麻豆传媒

Public health officials released details on how a 7-year-old boy from Texas died from a rare rabies infection last year.

Although the boy had informed his parents he had been bitten by a bat while playing outside his apartment home, there were no visible bite marks, so the parents did not seek rabies postexposure prophylaxis (PEP). They did not seek medical care until the child developed signs and symptoms 2 months later, starting with right-hand pruritus and right upper extremity pain.

Despite the use of investigational therapies, the boy died within 22 days of symptom onset and hospitalization, Faisal Minhaj, PharmD, of the CDC's National Center for Emerging and Zoonotic Diseases in Atlanta, and colleagues reported in .

"Bites might not leave observable puncture marks, and given the high risk for rabies virus transmission from bats, PEP is recommended for any bat contact when a bite or scratch cannot be ruled out," according to the authors.

Minhaj's group noted that although dogs more commonly cause rabies in humans, accounting for an estimated 59,000 cases annually worldwide, bats cause more rabies in the U.S., accounting for 81.6% of the 38 recorded human infections since the year 2000.

"This case serves as a reminder that rabies virus is still present in the United States and that exposures to bats and other mammalian wildlife should always prompt a consultation with public health officials or medical providers," the authors emphasized, noting that once symptoms begin, rabies is nearly always fatal.

The rabies diagnosis was not established for the boy until clinicians learned about the bat bite after several hospital visits.

When the 7-year-old first arrived at a freestanding emergency department (ED) on October 21, 2021, with pain in his right upper arm and an itchy right hand, he was sent home with an oral steroid.

The next day, he went to a different hospital ED with a rash on his head, right arm, and hand. There, he was diagnosed with presumptive herpes zoster (shingles) and prescribed 5 days of acyclovir, antihistamines, and ibuprofen.

On the third day, he returned to the hospital ED with delusions and itchiness on his forehead. He was given diazepam for the spasms and gabapentin for pain and discharged. Later the same day, he returned with nausea, vomiting, fever of 104°F, hypersalivation, and a change in mental status including confusion and delusions. At that point, he was intubated and admitted to hospital and treated with antimicrobials for central nervous system infection.

Initial testing included cerebrospinal fluid and blood cultures and testing for herpes simplex virus, varicella zoster virus, enterovirus, mycoplasma, Bartonella, Epstein-Barr virus, and cytomegalovirus, which were all negative.

Only on the third day after hospital admission, October 25, was the boy finally tested for rabies after clinicians learned of the bat bite that had occurred 2 months earlier. On October 27, nuchal skin biopsy and saliva specimens confirmed the presence of rabies viral RNA, confirming infection of the rabies virus harbored by the local Mexican free-tailed bat species.

Experimental intrathecal human rabies immune globulin treatment was started on hospital day 7, but the boy nevertheless died on day 16 in hospital.

Texas Department of State Health Services followed up and investigated the case, interviewing the family and community contacts to identify any other known exposures. Of the 10 family members interviewed, six who met PEP criteria were treated, as was one additional family member with no known risk.

All the residents of the apartment complex where the child lived were contacted by telephone and sent an email and a printed rabies advisory. Of the 175 contacts by telephone, 124 were successful. Of an additional 46 community members who met exposure criteria, 34 took PEP, most of them being students who had participated in the same extracurricular program that the boy had attended during his infectious period.

Rabies prevention education and rabies risk exposure assessment tools were provided to community area hospitals, and they were warned of a possible increase in requests for rabies PEP. No additional human rabies exposures or cases have been identified as a result of contact with the patient.

A local bat colony was found in the apartment complex and managed by a pest control company.

"It is important to inform animal control or local public health officials when bats build roosts within and around human dwellings. PEP is highly effective and should be administered as soon as possible after an exposure to prevent rabies," Minhaj and colleagues said.

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