STATISTICAL ANALYSIS OF THE REPORTED CASES OF ONCHOCERCIASIS (RIVER BLINDNESS) DISEASE FROM 2000-2011

1.1 Introduction

Onchocerciasis is a chronic parasitic infection caused by the filarial nematode, onchocerca volvulus. This disease is transmitted from one individual to another through the bites of black fly simulium damnosum of the family simulidae (Nwoke et al, 1991) normally found near streams and rivers (giving disease its common name River Blindness). Sometimes, the bite transmits parasitic worms into the body. As they spread, they cause terrible itching, muscle pains and weakness. Eventually when the worms reach the adult stage, they attack the eyes leading to permanent blindness. The entire process may take up to 30 years from the first bite.

This chapter will address the background information that motivated this study, the challenges that prompted it, its aim, and its objectives as a preface to subsequent sections of the study. Additional factors include the study's significance, scope, limitations, research questions and hypotheses, and the definition of technical terms.

1.2 Background of Study

As onchocerciasis spreads around the world, particularly in sub-Saharan Africa, it is becoming better acknowledged as one of the main illnesses with significant public health implications. One of the largest nations in West Africa, Nigeria, has been found to have a high incidence of onchocerciasis infection, with 7 million people suffering from the illness and 40 million at risk. West Africa is home to the majority of endemic areas worldwide. Leading infectious cause of blindness worldwide is onchocerciasis. Many people go blind due to a strong inflammatory reaction that is brought on by Wolbachia pipientis, the nematode's endosymbiont.

An estimated 18 million people suffer from Onchocerciasis, worldwide. One can ask, how common is Onchocercasis (River Blindness)? Currently 35 countries around the world are affected by Onchocerciasis. It is an ancient disease of Africa and accordingly, 28 of the affected countries and over 90% of all infected people are in Africa. With the rest occurring in 6 countries in Latin America at in Yemen and the Arabian Peninsula. In some communities in Africa, 50% of the men over age 40 have been blinded by Onchocerciasis. It is found in rural often poor populations living near fast flowing rivers, rapid and other turbulent waters where the black fly vector breeds. While the women draw water from village wells the men often fish and farm near the fast flowing rivers.

Onchocerciasis has become endemic in central and South America as well, affecting 70,000 people in Guatemala and Mexico alone. Other small isolated endemic foci occur in Venezuela, Colombia, and Brazil, Ecuador. The prevalence of infection is nearly zero at birth, since Onchocercasis can but seldom does; undergo intrauterine transmission and increases with age to a high plateau later in life reaching 100% in hyperedemic areas. Similarly, intensity of infection increases with age to a plateau between age 30 and 50 years.

• Geographical differences in the disease manifestation may result from variations in;
• Different forms of species of the vector with different life cycle and habits.
• Different parasite strains with varying pathology and antigenic make up.
• The degree of the host(s) susceptibility

Therefore, in Nigeria where the research was carried out, the activities that was conducted is to statistically analyze the Reported Cases of Onchocerciasis (River Blindness) Disease from 2000-2011.

1.3 Statement of Problems

The last two decades have seen a re-emergence of river blindness in Nigeria due to increasing poverty and insufficient social amenities in the rural areas. Nigeria is made up of 36 states plus F.C.T, 18 out of this number representing 49 percent of the states are river blindness prone states. They include Abia, Anambra, Benue, Cross-River, Ebonyi, Enugu, Ekiti, Edo, F.C.T, Imo, Kano, Kwara, Niger, Ogun, Osun, Oyo, Taraba and Zamfara. Out of these affected states, Ebonyi State has the highest case in the South-East zone.

The presence of Onchcercal skin lesions is unsightly and has a psychosocial effect on the affected. Onchocerciasis is among the five neglected disease in Nigeria (i.e. Guinea worm, River Blindness, Elephantiasis, Bilharzias and leprosy).

from 1969-1970 several African countries including Nigeria applied for aid from, World Bank, UNDP, WHO and USAID in launching control programs. July 1970 a meeting in Geneva set up an international study mission to collect and access epidemiological economic and other data in preparation for a multinational control program on river-blindness. They found out that about 90% of onchocerciasis cases occur in Africa. Onchocercasis is endemic in 28 African countries including Nigeria.

Of recent Ebonyi state government enacted a program that in every year there must be a workshop in the state in general in which citizens shall be educated particular on the issue of Onchocerciasis as one of its strategies for mass mobilization cause. But then the disease seems to be stubborn and obstinate. The Federal Government in conjunction with the state government and the NGO's established the primary health care program the disease proved the program null and void. The number of Onchocerciasis cases in Ebonyi state keeps on increasing by the day.

The improvement in the health status of the citizens is a significant co-factor in the poverty reduction efforts. Nevertheless, with all these failure, anxieties of the incessant increase of Onchocerciasis cases in our society today were the bases of this study. This study is also designed to find out the causes, control activities and solutions to eradicate onchocerciasis within the shorted period.

1.4 Aim and Objectives of Study

The aim of the study is to carry out a statistical analysis on the reported case of River Blindness (Onchocerciasis from 2000-2011 using). In achieving this aim, the following specific objectives were laid out as follows to:

1. Determine the distribution of Onchocerciasis patients by sex and age from 2000-2011.
2. Determine if there is any difference between the male and female reported cases.
3. Know if the number of River blindness cases is the same among the age groups.
4. Predict the possible number of Onchocerciasis patients in the year 2012-2014.
5. Find out how people can get Onchocerciasis, risk factors, symptoms and control activities.
6. Make appropriate recommendation based on the findings made.

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:

• Research Question 1:

  What is the distribution of Onchocerciasis patients by sex and age from 2000-2011?

• Research Question 2:

  What is the possible number of Onchocerciasis patients from 2012-2014?

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: The rate of occurrence of river blindness is the same among the age groups
• H1: The rate of occurrence is not the same among the age groups

1.7 Significance of Study

There is urgency for this type of research to be carried out for the following reasons;

There is a big hope that the information which this study will enumerate will then help the government and NGO's to know the predictable cases in the nearer future.

It will help to address one of the great challenges of Ebonyi state Ministry of health which is accurate data on Onchocerciasis. As a statisticians, to help the government far analysis of the present nature and statues of Onchocerciasis in Ebonyi state.

This research will come out with findings on the intervention strategies at present and provide invaluable perspective to the present generation which would serve as a guide to planners and managers in the health sector.

This project will suggest ways to conquer River Blindness projection despite all its construction efforts to get rid of us (Man) before the next generation.

1.8 Scope of Study

The study will limit it analysis with Ebonyi state based on the targeted objectives of the River Blindness disease. The data collected for this study may or may not indicates the total number of Onchocerciasis patients but the number of its occurrences within a given locality on a specified period as they have been recorded in the hospitals record.

Coming to the materials like chemicals, apparatus, specimen plus other laboratory agents and catalyst, that are involved in the River blindness test or diagnosis is somehow beyond the scope of this research work. Although it is necessary, but is was limited due to the statistical approach. For more information, the bibliography in chapter five of this work highlights you more in the stated field.

1.9 Limitations of the Study

The problems associated with the data collection are as follows:

1. The data was not originally collected and kept for the purpose of this study. This made the researcher to spend a lot of time arranging the data in order to suit his work.
2. The data was only released on request, after the researcher must have gone through series of interrogations. it was difficult to collect this data due to what the officials termed confidentiality.
3. The transportation fare associated with the collection of the data cannot be overemphasized, plus the unbearable altitude of the primary users.
4. The reliability of the data is yet another problem associated with the data. However, most onchocerciasis patients at times do not report or complain to the public so that any person who hears it can forward its solution or control techniques. Thus their cases might not be recorded.
5. Furthermore, those who made known their cases to the public sometimes may not get an answer, rather they take their cases to the native doctors, who may not brig an answer to their problems or keep record of such cases.
6. With all these therefore this research is based on reported cases of river blindness in Ebonyi State.

1.10 Definition of Terms

Blindness:

It is the condition of lacking visual perception due to physiological or neurological factors.

Epidemiology:

It is the scientific study of the spread and control of diseases.