Epidemiology
Worldwide, superficial fungal infections caused by dermatophytes are estimated to infect around 20-25% of the population and it is thought that dermatophytes infect 10-15% of the population during their lifetime. The highest incidence of superficial mycoses result from dermatophytoses which are most prevalent in tropical regions. Onychomycosis, a common infection caused by dermatophytes, is found with varying prevalence rates in many countries. Tinea pedis + onychomycosis, Tinea corporis, Tinea capitis are the most common dermatophytosis found in humans across the world. Tinea capitis has a greater prevalence in children. The increasing prevalence of dermatophytes resulting in Tinea capitis has been causing epidemics throughout Europe and America. In pets, cats are the most affected by dermatophytosis. Pets are susceptible to dermatophytoses caused by Microsporum canis, Microsporum gypseum, and Trichophyton. For dermatophytosis in animals, risk factors depend on age, species, breed, underlying conditions, stress, grooming, and injuries.Numerous studies have found Tinea capitis to be the most prevalent dermatophyte to infect children across the continent of Africa. Dermatophytosis has been found to be most prevalent in children ages 4 to 11, infecting more males than females. Low socioeconomic status was found to be a risk factor for Tinea capitis. Throughout Africa, dermatophytoses are common in hot- humid climates and with areas of overpopulation.Chronicity is a common outcome for dermatophytosis in India. The prevalence of dermatophytosis in India is between 36.6 and 78.4% depending on the area, clinical subtype, and dermatophyte isolate.
Amsel criteria
In clinical practice BV can be diagnosed using the Amsel criteria:
Thin, white, yellow, homogeneous discharge
Clue cells on microscopy
pH of vaginal fluid >4.5
Release of a fishy odor on adding alkali—10% potassium hydroxide (KOH) solution.At least three of the four criteria should be present for a confirmed diagnosis. A modification of the Amsel criteria accepts the presence of two instead of three factors and is considered equally diagnostic. Gram stain
An alternative is to use a Gram-stained vaginal smear, with the Hay/Ison criteria or the Nugent criteria. The Hay/Ison criteria are defined as follows:
Grade 1 (Normal): Lactobacillus morphotypes predominate. Grade 2 (Intermediate): Some lactobacilli present, but Gardnerella or Mobiluncus morphotypes also present. Grade 3 (Bacterial Vaginosis): Predominantly Gardnerella and/or Mobiluncus morphotypes. Few or absent lactobacilli. (Hay et al., 1994)Gardnerella vaginalis is the main culprit in BV. Gardnerella vaginalis is a short, Gram-variable rod (coccobacillus). Hence, the presence of clue cells and gram variable coccobacilli are indicative or diagnostic of bacterial vaginosis. Nugent score
The Nugent score is now rarely used by physicians due to the time it takes to read the slides and requires the use of a trained microscopist. A score of 0-10 is generated from combining three other scores. The scores are as follows:
0–3 is considered negative for BV
4–6 is considered intermediate
7+ is considered indicative of BV.At least 10–20 high power (1000× oil immersion) fields are counted and an average determined. DNA hybridization testing with Affirm VPIII was compared to the Gram stain using the Nugent criteria.