3 new MERS cases reported in Saudi Arabia
The Saudi Arabian Ministry of Health (MOH) reported three new MERS-CoV cases today, and announced the death of a former patient. All three new patients are listed as having primary exposure to the virus, which means it is unlikely they contracted the disease from another person.
The new patients are all Saudi men: a 58-year-old from Afif, a 78-year-old from Riyadh, and a 24-year-old from Al Hofuf. All patients presented with symptoms of MERS-CoV (Middle East respiratory syndrome coronavirus) and remain in stable condition. There have been other recent cases announced in these cities, but no suggestion yet of a cluster of infections.
The MOH also said that a 62-year-old Saudi man from Sakaka whose case was reported earlier has died.
The new cases raises Saudi Arabia's total from the disease to 1,501 since the first human infections were detected in 2012. So far 621 people have died from MERS. Seventeen people are still being treated for their recently announced illnesses.
Dec 6 MOH report
New drug-resistant Candida auris infections reported in Colombia
Researchers in Colombia yesterday reported 17 originally misclassified cases of an emerging multidrug-resistant yeast, including at least 6 fatal cases.
In a letter in Emerging Infectious Diseases, the researchers reported that 17 clinical isolates of Candida auris were recovered from 17 patients in 6 hospitals in northern Colombia from February through July 2016. C auris is a yeast that was first identified in a Japanese patient with an ear infection in 2009 and has since been reported in several other countries, including the United States. It has most commonly caused healthcare-associated invasive infections such as bloodstream infections, wound infections, and ear infections and has been associated with high mortality.
Of the 17 patients, 13 had fungemia (yeast in the blood). In the other 4 patients, C auris was isolated from peritoneal fluid, cerebrospinal fluid, bone, or urine. Most patients required a central venous catheter, a urinary catheter, and mechanical ventilation. The 30-day mortality rate in all patients was 35.2% (6 deaths); in those with fungemia, it was 38.4% (5 deaths).
One of the major concerns about C auris is that clinical isolates in several countries have shown varying levels of resistance to all three major classes of antifungal medicines used to treat Candida infections—including azoles, echinocandins, and polyenes. Another is that it is difficult to identify using common biochemical methods and is often misidentified as another type of Candida infection, which could lead to improper treatment.
In the reported cases, the authors write that the infections were originally misidentified as C haemulonii, C famata, C albicans, or C tropicalis. Correct identification was 27.5 days after hospitalization, on average. No categorical interpretation of antifungal susceptibility results was available from the lab that tested the patients' samples.
Dec 5 Emerg Infect Dis letter
US mosquito population increased 10-fold in past 50 years
Mosquito populations have increased by as much as 10-fold in New York, New Jersey, and California over the past 50 years, according to a study today in Nature Communications. Researchers suggest that the population boom is related to the waning effects of the banned insecticide DDT (dichlorodiphenyltrichloroethane) and increased urbanization.
Researchers from the University of California-Santa Cruz used three mosquito-tracking databases to document population changes on both US coasts. Though they originally hypothesized the increase in bugs was because of climate change, analysis showed population changes correlated to decreasing amounts of DDT in the environment. The Environmental Protection Agency (EPA) banned the use of DDT in 1972, and it's taken 30 to 40 years, the researchers said, for mosquito populations to recover.
While mosquito populations were recovering from DDT, urbanization, especially in warm cities such as Miami, also changed mosquito population composition, inviting species like the Zika-carrying Aedes aegypti to move into close contacts with humans. "Our results suggest that urbanization is likely to drive additional changes in mosquito communities, including the expansion of habitat for urban mosquitoes," the authors wrote.
Dec 6 Nat Comm study
Study: Interrupting Aedes aegypti during off-season decreases dengue
Monitoring mosquito populations and practicing insect control during non-transmission months can reduce the number of dengue cases, according to a pilot study published today in PLoS One. The study looked at Ae aegypti populations in India, and found that interventions made in December through May resulted in significantly fewer dengue cases in June through November.
The researchers used 28 sites around Delhi to conduct their experiment. They measured mosquito populations in different containers, including water storage tanks, coolers, overhead tanks, and garden pots. Containers were either emptied or treated with insecticides if mosquitoes or larvae were detected during the off-months at 20 sites, and the remaining 8 sites were used as controls.
The interventions led to reductions from 63% to 99% of mosquito populations in the containers monitored. No dengue cases were observed around the study sites, while 38 were reported in the areas around the controls.
"Community participation and social mobilization, coupled with regular active surveillance of key habitats for Aedes breeding during dry and wet months of the year and simultaneous interventions…can reduce the Aedes density and dengue cases in Delhi city," the authors concluded.
Dec 6 PLoS One study
