THE CAUSES AND EFFECT OF CHOLERA DURING RAINY SEASON IN BENIN CITY

CHAPTER ONE

INTRODUCTION

1.1 BACKGROUND TO THE STUDY

Cholera is an infection of the small intestine that is caused by the bacterium Vibrio cholerae 01 and 0139( Riyan 2004 & WHO 2010). The main symptoms are profuse watery diarrhea and vomiting. Transmission is primarily through consuming contaminated drinking water or food. The severity of the diarrhea and vomiting can lead to rapid dehydration and electrolyte imbalance. Every year there is an estimated 3-5 million cholera cases and 100,000-120,000 deaths due cholera. The short incubation period of two to five days, enhance the potentially explosive pattern of out breaks (Faruque 2008 and WHO 2010). Cholera transmission is closely linked to inadequate environmental management. Typical at-risk areas include peri-urban slums, where basic infrastructure is not available, as well as camps for internally displaced people or refugees, where minimum requirements of clean water and sanitation are not met.  The consequences of a disaster – such as disruption of water and sanitation systems, or the displacement of populations to inadequate and overcrowded camps – can increase the risk of cholera transmission should the bacteria be present or introduced. Epidemics have never arisen from dead bodies. Cholera remains a global threat to public health and a key indicator of lack of social development. Recently, the reemergence of cholera has been noted in parallel with the ever-increasing size of vulnerable populations living in unsanitary conditions (Emch 2008 and WHO, 2010).

Two serogroups of v. cholera - 01 and 0139 - causes out breaks (Alexander 2008).  v. cholera 01 causes the majority of outbreak, while 0139  -first indentified in Bangladash in 1992 –is confined to South-East Asia. Non-01 and non-0139 v. cholera can cause mild diarrhea but dot not generate epidemics. The bacteria are transmitted via contaminated drinking water or food.  Pathogenic v. cholera can survive refrigeration and freezing in food supplies. (Reildl et al 2002) The dosage of bacteria required to cause an infection in healthily volunteers via oral administration of living vibrios is greater than  1000 organisms (Hartely 2006 ).  After consuming an antacid, however, cholera development in most volunteers after consumption of only  100 cholera  vibrios experiments also show that  vibrios

consumed with food are more likely to cause infection than those from water alone (Finkelstein 1996). Cases tend to be clustered by location as well as season, with most infections occurring in children ages 1-5 years (WHO 2010).

Cholera is severe water-born infectious disease caused by the bacterium  vibrio cholerae.   In 2005, 131,943 cases including 2,272 deaths have notified from 52 countries. The year was marked by a particular significant series of outbreaks in West Africa, which affected 14 countries and accounted for 58% of all cholera cases world-wide (WHO 2006). In the same year Nigeria had 4,477 cases and 174 deaths. There was reported case of cholera in 2008 in Nigeria in which 429 death out of 6,330 cases. More so, 2,304 cases in Niger State in which 114 were reported death in 2008 (NBS 2009). Recent years have seen a strong trend of cholera outbreak in developing countries, including among others, those in India (2007), Iraq (2008), Congo (2008), Zimbabwe (2008-2009), Haiti (2010), Kenya (2010). Koko in Edo State (1989). In Nigeria, according to UN figure, 1,555 people have died since January and 38,173 cases have been reported. The figure is more than four times the death toll the government reported in August (Guardian. 2010)

Cholera is a disease characterized by profuse diarrhea accompanied with a severe dehydration and loss of electrolyte (Colwell and Huq, 1994), caused by toxigenic Vibrio cholerae, a serologically diverse, environmental, and gram-negative rod bacterium (Li et al., 2002). In the absence of appropriate treatment, there is a high mortality rate. Cholera is a major public health concern because of its high transmissibility, death-to-case ratio and ability to occur in epidemic and pandemic forms (Kaper et al., 1995). Cholera is responsible for an estimated death of 120,000 globally every year (WHO, 2001), and still continues to be a scourge worldwide covering all continents. In developing countries with endemic areas, cholera is still very significant with incidence of more than five million cases per year (Tauxe et al., 1994; Lan and Reeves, 2002). The explosive epidemic nature and the severity of the disease and the potential threat to food and water supplies have prompted the listing of V. cholerae as an organism of biological defense research (Zhang et al., 2003). In an epidemic, the great majority of cases can be recognized by clinical diagnosis easily and a bacteriological diagnosis is often not required.

Cholera is endemic in Nigeria (Falade and Lawoyin, 1999) and epidemiological features (Utsalo et al., 1991, 1992; Eko et al., 1994; Hutin et al., 2003) have been reported from various parts of the country with investigations on possible sources of outbreaks. Outbreaks of cholera had been reported from various State in Nigeria such as Ogun, Edo, Pleatue State etc, of Nigeria. Investigations on outbreak of cholera in Nigeria have focused on the epidemiological features, the probable source of contamination and the risk factors without spatial linkage of health data. However, advances in Geographical Information Systems (GIS) technology provides this opportunity and have become an indispensible tool for processing, analyzing and visualizing spatial data within the domains of environmental health, disease ecology and public health (Kistemann et al., 2002).

The use of GIS is not new in waterborne disease outbreaks and cholera studies. It has been applied in investigating waterborne disease outbreak (NWW, 1999), microbial risk assessment of drinking water reservoirs (Kistemann et al., 2001a), drinking water supply structure (Kistemann et al., 2001b), and spatial patterns of diarrhoea illness with regards to water supply structures (Dangendorf et al., 2002). In cholera studies, GIS technology has been applied in studying the correlation between socio-economic and demographic indices and cholera incidence (Ackers et al., 1998), environmental risk factors (Ali et al., 2002a), spatial epidemiology (Ali et al., 2002b), health risk prediction (Fleming et al., 2007) and spatial and demographic patterns of cholera (Osei and Duker, 2008). This study seeks to assess the causes and effect of cholera outbreak in Benin City, Edo State.

1.2 STATEMENT OF PROBLEM

The threat of cholera rampaging through Nigeria has long been of concern to many. The crowded settings coupled with minimal water, sanitation, hygiene and health services, present a fearsome breeding ground for cholera to quickly escalate beyond control. In an attempt to avoid this worse-case scenario, a massive response needs to be mounted by the Government to enlighten the general public about the causes of this deadly disease and also ways to avoid the outbreak. Hygiene promoters should be employed to work every day, sharing information on how to avoid contracting the illness and the signs and symptoms of the disease.

1.3 PURPOSE OF THE STUDY

The purpose of this study is to determine the causes and effect of cholera during rainy season in Benin City.

The specific objectives of the study are:

1. To identify the cause of cholera in Benin City.

2. To ascertain if cholera outbreak is usually rampant during the rainy season in Benin City.

3. To identify the problems associated with the prevention of cholera in Benin City

4. To determine the ways of preventing cholera outbreak in Benin City.

1.4 RESEARCH QUESTIONS

The following research questions were asked and answered in the study:

1. Does poor environmental sanitation lead cholera outbreak?

2. Does washing of hands before eating help to prevent cholera infection?

3. Can drinking and bathing with contaminated water lead to cholera outbreak?

4. Does poorly kept toilet cause cholera outbreak?

5. Is cholera outbreak rampant during the rainy season?

6. Does the use of pipe borne water for drinking and cooking help reduce cholera outbreak?

7. Does boiling of water reduce the risk of cholera infection? 

1.5 SIGNIFICANCE OF THE STUDY:

The research work is important in several ways both to the health personnel and the individual within the society. Firstly, this study will expose to us some of the causes of cholera outbreak in Benin City and also proffer ways of preventing cholera outbreak within our community.   

This study will also be of importance to the health personnel and our local community health workers in the sense that it will expose to them the various preventive measures to put in place to avoid cholera outbreak in our community and Benin City at large.

This study is also be relevant to the government by providing the number of cholera outbreak within the Nigeria economy and also presenting the figures of victims who dies as a result of this disease, by this the government will swing into action by providing various measures in other to prevent further outbreak of the disease.

1.6 SCOPE/DELIMITATION OF THE STUDY:

The study is set out to determine the causes and effect of cholera outbreak during rainy season in Benin City, Edo State. Therefore, the study is restricted to only community health workers, and other health related personnel in Benin City, Edo State. Respondents include students, teachers, civil servants, youths, and drivers.

1.8 DEFINITION OF TERMS:                                                                 

Cholera:- is an acute diarrhoeal infection caused by ingestion of food or water contaminated with the bacterium,Vibrio cholera

Outbrseak:-. a sudden, violent, or spontaneous occurrence, especially of disease or strife

Infection:-.  is the invasion of body tissues by disease-causing microorganisms, their multiplication and the reaction of body tissues to these microorganisms and the toxins that they produce.

Transmission:- The act or process of transferring a disease from a person to another.

WHO:- World Health Organization.

Threat:-. An expression of an intention to inflict pain, injury, evil, or punishment. An indication of impending danger or harm. One that is regarded as a possible danger; a menace.

Contamination: Is the term describing the state of a person or material on coming in contact with the disease pathogen.

Disease: Can be seen as a depart from the normal healthy state of the body soul and mind of a human being, which manifests itself in an abnormal development of the physical, physiological and mental state of the human being concerned.

Epidemiology: The study of disease that affect large numbers of people. Traditionally, epidemiologist have been concerned primarily with infectious diseases such as typhoid and influenza, that arise and spread rapidly among the population as epidemics.

Environment: This is the physical, chemical, and biological condition of the region in which one lives. 

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