Chad reports its first dengue outbreak

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Chad has reported its first dengue outbreak, though it has experienced other arbovirus outbreaks before, including chikungunya and yellow fever, the World Health Organization (WHO) said today.

albpictus
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The country’s health ministry declared an outbreak on August 15, and so far, 1,342 suspected cases have been reported, 41 of them lab confirmed. One death was reported among the patients with lab-confirmed cases.

The outbreak started in Ouaddai province in eastern Chad, currently the outbreak epicenter. Illnesses have also been reported in three other provinces. So far, the dengue virus serotype that is spreading in the country isn’t known.

Risk high in Chad

The WHO said Chad has limited surveillance, clinical, and lab capacities. It put the risk of further spread as high, owing to favorable conditions for mosquito spread and an evolving humanitarian crisis due to an influx of refugees from Sudan. The risk to the region is moderate, given movement of Sudanese refugees and Chad nationals, the WHO said, adding that the global threat from the event is low.

Chad's last mosquito-borne illness outbreak occurred in 2020, when it experienced a chikungunya outbreak that resulted in more than 34,000 cases.

Maryland survey finds high prevalence of worrisome pathogens in mechanically ventilated patients

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A statewide survey of hospitals and nursing homes in Maryland found that colonization with two multidrug-resistant pathogens is common in patients receiving mechanical ventilation, researchers reported last week in JAMA.

For the statewide cross-sectional point-prevalence study, researchers with the Maryland Multi-Drug Resistant Organism Prevention Collaborative obtained surveillance cultures from patients receiving mechanical ventilation at 33 acute care hospitals and 18 long-term care facilities from March 7 to June 8, 2023.

Their aim was to determine the prevalence of Acinetobacter baumannii and Candida auris, two emerging multidrug-resistant pathogens with limited treatment options that have been identified as an urgent health concern by the World Health Organization and the Centers for Disease Control and Prevention.

High risk for long-term care patients

Patient on ventilator
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All eligible facilities in the state participated, with a total of 482 patients screened for A baumannii and 470 for C auris. Among the 482 patients who had samples collected, 148 (30.7%) grew A baumannii, 88 (59.5%) of which were carbapenem-resistant A baumannii (CRAB). C auris was identified in 31 (6.6%) of 470. Both pathogens were more common in patients in long-term care facilities.

Assessment of relative risk (RR) found that patients in long-term care facilities were more likely to be colonized with A baumannii (RR, 7.66; 95% confidence interval [CI], 5.11 to 11.50), CRAB (RR, 5.48; 95% CI, 3.38 to 8.91), and C auris (RR, 1.97; 95% CI, 0.99 to 3.92) compared with patients in acute-care hospitals. Nine patients (29.0%) with cultures positive for C auris were previously unreported to the Maryland Department of Health.

"This prevalence represents a substantial burden to the health care system and suggests a large reservoir for potential transmission both to other patients within health care facilities and among different health care facilities when patients are transferred between care settings," the study authors wrote.

The authors conclude that increased surveillance and prevention efforts should be directed at long-term care facilities, given that both pathogens were more common in these settings. They also suggest that the study should be repeated in patients receiving mechanical ventilation in other states.

This prevalence represents a substantial burden to the health care system and suggests a large reservoir for potential transmission both to other patients within health care facilities and among different health care facilities when patients are transferred between care settings.

Trial clarifies safety risks with cefipime, piperacillin-tazobactam

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IV antibiotics
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The results of a randomized trial answer some important questions regarding the comparative safety of two antibiotics used for empiric treatment of adults hospitalized with acute infection, researchers reported late last week in JAMA.

In the Antibiotic Choice on Renal Outcomes (ACORN) trial, investigators with Vanderbilt University Medical Center compared cefepime with piperacillin-tazobactam in adults prescribed antipseudomonal antibiotics within 12 hours of presentation to the emergency department or medical intensive care unit. While both drugs have similar activity against gram-negative bacteria, some observational studies have reported an association between piperacillin-tazobactam and acute kidney injury (AKI), while others have suggested links between cefepime and neurotoxicity.

Patients were enrolled and randomized 1:1 to receive either drug from November 10, 2021, to October 7, 2022. The primary outcome was AKI, measured on a five-level ordinal scale, or death by day 15. Secondary outcomes included incidence of major adverse kidney events at day 14 and number of days alive and free of delirium and coma within 14 days.

Cefepime patients see increase in neurologic dysfunction

Among the 2,511 patients (median age, 58 years; 42.7% female) included in the primary analysis, the highest stage of AKI or death was not significantly different between the cefepime group and the piperacillin-tazobactam group. There were 85 patients (7%) with stage 3 AKI and 92 (7.6%) who died in the cefepime group, compared with 97 patients (7.5%) with stage 3 AKI and 78 (6%) who died in the piperacillin-tazobactam group (odds ratio [OR], 0.95; 95% confidence interval [CI], 0.80 to 1.13).

The incidence of major adverse kidney events at day 14 did not differ between the cefepime group (10.2%) and the piperacillin-tazobactam group (8.8%; absolute difference, 1.4%; 95% CI, −1.0% to 3.8%).

However, patients in the cefepime group experienced fewer days alive and free of delirium and coma within 14 days than those in the piperacillin-tazobactam group (mean, 11.9 days vs 12.2 days; OR, 0.79; 95% CI, 0.65 to 0.95).

"Among hospitalized adults in this randomized clinical trial, treatment with piperacillin-tazobactam did not increase the incidence of AKI or death," the study authors concluded. "Treatment with cefepime resulted in more neurological dysfunction."

Wisconsin, Illinois confirm measles cases

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Health departments in two Midwestern states—Wisconsin and Illinois—have reported measles cases, according to official statements.

measles virus
CDC /Cynthia S. Goldsmith & William Bellini, PhD

In Wisconsin, Milwaukee’s health department last week reported an infection in a Milwaukee resident who works in Waukesha County. City, county, and state health officials are working to identify people who may have been exposed.

Meanwhile, the Illinois Department of Public Health (IDPH) on October 13 announced that a measles infection has been confirmed in Cook County, which includes Chicago. The case is the state’s first since 2019. The patient is unvaccinated and had been exposed during international travel. The patient’s rash began on October 9, and the IDPH said the infectious period likely ranges from October 5 through October 13.

Sameer Vohra, MD, IDPH director, said the case is a reminder that up-to-date vaccination can prevent the disease.  "I urge everyone to make sure they and their family members are up-to-date on measles/mumps/rubella (MMR) vaccine and all other age-appropriate immunizations," he said.

The Centers for Disease Control and Prevention said that, as of September 29, a total of 29 cases have been reported this year in 16 jurisdictions.

Pertussis in adults aged 50 and older costs UK about $290 million yearly, study estimates

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Older man coughing
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Pertussis (whooping cough) costs among older adults in the United Kingdom are high, at about £238 million ($290 million) per year, with the greatest expense among those aged 55 to 59, estimates a study published late last week in Vaccine.

Researchers from the Erasmus School of Health Policy & Management in the Netherlands and tetanus, diphtheria, and pertussis (Tdap) vaccine maker GSK in Belgium estimated annual individual and combined medical, patient, and indirect costs of pertussis among older UK adults from 2009 to 2018.

Pertussis is a highly contagious respiratory tract infection caused by Bordetella pertussis bacteria and spread through the air. It can affect people of all ages, causing coughing and vomiting, but it can be particularly severe in those aged 50 and older.

Indirect costs made up 67% of total expense

In 2020, the total cost of pertussis in the United Kingdom was roughly £238 million ($290 million). Indirect costs such as those from lost productivity and informal care made up 67% (£159 million [$194 million]) of the total cost, followed by medical costs for diagnostic and medical care (28%; £66 million [$80 million]), and patient costs such as transportation and medications (5%; £13 million [$16 million]).

Costs were highest for patients aged 55 to 59 years, followed by those 60 to 64 years and those 50 to 54.

Visits to general practitioners or nurses accounted for the highest proportion (over 50%) of medical costs, while diagnostic tests (about £13,000 [$16,000]) had the least impact. Transportation accounted for most patient costs (£10 million [$12 million]). Lost leisure time (45%; £72 million [$88 million]) was the largest contributor to indirect costs, followed by lost productivity (£71 million [$86 million]).

Visits to general practitioners or nurses accounted for the highest proportion of medical costs, while diagnostic tests had the least impact.

The researchers said implementation of a Tdap vaccine booster program for people aged 50 and older could lower the risk of pertussis. "Policy makers could enhance the pertussis notification system to better inform healthcare professionals," they wrote. "Furthermore, if pertussis cases were detected faster and more often, additional secondary infections could be prevented by early treatment initiation." 

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