https://www.ncbi.nlm.nih.gov/pubmed/30680557

2019 Jan 24. doi: 10.1007/s10096-018-03451-5. [Epub ahead of print]

Impact of pre-operative antimicrobial treatment on microbiological findings from endocardial specimens in infective endocarditis.

Abstract

Treatment of infective endocarditis (IE) should be initiated promptly. This might hamper the chances to identify the causative organism in blood cultures. Microbiological sampling of infected valve in patients undergoing surgery might identify the causative organism. The impact of pre-operative antimicrobial treatment on the yield of valve samples is not known. This study evaluated the impact of the duration of the pre-operative antibiotic treatment on valve culture and 16S rRNA PCR findings from resected endocardial samples. Patients meeting the modified Duke criteria of definite or possible IE and undergoing valve surgery due to IE during 2011-2016 were included from Southern Finland. Eighty-seven patients were included.

In patients with shorter than 2 weeks of pre-operative antimicrobial treatment, PCR was positive in 91% (n = 42/46) and valve culture in 41% (n = 19/46) of cases. However, in patients who had 2 weeks or longer therapy before operation, PCR was positive in 53% (n = 18/34) and all valve cultures were negative. In 14% of patients, PCR had a diagnostic impact. In blood-culture negative cases (n = 13), PCR could detect the causative organism in ten patients (77%). These included five cases of Bartonella quintana, one Tropheryma whipplei, and one Coxiella burnetii. Long pre-operative antimicrobial treatment was shown to have a negative impact on microbiological tests done on resected endocardial material. After 2 weeks of therapy, all valve cultures were negative, but PCR was positive in half of the cases. PCR aided in diagnostic work-up, especially in blood culture negative cases.

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**Comment**

The dilemma “to treat or not to treat” because of hampered ability to subsequently test for organisms is real; however, the risk for not treating is potentially death.

The big point for Lyme/MSIDS patients; however, is the fact they found Bartonella and Coxiella burnettii, also known as Q-fever in patients with infective carditis.

https://www.columbia-lyme.org/q-fever  Those working with farm animals are at greater risk through inhalation or ingestion of soil or animal waste particles; however, ticks do transmit it.

Signs and Symptoms

Symptoms include high fever, headache, sore throat, malaise, nausea, diarrhea, chest pain, nonproductive cough, pneumonia, and hepatitis. Neurological manifestations occur in about one percent of patients and could develop into meningitis, encephalitis, myelitis and/or peripheral neuropathy. Endocarditis, infection of the heart valves, is the most serious manifestation. However, it is usually found in patients with preexisting valvular disease. Unfortunately, the mortality rate is increasingly high, currently at 65 percent.

Go here for a nifty table with the various coinfections, vectors, causative agent, endemic area, and symptoms: https://www.lymedisease.org/lyme-basics/co-infections/other-co-infections/

You will note that the brown dog tick, Rocky Mountain Wood tick, and the Lone Star Tick are all vectors and Q-fever is endemic throughout the U.S.  Treatment is doxycycline.

https://www.wrair.army.mil/Documents/TropMed/(18)%20Lyme%20and%20Rickettsial%20Disease_LTC%20Waterman.pdf  This document states endocarditis caused by Q fever may be chronic.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC88923/  Interestingly, even as far back as the 30’s, Q fever was noted to have properties of both viruses and rickettsiae. This document states Q fever may occur in patients without any animal contact due to it’s ability to be spread by wind.  The same document states human Q fever cases have occurred in the following:

  • An OB after an abortion on an infected woman
  • transplacental transmission
  • autopsies
  • intradermal inoculation
  • blood transfusion
  • tick bite
  • sexually in infected mice
  • possibly from infected dogs
  • infected cats

The real kicker on that last one was the 1984 report of 13 people who developed febrile respiratory disease by playing poker in a room where a cat had delivered kittens.  Abstract here:

Kosatsky T. Household outbreak of Q-fever pneumonia related to a parturient cat. Lancet. 1984;ii:1447–1449. [PubMed]

Symptoms were:

  • bradycardia (slow heart rate)
  • fever
  • palatal petechiae (red or purple spots on mouth palate)
  • rapidly enlarging bilateral pulmonary infiltrates (fluid in both lungs)