CHAPTER ONE
Introduction
1.1 Background of the Study
Yellow fever outbreaks are common in many regions of tropical Africa, especially in western Africa, and are responsible for thousands of cases annually. At least one yellow fever outbreak is reported to the World Health Organization (WHO) every year, and in the past 15 years, the incidence of yellow fever has steadily increased S.E. Robertson, B.P. Hull, O. Tomori, O. Bele, J.W. LeDuc, K. Es-teves[1996]. This is alarming, considering that a safe and efficacious yellow fever vaccine, 17D, has been avail-able for over 60 years. In addition, the maintenance cycle of yellow fever virus in the jungle and the epidemic transmission cycle in urban areas are fairly well understood, and urban yellow fever trans-mission is relatively easy to interrupt by mosquito control measures. Despite advances in preventive measures, yellow fever is still a major public health problem in many regions of tropi-cal Africa and South America. In the past 2 years alone, yellow fever outbreaks have been reported in five African countries (Nigeria, Ivory Coast, Liberia, Senegal and Guinea), and a total of 840 cases, including 216 deaths, were reported to the WHO. The recent epidemics in Africa indicate a break-down of yellow fever control measures, since most cases are in children under the age of 15, who were born after routine yellow fever vaccinations were abandoned J. Vainio, F. Cutts, [1998].
Yellow fever is a viral hemorrhagic fever. It is transmitted to humans and other vertebrate hosts by the bite of infected mosquitoes. The etiological agent is yellow fever virus. In humans, infections with the yellow fever virus cause a broad spectrum of disease, from mild symptoms to severe illness to a fatal disease. Clinical symptoms of yellow fever typically appear 3–6 d after the mosquito bite, but only about 15% of those infected develop clinical yellow fever, and the majority only have a mild disease and quickly recover. The clinical symptoms of yellow fever have been described in detail by Monath [1989]. Briefly, there are two main phases of the disease. Clinical symptoms in the first phase (also known as the period of infection) include sudden onset of fever, headache, muscle pain, backache, general weakness, failure of pulse to rise with temperature (Faget’s sign), red eyes (injected conjunctiva), nausea and vomiting. During this phase, patients have viraemia, and they are infectious to mosquitoes. Subsequently, there is a short period, the period of remission, when clinical symptoms disappear for up to 24 h, and following the remission period, the second phase (also known as the toxic phase) begins. Symptoms in the toxic phase include high fever, vomiting, epigastric pains, jaundice, hemorrhagic diathesis (hematemesis), coma and death. yellow fever virus is usually absent from the blood of patients during the toxic phase, and anti-yellow fever virus antibodies appear during this stage. The case mortality rate for patients who reach the toxic phase is 20–50%, and may be higher O. Tomori, [1994]. Death usually occurs within 10 d of the onset of symptoms; survivors are immune for life.
Although, there has been progress in the understanding of the causes and management of fever, it remains one of the most important symptoms of diseases globally. This is probably because parasitic and microbial infections present fever as symptom. The intensity of fever varies regionally, even in the same country.
Neonates and young infants may manifest fever than at any other time in childhood. The incidence of serious bacterial infection is higher in infants who are less than three months of age, particularly those under 28days. Similarly, these young patients do experience significant morbidity from viral infections (Byington, 2004).
In Nigeria, more than 80, 000 children die annually as a result of fever (Babaniyi, 1991). The prevalence of notable fever in infants younger than three months is approximately 6-10% (Pantell, 2004). Fever can be triggered by various infections such as bacterial, viral, and parasitic infections, as well as appendicitis, among others. Fever from bacterial meningitis is more common in the first month of life than at any other time (Brook, 2003). In spite of the enormous burden imposed on the primary health care delivery system by febrile infants fever in the country, there is still much to be unraveled about this clinical manifestation. There is need to have comprehensive longitudinal data on the epidemiological dynamics of fever among the children to ascertain the more significant medical conditions that are precursory to fever. This is essential as the dynamics of fever varies regionally, hence the findings from this study would assist us to have better understanding and achieve better management of fever in the country. This study is therefore aimed at filling these gaps and would attempt to achieve this by elucidating the yearly total hospital admittances due to fever among children under 13 years and the associated underlying medical conditions between the years 2000 and 2011.
1.2 State Of The Problem
Over the last decade, there has been alarming increase in the rate of recorded cases of yellow fever in our various hospitals especially in Illorin west Local government. This has led to a very serious questions on the minds of the citizenry in particular and the professionals in our medical field in general. Ordinary, since yellow fever is generally associated with a lot of symptoms such as fever headache, cough etc. these however make it a complicated disease with a very serious economic and social effect on the victims. This study seeks to find the prevalent rate of yellow fever and suggest possible solutions in preventing it.
1.3 Objectives of the Study
The following are the aims and objectives of this study.
To examine the trend of the yellow fever disease among children under the age of 5 illorin West Local government area
To examine the causes of yellow fever disease among children under the age of 5 illorin West Local government area
To examine the diseases condition of yellow fever disease among children under the age of 5 illorin West Local government area
1.4 Research Questions
What is the trend of the yellow fever disease among children under the age of 5 illorin West Local government area
What are causes of yellow fever disease among children under the age of 5 illorin West Local government area
What is the diseases condition of yellow fever disease among children under the age of 5 illorin West Local government area
1.5 Hypotheses
There is no significant effect of the trend of yellow fever disease among children under the age of 5 illorin West Local government area
There is no significant effect of causes of yellow fever disease among children under the age of 5 illorin West Local government area
There is no significant effect of the diseases condition of yellow fever disease among children under the age of 5 illorin West Local government area
1.6 Significance of The Study
This project is significant in the sense that health problem imposed by yellow fever in this part of the world makes it a serious health issue that requires adequate attention and care. This research work will be of great significance in the following ways:
- This study will help the hospital management, the state government and the general public to know the particular months or quarter of the year that were mostly affected by typhoid fever in order to carryout enlightenment campaign towards reducing the incidence of the disease.
- If the trend of reported cases of yellow fever is found to be on increase, it will enable the hospital management to put intensify effort towards applying more preventive measures in order to combat the disease.
1.7 scope of study
The study was delimited to causes of yellow fever among children under the age of 5 in Illorin West local government area.
1.8 Limitation of the study
The major limitation to this research work was basically on the collection of data and information is regarded as confidential, besides there was inadequate asses to the data due to reluctant attitude of the hospital medical record department to release the data on time as well as the limited available literature which the researcher was able to lay her hands on after much time wasted.
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