• Cave dwellers

• Soil that contains bird or bat dropping^[1]

• Palate and oral ulcers
• Splenomegaly

• Pancytopenia

• Urine antigen testing

• Rash on upper body or legs^[2]
• Night sweats

• Lymphadenopathy
• Hepatosplenomegaly
• Bone marrow dysfunction

• Elevated liver enzymes

• Hyperbilirubinemia

• Hypoalbuminemia

• Extremities
• Lymphadenitis (nodular)

• Cystic fibrosis or asthma. tuberculosis.

• Immunocompromised

• Wheezing

• Stuffiness, runny nose
• Hemoptysis
• Weight loss

• Painless skin ulcer with a black center ^[6]
• Bloody diarrhea

• Thrombocytopenia

• Hyponatremia

• ↑ BUN

• Hypoalbuminemia

• ↑ Troponin.

Building water systems

• Diarrhea
• Confusion

• + Urine Antigen

• Hyponatremia^[7]

• Night sweats
• Hemoptysis

• Hypercalcemia
• Elevated alkaline phosphatase levels
• fluorescence microscopy (auramine-rhodamine staining)+ for baccilli.

Adults > 65

Immunocompromised.

• Pregnancy can lead to miscarriage, stillbirth, premature delivery,
• Non-pregnant : headache, stiff neck, confusion, loss of balance, and convulsions

• Elevated titers of listeriolysin O

• CSF analysis :Pleocytosis lymphocytes  ↑CSF protein   ↓ CSF glucose 

Mexico, South and Central America

• Arthritis
• Testicular and scrotal swelling
• Endocarditis

• Antibody production against lipopolysaccharide and bacterial antigens
• Relative lymphocytosis and thrombocytopenia.

Australia

Afghanistan

• Maculopapular rash

• Indirect immunofluorescence

• + Weil-Felix test

• Jaundice

• Red eyes
• Kidney failure^[10]

• Antibodies labelled with fluorescent markers positive for leptospires.

• Microscopic agglutination test +

• Lymphadenopathy

• Papule or pustule at the infected site

• enzymatic immunoassay positive for antibody to B henselae
• lymphocytosis

• Pregnant women.
• Infants born at less than 28 weeks gestation^[12]
• Immunocompromised persons

• conjunctival and catarrhal symptoms

• Spots appearing in two or three waves

Rash, appears after episode of high fever.

• Weight loss

• H/o smoking
• Hemoptysis

• Patient is immunocompetent
• Focal symptoms indicative of a mass lesion
• Seizure

• Single solitary ring enhancing lesion on CT or MRI

• Prior history of residence in an endemic area
• Chronic cough, weight loss, hemoptysis

• PCR of CSF for tuberculosis
• Mycobacterial culture of CSF
• Brain biopsy for acid-fast bacilli staining
• Culture and acid stain positive for acid-fast bacilli
• CXR shows cavitations

• Pulmonary lesions in addition to CNS lesions
• Symptoms may include cough, chest pain, and hemoptysis

• CSF fungal culture, galactomannan

• Symptoms include cough, chest pain, and hemoptysis

• Cryptococcal antigen from CSF and serum
• CSF fungal culture

• History of residence in Central or South America
• Acute infection is rarely symptomatic
• Encephalitis or focal brain lesions
• Myocarditis
• Chronic infections in immunocompromised patients develop into encephalitis with necrotic brain lesions causing a mass effect

• Trypanosoma cruzi in blood, tissue, or CSF, PCR of tissue or body fluids, and serologic tests

• Most common CNS opportunistic infection in AIDS patients
• Presents with encephalitis, retinitis, progressive myelitis, or polyradiculitis
• In disseminated disease, it involves both the liver and kidneys

• Brain CT/MRI/biopsy: location of lesions is usually near the brain stem or periventricular areas
• PCR of CSF with detectable virus is diagnostic
• Brain biopsy with + staining for CMV or evidence of owl’s eyes is also diagnostic, but it is rarely performed because of the location of brain lesions

• Seizures, headache, confusion and/or urinary retention can be seen in disseminated disease, which usually affects only the immunocompromised or acute infections
• In pregnant women, it may be associated with concurrent genital/oral lesions; can be spread to the neonate during acute infection in the mother, or via viral shedding in the birth canal
• Neonatal HSV can range from localized skin infections to encephalitis, pneumonitis, and disseminated disease

• Brain CT/MRI/biopsy: location of lesions is usually the medial temporal lobe or the orbital surface of the frontal lobe.
• PCR of CSF with detectable virus is diagnostic

• Multifocal involvement has subacute course, usually only in immunosuppressed, with headache, fever, focal deficits, and seizures.
• Unifocal involvement is more typically seen in immunocompetent hosts, occurring after contralateral cranial nerve herpes zoster, with mental status changes, TIAs, and stroke
• Disseminated varicella zoster virus can occur in adults during primary infection, presenting with pneumonitis and/or hepatitis
• Disease is a vasculopathy with hemorrhage and stroke

• PCR of CSF with detectable virus is diagnostic

• Associated with sinusitis (abutting the sinuses) or with bacteremia
• Signs and symptoms includes fever and necrotizing brain lesions with mass effect

• CSF culture or culture of brain abscess

• Symptoms are often more insidious in onset and progress over months. Symptoms include progressive weakness, poor coordination, with gradual slowing of mental function. Only seen in the immunosuppressed. Rarely associated with fever or other systemic symptoms

• PCR of CSF for JC virus
• Biopsy reveals white matter lesions and not well-circumscribed lesions.

• Agents found in:
  • decaying vegetation
  • Soil
• Acquired by:
  • Inhalation
  • Ingestion
  • contamination of wounds with sporangiospores from the environment.
  • Air-conditioning systems, particularly during construction
  • Use of contaminated adhesive bandages or tape in surgical wound dressings

• Susceptible individuals:
  • Immunocompromised patients
  • Diabetics
  • Patients receiving deferoxamine therapy
  • Injection drug users
  • Patients with no apparent immune impairment
• Invasive mucormycosis is clinically similar to aspergillosis and is marked by angioinvasion and tissue infarction

• +

(Mucosal thickening on the paranasal sinuses is more common in rhinocerebral mucormycosis(ROCM) than bacterial orbital cellulitis(BOC)^[25]

• +

(Specially if there is invasion of the cavernous sinus)

• +

(Limited eye movement is more common in patients with rhino-cerebral mucormycosis (ROCM) than in those with bacterial orbital cellulitis)^[26]

• CT scan:
  • Reverse halo sign (characterized by central ground-glass opacity (GGO) which is surrounded by a partial or complete rim of consolidation)The opening <ref> tag is malformed or has a bad name is more common in patients with pulmonary mucormycosis than in those with invasive pulmonary aspergillosisThe opening <ref> tag is malformed or has a bad name

• Nonpigmented, wide (5- to 20-μm), thin-walled, ribbon-like hyphae with few septations (pauciseptate) and right-angle branching^[27]
• In lesions exposed to air, thick-walled spherical structures can form at the ends of the hyphae
• Fungal elements invading the blood vessel wall or inside their lumen

• Mucormycosis is generally more commonly observed in immunocompromised patients

• Patients with orbital fungal infections are more likely to be infected with mucormycosis compared with Aspergillus^[28]

• The prognosis of pulmonary mucormycosis has not improved significantly over the last ten years^[29]

• Aspergillosis is a heterogenous group of infectious diseases caused by Aspergillus(commonly A. fumigatus)
• Classified into:
  • Allergic bronchopulmonary aspergillosis (ABPA) 
  • Aspergilloma 
  • Chronic pulmonary aspergillosis  
  • Invasive aspergillosis 
  • Cutaneous aspergillosis 
• Trasmitted by:
  • Inhalation of airborne conidia (usually during dust exposure during building renovation or construction)
  • Contaminated biomedical devices, but not from one individual to another.
• Susceptible individuals:
  • Immunocompromised status (e.g. organ or stem cell transplant recipient)
  • History of prior lung disease

• +

• +

• +

(There may be painful ophthalmoplegia if there is invasion of the cavernous sinus)^[30]

• CT scan:
  • Reverse halo sign
  • Allergic bronchopulmonary aspergillosis (ABPA) are not specific, the demonstration of bronchial dilatation, wall thickening, and centrilobular nodules in an asthmatic patient should suggest the diagnosis

• Microscopic observation under ultraviolet light shows that the hyphae of aspergillus have characteristic dichotomous branching, parallel walls, and numerous septa. These septa structure is clearly different from those of the mucor
• Clusters of centrilobular nodules, peribronchial consolidations, and bronchial wall thickening, are more common in patients with invasive pulmonary aspergillosis^[31]

• Orbital cellulitis is an inflammation of the soft tissues of the eye socket behind the orbital septum, a thin tissue which divides the eyelid from the eye socket
• Infection isolated anterior to the orbital septum is considered to be preseptal cellulitis
• Orbital cellulitis most commonly refers to an acute spread of infection into the eye socket from either the adjacent sinuses, skin or from spread through the blood
• The most common pathogens in orbital cellulitis are streptococcus and staphylococcus

• +

• +

• +^[32]

(The ocular symptoms of bacterial orbital cellulitis (BOC) , such as facial edema, pain, and blepharoptosis, are similar to those of rhino-cerebral mucormycosis (ROCM) soon after infection onset, therefore it maybe difficult to distinguish the two during the initial phase of infection.

Eye lid swelling is more common in BOC than ROCM)^[33]

• CT scan:
  • Cross-sectional imaging demonstrates diffuse soft-tissue thickening anterior to the orbital septum and obliteration of the adjacent fat planes in pre-septal cellulitis

• Biopsy may show a neutrophilic infiltration of the tissues due to acute inflammation

• These tumors are more clearly classified as nasal-type extranodal T-cell/natural killer (T/NK) cell lymphoma and natural killer cell leukemia
• Epstein bar virus (EBV) has been found to be one of the major causes.
• They are characterized immunophenotypically by the expression of CD2, CD3ϵ (but not CD3 and the T-cell receptor), and CD56^[34]
• The lesion produced are destructive and involve the nasal cavity, oropharynx, upper palate, and larynx
• Immunophenotyping shows these lesions to be lymphoid in nature

• +

• +^[35]

(Primary CNS NK/Tcell lymphoma of the nasal type)

• +/-

• CT scan:
  • The CT and MR imaging appearances are nonspecific and do not allow reliable distinction of this disease from other nasal cavity tumors such as squamous cell carcinoma or from minor salivary gland tumor.

• “Angiocentric” invasion of lymphoid cells is Angiocentricity is seen in about half of all cases but is also found in other lymphoma subtypes.
• Invasion of vascular walls by lymphoid cells causes occlusion of the lumen.
• The vascular occlusion is usually associated with prominent ischemic necrosis of both tumor cells and normal tissue.

• Cutaneous anthrax is extremely rare in developed countries
• Usually patient history points towards the diagnosis of cutaneous anthrax
• Patient develops a painless ulcer with vesicles, edema, and has a history of exposure to animals or animal products^[36]; whereas patients with cutaneous mucormycosis are mainly debilitated (diabetics, hematological malignancies, organ transplant recepients) and present as a black necrotic eschar^[37]

• +

• Imaging modalities are not indicated in cutaneous anthrax

• Epithelium is edematous with loss of continuity.

• Sub-epidermal, chronic and acute infiltrates involving adipose tissue and capillaries, with areas of necrosis.

• Gram stain shows large solid and beaded gram-positive rods, particularly beneath the epithelium.

• The bacilli are not visible on the hematoxylin and eosin stain.