functional limitations that may persist for years. A frostbite injury is preventable, and hence, unacceptable from a public health perspective. Appropriate cold risk management includes awareness of the adverse effects of cold, individual adjustment of cold exposure and clothing, or in occupational context different organizational and technical measures. In addition, vulnerable population groups need customized information and care for proper prevention of frostbites.

Skeletal and hormonal responses to sunlight deprivation in Antarctic expeditioners

Serum 25(OH)D levels decline without sunlight exposure. We studied 120 expeditioners to Antarctica to determine the skeletal and hormonal responses to sunlight deprivation. With emerging vitamin D insufficiency, serum calcium decreased, PTH increased, and bone loss at the proximal femur was observed. Baseline serum 25(OH)D levels >100 nmol/L prevented vitamin D insufficiency.

INTRODUCTION

Vitamin D stores deplete without adequate sunlight exposure unless supplementation is provided. We studied 120 healthy adults who spent a year in Antarctica as a model for sunlight deprivation to define the timing and magnitude of the skeletal and hormonal responses to emerging vitamin D insufficiency.

METHODS

Fasting blood samples were assessed at baseline, 6 and 12 months for serum 25-hydroxyvitamin D (25(OH)D), osteocalcin (OC), bone formation (P1NP) and resorption (CTx), PTH and calcium. Lumbar spine and proximal femur BMD was measured using DXA. Differences over time were determined using repeated measures ANOVA. Percent changes were expressed as (Delta value/(value A + value B)/2) x 100. Relationships between outcome measures were determined using Spearman's correlations.

RESULTS

Vitamin D insufficiency (<50 nmol/L) was observed in 85% of expeditioners by 6 months when serum calcium decreased and PTH increased (p < 0.01). By 12 months, OC increased by 7.4 +/- 3.0% (p < 0.05), and BMD decreased by 1.0 +/- 2.0% at the total proximal femur (p < 0.05). For those with vitamin D sufficiency at baseline (>50 nmol/L), sunlight deprivation produced vitamin D insufficiency within 4 months unless baseline values were >100 nmol/L.

CONCLUSION

Supplementation may be necessary for expeditioners with limited access to UV light.

Changes in sleep patterns during prolonged stays in Antarctica

Various countries have permanent research bases in Antarctica that are manned year-round by a few members of an expedition team, facing extremes of temperature with the associated hardships. Acclimatisation to such an environment is associated with pyschophysiological changes along with alterations in sleep patterns. The present study was undertaken to explore the changes in sleep patterns of six members of the Indian expedition team during their winter stay at Maitri, the permanent research station of India in Antarctica. The mean (+/- SEM) age, height and weight of the subjects were 35.7 +/- 2.32 years, 168.3 +/- 2.37 cm and 71.0 +/- 1.88 kg, respectively. Polysomnographic sleep recordings were obtained as baseline data in November 2004 in Delhi (altitude 260 m, latitude 29 degrees N, longitude 77 degrees E); data on the same parameters were collected at Maitri, Antarctica (altitude 120 m, latitude 70 degrees 45' 39'' S, longitude 11 degrees 44' 49'' E) from January to December 2005. A one-way analysis of variance with repeated measures showed a significant variation with time (month effect) in most of the sleep parameters recorded. Total sleep time decreased from Delhi baseline values in all months, sleep efficiency decreased significantly during winter months, duration of waking period after sleep onset increased significantly in winter, sleep latency increased immediately after exposure in January, stages 3 and 4 (slow wave sleep) reduced during dark winter months, whereas stages 1 and 2 and rapid eye movement sleep increased during dark winter months. This study observed a prevailing general trend of sleep disturbances amongst overwintering members in a modern Antarctic station.

Leeches (Hirudinida: Piscicolidae)--parasites of Antarctic fish from Channichthyidae family

There has hitherto been very few research projects focusing on ectoparasites of Antarctic fishes. The presently reported study provides data on the prevalence and the intensity of leeches (Hirudinida: Piscicolidae) infecting fishes. The materials were collected in December-February 1986/87 off the Elephant Island, South Georgia, Joinville Island, and South Shetlands. The following leech taxa were recorded in the Antarctic fishes of the family Channichthyidae: Trulliobdella capitis (Brinkmann, 1947); Cryobdella antarctica Epstein, 1970; Nototheniobdella sawyeri Utevsky, 1997; and Cryobdella sp. The above findings constitute new geographic records from off Elephant and Joinville Island and South Georgia.

OUTBREAKS OF AVIAN CHOLERA IN HOPE BAY, ANTARCTICA

During austral summers 1999-2000 and 2000-01, two outbreaks of avian cholera occurred in the Hope Bay area (63 degrees 24'S, 56 degrees 59'W), located on the tip of the Antarctic Peninsula. Eighty-six dead birds were found: five kelp gulls (Larus dominicanus), 36 skuas (Stercorarius sp.), and 45 Adelie penguins (Pygoscelis adeliae). The carcasses were studied using clinical, pathological, and microbiological criteria. Water samples from ponds where birds were settled and samples from 90 healthy birds also were analyzed during the second outbreak. Pasteurella multocida isolates were identified by biochemical tests, capsular type, somatic serotype, and susceptibility to nine antibiotics. Molecular subtyping was performed by ApaI and SmaI pulsed-field gel electrophoresis (PFGE) and enterobacterial repetitive intergenic consensus (ERIC-PCR). In February 2000, mortality in skuas was 16% and 2% in kelp gulls. In the 2000-01 breeding season, mortality in south polar skuas was 47%, 24% in brown skuas, 1.4% in kelp gulls, and 0.01% in Adelie penguins. All birds had lesions of avian cholera. In kelp gulls the presentation was chronic, whereas skuas and penguins suffered subacute and acute disease, respectively. Fifty-five isolates recovered from dead birds and one from water were identified as P. multocida gallicida, type A:1. The strains presented a unique molecular pattern by PFGE and ERIC-PCR. A possible hypothesis to explain the origin of the outbreaks was that nonbreeder kelp gulls carried P. multocida gallicida to Hope Bay, and avian cholera was transmitted through water to skuas and penguins. This study reports avian cholera in new bird species, their potential role in the transmission of the disease, and the different responses of these species to the disease.

35 years of ICCH: evolution or stagnation of circumpolar health research?

The first Circumpolar Health symposium took place in Fairbanks in 1967. Approximately every three years since, an increasing number of researchers have met to present and discuss the health conditions of the North. We analysed the proceedings from the 11 congresses and the abstracts from the 12th congress in 2003 and found a shift of focus from biology to sociology of health. Today, circumpolar health research is primarily focused on three major topics: 1. epidemiology of indigenous peoples of the North; 2. health care delivery in the North; and 3. the effect of physical factors on human physiology and health. Despite the diverse research interests, it is remarkable how a community of circumpolar scientists and practitioners has emerged over the past 35 years.

Morbidity and health survey of wintering members in Japanese Antarctic research expedition

STUDY DESIGN

The Japanese Antarctic Research Expedition (JARE) started in 1956. Syowa Station is the mother station of JARE at 69 degrees 00'S and 39 degrees 35'E in East Antarctica. An epidemiological survey of the wintering team of JARE was carried out based on the annual reports of JARE over the period 1956-2001.

METHODS

The total number of personnel was 1,236 including 3 females. The age of personnel was from 21 to 56 (average 33.1). We examined the proportion of personnel who had contracted disease with healthy personnel, as reported by the medical department at Syowa as well as a health survey of the latest party by biochemical analyses.

RESULTS

The total number of diseases was 4,760. The ratios of surgical-orthopedic, internal medical, and dental cases were 45%, 23%, and 13%, respectively. Only one death from a blizzard was recorded. In the latest party, serum levels for triglyceride, calcium, and gamma-glutamyl transpeptidase increased during the wintering period.

CONCLUSION

The very low mortality of JARE may be due to the effective personnel selection and that there have been no severe accidents. There has been no deterioration in nutritional parameters in JARE recently.

The epidemiology of knee and ankle injuries on Macquarie Island

Macquarie Island is a small, rugged sub-Antarctic island with a scientific research station and a considerable reputation for knee and ankle injuries amongst the Australian Antarctic Division expeditioner population. In order to examine the accuracy of this reputation, a 10-year retrospective analysis of all knee and ankle injuries recorded by the Macquarie Island Medical Officer in the medical logs was undertaken. Knee and ankle injuries comprised 13% of the 2,678 recorded medical consultations. The majority of initial injuries occurred in the field and almost a third occurred during work related activities. Ankle ligament sprains were the most commonly recorded injury (17%), followed by achilles tendonitis (14%), enthesopathy of the knee (16%), and chondromalacia patellae (10%). Meniscal tears and collateral ligament of the knee sprains contributed a further 11 and 9%, respectively. While there were few significant knee and ankle injuries during this period, around a third of the expeditioners represented to the Medical Officer with recurrent difficulties.

Syphacia obvelata infections and reproduction of male domestic mice Mus musculus domesticus on a sub-Antarctic Island

The reproductive activity of feral male mice on an island of the sub-Antarctic Kerguelen archipelago was influenced by biological factors depending on periods within the breeding season. After having controlled host reproductive activity indices for body size, i.e. age, and body condition effects, Syphacia obvelata prevalence did not vary with host reproductive status or age either during the beginning or the middle-end of the reproductive season. Considering the beginning of the breeding season, worm abundance was more pronounced in males the year following a strong winter crash of the population than in years when high over wintering survival occurred. During the middle-end of the breeding season, males with the highest reproductive status were more infected than males with a lower reproductive status in years when oldest individuals dominated the population. It is suggested that this situation was due to an endocrine related increased host susceptibility partly influenced by a change in the age structure of the population, and that an increase in worm transmission was not directly related to male activity concurrent with reproductive status, nor to population density.

Pathological and serological evidence of Brucella-infection in baleen whales (Mysticeti) in the western North Pacific

Abnormal testes and uterus were observed in 13 males (33%) and one female (3%) out of 40 common minke whales (Balaenoptera acutorostrata) in the western North Pacific. Similar lesions were found in testis and ovary, respectively, in one male (2%) and female (2%) out of 43 Bryde's whales (Balaenoptera edeni) in the western North Pacific. Grossly, granular lesions with caseation and calcification were main pathological signs, and they were restricted to reproductive organs of mature whales. Chronic purulent or granulomatous orchitis was observed by microscopic analysis. Antibodies to Brucella species were detected in the serum samples of 15/40 (38%) of common minke whales and 4/43 (9%) of Bryde's whales. Neither pathological nor serological change was found in the examined sperm whales (Physeter macrocephalus) in the western North Pacific and Antarctic minke whales (Balaenoptera bonaerensis). These results strongly suggest that Brucella infection was involved in two species of baleen whales (Mysticeti) in the North Pacific.

Thelebolus microsporus mycelial mats in the trachea of wild brown skua (Catharacta antarctica lonnbergi) and South Polar skua (C. maccormicki) carcasses

Sixteen brown skuas (Catharacta antarctica lonnbergi) and seven South Polar skuas (C. maccormicki) were found dead near Boekella Lake, Hope Bay, Antarctica, in February 1997. Postmortem examination revealed conspicuous caseous, deep yellow fungal/mycelial mats or cores in the trachea of nine of 19 carcasses that were examined. These mycelial cores, highly suggestive of aspergillomas, completely occluded the tracheal lumen in four of these nine carcasses. Thelebolus microsporus, a psychrophilic ascomycetous fungus commonly isolated from skua dung and skua nesting material, was isolated in pure culture from these tracheal plugs. Awareness of pseudolesions resulting from Thelebolus microsporus profuse postmortem growth in the trachea of dead skuas will minimize potential confusion with aspergillosis when investigating causes of epornithics in Antarctica.

Survey of South Polar skuas (Catharacta maccormicki) for blood parasites in the Vestfold Hills region of Antarctica

Thin blood smears prepared from 125 South Polar skuas (Catharacta maccormicki) at breeding islands and feeding sites in the Vestfold Hills region of Antarctica between December 1999 and January 2000 did not contain hematozoa. These findings confirm results of previous smaller studies, and provide baseline data for this species.

Erythema UV-B exposure near the Antarctic Peninsula and comparison with an equatorial site

Observations of UV-B radiation in the area of the Antarctic Peninsula are described, with the objective to obtain an evaluation of the UV-B enhancements observed during ozone hole episodes, and compare these with equatorial values. The enhancements observed during Southern Hemisphere spring are described in terms of a specific case of enhancement, at the Antarctic peninsula, which has shown a maximum UV-B index of 8.7, in October 1998. The average enhancement between the autumn-unperturbed and spring-perturbed periods results in an UV-B index of 5.4, but with large fluctuations in which much larger indices are produced. These values are compared to indices normally observed in the equatorial region. For measurements obtained with the same kind of instrument at Natal (5.8 degrees S, 35.2 degrees W), the UV-B index varies between 7 and 14, which means that enhanced UV-B indices in the Antarctic Peninsula may become of the same order of magnitude of the lower limit equatorial values.

Antibody responses to bacteriophage phi X-174 in human subjects exposed to the antarctic winter-over model of spaceflight

BACKGROUND

It has been proposed that exposure to long-term spaceflight conditions (stress, isolation, sleep disruption, containment, microbial contamination, and solar radiation) or to ground-based models of spaceflight will alter human immune responses, but specific antibody responses have not been fully evaluated.

OBJECTIVE

We sought to determine whether exposure to the 8-month Antarctic winter-over model of spaceflight would alter human antibody responses.

METHODS

During the 1999 Australian National Antarctic Research Expeditions, 11 adult study subjects at Casey, Antarctica, and 7 control subjects at Macquarie Island, sub-Antarctica, received primary and secondary immunizations with the T cell-dependent neoantigen bacteriophage phi X-174. Periodic plasma samples were analyzed for specific antibody function.

RESULTS

All of the subjects from Casey, Antarctica, cleared bacteriophage phi X-174 normally by 1 week after primary immunization, and all had normal primary and secondary antibody responses, including immunologic memory amplification and switch from IgM to IgG antibody production. One subject showed a high normal pattern, and one subject had a low normal pattern. The control subjects from Macquarie Island also had normal immune responses to bacteriophage phi X-174.

CONCLUSIONS

These data do not support the hypothesis that de novo specific antibody responses of subjects become defective during the conditions of the Antarctic winter-over. Because the Antarctic winter-over model of spaceflight lacks the important factors of microgravity and solar radiation, caution must be used in interpreting these data to anticipate normal antibody responses in long-term spaceflight.

Salmonella in sub-Antarctica: low heterogeneity in Salmonella serotypes in South Georgian seals and birds

The number of human visitors to Antarctica is increasing rapidly, and with it a risk of introducing infectious organisms to native animals. To study the occurrence of salmonella serotypes in sub-Antarctic wildlife, faecal samples were collected from gentoo penguins, macaroni penguins, gray-headed albatrosses, black-browed albatrosses and Antarctic fur seals on Bird Island in the South Georgian archipelago during the austral summer of 1996 and 1998. In 1996, S. havana, S. typhimurium and S. enteritidis were isolated from 7% of gentoo penguins and 4% of fur seals. In 1998, however, 22% of fur seals were found to be infected with S. havana, S. enteritidis and S. newport. All isolates, except one, showed identical pulsed-field gel electrophoresis-patterns within each serotype, irrespective of sampling year and animal reservoir. No significant antibiotic resistance was found. The very low heterogeneity in the salmonella isolates found could either indicate a high genetic adaptation of the bacteria to the environment or a recent introduction of salmonella into the area.

Melanoma and other skin cancers in circumpolar areas

During the recent decades, the thickness of the ozone layer over the northern hemisphere has declined by 10 to 40 percent during the winter and spring months. Since ozone is the major barrier protecting the earth from dangerous short wave UV-radiation (UVB), the depletion in the ozone layer consequently increases the amount of UV-radiation reaching the earth's surface. As a rule a 10 percent reduction in the ozone layer causes ca. 20% increase in UV-radiation and a 40% increase in skin cancers. Thus relatively minor changes in ozone layer thickness may a have marked impact on the health of humans. Skin cancer is the most common cancer in humans, i.e. in Finland about 4000 new basal cell carcinomas, 700 other skin cancers, mostly spinous cell carcinomas and 500 melanomas occur yearly. Up to recent years the incidence of skin cancers has steadily increased in northern countries. As an explanation, changes in sunbathing habits have been suggested to play a central role. Due to the high mortality rate in melanoma, and marked morbidity in other skin cancers, it is important to try to prevent skin cancers and inform the public about the risks of excessive sun exposure, and of the ways in which the skin can be protected. Proper clothing and use of sunscreens have been shown to reduce the incidence of both melanomas and other skin cancers. Furthermore, it is important to identify those at high risk for acquiring skin cancers, like individuals with type 1 skin character (fair skin which burns easily), or numerous dysplastic nevi, or a family history of skin cancers.

The epidemiology of skiing injuries in Antarctica

A retrospective analysis of all skiing injuries experienced by members of the British Antarctic Survey between 1989 and 1995 was undertaken to test the hypothesis that skiing was responsible for a disproportionate number and severity of injuries compared with other activities. Fifty-nine new consultations for skiing injuries were recorded. This represented 3.2% of all consultations (annual range 1.3-6.7%), or 9.7% of all consultations due to trauma. The mean incidence was 84.3/1000 population/year. The annual proportion and rate of consultation fluctuated but no overall trends were noted. The lower limb was the commonest site of injury (76.3%), with the ratio of lower limb: upper limb injuries being 6.4:1. The commonest single injury was an isolated medial collateral ligament knee sprain (23.7% of all consultations). Head injuries comprised 8.5% and ulnar collateral ligament thumb sprains 5.1%. Assessment of injury by the Injury Severity Score (ISS) showed that skiing injuries were significantly more likely to be non-trivial (ISS > 2) than work-related injuries [chi 2(1, N = 56) = 55.6, p < 0.001] or injuries of all causes [chi 2(1, N = 56) = 65.0, p < 0.001]. They were significantly more likely to need radiological investigation than all injuries [chi 2(1, N = 59) = 22.0, p < 0.001]. The most severe (ISS 13), survivable injury seen during the study period resulted from a skiing accident. This excess of non-trivial injury raises important management issues, particularly as the majority (81%) were recreational.

The epidemiology of cold injury in Antarctica

METHOD

A retrospective study was performed of 10 yr of medical records to determine the type, severity, etiological factors and treatment of cold injury experienced by members of the British Antarctic Survey between 1986-95.

RESULTS

There were 61 new consultations for cold injury. These comprised 2.5% of all new consultations with an incidence of 65.6 per 1000 per year. Cold injuries seen were frostbite (95%), hypothermia (3%) and trench foot (2%). Superficial frostbite was the most common injury (74% of cases) with the face the most frequently affected area (47% of injuries). No cases of frostbite severe enough to cause permanent tissue loss were seen. The prevalence of cold injury increased with falling temperature to a maximum between -25 and -35 degrees C, despite these temperatures occurring infrequently. The relationship with windchill is not as clear cut with frequency of injury tending to follow the frequency of windchill values except at higher windchill values. Neither temperature nor windchill were found to significantly influence the severity of frostbite. Prior cold injury was shown to be significantly (chi2 p < 0.001) associated with further cold injury. Most injuries (78%) occurred during recreation; skiing and snowmobile driving were often implicated.

CONCLUSIONS

Cold injury is uncommon in Antarctica. Despite this, it warrants a continued high profile as under most circumstances it may be regarded as an entirely preventable occurrence.

Latitudinal differences in species and community richness and in community structure of metazoan endo- and ectoparasites of marine teleost fish

Relative species diversity of gastrointestinal helminths of 55 teleost fish species did not differ significantly at different latitudes, whereas relative species diversity of metazoan ectoparasites on the heads and gills of 108 teleost fish species showed a significant increase with decreasing latitude and from deep to surface waters. Abundance of endoparasites also was the same at all latitudes, whereas abundance of ectoparasites increased with decreasing latitude and from deep to shallow waters. A comparative analysis using phylogenetically independent contrasts supported these conclusions. Possible reasons for the differences between endo- and ectoparasites are discussed. A detailed analysis of the community structure of gastrointestinal helminths of five Antarctic and three tropical teleosts and of metazoan ectoparasites on the heads and gills of five Antarctic and seven tropical fish species showed the following: abundance and prevalence of infection of endoparasites are similar in Antarctic and tropical fish, but are much greater for tropical than for Antarctic ectoparasites. Relative species diversity of endoparasites is similar for Antarctic and tropical endoparasites, but much greater for tropical than Antarctic ectoparasites. In both Antarctic and tropical fish, different fish of the same species may have different dominant species of endo- and ectoparasites, although there is a greater range of dominant species of tropical ectoparasites, a consequence of the greater species pool available. The most dominant parasite (irrespective of species) represented 80-99% of all endoparasites of Antarctic, and about 50-80% of all endoparasites of tropical fish. The most dominant parasites (irrespective of species) represented about 90-100% of all ectoparasites of Antarctic, and about 20-70% of all ectoparasites of tropical fish, the difference a consequence of the greater species pool of tropical ectoparasites available. The data suggest that both endo- and ectoparasites live in assemblages not structured by interspecific competition.

Subsyndromal seasonal affective disorder in Antarctica

The seasonality of depressed mood was examined in 70 men and women who spent the 1991 austral winter at three American research stations in Antarctica. Seasonal Pattern Assessment Questionnaire global seasonality scores increased significantly from late summer (February/March) to midwinter (July/August; p < .001). Only one case of seasonal affective disorder (SAD) was found during midwinter, but the prevalence of subsyndromal SAD increased significantly, from 10.5 to 28.4 per 100, during this period. Station latitude was significantly associated with SAD-specific symptoms and global Structured Interview Guide for the Hamilton Depression Rating Scale-Seasonal Affective Disorders Version scores in midwinter and in early spring (October). The results suggest that even clinically normal individuals are likely to experience symptoms of subsyndromal SAD in high latitude environments, that these variations become more pronounced with increasing latitude, and that they can be detected through repeated administrations of instruments such as the Seasonal Pattern Assessment Questionnaire and Structured Interview Guide for the Hamilton Depression Rating Scale-Seasonal Affective Disorders Version.

Incidence and spread of Haemophilus influenzae on an Antarctic base determined using the polymerase chain reaction

A PCR-based method of detecting Haemophilus influenzae in cultures inoculated from throat swabs was evaluated using samples from groups of laboratory staff and medical students and then applied to samples originating from the closed human community of an Antarctic research station. Suitable PCR primers to an H. influenzae gene (ompP2) were used to amplify the gene from DNA preparations made from mixed growth on chocolate agar with added vancomycin. PCR product was reamplified and subjected to restriction endonuclease digestion to allow temporal and spatial mapping of strains over an 8-month period. Eleven different strains of H. influenzae were detected. One particular strain was detected in a third of the base members.

[Myxomatosis in the sub-antarctic islands of Kerguelen, without vectors, thirty years after its introduction]

Myxoma virus was introduced into the Kerguelen archipelago in 1955-1956. Thirty years after its introduction, the virus is present in most areas inhabited by rabbits. Rabbit fleas and mosquitoes are absent from this group of islands and the disease is transmitted by contact. The timing of the beginning of new myxomatosis outbreaks, the absence of real epizootics as well as the higher percentage of infected males over females are specific observations in favour of this mode of transmission. The majority of 34 isolates tested between 1984 and 1988 are of intermediate virulence (Grades IIIA-IIIB). In these conditions, the impact of myxomatosis virus on rabbit populations estimated on two sites is low. Myxomatosis therefore plays only a minor role in the regulation of rabbit populations.

Evidence of ortho- and paramyxoviruses in fauna from Antarctica

Serum antibodies to influenza A viruses and paramyxoviruses were detected in Adelie penguin (Pysoscelis adeliae) and Antarctic skua (Stercorarius skua maccormicki) sera in the Ross Sea Dependency. An avian paramyxovirus was isolated from a penguin cloacal swab.