Background
Cholera is an acute diarrheal disease caused by the bacterium,
Vibrio cholerae; an infection in the intestines that can kill even a healthy adult in a matter of hours [
1]. As from 2000, the incidence of cholera has increased steadily, culminating in 317,534 reported cases worldwide, including 7543 deaths with a case-fatality rate of 2.38 % in 2010 [
2]. The disease is now considered to be endemic in many countries and the pathogen causing cholera cannot currently be eliminated from the environment [
3]. Regions of the world where Cholera is currently prevalent are Africa, Asia and parts of the Middle East. Sub-Saharan Africa is broadly affected by many cholera epidemics [
4]. In Cameroon, the burden of cholera has increased during the past two decades. The annual number of reported cases had increased over the years [
2] with 4026 cases in 1991, 5796 in 1996, 8005 in 2004 [
5] and 10,759 in 2010 [
6]. Cholera can spread rapidly through a population resulting in individuals with dehydration and causing severe morbidity and mortality [
7]. The infection is transmitted through contaminated fecal matter, which can be consumed through tainted food and water sources or because of poor hygiene and sanitation, like unwashed hands [
8]. Cholera is most common in areas that lack clean water sources and sanitation services. Areas like refugee camps and urban slums, where people live in close proximity with little to no access to clean water and sanitation facilities are at a very high risk of experiencing a cholera epidemic [
8].
Access to potable water in both rural and urban centers of Cameroon is a great concern [
9,
10]. A study carried out by Jane-Francis and colleagues [
11] in Douala, Cameron reported wells as reservoirs of
V. cholerae. However, risk factors for cholera in Cameroon have not been evaluated systematically. Numerous possible explanations for the current outbreak exist, including poor hygiene and sanitation and environmental factors [
12]. A majority of cholera epidemics and deaths have been reported in sub-Saharan Africa [
6] where the risk of cholera infection is high. Typical at-risk areas include peri-urban slums where basic infrastructure is not available and camps for internally displaced people where the minimum requirements of clean water and sanitation are not met [
13]. The greatest risk occurs in over-populated communities and refuge settings characterized by poor sanitation, unsafe drinking water and increased person to person transmission [
14]. The 2010 cholera epidemic in Cameroon affected 10,741 people and killed 650. An ever increasing number of cholera cases were registered almost everywhere in the first week of 2011 in Cameroon. The South West Region of Cameroon was affected by this epidemic. Hence, it was necessary to assess the risk of cholera in the Buea Health District and to provide evidence-based cholera epidemic guidelines.
Discussion
Cholera continues to be a global threat to public health and a key indicator of lack of social development. Once common throughout the world, the infection is now largely confined to developing countries in the tropics and subtropics [
16]. For a cholera outbreak to occur, two conditions have to be met: there must be significant breaches in the water, sanitation, and hygiene infrastructure used by groups of people, permitting large-scale exposure to food or water contaminated with
Vibrio cholerae organisms; and cholera must be present in the population [
17]. Improving water, sanitation and other infrastructure has been associated with a 39 % decline in waterborne disease in informal urban settlements in Africa [
18]. It was necessary to determine a population specific level of awareness and risk factors of cholera infection in the country.
A number of demographic and socioeconomic factors including age, gender and social status are also known to play a crucial role to cholera infection. There were more females [20 (58.2 %)] cholera cases than males [14 (41.2 %)]. Most women are engaged in domestic activities which expose them to this infection. Cholera was mostly reported from students [14 (42.5 %)] than from other occupations. The Buea Health District is a cosmopolitan locality with people from various parts of the nation for academic purposes because of the presence of the University of Buea. The proportion of respondents with good knowledge of cholera was very high probably because of the cholera prevention programme from the Ministry of Public Health. This finding is consistent with published data from Peru [
16] which showed a high knowledge of cholera and that cholera prevention campaign successfully educated respondents. However, our findings were contrary to a Tanzanian cross-sectional survey conducted to assess knowledge, attitudes and practices [
19] in which the level of knowledge concerning cholera was very low. Analysis of knowledge levels compared to social, hygienic and personal practices showed that respondents obtained information about cholera mostly from the media [85 (65.4 %)] compared to health facilities. This may be because in most cholera-endemic communities, the governments use health education through mass media as the major preventive method against cholera. The strategy is to create awareness of the existence of the disease and also provide the population with the basic knowledge in first aid to handle cases. However, in our study area, a lot of sensitization is conducted to improve sanitary conditions in homes. Poor hygienic practices and contaminated water sources were the main transmission routes of cholera. Improving infrastructural, social, behavioral and personal hygiene and sanitation are the cornerstone of cholera prevention and have been shown to dramatically lessen the impact of epidemics [
20,
21]. From our study, poor food preservation methods, eating outside the home and below 21 years of age were independent risk factors of the cholera epidemic. High cholera mortality has been reported in both adults and children [
2]. Another study by Siddique and colleagues [
22] revealed that the proportion of severe dehydration among
V. cholerae-infected children was significantly higher compared to the proportion of rotavirus-infected children. However, our study reported that most of the participants below 21 years old were infected with cholera compared to those 21 years and above.
From our study, those with cholera were about 9 times more likely to practice poor food preservation methods than those without the disease. This is in line with an American study which showed that the cause of cholera from the U.S coastal waters was due to the consumption of raw, uncooked or contaminated shell fish [
23].
Lack of potable water and irregular water supply were independent protective factors of cholera. There is ample evidence of the importance of water quality from the Mexican 1991 epidemic [
24]. Contaminated water sources and the resultant water quality were found to be the most common causes for cholera in separate studies in Peru, Mexico and Ecuador [
25,
26]. However, the government of Cameroon has been building more potable water points to salvage this situation.
The lack of access to latrines has also been identified as a risk factor for cholera in informal settlement areas [
27]. In a study carried out by Alexander and colleagues [
28], cases of cholera were more likely to defecate in the open air or river than controls. Contrary to our results, cases that defecated in bushes and rivers (lack of home toilets) had equal odds of being infected with cholera compared to participants without the disease. Our finding is in line with those reported by Ali and colleagues [
29], Colobara and colleagues [
30], and Stacie and colleagues [
31] where increasing educational levels and decreasing cholera hospitalization risk have been reported to be associated. Also, Alexander and colleagues [
28] reported that, higher levels of education were correlated with reduced risk for cholera hospitalization in both rural and urban Bangladesh. Significantly, most participants who were infected with cholera practiced poor food preservation methods. This is similar to an American study on cholera epidemic [
31]. However, our study showed that participants with a tertiary level of education were equally likely to be infected with cholera compared to those who were less educated.
Competing interests
The authors declare that they have no competing interests.
Authors’ contributions
NDS participated in the conception, design, data collection, data analysis, drafting and revising the manuscript for academic content. AJ participated in the design, data management, analysis and interpretation. NFP participated in the design, literature search, analysis and interpretation of results. TEA participated in the data analysis, literature search, drafting and correction of the final manuscript. ACW participated in the literature search, data analysis, drafting, reading and correcting the final manuscript. KOD participated in the literature search, analysis and interpretation of results, drafting, reading and correcting the final manuscript. All authors read and approved the final copy.