Salmonellosis in Trinidad II: evidence for transovarian transmission in farm eggs - abstract

The aim of this study was to determine whether farm eggs (contents and shells) in Trinidad are contaminated with Salmonella and to demonstrate if transovarian transmission occurs in these eggs. A total of 750 fresh eggs from 10 farms were cultured for Salmonella. The United States FDA Bacteriological Analytical Manual's Official Standard culture methods for Salmonella were used. Salmonella and S. enteritidis were detected in 9 of the 750 pooled eggshells' cultures, which has not been previously demonstrated in Trinidad. The spectrum of Salmonella serotypes isolated from the pooled egg contents were S. enteritidis (0.8 percent) and S. typhimurium (0.4 percent), and that isolated from the pooled eggshells was S. typhimurium (3.06 percent), S. enteritidis (0.67 percent), S. ohio, S. cerro, S. infantis (0.27 percent each) and S. heidelberg (0.13 percent). Salmonella was found in the egg contents of only three farms, but on the eggshells' surface from all 10 farms. This variation in isolation rate was found to be related to farm management and quality control practices. The contamination of the egg contents with S. enteritidis was deduced to be by the transovarian transmission process whilst S. typhimurium contamination of the egg contents was through faecal transmission. This study provides the first hard evidence for Salmonella and more importantly, S. enteritidis contamination of eggs, and demonstated transovarian transmission of S. enteritidis in eggs. This is of major public health significance since such eggs can be of grade A quality and widely consumed by unsuspecting consumers, resulting in salmonellosis. (AU)

Salmonellosis in Trinidad I: impact of an emerging serotype on public health - abstract

Outbreaks of salmonellosis have been known to occur in Trinidad but their frequency and intensity have increased since August, 1994. Salmonella serotypes isolated between 1994 and 1996 show a decrease in S. typhimurium which, before 1995, was the most frequent cause of salmonellosis. The arrival in August 1994, of Salmonella enteritidis brought an increasing isolation rate of this serotype; e.g., 22.5 percent in 1994, 56.5 percent in 1995 and 70.9 percent to June 1996. The monthly distribution of frequently isolated serotypes shows that S. typhimurium was associated with outbreaks of salmonellosis in June and November 1994 but has since been on the decline (10 cases in November 1994 to no more than 2 per month). Meanwhile, outbreaks of salmonellosis associated with S. enteritidis were recorded in January 1995 (12 cases), July 1995 (8 cases), December 1995/January 1996 (25 cases) and April 1996 (25 cases). The most severely affected age group was the 0-4-year-old; e.g. 54.6 percent of cases 1994; 47.3 percent in 1995 and 52.9 percent to June 1996. This age group also reflected the highest age specific rates of 44.6, 47.7 and 44.9 per 100 000 population in 1994, 5.4 in 1995 and 7.2 to June 1996, per 100 000 population. Continued and heighten surveillance must prevail in order to determine the source of the S. enteritidis. Eggs have been implicated but hard evidence is thus far lacking.(AU)

The decreasing incidence rate of diarrhoeal disease occurrence in Trinidad and Tobago: 1992 - 1996

Data on diarrhoeal disease were collected from the community, hospitals and private physicians from August 1991 to September 1996. The diarrhoea disease rates in <5 - and > 5- year-olds are shown below: [a table accompanied the original abstract]. The spectrum of organisms isolated from diarrhoeal specimens was mainly enteropathogenic E. coli, Salmonella spp., Shigella spp. and Campylobacter spp. with a few Cryptosporidia seen. The arrival in August 1994 of Samonella enteritidis brought an increasing isolation rate of this serotype. S. typhimurium was associated with outbreaks of salmonellosis in June and November 1994 but has since been on the decline but outbreaks associated with S. enteritidis were recorded in January 1995 (12 cases), and April 1996 (25 cases). The most severely affectd age group was the 0-4 year-old and the 60+ years showed an increasing susceptibility trend. Continued and heightened surveillance must prevail in order to determine the source of the S. enteritidis. Eggs have been implicated but the hard evidence is thus far lacking. (AU)

Food borne disease outbreak at a major hotel in Trinidad - abstract

One hundred and twenty delegates at a major hotel in Trinidad attended a breakfast meeting soon after which some complained of being unwell and sought medical attention. 17 were treated of whom 2 were admitted to the Port of Spain General Hospital, 6/22 were admitted to a private hospital and 5 were treated by a private practitioner. Stool samples or rectal swabs were taken from the in-patients and from 3 hotel staff members who were also ill. Samples of the food served were sent for analysis. Of 30 delegates who were investigated, 24 had symptoms of vomiting and 17 had diarrhoea in combination with other symptoms. The mean incubation time was 3 hours, suggestive of toxin ingestion. The food specfic attack rates identified "saltfish buljol" as the contaminated food. All stool samples taken from the hospitalized delegates yielded Staphylococcus aureus which was also found in the swabs from the hotel staff members. All S. aureus isolates were sent for phage grouping and typing. Three delegates and one food item shared the identical phage group with that from the nasal swab of a worker. The other hospitalized delegate and another food item shared the identical phage group from the rectal swab of the same worker. It was concluded that the outbreak was due to food contaminated with Staphylococcus aureus originating from hotel staff. (AU)

Invasive streptococcal infections: report of four cases occurring in Trinidad

Many countries are reporting a resurgence of virulent streptococcal strains but there is little information from the Caribbean. Four cases of severe invasive streptococcal infections, three of them fatal, are reported. The portal of entry was infected scabatic lesions in one patient and infected mosquito bites in another patient who developed cellulitis and gangrene; but no portal of entry was detected in the other patients. Group A B haemolytic Streptococcus (GAS) was isolated from the blood of three patients, one of them GAS M type 3, which had the genome for streptococcal pyrogenic exotoxins A (SPeA)and B (SPeB). GAS M type 72, which had the genome for SPeB and SPeC, were isolated from the tissues (but not from the blood) of the patient who developed cellulitis and who was the sole survivor. Physicians in the Caribbean must be alerted to the presence of these virulent streptococcal strains, and must be prepared to manage serious invasive disease.

Invasive streptococcal infections: report of four cases occurring in Trinidad

Many countries are reporting a resurgence of virulent streptococcal strains but there is little information from the Caribbean. Four cases of severe invasive streptococcal infections, three of them fatal, are reported. The portal of entry was infected scabatic lesions in one patient and infected mosquito bites in another patient who developed cellulitis and gangrene; but no portal of entry was detected in the other patients. Group A B haemolytic Streptococcus (GAS) was isolated from the blood of three patients, one of them GAS M type 3, which had the genome for streptococcal pyrogenic exotoxins A (SPeA)and B (SPeB). GAS M type 72, which had the genome for SPeB and SPeC, were isolated from the tissues (but not from the blood) of the patient who developed cellulitis and who was the sole survivor. Physicians in the Caribbean must be alerted to the presence of these virulent streptococcal strains, and must be prepared to manage serious invasive disease. (AU)

HLA studies in a family with hereditary nephritis - abstract

In 1968, a four-year-old female (the index case) presented with post-streptococcal acute glomerulonephritis (PSAGN). A family visit was made and several members were found to have proteinuria and haematuria without evidence of PSAGN. This family was followed for over 20 years during which time six male members developed chronic renal disease (CRD). Three have since died and two of the three alive are now on dialysis. Mild proteinuria and/or haematuria has been found in other family members of the F and F 2 generations comprising 47 individuals. These observations led to the hypothesis that certain HLA antigens and/or haplotypes are associated with development of CRD in this family. HLA-A,B,C and DR typing were done on 25 available family members, 22 being absent for various reasons including migration. The studies revealed a homozygous condition for HLA-DR2 in the mother, resulting in the inheritance of DR2 in all siblings of the mother. Four of the five female offspring have been studied but only two have had proteinuria and haematuria. However, all male members of the f1 generation had copious proteinuria and three of the five studied had severe haematuria. More importantly, several members of the F 2 generation have already developed mild proteinuria and one female has severe haematuria though they are all clinically normal. Since it has been suggested that males of affected females tend to develop CRD, male offspring of the F 2 generation will be carefully monitored in future (AU)

Scabies: occurrence, control and treatment in the Caribbean

The mite, Sarcoptes scabiel, which causes scabies in man produces an uncomfortable itch which, in itself, is not life-threatening. It is easily controlled when treated with appropriate scabicides, and with effective public health education and proper hygiene an end to the infection is quickly achieved. However, secondary infection of the scabietic lesions with nephritogenic streptococci can lead to glomerulonephritis which, in the short term, results in hospitalization with oedema, haematuria and proteinuria as common presenting symptoms. In the long-term, chroni renal disease leading to costly dialysis and renal transplant can occur after this preventable itchy and uncomfortable infection (AU)

Scabies: occurrence, control and treatment in the Caribbean

The mite, Sarcoptes scabiei, which causes scabies in man produces an uncomfortable itch which, in itself, is not life-threatening. It is easily controlled when treated with appropriate scabicides, and with effictive public health education and proper hygiene an end to the infection is quickly achieved. However, secondary infection of the scabietic lesions with nephritogenic streptococci can lead to glomerulonephritis which, in the short term, results in hospitalisation with oedema, haematuria and proteinuria as common presenting symptoms. In the long-term, chronic renal disease leading to costly dialysis and renal transplant can occur after this preventable itchy and uncomfortable infection. (AU)

Estimation of specific streptococcal antibodies from immune complexes in sera of patients with post-streptococcal acute glomerulonephritis - abstract

The enzyme-linked immunoabsorbent assay (ELISA) was used to determine the specific streptococcal antibodies in the sera of patients with post-streptococcal acute glomerulonephritis. Attempts to use this same technique to determine the immunoglobulin content of immune complexes (IC) after immunochemical dissociation proved futile. It became necessary to perform an inhibition assay before performing the ELISA. This modification involved the determination of the antigen concentration necessary to produce 50 per cent inhibition of the dissassociated antibody. The antigen inhibitors, M-types 41 and 55 cell membranes, were found to inhibit optimally at 12.5 ug/ml and were used to absorb dissassociated immune complexes diluted 1/00. The absorbed solution was then used in the ELISA test system. While specific streptococcal antibodies to M-55 were lower than those to M-41 (p<0.001) in PSAGN patients and those in controls (p<0.001), in the IC controls, specific antibodies to both inhibitors were of the same order. In PSAGN, however, the antibody levels were increased when compared with controls. Interestingly enough, specific streptococcal antibodies were demonstrated in IC of resolved GN cases, chronic GN and in those with intermittent proteinuria (AU)

Neonatal sepsis at Mount Hope Women's Hospital: early detection for prevention by prophylaxis - abstract

The objective of the present study was to test the hypothesis that serum c-reactive protein (CRP) in neonates is a valid indicator of early noenatal sepsis. Two hundred and twenty-seven neonatal sera were collected within 6 hours of birth from a random selection of neonates who were delivered at the Mount Hope Women's Hospital, Trinidad, between April and September, 1989. Sera were examined for the presence of CRP by radial immunodiffusion using monoclonal antibodies to CRP. CRP was detected in 26 neonates of whom 3 remanined well until their discharge on the third day. There were 9 neonates with a positive blood cluture but CRP was not detected in the sera. The test, therefore, had a sensitivity of 72 percent, specificity of 98.5 percent, false-negative rate 28.0 percent, false-positive rate 1.5 percent, positive predictive value 88.5 percent, negative predictive value 95.5 percent, and an accuracy of 95 percent. Of 44 symptomatic neonates, CRP was found in 12, while of 183 asymptomatic neonates 14 had CRP, yielding a relative risk of 2.8:1. In developing countries, therefore, examination of neonatal sera for CRP combined with prompt prophylaxis of neonates with CRP may contribute to a decrease in neonatal morbidity and mortality (AU)

Immunologically determined prevalence rates of antibodies to toxocara canis in school children in Trinidad, West Indies - abstract

Preliminary observations of a high frequency of serum antibodies to Toxocara canis in patients attending Eye Clinic at the General Hospital, Port of Spain, Trinidad led to the hypothesis that children with pet dogs may have as high a frequency. Hence, the sera of 339 school children, randomly selected from the school register, were tested by ELISA for the presence of IgG and IgM antibodies to T. canis. The prevalence rate of T. canis antibodies in schoolchildren in Countries Victoria and St. Patrick (32.5 percent) were similar but higher than that in Country Caroni (12.7 percent). Overall, a prevalence rate for Trinidad was determined (77.6 percent) which was similar to that found in Dominica (78.9 percent), St. Kitts/Nevis (75.3 percent) and Grenada (78.5 percent). Apart from Toxocara, other helminths only, 12 had helminths and protozoan parasites and 26 had protozoan parasites only. Of 31/83 students without antibodies to T. canis, 7 had helminths only, 2 had helminths and protozoan parasites and 22 had protozoan parasites only (AU)

Blastocystis hominis in immunocompetent children in Trinidad - abstract

Blastocystis hominis, formerly described as an enteric yeast, was reclassified as a protozoan parasite. The organism has elicited tremendous interest as reports have been controversial regarding its status as a pathogen or non-pathogen. Between March and August, 1990, we examined the formed stools of 894 asymptomatic children (age range 1-14 years) by the modified Ritchie-formalin-ethylacetate method for ova and cysts of parasites. Fourteen of the 73 under-five (19.2 percent) had B. hominis with 8/10 having B.hominis only. Seventy-one of 96 (74 percent) orphans had parasites, 64 (66.7 percent) of whom had B.hominis with 22/64 (34.4 percent) having B.hominis only. In the survey sample of 705 school children 158 (22.4 percent) had parasites with 98 having B.hominis and 74/98 (75.55 percent) had B.hominis only. It was noted that 13 children who had heavy B.hominis burdens did not present with diarrhoea. Children 8-12 years old appeared to be most frequently colonised. From our experience, we conclude that B.hominis in immunocompetent children is not a pathogen (AU)

A common HLA haplotype in leukaemic families in Trinidad - abstract

In a previous study, 6 of 10 patients with acute lymphoblastic ;leukaemia (ALL) were found to have the HLA-B40 antigen, 4 of these 6 patients carrying both the HLA-A2 and B40 antigens. Three of these 4 patients have since died. In the present study, family studies were performed in order to determine whether the HLA-A2 and B40 antigens constituted a haplotype in these individuals. Of the 4 families, 3 were available for HLA typing. Results show that HLA-A2/B40 did constitute a haplotype in all three families. Furthermore, the haplotype in all cases was found to be of maternal origin. Whether this haplotype is associated with an immune response gene which conveys susceptibility of the disease cannot be determined from this small study. Further typing of leukaemic children and their families (including DR antigens) should be pursued. These findings may be found to have prognostic implications for treatment, since patients with the HLA-A2/B40 and A2/B12 haplotypes have been shown to have improved long-term survival with transfer factor immunotherapy in other populations (AU)

Lindane toxicity in an infant

A four-month-old infant with severe impetigo who had prolonged daily applications of lindane presented with two seizure episodes. His blood lindane level was 1.27 ppm. Caution should be exercised when using lindane in infants and children. Proper instruction and close supervision are essential (AU)

Scabies infestation: the effect of intervention by public health education

The objectives of this study were to determine the prevalence of scabies in an infested village; to educate the residents on self-treatment and prevention by the use of 5 percent monosulfiram soap; to evaluate the short term effectiveness of this intervention by determining, 2 weeks later, the compliance to self-treatment and prevention; and to determine the prevalence rate on the second visit. In 59 households (96.7 percent of the village) containing 313 persons, an educational session was held and a leaflet distributed on the use and availability of the soap. Thirteen persons (4.2 percent) from eight households (13.6 percent) had scabies. After 2 weeks, 7 persons (2.2 percent) (2 persiting and 5 new cases) from 5 households (8.5 percent) were infested. Thus a cure rate of 85 percent was obtained though the prevalence rate showed no statistically significant difference. Among the under 15 year olds, the numbers infected decreased from 10 to 3 while among the over 15 year olds, the numbers infected increased from 3 to 4, neither reading significance at the 5 percent level. (AU)

Immunophenotypic and HLA studies in childhood acute lymphoblastic leukemia in Trinidad, West Indies

Between October 1983 and May 1986, 17 cases of childhood acute lymphoblastic leukemia (ALL) were admitted to the General Hospital, Port of Spain, Trinidad. Fifteen of those cases were under 10 years of age, seven of whom presented with joint or bone pains. Boys outnumbered girls by almost 5:1 and the ethnic distribution showed a preponderance of patients of East Indian origin. At last follow-up (May 1989), the survival rate of the 15 under-ten-year-old patients was 71 percent. Immunophenotype studies on nine of the 17 patients revealed six carrying T cell markers and three carrying markers suggestive of a pre-B phenotype. HLA tissue typing on ten patients showed an enhanced frequency of the HLA-B40 antigen when compared with controls (p less than 0.05). This antigen was present in six of the patients typed and four carried the HLA-A2 and B40 antigens together, two of whom also carried the CW3 antigen and the other two carried untypable C antigens. Three of the four carrying HLA-A2 and B40 have died. Two of the three pre-B cases also carried the HLA-A2 and B40 antigens. HLA studies on three of the four families showed that HLA-A2 and B40 were on the same chromosome, i.e., a haplotype inherited from the mother in each case. None of the cases carried the HLA-B5 antigen although this antigen had a frequency of 37.8 percent in the control group (p less than 0.05 percent). None of the controls with the HLA-B40 antigen carried the CW3 antigen. Further evidence of a disease association must await typing of the D locus antigens but current evidence would suggest an association between HLA-B40 and childhood ALL in Trinidad. (AU)

Clinical manifestations of ocular toxocariasis - abstract

Fifteen symptomatic patients were seen at the Eye Clinic, General Hospital, Port-of-Spain from December, 1988 to October, 1989 and 12 cases were available for review. A complete eye examination was done, and serum IgG and IgM (to Toxocara) levels were measured by an ELISA method. There were 5 females and 7 males with ages ranging from 4 to 61 years. Toxocara titres ranged from 1:00 to 1:3, 200 with the most frequent value being 1:200. The commonest presenting complaint was a moderate to severe visual impairment (8/11 or 73 per cent). Two patients had sudden onset of visual loss due to lesions at the posterior poles with macular involvement. Other presenting features were pain and redness of the eye associated with anterior uveitis (2 patients) and 4-year old patient had a white reflex in the pupil (leucocoria) for which an important differential diagnosis is retinoblastoma. Overall, Toxocara granulomas were seen on 9 of 12 patients. Therapy consisted essentially of steroids, topical and systemic and a non-steroidal anti-inflammatory preparation (indomethacin). All patients available for follow-up (n = 11) showed significant improvement and none required surgery. These results emphasize that ocular Toxocariasis must be considered in cases of posterior uveitis in Trinidad (AU)

Cellular immune responses and HLA antigens in post-streptococcal acute glomerulonephritis - abstract

Cellular immune reactions to non-specific mitogen, phytohaemagglutinin in (PHA) and specific blastogenic response to the nephritogenic strain, M55, of the streptococcus were investigated in an East Indian family in which all six siblings exhibited concurrent symptoms of post-streptococcal acute glomerulonephritis (PSAGN) requiring hospitalization. These assays, as well as HLA typing, were done on the entire family to determine whether a specific non-responder status to the M55 antigen was present in the family, and to investigate the possible presence of an immune response gene controlling M55 response. With the exception of one sibling, cellular immune reactions to PHA were similar to control responses, indicating normal overall T cell functions. Specific M55 stimulation revealed a decreased response (30 percent reduction relative to controls) in the cells of the father and 3 of the siblings. The results of HLA typing showed the presence of the B52/DR2 halotype in all siblings due to the homozygous presence of this halotype in the father. The B52 antigen was also present in the mother, resulting in a homozygous condition for this antigen in 4 of the 6 children. While it cannot be concluded from this single family study that the presence of B52 antigen is related to disease susceptibility, the repeated occurrence of this antigen, as well as the B52/DR2 halotype, in this family is noteworthy. The study further illustrates the usefulness of family studies in resolving apparent "blanks" which occur with some frequency in our small inbred island population (AU)