It is unclear how imported melioidosis is able to persist in a completely new environment. Eventually, the outbreak terminated by itself after a period of time. It was only during the 1980s, Infectious Disease Association of Thailand started took notice of this disease. First conference on melioidosis was held in 1985 in Thailand. It was during this meeting that collaboration between Sappasitprasong Hospital, Thailand, and Wellcome-Mahido-Oxford Tropical Medicine Research Programme was established. Such collaboration made Thailand a world leader in clinical and epidemiology research on melioidosis.In 1989, several studies conducted in Thailand demonstrated ceftazidime as an effective antibiotic against melioidosis. Ceftazidime had been shown to reduce the risk of death of melioidosis from 74% to 37%. In 1990, a non-virulent arabinose-positive B. pseudomallei was found by Vanaporn Wuthiekanun. The organism was later reclassified into a new species called B. thailandensis. This species has become a useful tool in the laboratory for the studies of the pathogenesis of B. pseudomallei. B. pseudomallei was previously classified as part of the genus Pseudomonas. In 1992, the pathogen was formally named B. pseudomallei. In 1994, First International Symposium on melioidosis was held in Kuala Lumpur where 80 delegates attended. Papers were presented and later published as a book. Subsequent congresses were held in Thailand, Australia, and Singapore once every three years. In 2002, B. pseudomallei was classified as a "Category B agent". In 2004, the complete genome of B. pseudomallei was published.
Smooth Muscle Hypercontractility
At a cellular level, pathways that lead to enhanced myosin light chain phosphorylation promote vasoconstriction. Increased activity of Rho-kinase leading to enhanced myosin light chain phosphorylation has been implicated in the pathogenesis of coronary vasospasm. Diagnosis
There are no set criteria to diagnose coronary vasospasm. Thorough history taking by a clinician can assist in the diagnosis of coronary vasospasm. In cases where symptoms of chest pain are present, identifying features that distinguish episodes of vasospastic angina from traditional angina can aid in the diagnosis. Features such as chest pain at rest, a diurnal variation in tolerance for exercise with a reduction in tolerance for exercise in the morning, and responsiveness of chest pain to calcium channel blockers as opposed to beta blockers can be important clues.EKG can occasionally be used to diagnose episodes of coronary vasospasm. However, relying on EKG is not always possible due to the transient nature of coronary vasospasm episodes. Due to the challenge of capturing episodes of coronary vasospasm spontaneously, provocative testing to induce coronary vasospasm during coronary catheterization can be used to make the diagnosis. Provocative testing relies upon the use of pharmacological agents that promote or trigger episodes of vasospasm. Agents commonly administered include ergonovine and acetylcholine. Both pharmacological agents have vasoconstrictive effects on coronary arteries. However, in the clinical setting, provocative testing is not routinely performed. The reason for this is due to the adverse effects of these pharmacological agents.