National Centre For Disease Control, Directorate General of Health Services, Ministry of Health & Family Welfare, Government of India has come out with National Treatment Guidelines for Antimicrobial Use in Infectious Diseases. For most of common diseases guidelines for Antimicrobial treatment have been spelled out and which are hereunder.
“Diarrhea” is an alteration in a normal bowel movement characterized by an increase in the water content, volume, or frequency of stools. A decrease in consistency (i.e., soft or liquid) and an increase in the frequency of bowel movements to ⩾3 stools per day have often been used as a definition for epidemiological investigations.
“Infectious diarrhea” is diarrhea due to an infectious etiology, often accompanied by symptoms of nausea, vomiting, or abdominal cramps.
“Acute diarrhea” is an episode of diarrhea of <14 days in duration. “Persistent diarrhea” is diarrhea of >14 days in duration.
- If diarrhoea present WITH vomiting, low-grade fever with no mucus in stools think of viral infection
- If diarrhoea present WITH vomiting, abdominal cramps, blood and mucus in stools WITH fever, think of bacterial infection.
- If diarrhoea present WITH blood and mucus in stool WITH no fever, think of amoebiasis.
- If profuse diarrhoea present (rice water stools) WITH vomiting,think of cholera.
- If diarrhoea present WITH excessive vomiting (especially if in more than one member of the household or group) think of food poisoning.
Acute non-complicated disease: Acute typhoid fever is characterized by prolonged fever, altered bowel function (constipation in adults, diarrhea in children), headache, malaise and anorexia. Bronchitic cough and exanthem (rose spots on chest , abdomen, and trunk) may be seen in the early disease. Complicated disease: Severe disease can have abdominal pain, occult blood in stools, malena, perforation peritonitis, myocarditis, pneumonitis and enteric encephalopathy.
Confirmed case of typhoid fever
A patient with fever (38°C and above) that has lasted for at least three days, with a laboratory-confirmed positive culture (blood, bone marrow, bowel fluid) of S. typhi.
Probable case of typhoid fever
A patient with fever (38°C and above) that has lasted for at least three days, with a positive serodiagnosis or antigen detection test but without S. typhi isolation.
SPONTANEOUS BACTERIAL PERITONITIS
The diagnosis of spontaneous bacterial peritonitis (SBP) is made in transudative ascitis with increased absolute polymorphonuclear leukocyte (PMN) count (i.e., ≥250 cells/mm3 [0.25 x 109/L]) and without an evident intra-abdominal, surgically treatable source of infection. An abdominal paracentesis must be performed and ascitic fluid must be analyzed before a confident diagnosis of ascitic fluid infection can be made.
Acute inflammation of pancreas, usually caused by alcohol or gallstone migrating through the common bile duct. Less commonly caused by trauma, infections like mumps, ascariasis and drugs like diuretic, azathioprine, etc. Routine use of prophylactic antibiotics in patients with severe AP is not recommended. The use of antibiotics in patients with sterile necrosis to prevent the development of infected necrosis is not recommended. Infected necrosis should be considered in patients with pancreatic or extrapancreatic necrosis who deteriorate or fail to improve after 7 – 10 days of hospitalization. In these patients, either (i) initial CT-guided fi ne-needle aspiration (FNA) for Gram stain and culture to guide use of appropriate antibiotics or (ii) empiric use of antibiotics after obtaining necessary cultures for infectious agents, without CT FNA, should be given.
In patients with infected necrosis, antibiotics known to penetrate pancreatic necrosis, such as carbapenems, quinolones, and metronidazole, may be useful in delaying or sometimes totally avoiding intervention, thus decreasing morbidity and mortality.
ACUTE BACTERIAL MENINGITIS
Acute bacterial meningitis (ABM) is a potentially life-threatening neurological emergency.
Patients generally presents with short history of high-grade fever with prominent headache, neck stiffness, photophobia, nausea, vomiting and altered mental status (lethargy to coma). Infants, elderly, and immunocompromised patients may show only mild behavioural changes with low-grade fever and little clinical evidence of meningeal inflammation. Patients with ABM should be rapidly hospitalized and assessed for consideration of lumbar puncture (LP) if clinically safe. Ideally, patients should have fast-track brain imaging before LP, but initiation of antibiotic therapy should not be delayed beyond 3 h after first contact of patient with health service.
CSF examination reveals elevated pressure (200-500 mm H2O) and protein (100- 500 mg/dl, normal 15-45 mg/dl), decreased glucose (<40% of serum glucose) and marked pleocytosis (100-10,000 white blood cells/μl, (normal <5) with 60% or greater polymorphonuclear leucocytes.
Pyogenic meningitis should be differentiated from tubercular meningitis, which has relatively longer history of low to high grade of fever, constitutional symptoms, and CSF shows lymphocytic predominance, normal to mildly reduced sugar and raised proteins.
Brain abscess is defined as a focal suppurative infection within the brain parenchyma, typically surrounded by a wellvascularized capsule. The most important investigation to diagnose brain abscesses is cranial imaging, either cranial tomography (CT) or magnetic resonance imaging (MRI).
Headache is the most common presenting symptom of brain abscess. Fever is generally present but its absence does not rule out the diagnosis. Mostly patients have a focal neurologic deficit such as hemiparesis, apahasia, visual field defects depending on the location of abscess.
Bacterial endocarditis is a life-threatening infectious disease. Clinical manifestations of bacterial endocarditis include fever, toxaemia, clubbing, splenomegaly, anaemia, microscopic haematuria, a new onset or changing murmur, evidence of immune phenomena such as roth spots, osler nodes.
The diagnosis of bacterial endocarditis is based on Modified Duke s criteria which involves clinical, laboratory and echocardiographic findings.
- Microorganisms demonstrated by culture or on histological examination of a vegetation, vegetation that has embolized, or an intracardiac abscess specimen; or
- Pathological lesions; vegetation or intracardiac abscess confirmed by histological examination showing active endocarditis
- 2 major criteria; or
- 1 major criterion and 3 minor criteria; or
- 5 minor criteria
- 1 major criterion and 1 minor criterion; or
- 3 minor criteria
- Firm alternate diagnosis; or
- Resolution of symptoms suggesting IE with antibiotic therapy for ≤4 days; or
- No pathological evidence of IE at surgery or autopsy, with antibiotic therapy for ≤4 days; or
- Does not meet criteria for possible IE, as above
Modified Duke s criteria for the diagnosis of endocarditis
1. Blood cultures positive
a. Typical microorganisms consistent with IE from 2 separate blood cultures
- Viridans streptococci, Streptococcus gallolyticus (Streptococcus bovis), HACEK group, Staphylococcus aureus; or
- Community-acquired enterococci, in the absence of a primary focus; or
b. Microorganisms consistent with IE from persistently positive blood culture
- ≥2 positive blood cultures of blood samples drawn >12 h apart; or
- All of 3 or a majority of ≥4 separate cultures of blood (with first and last samples drawn ≥1 h apart); or
c. Single positive blood culture for Coxiella burnetii or phase I IgG antibody titre >1:800
2. Imaging positive for IE
a. Echocardiogram positive for IE
- Abscess pseudoaneurysm, intracardiac fistula
- Valvular perforation or aneurysm;
- New partial dehiscence of prosthetic valve
b. Abnormal activity around the site of prosthetic valve implantation detected by “F-FDG PET/CT (only if the prosthesis was implanted for >3 months) or radiolabelled leucocytes SPECT/CT
c. Definite paravalvular lesions by cardiac CT
- Predisposition such as predisposing heart condition, or injection drug use
- Fever defined as temperature >38°C
- Vascular phenomena (including those detected by imaging only): major arterial emboli, septic pulmonary infarcts, infectious (mycotic) aneurysm, intracranial haemorrhage, conjunctival haemorrhages, and Janeway’s lesions
- Immunological phenomena: glomerulonephritis. Osler’s nodes, Roth’s spots, and rheumatoid factor
- Microbiological evidence: positive blood culture but does not meet a major criterion as noted above or serological evidence of active infection with organism consistent with IE.
Cellulitis is an acute spreading infection that involves subcutaneous tissue, most commonly caused by group a streptococcus and staph aureus. Trauma and underlying skin lesion can lead to the development of cellulitis. Cellulitis may also develop due to the spread of adjacent infections like osteomyelitis.
Clinical findings: Clinically rapidly intensifying pain and redness is a common presentation. Fever and lymphadenopathy may be present. The borders in cellulitis are not well demarcated. Though group A streptococci and staphylococcus are the most common organisms rarely organisms like H influenza, pneumococcus may also cause cellulitis.
Furunculosis is a deep infection of the hair follicle leading to abscess formation with accumulation of pus and necrotic tissue. Furuncles appear as red, swollen, and tender nodules on hair-bearing parts of the body, and the most common infectious agent is Staphylococcus aureus, but other bacteria may also be causative. Furunculosis often tends to be recurrent and may spread among family members.
A carbuncle is a coalescence of several inflamed follicles into a single inflammatory mass with purulent drainage from multiple follicles.
URINARY TRACT INFECTIONS
The term UTI encompasses a variety of clinical entities viz asymptomatic bacteriuria (ASB), cystitis, prostatitis and pyelonephritis.
Uncomplicated UTI refers to acute cystitis or pyelonephritis in non pregnant outpatient women without anatomic abnormalities or instrumentation of urinary tract. Complicated UTI includes all other types of UTI. Cystitis: The typical symptoms of cystitis are dysuria, urinary frequency, and urgency. Other symptoms are nocturia, hematuria, suprapubic discomfort, and hesitancy.
Pyelonephritis : severe pyelonephritis present as high fever, rigors, nausea, vomiting, flank or loin pain.symptoms are acute in onset and symptoms of cystitis may not be present. Fever is the main distinguishing feature between cystitis and pyelonephritis.
Prostatitis: Acute bacterial prostatitis presents as dysuria, frequency and pain in pelvis or perineal area. Fever and chills are usually present and symptoms of bladder outlet obstruction are common.
Pneumonia is an inflammation in alveolar tissue, most often caused by a microbial agent. The community acquired pneumonia is most commonly caused by Streptococcus pneumoniae (typical) and less frequently by Mycoplasma pneumoniae, H. influenzae, Chlamydia pneumoniae, Staphylococcus aureus or Legionella pneumoniae (atypical). Haemophilus influenzae infection is seen mostly in patients with chronic bronchitis. Nosocomial pneumonia is likely to be caused by Gram-negative bacilli or Staphylococcus aureus.
Sudden onset of fever, productive cough, chest pain, shortness of breath and (in some cases) pleuritic chest pain; systemic symptoms like headache, bodyache and delirium are more severe with atypical pneumonia.
For assessment of the severity of pneumonia “CURB- 65” severity score can be usedConfusion,Urea >7 mmol/l,Respiratory rate ≥30/min,low Blood pressure (diastolic blood pressure (DBP) ≤ 60 mm Hg or systolic BP ≤ 90 mm Hg) and
Age ≥65 years
Patients with scores 0 and 1 are at low risk of mortality (1.5%) might be suitable for management as hospital outpatients.
Patients with a score of 2 are at intermediate risk of mortality (9%) and should be considered for hospital supervised treatment.
Patients with a score of >2 are at high risk of mortality (>19%) and requires ICU care.