Asthma in the Caribbean

Bronchial asthma is a common problem in the Caribbean. Recent questionnaire surveys of asthma and other allergic diseases among school-aged children in Barbados and Trinidad, using the International Study of Asthma and Allergy in Childhood (ISAAC) standardised questionnaire, have revealed that the prevalence of the disease in these islands is at the upper end of the global scale. The article discusses the following house dust mites: an important trigger; acute asthma admissions increase in the last quarter; knowledge, attitudes and practice; Caribbean Guidelines' and the Caribbean Allergy & Respiratory Association. Asthma in the Caribbean mirrors the global experience in many ways, yet still affords the opportunity to study unexplored areas of the disease from a global and regional perspective, such as the role of ethnicity in the expression of disease severity. These guidelines were adapted from those of the World Health Organisation/US National Heart, Lung & Blood Institute by a Commonwealth Caribbean Medical Research Council (CCMRC) workshop held in 1997. They are aimed at improving the care provided for patients with asthma. The need for a regional association that focussed on allergic and respiratory disease in the region was also conceived at that CCMRC workshop, and this led, a year later, to the birth of the Caribbean Allergy and Respiratory Association (CARA)(AU)

CARA: a breath of fresh air

Few conditions are of more concern in the Caribbean today than asthma. This much was clear from the large turn-out and enthusiastic response to a meeting organised in Port-of-Spain by the Caribbean Allergy & Respiratory Association (CARA). The meeting took place immediately before the annual scientific gathering of the Caribbean Health Research Council. The meeting also heard feature lectures on allergic rhinitis in Jamaica, new techniques under development for the assessment of inflammation, and patient education. The importance of the latter was indeed a recurring theme throughout the discussions. There were also presentations of recent Caribbean asthma research, which included accounts of experience in paediatric asthma clinics in Tobago and Jamaica. Results were presented from a study seeking to determine whether there were seasonal peaks in the incidence of asthma attacks in Trinidad. Rises in temperature, humidity, and wind speed all seem to be able to increase the number of attacks. Prior to the main CARA meeting there had been a mini-symposium on asthma in Tobago, and a public meeting at the Eric Williams Medical Complex in Trinidad. The three-day event was popular with those who attended and was a fine example of continuing medical education in action (AU)

Considerations for implementing an antibiotic policy in hospital practice

An antibiotic policy should aim for the safe, effective and economical use of antimicrobial drugs, and to prevent their indiscriminate use and development of resistant bacterial strains. The term 'antibiotic' is used as a general term for all antimicrobial drugs. Antibiotics prescriptions should be based on clinical evidence of bacterial infection, preferably substantiated by appropriate laboratory culture and sensitivity tests. Viral infections are not an indication for antibiotic prescriptions. Patient factors to be considered for choice and dose of an antibiotic are age, pregnancy, lactation, renal and hepatic impairment. Immunodeficient patients should receive only bactericidal drugs. Severity of infection determines the route of administration. Duration of therapy should not exceed five days, unless specifically prescribed by the physician. An antibiotic should, if started as an empirical therapy not be changed before a minimum of three days trial. Prescriptions of drugs such as aztreonam, imipenem, vancomycin, piperacillin and amphotericin are to be restricted due to cost and toxicity and should be reviewed by the microbiologist (AU)

Allergy in the West Indies - abstract

Allergy-related illnesses (respiratory, food and others) occur frequently in West Indians. A prospective study of 1038 Jamaican adolescents revealed high levels (males 52 percent, females 41 percent) of allergy prevalence. The respiratory allergies were the most common; 21 percent of the allergic subjects gave a history of bronchial asthma. Only 19 percent of the latter group had their illness diagnosed by a doctor. A retrospective study of 512 patients in a local allergy practice showed that respiratory allergies usually occurred perenially, and the patients' skin tested positive to house dust mite, moulds and pollens. Immunotherapy was effective if very dilute dosages were used. Laboratory investigations of allergic and non-allergic medical students and technologists at the University of the West Indies revealed normal total serum IgE levels (0-380 kU/L) in 18 of 24 subjects and only moderately elevated levels in the remaining 6 subjects. Total serum IgG4 was unexpectedly found to be increased in most of the study subjects (18 of 24). Further studies are necessary to further clarify these findings (AU)

The role of the house dust mite and other household pests in the incidence of allergy among Barbadian asthmatics - abstract

The incidence of allergy to 14 different household pests, including 2 house dust mite species (D. farinae and D. pteronyssinus), was investigated among 156 asthmatic children in Barbados. Independent variables, including urban/rural residence, building material of the home, and presence of carpeting, were found to be significant factors related to the house dust mite allergy. The continuing trend of modernization of the domestic environment, which provides an optimal microhabitat for several household pests, is implicated as a probable contributing factor in the increasing overall prevalence of asthma reported in Barbados. Children between the ages of 5 and 18 years with a diagnosis of bronchial asthma were selected from attendees at six polyclinics distributed throughout the island, an urban private general practice, and the accident and emergency department of the only acute general hospital on the island. Skin tests were done by scratching, and by intradermal injection, if the scratch test proved negative. Allergy to the house dust mite was the most common of the reactions to the household pests tested, and was found in 81 percent of the asthmatic children (AU)

Bronchial asthma management in the 90s - abstract

Bronchial asthma is among the most common medical emergencies confronting the practising physician and, being very responsive to therapeutic intervention, it is one of the most rewarding diseases to treat. The increasing recognition that airway inflammation underlies much of the dysfunction in bronchial asthma is leading to a change of emphasis away from symptomatic bronchodilator treatment towards the earlier use of anti-inflammatory or disease-modifying strategies. Like many other disease states, asthma has numerous triggers, some of which are present in the environment and therefore avoidable. Hence one of the first considerations is to accurately define the offending allergens or culprits and to develop measures to minimise exposure to them. Bronchodilators have traditionally been considered as first-line treatment. Although the theophyllines are effective, their usefulness is limited by several side-effects. Aerosolised beta-2 agonists with a longer duration of action are currently undergoing clinical trials and are likely to be used more in furture for pro-phylaxis rather than symptomatic treatment. Corticosterois provide the mainstay of treatment for both acute and chronic asthma, although their mechanism of action is not fully understood. The problems with steroids are the well-known side-effects which complicate chronic use. This is being addressed by the development of a group of steroid-like drugs called Lazaroids which have potent anti-inflammatory effects but are free of hormonal effects and the recent availability of potents aerosolised steroids with greatly improved delivery systems. Finally, in selected cases of asthma, where allergy is playing a significant causative role immunotherapy as a treatment modality should be seriously considered (AU)

Year-round total serum IgE and IgG4 levels in allergic and non-allergic West Indian medical students

Twenty-four allergic and non-allergic West Indian medical students and pathology technologists had repeated serum IgE an dIgG4 levels determined over a one-year period. Contrary to previously published reports on this type of population, total serum IgE levels were usually consistently normal (18 of 24 subjects) with little variation throughout the year. The remaining six subjects, all allergic and non-allergic elevated levels (620-1096 kU/1). Total serum IgG4 was elevated in most of the allergic and non-allergic subjects (18 0f 24). Perennial exposure to molds and house dust mite in this tropical environment could possibly produce the chronic antigenic stimulation reponsible for the elevation in serum IgG4 levels found in this study (AU)

Total serum IgE and IgG4 levels in allergic and non-allergic West Indian medical students - abstract

Despite high prevalence rates of allergic illnesses in the region, the laboratory indices of these disorders have not been documented. This prospective controlled study was undertaken to determine the levels of sensitizing antibodies (IgE and IgG4) and their variation over a one-year period. The subjects, 17 allergic and 7 non-allergic pre-clinical medical students and laboratory technologists, were selected by questionnaire. Blood samples were collected at approximately 3-monthly intervals and a stool sample at the beginning of the study. Routine haematological and microbiological investigations were carried out on blood and stool samples respectively. IgE was measured by enzyme immunoassay and IgG4 by radial immunodiffusion. Haematological and coprological investigations were normal in all subjects. Total serum IgE levels were higher in allergic subjects than in controls (geometric means 192ñ4.5 and 77ñ3.5 Ku/1 respectively) and there were no seasonal fluctuations in either group. Both groups had similar IgG4 levels which also showed no seasonal variation (geometric means 0.88ñ2.18 and 1.01ñ1.89g/L respectively). These IgG4 values were elevated in comparison with those reported for Europeans (mean 0.6g/1). The total IgE levels in our study, which were within the normal range for temperate populations, were much lower than those reported for tropical populations. Total serum IgE levels in isolation were unable to distinguish between allergic and non-allergic individuals. There was no evidence of a seasonal allergen. The elevation in IgG4 levels in control and allergic subjects has not been previously reported. Chronic antigenic stimulation is thought to produce elevated IgG4 levels. It is possible that chronic perennial allergenic stimulation may contribute to the raised IgG4 levels found in this study (AU)

Allergies in Trinidad and Tobago - abstract

Observations for over eighteen months with the establishment of an Allergy Clinic at the Port-of-Spain General Hospital are being presented. Skin testing for immediate Type I hypersensitivity by the Gell and Coombs classification was done on all patients with a history of allergy. The skin testing results showed that 63 percent of the patients were positive to Dermatophagoides pteronys-sinus; 55 percent positive to D. fariniae; 48 percent to house dust; 31 percent to a mixture of 4 moulds and 32 percent to a mixture of feathers. Therefore house dust mites and house dust were the major offending allergens. This confirms the observation in the temperate region that asthma is related to allergy and to house dust mites. During the course of this clinic, it was observed that in the majority of the patients with allergies, illnesses seemed to occur at the time of the year coinciding with that of the highest humidity. Consequently, a retrospective study of asthma with hospital data on admission was reviewed over a five-year period, 1975-1979. The mean monthly admission rate was 66 (range 46 to 98) with a rate of 57 (range 46 to 69) from January to September and 90 (range 86 to 98) from October to December. This seems to correlate with humidity which is low January to May (mean 79.4 percent) and high in July to December (mean 85.3 percent). The lag between the rise in humidity and the rise in admissions in October could suggest that the relationship is not a direct cause-effect one. The radioimmunoassay method was used for quatitating the serum IgE in a selected group of patients. Mean for the first 26 patients was 485 iu/ml and in only 7 of the first 26 patients done for IgE was less than 300 iu/ml the suggested upper limit. These are high values compared with non-allergic Swedish children whose mean is 66 iu/ml. and healthy Ethiopian children free of parasites whose mean was 325 iu/ml using a similar technique (AU)

The prevalence of allergic disease in Jamaican adolescents

A study of 349 male and 689 female adolescents revealed allergies in 182 (52 percent) and 285 (41 percent) respectively. Many of the allergic subjects reported histories suggesting bronchial asthma, (44 percent of the males and 49 percent of the females), high rates of family involvement and low rates of confirmation by a doctor. Various factors contributing to this high prevalence are discussed. Little research has been done in Jamaica on this important problem.(AU)

The placental bed vessels in normotensive and hypertensive pregnancy (abstract only)

During Caesarean section biopsies of the placental bed have been taken from normotensive and hypertensive women. Historical examination has been especially directed at the maternal vessels and any changes found related to the clinical histories of the patients. Changes have been found in the maternal vessels of women suffering from essential hypertension and pre-eclampsia. They do not differ from one another except in degree and are indistinguishable from those changes known to occur in association with systemic hypertension. They have not been found in normotensive patients. It is felt that the hypertension and the accompanying vasular lesions may be responsible for the reduction of the maternal placental blood flow found to occur in patients with pre-eclampsia and essential hypertension. (AU)

Some observations on filariasis in British Guiana and its treatment

The pathological manifestations of parasitization by Wucheria bancrofti appear to result from a combination of three causes namely: (a) an allergic reaction to the parasite evidenced by oedema, urticaria and itching of the skin with occasionally arthritis and synovitis. (b) invasion of the oedematous and devitalized tissues by pathogenic micro-organisms. (c) lymphatic obstruction caused by the parasite itself and partly by a reactive fibrosis. Treatment by streptococcal vaccines is useful but symptoms recur sooner or later. Treatment of the allergic symptoms by desensitization with extracts of Dirofilaria immitis may be helpful. Treatment by a combination of vaccines and desensitizing extracts promises to be of value in amelioration of symptoms, prevention of attacks and prevention of elephantiasis (Summary)