AN ASSESSMENT OF DERMATOPHYTES MOLECULAR CHARACTERIZATION AND EPIDEMIOLOGICAL STUDIES

1.1 Introduction

Dermatophytes are keratinophilic fungi capable of causing dermatophytosis and are among the most adaptable parasitic associates of humans (Li et al., 2008). Dermatophytes are responsible for most superficial fungal infections and the estimated lifetime risk of acquiring a dermatophyte infection is between 10–20% (Jaya et al., 2009). Numerous studies have used morphological based criteria which could not reflect the entire spectrum of dermatophytes species (Ghojoghi et al., 2015). All in all, epidemiology of dermatophytosis in Iran has shown significant changes in various regions of the country over the last decades which is not clarified, is this variation caused by inefficiency of conventional methods or is reflecting the local fungal infection distribution’s pattern (Ghojoghi et al., 2015).

As a prelude to other parts of this study, this chapter will discuss the background upon which this study was initiated, the statement of problems that led to this study, the Aim and Objectives of the study. Others are Significance of the study, Scope of work, Research questions and hypothesis, Limitations of the Study and Definition of technical terms.

1.2 Background of Study

Since the accurate identification of etiologic agents from suspected lesions is important for appropriate treatment and control of potential environmental sources of infection (Ghojoghi et al., 2015), application of conventional methods simultaneously with molecular methods and comparing them considering all involved factors, can lead us to useful and practical information about best identification formula. Dermatophytosis lesion takes a ring shape with inflammatory edges and clear center of normal skin. The lesions are often roughly circular with raised border, but may coalesce to form confluent areas of dry, scaling skin, inducing itching and scratching which in severe cases may ulcerate (Abdul and Al-Janabi, 2014).

The use of molecular methods for genotyping of dermatophyte species have proven to be more specific, precise, rapid and less likely to be affected by external influences such as temperature variations and chemotherapy. It is therefore very useful in identifying strain of fungi which under normal circumstances may not possible with conventional methods. Recent developments and applications of nucleic acid amplification technology have provided the opportunity to enhance the quality and speed of dermatophyte diagnosis (Liu et al., 2002).

Infections are more common in children than adults. The real prevalence of dermatophytosis is not known because patients do not seek medical advice unless their quality of life is affected as these are not life threatening diseases (Joseph et. al., 2000). This distribution pattern of dermatophytes infection in different part of the world has been attributed to climatic factors, lifestyle, and prevalence of immunodeficiency diseases in the community and also the reluctance of patients to seek treatment because of embarrassment or minor nature of disease unless the condition becomes sufficiently serious to affect the quality of life (Al-sheikh 2009).

Fungal elements are always found in active state in the edge of lesion and that is why it is preferable to take scraping sample for microscopical diagnosis from the lesion edges and not from the clear zone (Hainer, 2003). The ring shape of dermatophytosis can also be used to differentiate it from other skin diseases, such as psoriasis or lichen planus in which the inflammatory responses tend to be uniform over the lesion (Hainer, 2003).

The etiologic agents of the dermatophytoses are classified in three anamorphic genera, Trichophyton, Microsporum and Epidermophyton. World Health Organization (WHO) survey on the incidence of dermatophytic infections shows that about 20% the people worldwide come down with cutaneous infections (Marques et al., 2000). Based on their ecological characteristics, dermatophytes are divided into geophilic, zoophilic (from animal sources) and anthrophilic species (Chander, 2009).

Dermaphytoses are transmitted from person to person directly by means of contact or indirectly via formites contaminated with infected skin, scales or hairs. Infection occurs by contact with arthrospores. It can also be acquired by humans from infected animals and by direct exposure to infected soils (Greenwood et al., 2005). Transfer of infecting organisms from soil, animals or humans is accomplished by means of arthrospores which are vegetative cells with thickened cell walls formed by dermatophytes hyphae in vitro or in vivo (Mandell et al., 2000).

Therefore, in Nigeria where the research was carried out, the activities that was conducted is to know the Dermatophytes Molecular Characterization and Epidemiological Studies.

1.3 Statement of Problems

Investigation revealed that dermatophyte infections are often untreated or unreported. The inadequate health attention accorded this infection allows it to continue in the population unnoticed and spread to others. They are often overlooked as they do not produce severe debilitating illness and their treatment is not pursued vigorously.

In tropical and subtropical countries, it occurs in increased frequencies (Havlickova et. al., 2008) due to warm and humid climate, poor nutrition, poor hygiene; overcrowding and poor sanitary conditions all promote the spread of these infections (Nweze, 2001). During the last decades, mycotic infections have increased to more than 20% - 25% of the world‘s population (Havlickova, et al., 2008; Sharma et al., 2015).

Dermatophytoses is one of the most common cutaneous infections worldwide (Havlickova et al., 2008), posing a great public health problem to humans and animals (Ameen, 2010; Ghojoghi et al., 2015). The prevalence of dermatophytosis varies from place to place throughout the globe and reported to vary in different parts of same continent (Havlickova et al., 2008).

1.4 Aim and Objectives of Study

The aim of the study is to assess the Dermatophytes Molecular Characterization and Epidemiological Studies. In achieving this aim, the following specific objectives were laid out as follows:

1. To examine the molecular characteristic of dermatophytes from infected students;
2. To determine the prevalence of dermatophytes among students in relation to age; and
3. To investigate the associated risk factors for dermatophytosis among students in the area under study.

1.5 Research Questions

The study came up with research questions so as to be able to ascertain the above stated objectives. The specific research questions for the study are stated below as follows:

• What is the molecular characteristic of dermatophytes from infected students?
• What is the prevalence of dermatophytes among students in relation to age?
• What are the associated risk factors for dermatophytosis among students in the area under study?

1.6 Research Hypothesis

In order to pursue the objective of this study, the following generalized statements have been designed to guide and aids in obtaining the result for the experiment to be conducted. For this work, the null hypothesis will be represented with H0 while the alternative hypothesis will be represented with hypothesis H1.

Hypothesis One

• H0: There is no difference in the prevalence of dermatophytes among the various age groups of students
• H1: There is a difference in the prevalence of dermatophytes among the various age groups of students

Hypothesis Two

• H0: There are no associated risk factors for dermatophytosis among students in the area under study
• H1: There are associated risk factors for dermatophytosis among students in the area under study

Hypothesis Three

• H0: There is no difference in the isolated dermatophytes from infected students using molecular tools
• H1: There is a difference in the isolated dermatophytes from infected students using molecular tools

1.7 Significance of Study

This study will investigate the epidemiology of dermatophytic infection among students relative to nature of school facilities, interaction with domestic animals and their play pattern with the aim of assessing a correlation and also carry out molecular studies on dermatophytes in the country and possible strains that circulate within the system.

The study will establish the prevalence and predominant dermatophyte species that are associated with the system with a view to making recommendation on its control. It also intends to identify the risk factors associated with the disease spread within the study population. Since plans are on the way by the Government to get the system integrated with the formal educational system, the study on the risk factors will provide information on areas that need to be addressed to prevent its spread.

This study will be of immense benefit to other researchers who intend to know more on this study and can also be used by non-researchers to build more on their research work. This study contributes to knowledge and could serve as a guide for other study.

1.8 Scope of Study

The scope of the research is focused on the Assessment of Dermatophytes Molecular Characterization and Epidemiological Studies using Warri-South Local Government Area, Delta State as a case study.

1.9 Limitations of the Study

During the course of this study, many things militated against its completion, some of which are:

1. Time Constraint: The time frame given to accomplish this project was very short due to school academic calendar and it was carried out under pressure which made the researcher not to implement some necessary features.
2. Research material: availability of research material is a major setback to the scope of the study.
3. Frequent power failure: This made the researcher append more money on fuel to ensure sustainable power.
4. Financial Constraint: Insufficient fund tends to impede the efficiency of the researcher in sourcing for the relevant materials, literature or information and in the process of data collection (internet, questionnaire and interview).