THE INCIDENCE OF CHOLERA AMONG SCHOOL CHILDREN IN BENIN CITY
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).