Multidrug-Resistant Outbreak-Associated Salmonella Strains in Irrigation Water from the Metropolitan Region, Chile

Salmonella enterica (S. enterica) is the main cause of foodborne diseases in the Chilean population. With the aim of characterizing the presence of S. enterica in bodies of water, samples from 40 sources were obtained, including rivers and irrigation canals used by agricultural farms in the most populated regions of Chile. As result, 35 S. enterica isolates belonging to several serotypes were detected, with the highest frequency represented by Typhimurium and Enteritidis. All strains showed phenotypic antimicrobial resistance, and most of them were multiresistant to critically important antimicrobials. In addition, the pulse-field gel electrophoresis analysis using XbaI and BlnI endonucleases showed that seven Salmonella isolates belonging to serotypes Typhimurium, Enteritidis and Infantis had identical pulsotypes to outbreak-associated clinical isolates detected in the Chilean population, suggesting a public health risk of water pollution in this region. Among sampling sites, the higher detection rates were observed in rural than urban and peri-urban areas, suggesting that the animal husbandry might contribute for environmental dispersion of this pathogen. Future efforts should address the characterization of cause-and-effect relationship between water contamination and foodborne disease, including the implementation of surveillance programmes to tackle potential risks for both human and animal populations.

[Tuberculosis: a re-emerging zoonosis?]

Tuberculosis is an infectious disease that is found throughout the world and which can have a dramatic impact on the economy and on human and animal health. In humans, the principal cause of infection is Mycobacterium tuberculosis, but the animal-specific pathogen, M. bovis, is arguablythe most important zoonotic agent in human history. Despite the fact that several countries have implemented control programmes for M. bovis infection in animals, which has resulted in a reduction in the number of human cases as well, recent years have witnessed a re-emergence of tuberculosis. This is due to the appearance of strains that are resistant to the main antibiotics used to treat the infection in humans, the spread of the human immunodeficiency virus, the maintenance of wild reservoirs and the persistence of the infection in livestock, particularly in developing regions. Coordinated efforts by human and animal health services, the improvement of diagnostic techniques and the development of more effective vaccines to prevent the infection are the main strategies for controlling this disease.

[Antidepressant psychopharmacotherapy]

Considering the prevalence of major unipolar depression, the economical costs of its management and the different medications available for its treatment, it is imperative to have a good knowledge of the basic principles used to classify anti depressive medications. A good acquaintance on their mechanisms of action on neurotransmission and receptors, wil allow a better understanding of their therapeutic action and secondary effects. Tricyclics, non selective MAO inhibitors, reversible MAO inhibitors, selective serotonin reuptake inhibitors, dopamine and noradrenalin reuptake inhibitors, 5-HT2 blockers with serotonin reuptake blocking effect, serotonin, noradrenalin and dopamine reuptake inhibitors, alfa 2 receptor blockers and 5-HT/2-3 inhibitors are the eight available types of antidepressants.

[Treatment of bipolar disorder during pregnancy and puerperium period. A case report]

We report a 37 years old woman with a severe bipolar disorder, that became pregnant during treatment with lithium. The patient and her family were informed about the 0.05-0.1% risk of cardiac malformations of the newborn, but decided to maintain her pregnancy and not to discontinue the use of lithium, fearing a relapse of her psychiatric ailment. She continued under medical surveillance and had a normal delivery, but no breast feeding was allowed.

Occurrence of suicide and seasonal variation

OBJECTIVE

To review the estimated suicide rates for the Region Metropolitan, the main socio-political center in Chile, for the period 1979-1994, and to determine whether they follow a seasonal pattern.

METHOD

Data available for the period 1979-94 at the Forensic Services in Chile was analyzed using Analyses of variance.

RESULTS

It was register 5,386 suicides. While the "warm" months (October, November, December & January) concentrated 39.0% of cases, the so called "cold" months reported 28.7%. This contrast is made even clearer by the month-to-month analysis, showing the highest suicide rate in December (10.6%) against the lowest rate in June (7.0%). Further statistical analysis revealed these differences to be significant.

CONCLUSION

The study shows that in Chile, representing as it does the Southern Hemisphere, the suicide rates tend to present a seasonal variation as has elsewhere been determined for in the North Hemisphere.

[The need for psychiatrists in Chile. A projection for the year 2,000]

In less than 15 year's time, the number of psychiatrists available should have increased twofold. It is thus calculated that about 500 psychiatrists would be working by 1990. An uneven regional distribution, however still survives with 80% of professionals congregated in the Chilean capital city area--less than 25% professionals working with the Health Services National System (SNSS) which is supposed to cover 75% of nationwide care. Besides, no psychiatric care is available as far as peripheral offices are concerned. By resorting to several parameters (vg. psychiatric needs according to prevalent pathologies, care demands, and ratio), as well as national data, and various author's opinion, it is estimated that about 650 psychiatrists will be needed in the year 2000. Hence, about 220 new psychiatrists should be trained during the 10 years ahead, if population's vegetative growth as well as replacements due to retirement, death, etc. are taken into account.

[Neuroleptic malignant syndrome]

This is a review article on neuroleptic malignant syndrome. Clinical manifestations and differential diagnosis are discussed. Treatment is based on suppression of the drug and administration of bromocriptine and dantrolene. After recovery, neuroleptics should be withheld or a drug with low dopaminergic blocking effect would be selected.