By Bobbi-Jo Lowie, MD
Assistant Professor
Emergency Medicine
University of Maryland School of Medicine
Since April of 2024 there have been 36 confirmed cases of avian influenza A across the United States. Avian influenza, primarily caused by influenza viruses that infect birds, can pose significant health risks to both animals and humans. The most notable strains include H5N1 and H7N9, with H5N1 being particularly alarming due to its high mortality rate among infected humans. The virus primarily spreads from birds to humans through direct contact with infected birds, their droppings, or contaminated environments. Although there have been recorded cases of human-to-human transmission, this usually occurs only in close-contact situations.
In humans, avian influenza can present with symptoms ranging from mild respiratory illness to severe pneumonia. Patients may experience fever, cough, sore throat, muscle aches, and in severe cases, gastrointestinal symptoms. Those that have more moderate or severe illness may develop shortness of breath, altered mental status, or seizures. Complications include acute respiratory failure, pulmonary hemorrhage among others, with respiratory failure being the most common cause of death in this patient population.
Diagnosing avian influenza involves a combination of clinical presentation, travel history, and exposure to birds and confirmation through PCR testing of upper respiratory tract samples like a nasopharyngeal swab.
Treatment for avian influenza focuses on antiviral medications such as oseltamivir which is most effective when administered early in the course of the illness but still administered after 48 hours of illness. Supportive care is essential for managing severe cases, especially those that progress to acute respiratory distress syndrome.
Background:
What’s new?
Who is at risk?
Patients with epidemiologic characteristics and lesions or other signs and symptoms consistent with mpox. This includes anyone with travel to DRC or any of its neighboring countries (ROC, CAR, Rwanda, Burundi, Uganda, Zambia, Angola, Tanzania, and South Sudan) in the previous 21 days.
What to look for?
(Above photos from https://www.cdc.gov/poxvirus/mpox/clinicians/clinical-recognition.html)
What to do?
If mpox is suspected in a patient:
The Infectious Disease Society of America in 2023 recommended a single dose of an aminoglycoside for uncomplicated cystitis treatment in those with resistance or other contraindications to first line oral agents who were otherwise well enough to be discharged. This very small study (13 participants) suggest this strategy works for complicated (“male sex, urinary flow obstruction, renal failure or transplantation, urinary retention, or indwelling catheters”) cystitis patients who could otherwise be discharged home.
| Clinical Definition | Treatment | |
| Initial episode, non-severe | WBC ≤ 15,000 AND SCr <1.5 |
If above agents unavailable, metronidazole PO 500mg 3x daily
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| Initial episode, severe | WBC ≥ 15,000 OR SCr >1.5 |
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| Initial episode, fulminant | Hypotension, shock, ileus, megacolon |
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| First Recurrence |
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Debating between cefepime or piperacillin/tazobactam for your septic patient? Use this table to help you decide.
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| Cefepime | Piperacillin/Tazobactam |
| Gram Negative Spectrum | Pseudomonas aeruginosa | Yes | Yes |
| Aerobic gram negative organisms | E. coli Klebsiella sp. Proteus mirabilis M catarrhalis H. influenza | E. coli Klebsiella sp. Proteus mirabilis M. catarrhalis H. influenza | |
| Anerobic gram negative organisms | No | B. fragilis
| |
| Gram Positive Spectrum | MRSA | No | No |
| Aerobic gram positive organisms | MSSA CoNS Group A Strep S. pneumoniae
| MSSA CoNS Group A Strep S. pneumoniae E. faecalis | |
| Anaerobic gram positive organisms | P. acnes Peptostreptococci | P. acnes Peptostreptococci Clostridium sp. | |
| Infection Site Concerns | CNS Penetration | Yes | No1 |
| Urine Penetration | Yes | Yes | |
| Lung Penetration | Yes | Low2 | |
| Dosing Frequency (Normal Renal Function) | Q8h | Q6h | |
1. Tazobactam CNS penetration is limited, thus limiting antipseudomonal activity in the CNS
2. Low pulmonary penetration, may not achieve therapeutic levels in patients with critical illness
Community-associated Clostridium difficile infection (CA-CDI) represents 41% of all CDI cases annually. The association of specific outpatient exposures was assessed in a case control study by Guh, et al. They reviewed the CDC’s active surveillance reporting from 10 states through the Emerging Infections Program (Maryland participates).
Cases: ≥18, + C. difficile stool specimen collected as an outpatient or within 3 days of hospitalization, with no overnight stay in a health care facility in the prior 12 weeks, and no prior CDI diagnosis
Controls: matched 1:1 for age and sex within the same surveillance catchment area as the case patient on the date of the collection specimen. Exclusion criteria: prior diagnosis of CDI, diarrheal illness, overnight stay in health care facility in the prior 12 weeks
Data Collection: telephone interview, standardized questionnaire or comorbidities, medication use, outpatient health care visits, household and dietary exposures in the prior 12 weeks
Results: 452 participants (226 pairs), over 50% were ≥ 60 years of age, 70.4% female, and 29% were hospitalized within 7 days of diagnosis, no patients developed toxic megacolon or required colectomy.
Cases had more health care exposures, including the emergency department (11.2% vs 1.4% p <0.0001), urgent care (9.9% vs 1.8%, p=0.0003). In addition, cases also reported higher antibiotic exposures (62.2% vs 10.3%, p<0.0001) with statistically significant higher exposure to cephalosporins, clindamycin, fluoroquinolones, metronidazole, and beta-lactam and/or beta-lactamase inhibitor combination. The most common antibiotic indications were ear or sinus infections, URI, SSTI, dental procedure, and UTI. No differences were found in household or dietary exposures.
Take-home point: This study highlighted the risk for CA-CDI infection for patients presenting to an ED and reiterates that exposures to fluoroquinolones, cephalosporins, beta-lactam and/or beta-lactamase inhibitor combinations, and clindamycin significantly increases the risk of CA-CDI infection. Reducing unnecessary outpatient antibiotic prescribing may prevent further CA-CDI. 36% of case patients did not have any antibiotic or outpatient health care exposure; therefore, additional risk factors may exist.
Take home points:
Zika virus and its transmission is currently an important infectious disease topic in the United States and the Western Hemisphere. With domestic spread in the Continental United States, and the likely further spread to other parts of the southern United States, continued vigilance by healthcare providers remains important.
What are the signs and symptoms of Zika?
Most common signs and symptoms are:
Other symptoms can include
Symptoms can generally last 2 to 7 days. Most individuals will have minimal or no significant symptoms and may not seek medical care. These symptoms are similar to other arboviruses, such as dengue or chikungunya. Potential serious complications include Guillian Barre syndrome.
Of course, the main concern remains infection of pregnant women and the impact that Zika has on the developing fetus, especially for the brain.
Cutaneous larva migrans (CLM) is an acquired dermatosis
Clinical manifestations:
Treatment:
Bottom Line:
Borrella mayonii a new species
There is a new bacteria that is causing Lyme disease. Borrella burgdorferi is the typical bacteria associated with lyme disease, but now several cases of Borrelia mayonii have been isolated from patients and ticks that live in Minnesota, Wisconsin and North Dakota. What is unique about this new species is that it is associated with nausea, vomiting, diffuse macular rashes, and neuro symptoms [e.g.: confusion, visual disturbance, and somnolence) along with the typical lyme disease symptoms of arthralgias and headaches.
Current lyme tests should detect this new species and treatment is the same as Borrella burgdorferi. The take home pearl is that we may see patients with "atypical" lyme disease symptoms so this should be on our differential for patients presenting with rashes, nausea, vomiting and neurologic complaints.
C. Diff Colitis
The general treatment recommendations for C. Diff Colitis are to place the patient on PO metronidazole and if they fail this treatment PO vancomycin (125 mg 4x day). Vancomycin is generally reserved for resistant cases due to the fear that it could induce Vancomycin resistant enterococcus.
For severally ill patients it is recommended that you prescribe IV metronidazole and PO vancomycin when they are not actively vomiting. Remember there is no role for IV vancomycin as it does not get into the bowel lumen to eradicate the infection.
There is some great news though, the FDA recently approved a new drug, a macrolide antibiotic fidaxomicin (Dificid), for the treatment of C. Diff Colitis. Fidaxomicin was found to be as effective as vancomycin in preventing recurrence 3 weeks after treatment. Currently it is recommended that fidaxomicin be reserved for cases where patients are having recurrences after 3 weeks of vancomycin treatment.
The FDA news release can be found at http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm257024.htm
Hemorrhagic bullae in an ill-appearing patient with underlying cirrhosis should prompt consideration for an invasive infection due to Vibrio vulnificus.
V. Vulnificus is a gram negative rod and causes a highly lethal infection in patients with cirrhosis.
Antibiotics for these patients should include coverage for this organism. This should include doxycycline and a third genaration cephalosporin.
The number of rabies vaccines recommended by the ACIP (Advisory Committee on Immunization Practices) has been reduced from 5 to 4 doses for unvaccinated patients.
This was based on evidence from multiple source, including pathogenesis data, animal trials, clinical studies, and epidemiological surveillance. The first dose of the 4-dose regimen should be administered as soon as possible after exposure (day 0). Additional doses are then given on day 3, 7, and 14. The first dose of rabies vaccine should be administered with HRIG, infiltrating as much as possible into the wound, with the remainder given IM at a distant site from the vaccine.
This recommendation is not applicable to immunocompromised patients, who should continue to receive the full five doses.
http://www.cdc.gov/vaccines/pubs/vis/downloads/vis-rabies.pdf
Spinal Epidural Abscess Pitfalls
Take Home Point: In the patient with risk factors for spinal epidural abscess (IVDU, DM, indwelling catheters, etc) do not exclude the diagnosis based upon the absence of a fever, a normal WBC count, and a normal neurologic exam.
Herpes Encephalitis-When to Consider
Herpes encephalitis is a potential lethal condition with high morbidity. Obviously our job in the ED is to rule-out bacterial meningits. So, when should we consider the diagnosis of herpes encephalitis?
Although no great guidelines exist, consider ordering a herpes PCR when sending studies on the "rule-out meningitis" patient. What about emperically treating a patient with Acyclovir? Again, no great data. Consider treating with 10 mg/kg IV q 8 hours for patients with abnormal CSF (in addition to the Ceftriaxone/Vanc, etc.) if you are worried about them, if they are altered (or encephalopathic), and if the CSF is abnormal (elevated wbc) with a negative gram stain. Acyclovir can always be discontinued when the PCR returns negative.
Daptomycin and MRSA
This pearl is dedicated to Dr. Michael Rolnick....
Infections That Cause Temperature-PulseDissociation
Certain infections may cause temperature-pulse dissociation (relative bradycardia in association with fever).
Remember that normally there will be an increase in pulse rate by 10 bpm for every 1 degree increase in temperature. So, if a patient has a temperature of 103 F, expect them to be tachycardic.
Any intracellular organism has the potential to cause a relative bradycardia (Faget's sign)
Infections that cause dissociation:
It is almost impossible to get through a shift these days with out seeing an abscess that is caused by CA-MRSA. As of the 2007 Antibiotic nomogram (2008 data not yet available) at University of Maryland CA-MRSA was only 70% sensitive to clindamycin, and >98% sensitive to bactrim and > 96% sensitive to doxcycline. A local community hospital in Baltimore is showing only 55% sensitivity to clindamycin.
As a New Year's resolution to yourself I recommend that you check with your local hospital's Micrology department to see what the sensitivities are to bactrim, clindamycin, doxycycline. If sensitivities are less than 80% it would generally be recommended that these medications not be used as initial empiric treatment.
For Baltimore bactrim and doxycycline should probably be the preferred treatment options.
Have a Great New Year.
Healthcare Associated Pneumonia (HCAP)....why is this important for the emergency physician?
Most of us are very familiar with the types of pneumonias commonly seen in clinical practice: community-acquired pneumonia (CAP), hospital-acquired pneumonia(HAP), and ventilator-associated pneumonia (VAP). But, some may not be that aware of a relatively newer type of pneumonia that has been well-defined, healthcare-associated pnemonia (HCAP). Experts in infectious disease and critical care now say that we (the ED) should be assessing ALL pneumonia patients for HCAP risk factors.
Why care, you ask?
Risk factors: (most are common sense)
Treatment:
