However, 8% of children and 20% of adults with melioidosis have no risk factors. HIV infection does not appear to predispose to melioidosis, although several other co-infections have been reported. Infant cases have been reported possibly due to mother-to-child transmission, community-acquired infection, or healthcare-associated infection. Those who are well may also be infected with B. pseudomallei. For example, 25% of children started producing antibodies against B. pseudomallei between 6 months to 4 years of staying in endemic areas although they did not experience any melioidosis symptoms; suggesting they were exposed to it over this time. This means that many people without symptoms will test positive in serology tests in endemic areas. In Thailand, the seropositivity rate exceeds 50%, while in Australia the seropositivity rate is only 5%. The disease is clearly associated with increased rainfall, with the number of cases rising following increased precipitation. Severe rainfall increases the concentration of the bacteria in the topsoil, thus increasing thus of transmitting the bacteria through the air. A recent CDC Advisory indicated that the recent detection of the organism in the environment in Mississippi following the occurrence of two indigenous cases of melioidosis, confirms that parts of the southern USA should now be regarded as melioidosis-endemic. History
Pathologist Alfred Whitmore and his assistant Krishnaswami first reported melioidosis among beggars and morphine addicts at autopsy in Rangoon, present-day Myanmar, in a report published in 1912. Whitmore was able to grow the organism in culture and its showed similarity with B. mallei, another bacteria that was known causing glanders in animals.
For those with kidney impairment, the dosage of ceftazidime, meropenem, and co-trimoxazole should be lowered. Once the clinical condition improved, meropenem can be switched back to ceftazidime. Eradication phase
Following the treatment of the acute disease, eradication treatment with co-trimoxazole is the drug of choice and should be used for 3 months (12 weeks) as all-cause mortality was lower in 12 weeks group when compared to those receiving treatment for 20 weeks. For those with neurological melioidosis and osteomyelitis, drugs should be given for more than 6 months. Co-amoxiclav and doxycycline are drugs of second choice. Co-trimoxazole should not be used in those with glucose-6-phosphate dehydrogenase deficiency as it can cause haemolytic anemia. However, in Thailand, usage of co-trimoxazole does not accompany G6PD screening. Other side effects such as rash, hyperkalemia, renal dysfunction, and gastrointestinal symptoms should prompt the reduction of co-trimoxazole doses. Chloramphenicol is no longer routinely recommended for this purpose. Co-amoxiclav is an alternative for patients unable to take co-trimoxazole and doxycycline (e.g. pregnant women and children under the age of 12), but is not as effective and has a higher relapse rate. Single-agent treatment with fluoroquinolone (e.g., ciprofloxacin) or doxycycline for the oral eradication phase is ineffective.In Australia, co-trimoxazole is used with children and pregnant mothers after the first 12 weeks of pregnancy. Meanwhile, in Thailand, co-amoxiclav is the drug of choice for children and pregnant women. B. pseudomallei rarely acquires resistance when co-amoxiclav is used.