Respiratory syncytial virus infections in Curacao

OBJECTIVE: To collect epidemiological data on the prevalence of respiratory syncytial virus (RSV) in Curacao and to assess a possible relation to seasons. DESIGN AND METHODS: All children aged 0 to 24 months admitted to the paediatric ward of St. Elisabeth Hospital in Curacao with acute lower respiratory tract illness (tachypnoea, dyspnoea with wheezing, crepitations or cough), from October 1998, to October 1999, were enrolled. Excluded from the study were patients whose respiratory symptoms were caused by a foreign body, congenital malformation of heart, lung or thorax. RESULTS: Forty-four children fulfilled the study criteria; 20 (47 percent) were RSV positive for parainfluenza virus. Almost half (48 percent) of the total population was ex-premature. The majority of the RSV infections occurred during the two rainy periods and >50 percent (n=34) of all children had acute otitis media. The frequency of otitis media, positive RSV test and length of hospital stay was higher for the ex-prematures. Cyanosis was present in 2/10 (20 percent) of RSV positive and 2/23 (9 percent) of RSV negative cases. None of the patients required artificial ventilation and none died. CONCLUSION: RSV infection does occur in Curacao mostly during the rainy season. Ex-prematures seem to be especially at risk and otitis media is found in the majority of cases. In the light of the growing number surviving extreme prematurity, RSV prophylaxis needs to be considered.(Au)

Detection of dengue infection in patients investigated for leptospirosis in Barbados

The annual incidence of leptospirosis in Barbados is approximately 13 severe cases/100,000. The peak incidence occurs in October to December of each year, coinciding with the months of heaviest rainfall. During the second half of 1995, the epidemic of dengue type 1 infection produced almost 1.000 laboratory-confirmed cases. During the same period, leptospirosis mortality was twice the average, suggesting that some cases of leptospirosis were being misdiagnosed and treated inappropriately. Sera from patients investigated for dengue or leptospirosis were analyzed retrospectively to determine the extent of misdiagnosis. During 1995 and 1996, 31 of 139 and 29 of 93 patients, respectively, were confirmed as having leptospirosis. Sera from the remaining leptospirosis-negative patients were tested for IgM antibodies to dengue virus. During 1995 and 1996, 48 of 108 patients and 21 of 64 patients, respectively, were found to have dengue. In 1997, sera from all patients investigated for leptospirosis were treated prospectively for IgM antibodies to dengue: 38 of 92 leptospirosis-negative patients (41 percent) were dengue IgM-positive, while 2 of 25 leptospirosis cases also had serologic evidence suggesting acute dengue infection. A second large outbreak of dengue caused by serotype 2 occurred in 1997 dengue epidemics in Barbados, dengue cases outnumbered leptospirosis cases investigated in the leptospirosis diagnostic protocol. During, 1997, patients investigated but negative for dengue were also tested for anti-leptospiral IgM: 7.3 percent (19 of 262) were IgM-positive. Substantial misdiagnosis of both dengue and leptospirosis can occur and greater public awareness and clinical suspicion of the similar presentations of these two diseases are necessary. (AU)

A comparison of surveillance systems for the dengue vector Aedes aegypti in Port of Spain, Trinidad

When the currently used larval surveillance system (visual inspection) for the dengue vector Aedes aegypti was compared with the surveillance for the presence of eggs by ovitrapping in Port of Spain, Trinidad, it was found that the latter (39.1 percent) was significantly more sensitive than the visual inspection system (10.1 percent). At the same time, the presence of the nuisance mosquito Culex quinquefasciatus was detected in 38.4 percent of the households. Both Ae. aegypti and Cx. quinquefasciatus showed preference for ovipositional attractants in ovitraps: hay infusion > yeast suspension > plain tap water. Although all the socioeconomic and geographic areas produced both mosquito species in 1996, upper middle class (UMC) areas (8.6-43.4 percent), produced more Ae. aegypti than did lower middle class (LMC) area 7.8-38.8 percent), which produced more than working class (WC) areas (3.9-29.9 percent). For Cx. quinquefasciatus, the order of production was reversed with WC areas (50.1 percent) > LMC areas (30.0 percent) > UMC areas (26.0 percent). Change in vector surveillance strategies incorporating some ovitrapping and stratified sampling are recommended for Caribbean countries(AU)

The microbiological analysis of Sahara dust and its association with asthma in Barbados

Sahara or African dust originates on the African continent and its transported across the North Atlantic to Barbados and other Caribbean Islands by the North East Trade Winds. The amount of dust deposited in Barbados has shown a steady increase over the years and so has the incidence of respiratory disease and asthma. This study investigated the monthly variation of the concentration of Sahara dust in the atmosphere the presence of micro-organisms in it. It also examined whether there was any association between these and asthmatic attendances at the Asthma Bay of the Accident and Emergency Department of the Queen Elizabeth Hospital (QEH). During the one year study period, dust deposition was lowest during February and March 1996 and heaviest during April to July 1996 with the peak in April. The peak in April did not coincide with any noticeable increase in asthma attendances during that month. A total of 289 dust samples were collected and cultured. The cultures grew mainly bacillus species and fungi, including several species of Aspergillus. 43 samples (14.8 percent) grew bacilli and fungi and 5 (1.7 percent) grew organisms other than bacilli and fungi, such as micrococci. More colonies of fungi were isolated during the early part of the year and more bacilli were found during the latter part of the year when there was the peak attendance at the QEH Asthma Bay. It is concluded that the content of Sahara dust may be of greater importance to the development of asthma than the concentration of the dust.(AU)

The epidemiology of Haemophilus influenzae invasive disease n the Kingston and St. Andrew Region, Jamaica - abstract

Haemophilus influenzae invasive disease was studied retrospectively over a four year period in children admitted to the Bustamante Hospital for Children in Kingston, Jamaica. A total of 86 cases wwere identified. The estimated annual incidence of H. influenzae invasive disease in Kingston and St Andrew ranged from 39 to 45 per 100,000 children <5 years of age. The majority (77 percent ) of cases were in the < 2 year age group. A distinct seasonal pattern was noted, with a significantly higher proportion of patients (57 - 73 percent ) presenting in the cooler months. Similar seasonal variations have been described in the literature. Meningitis was the most clinical diagnosis, accounting for 76 percent of the cases. Poor outcome was demonstrated in 21.5 percent of patients with meningitis. Sensitivity testing of Haemophilus isolates revealed a resistance rate oof 26 percent for ampicillin and 7 percent for chloramphenicol. The epidemiological findings in this study do not differ significantly from those described in the literature for many developed countries. (AU)

Social economics of childhood glucocorticoid stress response and health

This study examines socioeconomic conditions, psychosocial stress, and health among 264 infants, children, adolescents, and young adults aged 2 months to 18 years residing in a rural Caribbean village in Dominica. Fieldwork was conducted over a 9 year period (1988-1996). Research methods and techniques include salivary cortisol radioimmunoassay (N = 22, 438), systematic behavioral observation, psychological questionnaires, health evaluation, medical records, informal interviews, and participant observation. Analyses of data indicate complex relations among socioeconomic conditions, stress, and health. Household income, land ownership, parental education, and other socioeconomic measures are weakly associated with child illness. There is no evidence that apparent material benefits of high socioeconomic status such as improved housing, diet, work loads, and access to private health care have important direct effects on child health in this population. However, social relationship, especially family environment, may have important effects on childhood psychosocial stress and illness. Abnormal glucocorticoid response profiles, diminished immunity, and frequent illness are associated with unstable mating relationships for parents/caretakers and household compositon. We suggest that family relationships and concomitant stress and immunosuppression are important intermediary links between socioeconomic conditions and child health.(AU)

The Seasonality of schizophrenic births in Barbados - abstract

There are many reports that births during the cooler winter months produce an excess of schizophrenics diagnosed in later life. This is also reported to be true in South Africa where the seasons are reversed. Thus, the seasonality effect of schizophrenic births is fairly well established. If this hypothesis is true, then in countries without a true winter, there should not be an increase in schizophrenic births during the so-called winter months. We tested this hypothesis on a group of 466 schizophrenics (who met the DSM III R diagnostic criteria) born between the years 1915 and 1976 and treated at the psychiatric Hospital in Barbados. Barbados is a tropical island situated at 13§08'N and 59§36'W, has no pronounced winters (average monthly temperature - 78.8§F; SDñ 1.7) with a population which is predominantly of African descent. We searched for seasonal/quarterly and monthly birth trends, using the total population as controls. We used Chi Square Test, Edwards Test and the GLIM programme to analyze the data. We did not find any significant differences in the monthly or quarterly birth patterns of schizophrenics when compared to the general population. There was also no significant difference when the paranoid subgroup was compared with the controls. Our findings suggest the lack of seasonality in Barbados results in a more uniform monthly distribution of births of persons who subsequently become schizophrenic (AU)

Vitamin D supplementation of post-menopausal women in Curacao, and pre- and post-menopausal women in the Netherlands - abstract

Pre- and post-menopausal white women living in The Netherlands in late winter/early spring and black and white post-menopausal women living in Curacao were supplemented with either 400,800 and 2x400 IU vitamin D (3)/day or placebo for 4, 5, or 9 weeks. Baseline plasma 25-hydroxyvitamin D [25(OH)D] of Dutch women was lower than that of Curacao women. Post-menopausal Dutch women had higher parathyroid hormone (PTH) than pre-menopausal Dutch and post-menopausal Curacao women. There were no differences in 1,25-dihydroxyvitamin D [1,25(OH)2D]. Vitamin D supplementation increased 25(OH)D levels in all groups, PTH and 1,25(OH)2D in post-menopausal Curacao women, and PTH in pre-menopausal Dutch women. Serum and urinary calcium and phosphate did not change. There were no response differences between 400 and 800 IU daily doses, or 800 and 2x400 IU doses. Oral vitamin D supplementation raises late winter/early spring plasma 25(OH)D of women living at high latitudes to baseline levels encountered in the tropics (AU)

Seasonal abundance, biting cycle, and parity of the mosquito anopheles homunculus in Trinidad, West Indies

Seasonal abundance, daily biting activity, and the age composition of adult Anopheles homunculus female populations were monitored weekly during 1989-90 by human bait on the ground at Cumaca Forest, Platanal, Trinidad. Landing collections of An. homunculus showed diurnal and nocturnal activity, with a single peak between 1600 and 2000 hours. Overall, 27.7 percent of An. homunculus were collected during the dry season and 72.3 percent during the wet season. Similar seasonal parous rates were observed in wet (58.9 percent) and dry (56.1 percent) seasons. Diel periodicities of nullipars and pars were almost identical during the wet and dry seasons(AU)

Molecular and clinical epidemiology of endemic acinetobacter antiratus infections in an urban teaching hospital - abstract

Acinetobacter anitratus is an important nosocomial pathogen with an environmental reservoir. An increased rate of isolations from hospitalised patients prompted this study. Infections were identified in 62 of 81 patients (76 percent), aged 2 months to 95 years in whom A. anitratus was isolated. Seventy-one episodes occurred in the summer and spring versus 10 in the winter and fall of 1990 to 1992 (p<0.0000001). Thirty percent of the patients had pneumonia, 7 percent had peritonitis, and urinary tract infections occurred in 23 percent of patients. The organism was also isolated from deep abscesses and cases of tracheobronchitis. The use of ventilators and continuous ambulatory peritoneal dialysis were significant contributors to the occurrence of infection (OR 11.5, p<0.0004; p<0.000005, respectively). Other features included recent antibiotic use (70 percent), recent hospitalisation (37 percent), Foley catheters (69 percent), total parenteral nutrition (39 percent), angiography (37 percent), chest tubes (25 percent), tracheostomy (23 percent) and epidural anaesthesia (9 percent). Ninety-seven percent had underlying illnesses, 63 percent had major surgery and 34 percent were immunosuppressed. Fifty-five percent of the patients acquired the organism in ICU, and 12 (15 percent) patients died. DNA fingerprinting, using pulsed-field gel electrophoresis (PFGE) of the whole cell DNA digested with Sma 1, revealed 6 PFGE banding patterns among 27 isolates (8 isolates with a common pattern were clustered in the Surgical ICU) and distinct patterns in 44. A.anitratus causes device-associated nosocomial infections in severely ill patients with marked seasonal variation (AU)

Seasonal incidence and diel oviposition periodicity of Haemagogus mosquitoes (Diptera: Culicidae) in Trinidad, W.I. Part III. Haemagogus celeste (Dyar and Nunez Tovar) and Haemagogus leucocelaenus (Dyar and Shannon).

The seasonal incidence and diel oviposition patterns of sylvan Haemagogus celeste and Hg. leucocelaenus in the Pt. Gourde Forest, Trinidad, were monitored weekly for 53 consecutive weeks using conventional ovitraps. During the dry season peak oviposition by Hg. celeste occured between 10:00 and 12:00 hours, and that by Hg. leucocelaenus between 12:00 and 14:00 hours; during the wet season peak oviposition by both species occurred between 12:00 and 14:00 hours. Diurnal patterns of oviposition were observed for both species during the wet and dry seasons. The numbers of ovipositions and of eggs laid during the wet season were, for both species, significantly higher (P greater than 0.001) than those observed during the dry season. (AU)

Seasonal incidence and vertical distribution patterns of oviposition by Aedes aegypti in an urban environment in Trinidad, W. I

The oviposition patterns of Aedes aegypti were investigated using modified ovitraps placed along 4 vertical transects and monitored weekly for 52 wk in St. Augustine, Trinidad, W. I. From the 832 ovitraps exposed at ground level, 1.2, 3.0 and 4.6-m elevations, 43 percent(361) were found containing 20,114 Ae.aegpti eggs. During the wet season, 52.7 percent of the eggs were collected whereas during the dry season only 47.3 percent were collected. Egg populations were highest at the 1.2-m elevation. The implications of these results are discussed. (AU)

Seasonal abundance and diel landing periodicity of Sabethes chloropterus (Diptera: Culicidae) in Trinidad, West Indies

The seasonal occurrence and diel landing periodicity of Sabethes chloropterus (Humboldt) was studied weekly for 1 yr using the human bait catch in the Pt. Gourde Forest, Trinidad, WI. Population abundance remained low throughout the dry season (16 percent) but increased after the onset of the rains in May and peaked by the middle of the rainy season (July-October). The diurnal periodicity of landing was unimodal during the wet season with a major peak between 1200-1600 hours and bimodal during the dry season with peaks at 0800-1000 hours and 1200-1400 hours. This study documents for the first time the periodicity of landing by Sa. chloropterus at ground level and suggests reasons for failure to detect the yellow fever virus at this level. (AU)

Observations on the seasonal incidence and diel oviposition periodicity of Haemagogus mosquitoes (Diptera culicidae) in Trinidad, W. I. II. Heamagogus equinus Theobald

Diel patterns of oviposition of sylvan Haemagogus equinus in the field in Trinidad, West Indies, were monitored weekly for 53 consecutive weeks using standard ovitraps. During the wet season (September to November 1981 and May to September 1982) a large well-defined unimodal peak (comprising 97 percent of all eggs laid and 89 percent of occurrences) occurred at 12.00-14.00 hours, four to six hours before sunset. During the dry season (December 1981 to May 1982), two small less-well-defined peaks occurred at 10.00-12.00 and 14.00-16.00 hours (comprising 4.9 percent of eggs laid and 14 percent of occurrences). A diurnal oviposition pattern was observed when the wet and dry season data were combined. The number of eggs and occurrences found during the wet season was significantly higher (P greater than 0.001) than that observed during the dry season. (AU)

Incidence and diel pattern of oviposition outdoors of the mosquito Aedes aegypti (L.) (Diptera: Culicidae) in Trinidad W. I. in relation to solar aspect

The incidence and diel patterns of oviposition of domestic Aedes aegypti in Trinidad, West Indies during the middle of the wet season (July and August) was compared, using modified ovitraps, in unshaded peridomestic outdoor sites facing east or west. Sites close to each other along a transect differed greatly in the total eggs they received, 18.2 percent of sites receiving 50.6 percent of the eggs. Sites receiving most eggs were close to other breeding sites. The incidence of oviposition in sites facing west, as measured by the number of eggs laid (>59 percent) and by the number of occurrences of eggs (>57 percent), was greater than in sites facing east. The diel pattern of oviposition was closely similar in sites facing east and west, indicating that the sun's azimuth at the moment of oviposition does not determine whether a female lays in sites facing east or west. The diel pattern of oviposition resembled an earlier study in being bimodal but differed from it in featuring a much larger morning peak (comprising more than 34 percent of eggs laid v. about 5 percent in the earlier study). This bimodal pattern closely resembles, the diel periodicity of landing on humans described previously by several authors and is probably close to the typical oviposition pattern for Ae. aegypti; an artefact may have modified the oviposition periodicity characterized earlier. In the evening significantly more eggs were laid facing east. These findings have implications for effective placement of ovitraps for surveillance or suppression of Ae. aegypti, and give rise to an hypothesis which invokes responses to microclimate to account for the form of the bimodal oviposition pattern (AU)

Observations on the seasonal incidence and diel oviposition periodicity of haemagogus mosquitoes (Diptera: Culicidae) in Trinidad, W.I.: part I

The diel oviposition periodicity of sylvan Haemagogus janthinomys Dyar in the Pt. Gourde Forest, Trinidad, West Indies was monitored weekly for 53 weeks using conventional ovitraps. During the wet season (September to November 1981 and May to September 1982) a large well-defined unimodal peak occurred six to eight hours after sunrise (comprising 94 percent of eggs laid and 91 percent occurrences). During the dry season (December 1981 to May 1982), a small less-well-defined peak occurred two to four hours before sunset (comprising 6 percent of eggs laid). The combined data showed a diurnal oviposition pattern with eggs laid from noon to sunset. The numbers of eggs and of used ovitraps found during the wet season were significantly (P<0.001) higher than those found during the dry season.(AU)

Amblyomma variegatum ticks and the occurrence of bovine streptothricosis in Antigua

The association between the occurrence of Amblyomma variegatum ticks and streptothricosis was higher on animals having A. variegatum ticks compared to that of animals not infested with A. variegatum ticks. There was a steady increase in the prevalence of severe lesions as the level of infestation with adult A. variegatum ticks increased. However the distribution of skin lesions could not be related to the predilection feeding sites of adult A. variegatum ticks (Summary)