Surveillance of leptospiral carriage by feral rats in Barbados

Rodents, particularly rats, are widely held to be the source of most human cases of leptospirosis. Feral rats were trapped at sites throughout Barbados during two-six month surveys: from October to March 1986/87 and from October to March 1994/95. During the first survey, 63 rats were trapped, of which 26 (41 percent) were identified as Rattus rattus and 37 (59 percent) as Rattus norvegicus. In the second study, 100 rats were trapped, of which R. rattus comprised 24 percent (24) and R. norvegicus 76 percent (76). Cultures of blood, urine and kidney were made in EMJH medium. Leptospires were isolated from 12/63 (19 percent) and from 16/100 (16 percent) of the rats during 1986/87 and 1994/95, respectively; 27/28 isolates were recovered from the kidneys or urine or both, while only one isolate was recovered from the blood. During the first study, isolates were identified as serovars copenhageni (11), arborea (1), while in the second study, serovars copenhageni (9), arborea (5) and bim (1) were identified; one isolate was lost before it could be identified. In the first study, antibodies were detected by microscopic agglutination at a titre of > or = 100 in 26/62 (42 percent) of rats tested, while in the second survey, 5/100 (5 percent) of rats had similar titres. In two surveys, conducted eight years aparts we confirmed that rats in Barbados are commonly infected with leptospires, and that viable organisms are found in the kidneys and urine, evidence of chronic infection and thus excretion of leptospires in rodent urine. Moreover, the predominant serovar isolated was copenhageni, of which Rattus spp. are the worldwide reservoir. There was little evidence that rats act as a reservoir for the serovar bim, the most common cause of human leptospirosis in Barbados.(AU)

Socio-biological associations of bacteriuria in pregnancy

The prevalence and socio-biological relations of bacteriuria was found to be 16.7 percent and it was more common in the 30-39 age group, among parous women, among negroes, and in patients with a low family income and overcrowded living conditions. Symptoms were present in 19 percent of bacteriuric patients and almost one-third gave a past history of urinary tract infection. Only 10 percent had been previously exposed to sexually transmitted diseases such as syphilis, gonorrhoea and herpetic genital infections. Because of the serious consequences to mother and foetus, we advocate quantitative urine cultures for all antenatal patients, especially those from disadvantaged socio-economic conditions (AU)

Bacteriuria in pregnancy: a comparative study of women seen in two antenatal clinics in Kingston, Jamaica using a group of non-pregnant women as controls

Significant bacteriuria in pregnancy, particularly when asymptomatic remains a major problem due to the many complications that have been associated with this condition. In this study, 457 samples of midstream urine from pregnant women attending the UWI-ANC and the CHC-ANC and 164 from non-pregnant women attending the Freezone clinic were collected between March 18 and April 11, 1994. Laboratory investigations to determine significant bacteriuria, the distribution of isolates and their antimicrobial susceptibility were performed. Population characteristics such as age, parity, socio-economic status and gestational age as well as the presence of symptoms consistent with urinary tract infection and choice of treatment were ascertained via the use of a questionnaire. The level of contamination among the samples was compared with that found in the Microbiology Laboratory UWI within the same period. While the prevalence of significant bacteriuria in pregnancy was 19.6 percent, that of asymptomatic bacteriuria was 13.3 percent compared with 7.3 percent among non-pregnant women. This difference was of statistical significance (p < 0.01). Statistical significant association existed between bacteriuria and the presence of symptoms, pyuria, gestational age. None was found with age, parity and socio-economic status. The three most common isolates were Streptococcus group B, Streptococcus faecalis and Staphylococcus aureus. Resistance to Ampicillin was high (37.8 percent) while resistance to Bactrim was low (3.3 percent). The level of contamination of samples from pregnant women was 4.2 percent compared to 11.5 percent found in the laboratory. This study highlighhts the problem of asymptomatic bacteriuria and suggests the need for further studies using larger samples to confirm these interesting findings (AU)

Analysis of pathogens isolated from urinary tract infections in Barbados

The isolation of pathogens from urine specimens was surveyed during a six-month period when 1611 urine specimens were examined in the Public Health Laboratory, and 8769 were examined in the Microbiology Laboratory of the Queen Elizabeth Hospital. Significant growth (defined as >10 organisms/ml urine) was detected in 393 (24,4 percent) of the urine cultured in the Public Health Laboratory and in 1218 (13.9 percent) of urines cultured in the Queen Elizabeth Hospital. The overall isolation rate 15.5 percent; Gram-negative bacilli were more commonly isolated from hospital patients, whereas Gram-positive cocci were relatively more common in community patients. The most common pathogens detected were coliforms (1233 isolates), streptococci (197) and coagulase-negative straphylococci (182); 50 percent of all isolates were sensitive to amoxycillin, 68 percent to cephradine, 61 percent to co-trimoxazole, 62 percent: to nalidixic acid and 79 percent to nitrofurantoin. Anti-bacterial activity was detected in 130 (8 percent) of the urine specimens received in the Public Health Laboratory. (AU)

The screening of urines with leucocyte esterase/nitrite test strip - abstract

The culture of mid-stream specimen of urines for significant bacteriuria forms the bulk of the workload of the microbiological laboratory. Any screening test which can effectively reduce this load will be most useful. This study evaluated the LN strip in 942 urine samples, using 10 (to the 4th power) Colony Forming Units/ml of one or two species as the criterion for signiifcant bacteriuria. The prevalence rate of infection was 32.1 percent. The sensitivity of the LN test was 82.5 percent, the specificity was 38.5 percent and the negative predictive value was 81.9 percent. These results have demonstrated that the LN test in this study was not cost-effective. Further study in more selected populations with a lower prevalence rate of infection may yet prove the LN strip to be cost-effective (AU)

Chyluria as a cause of heamaturia in patients from endemic areas

Chyluria is an unusual cause of haematuria in temperate regions and is rarely considered even when no apparent cause has been found. We report 3 Guyanese men who presented with macroscopic haematuria in whom pyelo-lymphatic fistulae were found. In none of the patients were the symptoms severe enough for surgical disconnection of the fistula to be required. (AU)

The evaluation of urine testing in an out-patient drug treatment programme in Trinidad and Tobago - abstract

The purpose of this paper was to investigate the efficiency of urine screening in an out-patient population of drug addicts. A total of 294 urine samples were collected from 115 patients and divided into two groups: samples from a high-suspect group (HSG, n = 144) and from a non-suspect group (NSG, n = 150). These were screened for cocaine and its metabolites by thin-layer-chromatography (TLC). Patients found with positive urines were followed up for eight sessions in group psychotherapy. Drop-out rates were compared between the groups for a period of three months. Eight point three per cent of urine samples were found positive for cocaine and its metabolites in the HSG and 6.7 per cent in the NSG. Only 7.5 per cent of the total sample was positive, an unexpectedly low figure. Of all patients with positive urines, only 12.5 per cent in the NSG failed to complete eight sessions of group psychotherapy compared with 83.3 per cent in the HSG. These findings suggest that urine testing as practised at our centre is a poor method of monitoring drug addicts. Suspicion does predict those who are likely to default (AU)

Increased urinary output of mercapture acids in severely malnourished children - abstract

Mercapturic acids (MA) are a group of compounds produced during detoxification processes in vivo. The extent to which a cell is exposed to toxic substances is therefore reflected by increased urinary. MA output. Toxins are effectively neutralised by the formation of a conjugate with glutathione (GSH); this reaction is catalysed by glutathione s-transferase (GST). Severely malnourished children have poorly functioning antioxidant systems and are often exposed to increased oxidant stress; their detoxification systems are probably being overworked. This is supported by our previous finding that erythrocyte GST activity is induced in malnourished children. As MA are the end product of GST activity, we reasoned that hte urinary MA output should also be elevated. This may assist in explaining the low level of GSH foun in children with oedematous malnutrition and provide a quantitative measure of the total body load of exogenous and endogenous carbony-like toxins. Twenty -four-hour urinary output of MA and creatinine were measured in 19 severely malnourished children, on admission and at discharge. Three healthy children served as controls. The results are as follows: MA (æmol/kg child) Control - 1.2ñ0.1, Malnour - 4.2ñ0.6, Maras. - 3.4ñ0.8, Mar/Kwash. - 5.1ñ1.2, Kwash. 4.4ñ1.1 . MA (æmol/mmol creat) Control - 5.8ñ0.9, Malnour. - 37.3ñ5.7, Maras. - 26.0ñ7.1, Mar/Kwash. - 57.3ñ13.0, Kwah. - 32.6ñ7.3. The MA levels were maintained at discharge. Creatinine levels on admission were significantly lower than normal, they were increased at discharged. We conclude that the urinary MA output of severely malnourished children is significantly higher than normal; this is probably indicative of their burden of toxins. The high MA output at discharge is possibly as a result of oxidant stress imposed by the high polyunsaturated fat content of the recovery diet (AU)

Water requirements of breast-fed infants in a hot climate

To estimate the water requirements of exclusively breast-fed infants in a hot climate, theoretical calculations of water requirements were made and field study was carried out in Jamaica. Three urine samples ranged from 1.005 through 1.015, with a mean of 1.009 (SD ñ 0.002). Corresponding values for osmolality were calculated to be 103 through 468 mOsmole/liter with a mean of 258 mOsmole/liter. The mean specific gravity for an infant ranged from 1.006 through 1.012, or 139 through 358 mOsmole/liter. The mean outdoor temperature was 27.6 C and the humidity 76 percent. Because the values for specific gravity were universally low it was concluded that healthy, exclusively breast-fed infants living in a hot climate will manage well without additional water. Additional water may be desirable during illness (AU)

Studies on acid excretion in adults with sickle-cell anaemia

The acid excretion of patients with sickle-cell anaemia has been studied. There is a mild defect in urinary acidification and a decreased H+ excretion in response to ammonium chloride loading. The acidification defect was not corrected by oral administration of a phosphate solution. Infusion of sodium sulphate solution in subjects who were avidly reabsorbing sodium produced equal degrees of urine acidification in patients and controls. Studies on bicarbonate reabsorption were inconclusive. We conclude that patients with sickle-cell anaemia have a mild form of incomplete distal renal tubular acidosis (AU)

Renal synthesis of ammonia and its implications

Urinary excretion of ammonia serves as an important mechanism for sparing cations as well as for eliminating hydrogen ion from the body. The free base NH3 is lipid-soluble and lacks electrical charge, so it readily diffuses across cell membranes and tends to equilibrate in renal tubular cells, tubular urine, and peritubular blood. In contrast, the ammonium ion NH4+ is trapped wherever it is formed. This process of ionic diffusion and trapping is the mechanism by which almost all, if not all, ammonia is excreted into the urine. (AU)

The "Uroscreen" test for significant bacteriuria in pregnancy

The "Uroscreen" as a screening test for significant bacteriuria has been assessed and shown to have an accuracy of 88.3 percent: there is a false positive rate of 56.6 percent of positive tests, or 14.4 percent of all tests, when compared with single plate cultures. All cases of significant bacteriuria associated with E.coli were detected by the "Uroscreen". It is recommended that the routine described be used. A urine screening test for significant bacteriuria has for the second time been assessed against the standard of significant bacteriuria; which in this series has been shown to have a confidence of 96 percent. It has been confirmed that routine screening for significant bacteriuria post partum is necessary, and appears most important in the primigravida. Post partum infection offers an explanation for the increase in prevalence of significant bacteriuria with parity. The figures confirm those of the University of the West Indies and indicate the prevalence of significant bacteriuria in the general pregnant population of Jamaica and the Caribbean may be similar to or higher than that found in series from other countries (AU)

Acid-base balance in adults with sickle cell anaemia

This study of acid-base balance in adults with sickle cell anaemia was undertaken because of the reports of severe metabolic acidosis during "Painful Crisis". Metabolic acidosis has been incriminated as the cause of the "Painful Crisis" and it has been claimed that alkali treatment can prevent and even abort these painful episodes. It was therefore possible that a defect in urinary acidification could explain this tendency to develop acidosis with its serious consequences. The results of acid-base parameters during the steady state showed a mild respiratory alkalosis which is a non-specific finding in patients with severe anaemia. The response to oral NH4Cl loading revealed a slight but significant defect in urinary acidification (minimum pH in SCA 5.38 against 4.83 for controls). Titratable Acid excretion was reduced but the urinary NH4+ though reduced was normal when related to the urine pH. The glomerular filtration rate was normal. These findings are compatible with the syndrome of Incomplete Renal Tubular Acidosis. The administration of oral neutral phosphate resulted in a marked increase in titratable acid excretion but the defect in urinary acidification persisted. A maximal acidifying stimulus (Na2SO4 infusion) produced intense urinary acidification in both normal controls (minimum pH 4.55) and patients with SCA (minimum pH 4.59). Since the sulfate infusion is a known test of distal tubular acidification, a gradient type defect (Distal RTA) was ruledout. The threshold for bicarbonate excretion was reduced in 3 of 6 patients and it was therefore suggested that these patients have a form of Proximal Renal Tubular Acidosis due to defective bicarbonate reabsorption. There was no evidence of metabolic acidosis during "Painful Crisis". This would suppport our belief that Alkalis are of little use in the treatment or prevention of "Painful Crises", at least in our population (AU)

Multiple myeloma in Jamaica: a study of 40 cases with special reference to the incidence and laboratory diagnosis

For two years protein abnormality was studied in 40 cases of myelomatosis in Jamaica. Thirty-nine of these were in West Indian Negroes. The minimum incidence of myelomatosis in this group was estimated to be of the order of 50 cases per million per annum which is considerably higher than in Caucasians as reported by previous workers. A larger number showed myeloma protein with á-globulin mobility and hypogammaglobulinaemia than with gamma-globulin mobility. As in the Caucasians the disease is more common in men than in women and the age incidence in both seems to be the same. Combined serum and urinary electrophoresis was diagnostic in every case, and examination of the urine for Bence-Jones protein by electrophoresis yielded more consistent findings than the classical heat test. It is suggested that combined serum and urine electrophoresis should be done in all cases of suspected myelomatosis

Hydroxyproline and creatinine excretion in infantile protein malnutrition

Total urinary hydroxyproline and urinary creatinine were measured in ten malnourished male infants shortly after admission to hospital and at intervals until they had fully recovered. Urinary hydroxyproline excretion was initially low and later rose to levels higher than reported for normal controls. This high level of hydroxyproline excretion was maintained for severalweeks. The pattern of urinary creatinine was similiar to that of urinary hydroxypoline. It is suggested that the rate of catabolism of collagen is greatly reduced in the malnourished infant (Summary)