Immunogenicity and feasibility of intradermal vaccination against rabies in Quebec

OBJECTIVES

Preexposure vaccination against rabies is recommended for some travellers and individuals exposed to the virus through their work. At a cost of at least $150 per intramuscular (IM) dose, few follow this recommendation. In Canada, provided certain conditions are met, the National Advisory Committee on Immunization (NACI) and the Comité d'immunisation du Québec allow a more economical alternative, intradermal vaccine administration (ID) which uses 1/10 the IM dose. The purpose of this study is to assess the feasibility and immunogenicity of intradermal preexposure vaccination.

METHODS

Students and employees at the Faculty of Veterinary Medicine received three doses of ImovaxRage™ (Sanofi Pasteur) inactivated, human diploid cell rabies vaccine at days 0, 7 and 21 or 28. An IM or ID booster dose was administered after two years when indicated.

OUTCOMES

Among the 159 participants who received three doses, 139 underwent serological testing in the year following vaccination and all achieved protective antibody levels. The antibody level was higher when measured within five weeks of the third dose. When the serological control was performed two years later, 65% of participants had a <0.5 IU/ml titre. Of the 22/30 participants who chose an ID booster, 100% responded and the average antibody titres were multiplied by 11, indicating a strong anamnestic response.

DISCUSSION

ID rabies vaccination is immunogenic, economic and could be considered for the booster dose. Protective antibodies decline rapidly after primary immunization by ID, so it would seem prudent to perform a serological control one year later on individuals at high risk of occult occupational exposure. An alternative would be to give these individuals a routine ID booster dose one year after primary vaccination, which would simplify initial treatment and reduce related costs (follow-up, blood sampling, serological tests, etc.). The persistence of protective antibodies after this booster dose should be assessed to determine the need for subsequent serological tests and the ideal interval between tests.

Evaluation of a user guidance reminder to improve the quality of electronic prescription messages

BACKGROUND

Prescribers' inappropriate use of the free-text Notes field in new electronic prescriptions can create confusion and workflow disruptions at receiving pharmacies that often necessitates contact with prescribers for clarification. The inclusion of inappropriate patient direction (Sig) information in the Notes field is particularly problematic.

OBJECTIVE

We evaluated the effect of a targeted watermark, an embedded overlay, reminder statement in the Notes field of an EHR-based e-prescribing application on the incidence of inappropriate patient directions (Sig) in the Notes field.

METHODS

E-prescriptions issued by the same exact cohort of 97 prescribers were collected over three time periods: baseline, three months after implementation of the reminder, and 15 months post implementation. Three certified and experienced pharmacy technicians independently reviewed all e-prescriptions for inappropriate Sig-related information in the Notes field. A physician reviewer served as the final adjudicator for e-prescriptions where the three reviewers could not reach a consensus. ANOVA and post hoc Tukey HSD tests were performed on group comparisons where statistical significance was evaluated at p<0.05.

RESULTS

The incidence of inappropriate Sig-related information in the Notes field decreased from a baseline of 2.8% to 1.8% three months post-implementation and remained stable after 15 months. In addition, prescribers' use of the Notes decreased by 22% after 3 months and had stabilized at 18.7% below baseline after 15 months.

CONCLUSION

Insertion of a targeted watermark reminder statement in the Notes field of an e-prescribing application significantly reduced the incidence of inappropriate Sig-related information in Notes and decreased prescribers' use of this field.

Measuring pesticide ecological and health risks in West African agriculture to establish an enabling environment for sustainable intensification

We outline an approach to pesticide risk assessment that is based upon surveys of pesticide use throughout West Africa. We have developed and used new risk assessment models to provide, to our knowledge, the first detailed, geographically extensive, scientifically based analysis of pesticide risks for this region. Human health risks from dermal exposure to adults and children are severe enough in many crops to require long periods of up to three weeks when entry to fields should be restricted. This is impractical in terms of crop management, and regulatory action is needed to remove these pesticides from the marketplace. We also found widespread risks to terrestrial and aquatic wildlife throughout the region, and if these results were extrapolated to all similar irrigated perimeters in the Senegal and Niger River Basins, they suggest that pesticides could pose a significant threat to regional biodiversity. Our analyses are presented at the regional, national and village levels to promote regulatory advances but also local risk communication and management. Without progress in pesticide risk management, supported by participatory farmer education, West African agriculture provides a weak context for the sustainable intensification of agricultural production or for the adoption of new crop technologies.

[Primary lymphomas of the urinary in the urological service of the Yaounde Central Hospital]

OBJECTIVE

The objective of this study were to recruit and present epidemiological, clinical, histological and therapeutic aspects of primary lymphomas of the urogenital tract in Cameroon.

MATERIAL AND METHOD

This was a retrospective study over a 10-year period (1999-2008) done on clinical records of the Urological Unit of the Yaounde Central Hospital. From these records, we noted the age and the sex of the patients, their clinical presentation and histological aspect. The patients were treated by surgical resection and chemotherapy.

RESULTS

Twenty cases were recruited between this period of the study. The age of the patients varied from 6 to 60 years with a mean age of 35 years. There were 19 men and one woman. Eighteen cases involved the testis, one case the kidney and one penile involvement. On histology, there were 19 cases of Burkitt's lymphoma and one case of large B cell lymphoma involving the penis. Three patients had positive syphilis serology and two other were HIV positive. All the patients in this series had a complete remission after treatment but the tumour recurs after 6 to 9 months.

CONCLUSION

Burkitt's lymphoma is the first malignant tumour of the testis in Cameroonian. Unfortunately, patients consult late, there are no supports for the treatment and this will lead to a poor prognosis.

Detection by broad-range real-time PCR assay of Chlamydia species infecting human and animals

BACKGROUND

Tests available for molecular diagnosis of chlamydial infections detect Chlamydiatrachomatis, but do not find other Chlamydia species associated with genital, ophthalmic, cardiovascular, respiratory or neurological diseases. The routine detection of all Chlamydia species would improve the prognosis of infected people and guide therapeutic choices.

AIM

To design and validate a sensitive, specific, reproducible, inexpensive and easy-to-perform assay to quantify most Chlamydia species.

METHODS

Primers and probe were selected using the gene coding for the 16S rRNA. The detection limits were assessed for suspensions of Chlamydia trachomatis, Chlamydia psittaci and Chlamydia pneumoniae. The performance of this test was compared with that of two commercial kits (Amplicor-Roche and Artus) on 100 samples obtained from children with trachoma.

RESULTS

The detection capacities for Chlamydia trachomatis of the broad-range real-time polymerase chain reaction (PCR) were similar or slightly better than those obtained with commercial kits (0.2 copies of DNA/microl). Only the broad-range PCR identified specimens containing Chlamydia psittaci and Chlamydia pneumoniae. The commercial kits and the broad-range assay detected Chlamydia species in 5% and in 11%, respectively, of samples from children with trachoma.

CONCLUSIONS

This new real-time PCR offers a sensitive, reproducible assay that produces results in <3 h. With panels of quantified Chlamydia species, this real-time PCR can be run with all real-time PCR equipment. Larger trials are needed to confirm the utility of this test in diagnosis and for therapeutic follow-up.

The distribution and inversion polymorphism of chromosomally recognized taxa of the Anopheles gambiae complex in Mali, West Africa

Data from polytene chromosome studies on the Anopheles gambiae complex in Mali were reviewed. The banding pattern was successfully scored in 17,705 specimens from 76 sampling sites representing the main ecological strata of the country. Two members of the complex, namely An. arabiensis and An. gambiae, were found widespread and frequently sympatric, with the latter prevalent in most localities. Population genetic analysis of the inversion polymorphisms indicated the existence of panmictic conditions for An. arabiensis only, whereas the parallel study of An. gambiae supported its splitting into at least three reproductive units, characterized by different 2R chromosome arrangements, designated Bamako, Mopti and Savanna. The chromosomal evidence was consistent with the hypothesis of complete reproductive isolation between Bamako and Mopti. Partial isolation between these two taxa and Savanna was suggested by the scoring of hypothetical hybrid 2R heterokaryotypes in various samples, but the actual hybrid origin of these specimens was not confirmed. Different patterns of geographical and seasonal distribution were shown as follows. An. arabiensis prevails in arid savannas (Sahel and Northern Sudan savanna) out of the flooded or irrigated zones; it is able to withstand the most arid conditions of Saharan localities and its breeding might extend throughout the dry season. An. gambiae Savanna and Bamako prevail in relatively humid savannas (Southern Sudan savanna) and their breeding generally occurs only during the rainy season. The Savanna taxon was almost absent in flooded or irrigated zones and in riverine localities; the Bamako taxon is distributed along the upper river Niger and its tributaries. An. gambiae Mopti extends its range in all ecological zones present in Mali including the Sahel and predesertic areas, showing high relative frequencies up to absolute dominance in flooded or irrigated areas; its breeding is highly successful also during the dry season. Rainfall at the sampling sites was found to correlate positively with the frequency of Savanna and negatively with the frequency of Mopti. The remarkable ecological flexibility of the latter was found associated with wide seasonal and geographical variations in its 2R inversion polymorphism bc/u. Higher frequencies of the bc arrangement were recorded both in the Southern localities during the dry season and in the Northern more arid localities during the rainy season. The absence or scarcity of An. arabiensis and An. gambiae Savanna in most flooded or irrigated zones suggests their competitive exclusion by An. gambiae Mopti.

Ecological genetic studies in the chromosomal form Mopti of Anopheles gambiae s.str. in Mali, west Africa

Among the sibling species of the Afrotropical Anopheles gambiae complex, the nominal taxon (An. gambiae s.str.) is the major malaria vector. Its bionomics suggest a man-dependent speciation process which involves, in West Africa, various incipient species chromosomally recognized by different combinations of 2R paracentric inversions. One of the most recent evolutionary steps of such a speciation process appears to be the chromosomal form Mopti, which is associated with dry season irrigation in arid zones, and is characterized by a remarkable ecological flexibility related to three 2R alternative arrangements, namely bc, u and +, whose expected karyotypes are found in Hardy-Weinberg equilibrium. The study of this chromosomal polymorphism in samples from a 16-locality transect in Mali shows wide variations and highly significant correlation with both temporal and spatial climatic differences. Mosquitoes homokaryotypic for 2Rbc are the actual dry season and arid areas breeders. The regular rise of 2Rbc frequency, up to fixation, during each dry season, corresponds to the South-North clinal increase of the same arrangement along the transect, from about 30% in the humid savanna to near fixation in the South-Saharan zone. This coherent ecological genetics case provides full support to the hypothesis of the adaptive nature of paracentric inversions. Moreover, the very peculiar system of combinations of contiguous 2R inversions, utilized by Mopti as well as by other chromosomal forms of An. gambiae, suggests a process of polygenic reorganization based on linkage disequilibria and involving the inversions as driving selection units.

[Kidney tumors in Africa. Incidence and anatomo-clinical aspects. Apropos of 123 observed cases at the Central Hospital and at the University Hospital Center in Cameroon]

123 renal tumours, among which 4 benign, were observed in 13 years. Renal tumours have a low incidence in Africa and are mostly seen in young patients. Nephroblastoma is the most frequent of these tumours. The clinical and paraclinical aspects of these tumours have nothing particular but the diagnosis is usually late.

[Conservative treatment of splenic lesions by splenorrhaphy and incomplete splenectomy in abdominal injuries]

Fifteen cases of rupture of the spleen were reported, in which a conservative form of treatment was applied with success. These consisted of 4 splenorrhaphies and 11 partial splenectomies. Collagen (PANGEN) was used in 6 of the cases to buttress the suture. In view of the relatively low incidence of post of complications, the authors are of the opinion that the above described treatment be widely applied in cases of rupture of the spleen, especially in the child where the spleen still plays a vital role.

Epidemiology of hepatitis B virus infection in the rural community of Tip, Senegal

The distribution of responses to hepatitis B virus infection in the rural community of Tip, Senegal, has been determined. Children are rarely persistently infected before two years of age, at which time about 25% of the population are infected. Uninfected members continue to be at risk. Vaccination programs instituted at an early age could prevent infection in most of the population and considerably decrease the risk of chronic liver disease and primary cancer of the liver in adults.

[Epiphrenic diverticula of the esophagus. Apropos of 16 surgically-treated cases]

The authors report on a series of 14 cases (10 men and 4 women) of epiphrenic diverticula treated surgically over a period of 14 years. Size was variable and the neck was narrow in 7 cases, wide in 5, and very wide in 2. Four patients presented with a double diverticulum. The diverticula are normally found on the right side (9 cases), and underlying dyskinesia is always present, often accompanied by major or minor cardiospasm (11 cases) or reflux from sliding hiatal hernia (3 cases). No manometric exploration was carried out in this series. Management was based on physiopathological considerations - 6 diverticulectomies with 5 myotomies, 6 myotomies with no diverticulectomy. The approach was left thoracic in 7 cases and abdominal in the others. The mortality rate was zero, and functional results are good. They are all the better in that the diverticulectomy, the myotomy and the repair of the gastroesophageal reflux have now been performed.