Alteration in sample preparation to increase the yield of multiplex Polymerase Chain Reaction assay for diagnosis of genital ulcer disease.

Purpose: Genital Ulcer Disease (GUD) is common sexually transmitted infection (STI). Multiple studies have shown that GUDs are strongly associated with the transmission and the acquisition of HIV infection. An accurate diagnosis of common etiology of GUD namely Herpes, syphilis and Chancroid is possible using Multiplex PCR (M-PCR). However, frequent presence of Polymerase Chain Reaction inhibitors in the ulcer swab specimen limits the performance of the assay. In order to overcome this problem, alternative specimen preparation method was used. Materials and Methods: To determine the common etiology, GUD specimens obtained under an STI operations research study were tested with M-PCR after the samples were prepared using Roche Amplicor specimen preparation kit. PCR inhibiting samples were identified from that, which showed negative results. These samples were subjected to phenol-chloroform extraction and ethanol precipitation before the conduct of M-PCR on them. Results: Of the 237 GUD specimens tested, in 145 etiologies could be detected, whereas 92 samples were found negative. Further spiking with one of the target DNA, 128 of the negative samples were found to contain the inhibitors. These 126 samples were then subjected to phenol chloroform extraction and ethanol precipitation followed by M-PCR. Using this method for sample preparation, etiology could be determined in 46 (23%) additional samples. This success rate of altered sample preparation method has been lower than that has reported. Conclusion: The results indicate that sample preparation using phenol chloroform extraction and ethanol precipitation, prior to M-PCR helps to eliminate the inhibitors and increase the yield of the assay. However, being a laborious procedure, it may be used for samples giving negative results after the screening by Roche Amplicor specimen preparation kit.

Extended-spectrum beta-lactamase producing enterobacteriaceae in a tertiary care hospital in Trinidad and Tobago

Extended-spectrum beta-lactamase (ESBL) mediated resistance to third generation cephalosporins, amongst the family Enterobacteriaceae, is emerging worldwide. This is the Caribbean's first survey on ESBL production, and was conducted during two six-month periods in 1998 and 2001, in a tertiary health institution in Trinidad and Tobago. Consecutive ampicillin resistant isolates of the family Enterobacteriaceae from in-patients were screened for resistance to third generation cephalosporins, and for ESBL production. The proportion of isolates found to be ESBL producers was similar in both samples (40 of 560 and 23 of 361). Overall, ESBL production was more frequent in enterobacter, citrobacter and proteus (and related organisms) than in Klebsiella and Escherichia (11.2 and 4.6, respectively, p < 0.001). In the 1998 sample, this proportion (9.8 versus 5.8) was significant (p < 0.05), but the difference was more marked in the 2001 sample (13.6 versus 2.9, p < 0.001). Continued distribution of these resistant bacterial strains is of concern. In the Caribbean region, more laboratory surveillance and increased infection control vigilance are recommended, with focus on specific genera in the family

Single dose (direct observed) azithromycin therapy for Neisseria gonorrhoeae and Chlamydia trachomatis in STD clinic attenders with genital discharge in Trinidad and Tobago

The purpose of this study was to determine the prevalence and to assess the efficacy of a single one gram oral dose of azithromycin under direct observed therapy of genital discharge due to Neisseria gonorrhoeae and Chlamydia trachomatis infections in STD clinic attenders in Trinidad and Tobago. All patients with genital discharge and their contacts were given one gram oral dose of azithromycin under direct supervision after collection of urethral and cervical swabs for N gonorrhoeae culture and smear and for C trachomatis antigen detection by ELISA. Clinical and microbiological evaluation was done on those who returned after 7-10 days for follow-up. Of the 735 patients who were enrolled in the study, 319 (43.4) had N gonorrhoeae and 100 (13.6) had C trachomatis. Only 151 (36) of the 419 patients with a pathogenic isolate returned for clinical and microbiological assessment. The remaining 268 (64) of the 419 patients were lost to follow-up. One hundred and forty-three patients (94.7) had total abatement of signs and symptoms after taking azithromycin. One patient (0.65), who had both N gonorrhoeae and C trachomatis, improved clinically with the drug. Seven patients (six with N gonorrhoeae and one with C trachomatis) failed to respond clinically to azithromycin. Microbiological eradication was achieved in 115 (100) patients who had single infection with N gonorrhoeae and in 23 patients (96) with C trachomatis infection. Of 12 patients with combined infections, N gonorrhoeae and C trachomatis were eradicated in 10 and 12 patients, respectively, after initial treatment. In two patients with combined infection, N gonorrhoeae continued to be isolated after treatment with azithromycin. A single one gram oral dose of azithromycin under direct supervision is useful in the treatment of uncomplicated genital infection with N gonorrhoeae and C trachomatis in STD clinic attenders in Trinidad.

Cryopreservation of cardiac homografts.

A homograft valve bank for cryopreservation of cardiac homografts was established at the Institute of Cardiovascular Diseases in July 1995. From July 1995 to February 1999, 169 donor hearts were processed. All except four hearts were procured post mortem. Aortic valves (149) and pulmonary valves (139) were the common homografts dissected out for use. The valves were immersed in a cocktail of five broad spectrum antibiotics and antifungals for an average of 48 to 72 hours before cryopreservation. Fifty-three (35.57%) aortic and 42 (30.21%) pulmonary valves had to be discarded for various reasons like fungal contamination, failure to sterilise, HBsAg positivity etc.; 153 homografts have been released for use so far. Analysing the usual methods of procurement, sterilisation protocol, culture and cryopreservation used for cardiac homografts at this centre, this paper recommends observance of timeliness, use of appropriate media for preservation of heart parts, administration of specific drugs and safeguards necessary for cryopreservation procedure.

Phosphoglycerate kinase--glyceraldehyde-3-phosphate dehydrogenase interaction: reaction rate studies.

Rate studies using phosphoglycerate kinase (PGK)--glyceraldehyde-3-phosphate dehydrogenase (GPDH) enzyme pair have been carried out to distinguish between the two mechanisms of intermediate metabolite transfer, namely diffusion through the solvent versus "substrate channelling" within an enzyme-enzyme complex. A procedure has been described for the assay of the rates of PGK-catalysed and the PGK-GPDH coupled reactions at high (saturating) GPDH concentration. With PGKs of rabbit muscle and yeast, the coupled reaction proceeded faster than the PGK-catalysed reaction. At a high salt concentration (0.5 M KCl), where a PGK-GPDH complex is known to dissociate, the two reactions proceeded at almost equal rates. At fixed PGK concentration, the rate of the coupled reaction at high (saturating) GPDH concentration varied with the nature (biological origin) of the latter enzyme. In the presence of 0.5 M KCl, the saturating rate values with different GPDHs were almost equal. The PGK-catalysed reaction exhibited typical Michaelian behaviour on varying the substrate concentrations (linear double reciprocal plots). The Km values for 3-PGA (0.51 mM) and ATP (0.40 mM) were independent of the concentration of the second substrate. The double reciprocal plots for the coupled reaction showed downward curvature, i.e. activation at higher substrate concentrations. The ratio of the rate of the coupled reaction: the rate of the PGK catalysed reaction was found to be a function of the nature of PGK, nature of GPDH, nature of buffer, pH, salt concentration and substrate concentrations. The ratio varied between close to unity at low substrate concentrations, to three when the Vmax values of the two reactions were compared. At low substrate concentrations, the rate of the coupled reaction became independent of the nature of GPDH. It has been suggested that in the PGK-GPDH pair, the intermediate metabolite (BPG) is transferred directly from one enzyme to the other within an enzyme-enzyme complex, except at high salt or low substrate concentrations. Under the latter conditions, data were consistent with metabolite transfer by diffusion. Implications of these results for coupled enzyme assays have been discussed.

Salmonellosis in Trinidad: evidence for transovarian transmission of Salmonella in farm eggs

The aim of this study was to determine whether the contents of farm eggs in Trinidad are contaminated with Salmonella and if transovarian transmission occurs. 750 fresh eggs from 10 farms supplying 75of the country's eggs were cultured for Salmonella. Salmonella was found on the egg shells' surfaces from all farms, and in the egg contents from three farms. Isolates were obtained from the cultures of the contents and shells of nine (1.2) and 35 (4.66) eggs, respectively (p or = 70 degrees C) of all egg dishes and the refrigeration (< 10 degrees C) of shell eggs and egg dishes, are recommended.

Antibiotic susceptibility of Neisseria gonorrhoeae in Trinidad and Tobago

Treatment failures with standard doses of penicillin have been observed in the Sexually Transmitted Diseases (STD) clinics in Trinidad and Tobago. In the absence of an ongoing surveillance system, the antimicrobial susceptibility of 518 Neisseria gonorrhoeae strains was determined in order to guide treatment. 39 (7.6) strains were resistant to penicillin, including 27 (5.2) positive for beta-lactamase; that is penicillinase-producing Neisseria gonorrhoeae (PPNG). 51 (10) strains were resistant to tetracycline, with 26 (5.0) of these exhibiting high levels of resistance compatible with tetracycline resistant Neisseria gonorrhoeae (TRNG). Six strains showed evidence of having both PPNG and TRNG plasmids, and five strains showed chromosomally-mediated resistance to both penicillin and tetracycline. The overall resistance rate to penicillin and tetracycline was 17.7. There was no resistance to spectinomycin, cefuroxime, ceftriaxone and norfloxacin. The resistance rates demonstrated in this study are sufficiently significant to preclude the use of penicillin and tetracycline in the STD clinics and to justify the use of newer antimicrobials. It is essential that resistance patterns be monitored by continued surveillance.

Routine antibiotic cover for newborns intubated for aspirating meconium: is it necessary?

A retrospective analysis was performed on 215 babies to evaluate the incidence of septicemia in babies intubated at birth for aspirating meconium from the trachea. Only term, appropriate for gestational age babies were included. Babies with any known perinatal risk factor for infection were excluded from the study and none of the babies had been put on "prophylactic antibiotics." There were 88 babies in the intubated group in a one year period from January 1991 to December 1991. One hundred and twenty seven babies were taken as controls. There was no significant difference in the incidence of early septicemia in the two groups. There were no deaths in either group. It is concluded that well term babies who are intubated for aspirating meconium need not be put on routine antibiotic cover.

Seroprevalence of toxoplasma gondii, rubella virus, cytomegalovirus herpes simplex virus (TORCH) and syphilis in Jamaican pregnant women

Seroprevalence of toxoplasma gondii, rubella virus, cytomegalovirus, herpes simplex virus infections (TORCH) and syphilis were determined in order to assess the immune/susceptibility status in Jamaican pregnant women in 1986. The positive rates were 57%(T. gondii), 69%(rubella), 97%(CMV), 91%(HSV), and 4.9%(syphilis), respectively. The rate of reactivity for rubella was over 50%in all parishes, the highest being 85%in St. Thomas. The seroprevalence of T. gondii was lowest in Trelawny (37.5%). There were no significant differences in seropositivity of CMV and HSV infections between women from various parishes. The importance of seroprevalence of the TORCH group of agents and syphilis on perinatal morbidity and mortality in Jamaican women is discussed, and appropriate recommendations for prevention and control of congenital infections in Jamaica are suggested.

Infectious mononucleosis in the University of the West Indies

The clinical features and laboratory parameters in sixteen confirmed cases of Infectious Mononucleosis (IM) seen at the University Hospital of the West Indies between 1975 and 1989 were reviewed. The common presenting features were lymphadenopathy (14/16), fever (13/16) and pharyngitis (7/16). Atypical lymphocytosis was present in 10 cases and heterophile antibodies (HA) in 9 cases. The aetiology and laboratory diagnosis of IM are briefly discussed.

Prevalence of reactive serological tests for syphilis in the Jamaican population

Serological tests for syphillis (STS) were performed on sera from 15,876 members of the general adult population, 3,039 pregnent women and 1,029 children, in order to assess the prevalence and value of reactive STS inJamaicans; 2.7% of sera from the general adult population, 4.7% from pregnant women and 2.2% from children were reactive in the Venereal Disease Research Laboratory (VDRL) test. Reactive Flourescent Treponemal Absorption (FTA-ABS) tests occurred in significantly higher frequency in pregnant women (4%) than in the general population (2.2%; p<0.001). The prevalence of reactive STS in children didnot differ significantly from that of the general adult population. The predictive value of a reactive VDRL test in pregnant women (85%) was higher than that of the general population (79%). These results suggest that inadequate screening with the inexpensive VDRL test would enable the early detection and treatment ofsyphilis, and could prevent increasing incidence of congenital syphilis in Jamaica

Infective endocarditis at the University Hospital of the West Indies: a postmortem evaluation

Thirty cases of infective endocarditis identified in the autopsy of the University Hospital over a 10-year period are reviewed. The mean age of the patients was 30.6 years, and 70%) were below the age of 40 years. Sixty per cent of the cases had previous heart disease of which rheumatic heart disease was the most common. Degenerative heart disease and floppy mitral valve contributed one case each. The mitral valve was most commonly affected, and there were only 2 cases of right-sided endocarditis. Evidence of systemic embolization was present in 83% of the patients. The results of this stuy are compared with others from both developed and under-developed countries

Knowledge and understanding of AIDS among health-care workers in Jamaica

Six hundred and fifty questionnaires were sent to Health-care Workers (HCW) in four hospitals to assess the knowledge and understanding on HIV transmission and isolation precautions to be instituted for control and also ascertain whether any differences in knowledge existed between HCW of teaching and nonteaching hospitals. Five hundred and nine questionnaires were returned, a response rate of 79%. Questions on HIV transmission via blood transfusión and sexual intercourse and proper disposal of sharp instruments received the highest scores (85-100), embracing all groups of teaching and non-teaching hospitals. The greast area of misconception and misunderstanding was reflected in responses obtained on isolation precautions (<30) for both teaching and non-teaching hospitals. Oure study emphasizes an urgent need for a comprehensive, continuous education of HCW on prevention and control of HIV infections in Jamaica

Herpes simplex virus infections in immunocompromised jamaican patients

Data are presented on 13 immunocompromised patients with herpes simplex virus (HSV) infection. Eleven patients had recurrent HSV infevtion. Eight had genital herpes, 3 had disseminated infection and two had localised extragenital infection. Nine patients had confirmed recurrente HSV-type 2 infection. The benefits of recent antiherpetic therapy in the prevention of recurrent HSV infections in immunocompromised Jamaican patients are discused

Influenza virus infections in Jamaica between 1977 and 1985

Data on influenza virus infections between 1977 and 1985 in Jamaica are presented. The occurrence of influenza varied each year. The peak incidence correlated generally with the peak occurence of acute respiratory illness each year. The influenza-associated neurological (17%) and cardiac (9.7%) manifestations were seen during the perido of study. Antigenic variants of influenza viruses circulating in Jamaica were similar to those recorded world-wide. continous virological and non-virological surveillance are vital in determining the impact of influenza on associated mortality and morbidity in a developing countrylike Jamaica

Genital herpes in Jamaica: a clinical and pathological study 1982-1984

Five hundred and four patients with suspected genital simplex virus (HSV) infection were investigated in Jamica between 1982 and 1984. Of these, 100 (1908%) were virologically confirmed. There were 12 patients with primary/first episode, 45 recurrente and 6 "provoked" type of genital herpes simplex virus infections. Genital herpes in women was more severe than in men. Eighty-eight per cent of genital herpes was confirmed by virus isolation. Forty HSF isolates were identified as HSV type 2. There was seroresponse in 75% primary, 18% recurrent and 17% provoked type of genital herpes. Virus isolation is the most sensitive and specific test for the diagnosis of genital herpes simplex virus infection. The measuremem of serum anti herpes simplex complement-fixing antibodies was not useful in the diagnosis of suspected patients with genital ulcers and their contacts. The infectiousness of the virus, clinical manifestations, complications such as neonatal herpes infections, psychosocial problems and methods of prevention are issues that clinicians should discuss with patients with genital herpes

Risk factors for carninoma of the uterine cervix in jamaican women

Risk factors of cervical cancer include early age at coitus, multipli sexual partners and antibodies to herpes simplex virus, type 2(HSV-2). To examine the interrelationships of these risk factors, a comparison was made between 78 histologically confirmed cancer cases (stages 0-IV) and 151 control women in Jamica. The rank of order of the percentages of control women with low socieconomic status, first coitus before 20 years of age, first pregnancy before 20 years of age and more than two sexual partners were: 77,97,65, and 76 respectively. The percentage of women with cancer who had coitus before 20 years of age (77) and 2 or more partners (55) were lower than that of controls. A third factors associated with cervical cancer is the presence of HSV-2 antibodies. The age-specific prevalence of HSV-2 antibodies varied from 7% to 32% in women aged 21-69 years. An increase in prevalence of HSV-2 antibodies was observed with increasin age. The age-adjusted prevalence was 11 per cent. The age-specific occurrence of HSV-2 antibodies in cancer cases varied from 6% to 28% with a prevalence of 7.8%. The mean antibody titres in cancer cases were not statistically significant as compared with matched controls (p > 0.01). the data suggest that infection with HSV-2 is a covariable of veneral factors, and the role of the virus in the genesis of some cases of cervical cancer in Jamaican women may not be excluded