Case Report: A rare case of septic pulmonary embolism from a focus of soft tissue infection: A case report

The Authors present a case of septic pulmonary embolism in a patient with a site of infection unusually associated with this pulmonary condition. The insidious presentation with mild respiratory symptoms, the important differential diagnosis of tuberculosis, and the finding of the unusual association of septic pulmonary emboli with an infection in the foot are reported. The Authors clearly emphasize as take-home message the need of a high index of suspicions of physicians treating patients with a specific pulmonary symptoms in the presence of soft tissue infections far from the lungs, and also put correctly the finding of the association with a non-pulmonary infection in the context of recent literature describing a possible epidemiologic shift in the association between non-pulmonary infectious foci and septic pulmonary emboli.

The article is generally well-written in all aspects: structure (the required section are in the required order and include the information necessary in each section), interpretation/conclusions (the peculiarities of the case and the learning point for clinicians are clearly identified), and quality/clarity of written English. I commend the Authors for clearly describing the timing of diagnostic tests, often unclear in case reports, and in particular the duration of symptoms and previous medication received in another institution, details that are often forgotten in case reports in the field of septic thrombophlebitis (most patients will have presented to either primary care or to an emergency department before the hospitalisation in which the diagnosis is made and where the case report originates). However, I have a number of suggestions to improve clarity, especially regarding the structure and conciseness of the Discussion and some information (namely, figures) that belong to the Case presentation, as well as recommendations to provide the reader with updated literature on the topic. 

1. Abstract: Rather than "We describe a case of septic pulmonary embolism in a patient who presented with a right foot ulcer primary infection focus."
2. Abstract: In "A Septic Pulmonary Embolism", neither the article "A" nor the capital letters are necessary. Please also remove the capital "P" in "Pleural effusion" toward the end of the Abstract.
3. Abstract: I suggest correcting the sentence "in which case an infected thrombus from an infectious focus; distal to the lung vasculature travels through the lung and results in occlusive, inflammatory and infectious insult to the lung" into "in which a septic thrombus from an infectious focus distal to the lung vasculature travels to the lung and results in occlusive and inflammatory pulmonary damage." 
4. Abstract: "such as cough, fever" works better as "cough with fever", as the two symptoms usually co-exist in mild cases, and a comma is in appropriate for a list of only two elements. 
5. Abstract: Acronyms should not be present. Please remove "(SOB)" and "(CT)". They should be introduced upon first occurrence in the main text of the article itself, not in the Abstract.
6. Abstract: I suggest that the Authors replace "cavitary or non-cavitary" with "often cavitary". "Cavitary or non-cavitary" is not informative, as it means that whether the nodule is cavitary is irrelevant. In contrast, what is known about the radiological appearance of SPEs is that they are often cavitary - meaning that the finding may be specific enough to support the diagnosis if it is present, but not sensitive enough as to rule out the diagnosis if it is absent.
7. Abstract: Please replace the last sentence, "In this case report, we present a rare case of septic pulmonary emboli from a foci of soft tissue infection.", which is an unnecessary repetition of the first sentence, with a conclusion specific to this case such as "This case suggests that septic pulmonary embolism should be suspected even in patients with infections far from the pulmonary vasculature". 
8. Abstract: The Abstract should not include any references. Please remove references (1) and (2). References and abbreviations should only be included in the main text.
9. Introduction: "migrates to the lung" whould be correct, as "migrates through the lung" suggests that the thrombus may completely pass the lungs without affecting them. 
10. Introduction and Discussion: Please write “Lemierre syndrome” without the genitive "'s" (possessive form). "Lemierre syndrome" is the most common name of the condition, the recommended standard for medical eponyms (see for instance [Ayesu K et al. 2018 (Ref - 3) doi: 10.5195/jmla.2018.284] and [Jana N et al. 2009 (Ref - 4) doi: 10.1186/1471-2288-9-18], and the main MeSH entry in the National Library of Medicine (https://www.ncbi.nlm.nih.gov/mesh/?term=Lemierre).
11. Introduction/Discussion: References (5), (6) and (9) are not recent (one is 20 years old, the other 13 years old, the last 15 years old) and all can be replaced, in the sentences in the Introduction and Discussion in which they are used, by the more recent review on the topic: [Valerio L et al. 2023 (Ref - 1) doi: 10.1055/s-0043-1760843]. The review provides a comprehensive reference for the sentence "However, in recent years, there has been a shift in the epidemiology, highlighting the significance of infected vascular catheters, implantable devices, and more recently, septic thrombophlebitis due to contiguous deep soft tissue or bone infection of the extremities."
12. Case presentation: The AMA Manual of Style, 11th Edition, recommends that "woman" is used rather than "female patient" or "female individual" (with the exception of studies with sample sizes including both children and adults); AMA Manual of Style, paragraph 11.7, "Whenever possible, a patient should be referred to as a man, woman, boy, girl, or infant.". Therefore, please write "A woman aged 55 years" rather than "A female patient aged 55 years". 
13. Case presentation: "exhibiting symptoms such as" can be written more concisely, and it wrongly suggests that the list of symptoms is non-exhaustive (it should be exhaustive: all relevant symptoms should be listed). Therefore, I suggest that it is replaced with simply "with". 
14. Case presentation: the sentence "Additional information revealed that" is unclear. Who provided the additional information? The previous hospital? Maybe the Authors mean "Upon repeated history taking, it emerged that..." or simply "In addition, ...".  
15. Case presentation: the medical term for "big toe" is "hallux". Please correct upon all occurrences throughout the article.
16. Case presentation: More concise than "Her medical history did not indicate any presence of diabetes or hypertension, nor did it include any contact with individuals suffering from chronic cough or tuberculosis." would be "Her medical history did not include diabetes, hypertension, or any contact with individuals sufferings from chronic cough or tuberculosis". 
17. Case presentation: rather than writing "edema was observed in her right foot (non-pitting edema)" you could simply write "non-pitting edema was observed in her right foot".
18. Case presentation: it does not make sense to provide acronyms for terms that do not recur any longer in the rest of the article. For instance, there does not seem to be any reason for the acronyms "CBC", "CRP", "hsCRP", and "ESR" to be provided and they can be removed completely. 
18. Case presentation: the sentence "Comprehensive metabolic panel and Organ function tests yielded normal results, ruling out the presence of tuberculosis." should be clarified: it should be specified which tests exactly were conducted, as "organ function tests" is not a standard label for specific medical tests worldwide (in contrast with CBC, which means quite the same everywhere in the world). In addition, I do not believe that any organ function test is so sensitive for tuberculosis that it can rule out tuberculosis: one can have tuberculosis with perfectly normal "organ functions". I believe TB skin tests, sputum smear, adn culture are necessary (even though not perfectly sensitive). 
19. Case presentation: please write out the meaning of "VDRL" rather than writing the abbreviation only. 
20. Case presentation: "Urinalysis results were also normal" can be written more simply as "Urinanalysis was also normal".
21. Case presentation: "Imaging revealed an unremarkable ultrasound of the abdomen and pelvis, except for right lower lobe consolidation on the lung." can be more succinctly written as "Abdomen and pelvis ultrasound showed a pulmonary consolidation in the right lower lobe and was otherwise unremarkable".
22. Case presentation: "The Trans-thoracic Echocardiography" could better be written as "A transthoracic echocardiography". 
23. Case presentation: the finding of the transthoracic echoocardiography can be written more succinctly as "A transthoracic echocardiography showed no structural abnormalities or valvular vegetations.".
24. Case presentation: The findings of blood, sputum and wound cultures should be reported in very thorough details, and the choice of the antibiotics in the treatment regimen (Ceftriaxone, Vancomycin) should be chosen with care. Was it an empiric treatment? Was it recommended by microbiologists/infectious disease specialists, based on the coverage of which agents? In particular, specify whether, when, and with what results blood cultures and wound cultures of the right foot ulcers were conducted. This is extremely important in a case of infection. I read later that the discussion of blood cultures is contained in the Discussion in the sentence "blood culture was not performed in the current case due to prior antibiotic exposure and test unavailability", but this should be moved to the case presentation! 
25. Case presentation: the sentence "Furthermore, wound debridement and twice daily wound care initiation took place, " could be better written as "Furthermore, wound debridement was performed and wound care took place twice daily.". 
26. Case presentation: I believe that "patient's admission to the Inpatient department" simply means "patient's admission into hospital". By definition, an admission is always to an inpatient department (and an inpatient department or ward only includes patients that were admitted).
27. Case presentation: The sentence "The patient was discharged from the hospital on the 14th day of admission without any relapses during the follow-up period." could probably be simply written as "The patient was discharged from the hospital on the 14th day of admission.". The second part, "without any relapses during the follow-up period.", is unclear: if it refers to the inpatient follow-up, then the sentence is unnecessary, because the previous sentence had already stated that the patient had complete recovery until discharge. If it refers to post-discharge follow-up, then this should be stated clearly, including when exactly and how many times the patient was seen after discharge.
28. Discussion: "In previous times" should be amended to "Until recently" or "In the past" or other similar expression. 
29. Discussion: The reference currently numbered as (4), Goldenberg 2005 et al., is quite old and it only refers to children, while the case described here is an adult. The Authors may better replace it with a more recent sources on the topic, such as [Valerio L et al. 2020 (Ref - 2) doi: 10.1055/a-1177-5127].
30. Discussion: rather than "Consequently, an escalating number of patients are exhibiting symptoms stemming from an extrapulmonary origin of infection, diverging from the traditional presentation documented in earlier literature.", I suggest "Consequently, septic pulmonary emboli are increasingly found in patients with an extrapulmonary primary infection focus, diverging from the traditional presentation". 
31. Discussion: The figures 1A and 1B should be moved to the Case Presentation, and not shown first in the Discussion.
32. Discussion: There are some issues with the order of the information, the logics of the literature reviews, and the quantity of information. I suggest that the Discussion is reordered as follows: first, the pathogenesis and the diagnosis of SPE in general should be discussed, so that the discussion should start with the section from "The pathogenesis of septic pulmonary emboli..." up to "aligning with findings from numerous studies". However, this section should be adapted: the CT figures should be presented and mentioned first in the case presentation, and not in the Discussion for the first time. 

Then, the specific issue of the extrapulmonary sources of infection should be discussed. Now, the section from "In previous times..." to "52.6% of cases" should be included. However, this section should be amended as follows. In this section (again, from "In a retrospective study..." to "52.6% of cases"), several narrative reviews of previous studies are shown. However, in the Discussion of a case report, this should be done with a specific goal, which here is not clear. I assume the main idea is to show the distribution of primary infectious foci in other studies. If this is correct, please simplify "pulmonary complaints (66%), such as pleuritic chest pain (22%), cough (19%), and dyspnea (15%)." into "diverse symptoms consistent with lower respiratory infection (66%)". In the mention of the previous literature, please simplify the way the previous study is referenced: "In a retrospective study conducted from January 2000 to January 2013 at Hennepin County Medical and an urban teaching hospital in Minneapolis, Minnesota, USA, " can be simplified into "In a retrospective study conducted from 2000 to 2013 in a teaching hospital in Minnesota, USA,". Instead, the phrase "As observed by Umesh Gswami et al." does not provide enough information - it is a retrospective study, a review, a meta-analysis? Please include this detail and the country rather than the name of the first Author.

Please simplify "In a retrospective analysis of patients with septic pulmonary emboli admitted between January 2007 and June 2018 at the Department of Respiratory and Critical Care Medicine, Hospital of Guangxi Medical University, China," into "In a single-center retrospective analysis of China including patients with septic pulmonary emboli admitted between 2007 and 2018,", and "Similarly, in a recent retrospective study conducted from January 1, 2018 to December 22, 2020 at Mogadishu Somali Turkey Education and Research Hospital, Somalia" into "Similarly, in a recent retrospective study conducted in Somalia on patients admitted from 2018 to 2020". Please also discuss the recent review [Valerio L et al. 2023 (Ref - 1) doi: 10.1055/s-0043-1760843].

Finally, the section on treatment, starting from "Treatment of septic pulmonary embolism" to "subsequent follow-up assessment" can remain as last, where it is now. This section is well-written and I only recommend one amendment: the Discussion should not repeat points already reported in the Case presentation. Therefore, the final sentences "In our case report, blood culture was forgone due to the patient’s prior exposure to antibiotics and the unavailability of the test in our facility. Therapy was initiated with vancomycin 1gm IV BID and Ceftriaxone 1gm IV BID, considering coverage for Staphylococcus and broad-spectrum antibiotic inclusion. This approach yielded favorable outcomes in our patient, as evidenced by clinical amelioration, reduction in white blood cell count and acute inflammatory markers, and resolution of chest abnormalities in subsequent follow-up assessments." can be shortened into "In our case, blood culture was forgone due to the patient’s prior exposure to antibiotics and the unavailability of the test in our facility. Empiric intravenous antibiotic therapy with ceftriaxone and vancomycin was followed by clinical improvement, reduction of the acute inflammatory markers, and resolution of chest abnormalities.".
33. Conclusion: well-written, no strong recommendation here.