Socioeconomic, hygienic, and sanitation factors in reducing diarrhea in the Amazon

ABSTRACT OBJECTIVE To analyze the contributions of the socioeconomic, hygienic, and sanitation improvements in reducing the prevalence of diarrhea in a city of the Amazon. METHODS In this population-based cross-sectional study, we analyzed data from surveys conducted in the city of Jordão, Acre. In 2005 and 2012, these surveys evaluated, respectively, 466 and 826 children under five years old. Questionnaires were applied on the socioeconomic conditions, construction of houses, food and hygienic habits, and environmental sanitation. We applied Pearson’s Chi-squared test and Poisson regression to verify the relationship between origin of water, construction of homes, age of introduction of cow’s milk in the diet, place of birth and the prevalence of diarrhea. RESULTS The prevalence of diarrhea was reduced from 45.1% to 35.4%. We identified higher probability of diarrhea in children who did not use water from the public network, in those receiving cow’s milk in the first month after birth, and in those living in houses made of paxiúba. Children born at home presented lower risk of diarrhea when compared to those who were born in hospital, with this difference reversing for the 2012 survey. CONCLUSIONS Sanitation conditions improved with the increase of bathrooms with toilets, implementation of the Programa de Saúde da Família (PSF – Family Health Program), and water treatment in the city. The multivariate regression model identified a statistically significant association between use of water from the public network, construction of houses, late introduction of cow’s milk, and access to health service with occurrence of diarrhea.


INTRODUCTION
Sanitation, recognized as an important health promotion strategy, figures on the international agenda among the eight Millennium Development Goals, whose aim to halve the population without access to drinking water was reached in advance. However, 11.0% of the world's population still remains without access to drinking water. Overcoming this challenge requires facing technological, political, and managerial barriers, which are even more complex in the Amazon because of natural obstacles.
In Brazil, basic sanitation is a right ensured by the Constitution and defined by the Law 11,445/2007, which establishes the national guidelines for sanitation, defined as the set of services, infrastructure, and facilities of water supply, sewage system, urban cleaning, urban drainage, solid waste and rainwater management a . These services promote the improvement of the quality of life of the population, reflecting directly on child health, with reduction of child mortality and of diarrheal, parasitic, and skin diseases. Besides, they protect the health of the population, minimizing the consequences of poverty and also protecting the environment b .
Diarrhea is a serious public health problem related to hygiene conditions and quality of water used 9 . It is the second most common cause of childhood deaths, representing around 1.5 million deaths/year in children under five years c . There are many determinant factors 13 ; about 88% of diarrhea deaths are attributed to unsafe drinking water, inadequate sewage system, and precarious hygiene c . Thus, measures to prevent infant diarrhea must be prioritized as key strategy for improving child health. Among the measures, are the following: provision of water, both in quantity and quality; removal and treatment of domestic sewage; and promotion of sanitation actions in all community c . The infrastructure sector must supply treated water, sewage system, solid waste cleaning and collection, and rainwater drainage and management, with participation of the public health sector and community, as foreseen in the Federal Constitution of 1988 d .
In some isolated and poorer localities of the State of Acre, as is the case of Jordão, the expansion of the supply network of drinking water and sewage system and also of medical care occurred slowly because of logistical difficulties, especially for the rural population. This study aimed to analyze the contribution of sanitation actions such as drinking water supply, construction of houses, introduction of cow's milk, and place of birth on the reduction of the prevalence of diarrhea in children under five in the urban and rural area of the city.

METHODS
This population-based cross-sectional study used data from two surveys conducted in the city of Jordão, Acre, in the years of 2005 and 2012, which evaluated, respectively, 466 and 826 children under five in the urban and rural area 8 .
Jordão is located at 700 km from Rio Branco, in the State of Acre, and was created in 1992, after separation from the city of Tarauacá, located in Vale do Juruá. It has an area of 5,429 km 2 , bathed by the rivers Jordão and Tarauacá, and borders the cities of Marechal Thaumaturgo, Feijó, and Tarauacá, and the country Peru. The population of the city in the 2010 Census was of 6,577 inhabitants, with 2,272 in the urban area and 4,305 in the rural area e . It is one of the most isolated cities of the State for having access only by water and air, contributing to the maintenance of high prices of goods and food. Until 2005, it did not have water treatment nor sewage system.
In the context of Amazonian and Acre reality, Jordão is considered one of the poorest cities of the Country. In 2000, its Human Development Index (HDI) was of 0.222 and, in 2010, it increased to 0.469 f . However, this is still considered a very low HDI, figuring among the 10 lowest of Brazil. In both surveys, the information of the characteristics of houses, environmental sanitation, and health were obtained by questionnaires, conducted by properly trained researchers. The respondent was an adult responsible by the home, who was asked to characterize the occurrence of diarrhea and whether the child(ren) of the house presented in the last 15 days more than four bowel movements/day of liquid consistency or with increase in volume. For the socioeconomic assessment, we evaluated the presence of electrical energy; benefit from Bolsa Família Program; maternal education; and household income. Regarding the houses, we considered the type of construction material of the house, roof, and floor, and the total rooms. Concerning infant feeding, we considered the period of introduction of cow's milk. About the place of birth, we considered whether it occurred at home or in hospital. To evaluate environmental sanitation, we considered the type of toilet in the home and the destination of trash, as well as the origin, frequency of lack, and type of treatment carried out on drinking water.
For the categorical variables, we applied Pearson's Chi-squared test and linear trend test, which consider the exposure level at the moment of identifying differences between the two surveys. To obtain the crude and adjusted association measures and assessment of the association strength between independent variables and outcome, we used Poisson regression with robust error estimation (Stata 9.0).   Table 3 provides information about the presence of insects and rodents in the houses, as well as the care of families with food handling. Concerning flies, 28.0% of families classified as high the presence of this insect at home. The presence of cockroaches took place on 89.7% of houses, with 42.8% of families classifying as high the infestation of this insect. In relation to rodents, 78.8% reported presence, with 27.5% of houses showing high infestation. Regarding hygienic care during food handling, 88.7% reported washing their hands before handling food that will be consumed by children. Concerning the hygiene of fruits and vegetables eaten raw, only 23.8% of families washed them with treated water, 43.4% washed with untreated water, and 25.3% did not wash the fruits and vegetables consumed by children under five. Table 4 describes the association between diarrhea and the four determining factors selected: origin of water, type of house, age of introduction of cow's milk, and place of birth for the years 2005 and 2012. About the origin of the water used, we identified, in both surveys, more probability of diarrhea among children who did not use water from the public supply network. In 2005, this risk was 1.38 times and in 2012, 1.60 times higher, when compared to children who used well water.  In relation to the type of house, even not reaching statistical significance, this variable was kept in the model because of the significant changes observed in the construction of houses in the comparison between 2005 and 2012. This variable suggests higher probability of developing diarrhea in children living in households of paxiúba, which reached 1.21 times when compared to the value observed among children living in masonry or processed wood houses, in 2012.
In 2005, children receiving cow's milk in the first month after birth showed probability of developing diarrhea 1.3 times higher than that of children who had never consumed cow's milk and a probability 17.0% higher than the observed between those who received cow's milk after 30 days. This same trend was observed in 2012, reaching twice the probability of   occurrence of diarrhea episode of the first group and 1.76 times in relation to the second.
Regarding the place of birth, in 2005, children born at home presented lower risk of diarrhea when compared to those who were born in hospital, with this difference reversing in 2012.

DISCUSSION
In the seven years between the two surveys, we identified a high prevalence of diarrhea among children living in the city, but with a 9.7% reduction in the occurrence of this harm. Cesário et al. 3  Jordão still has a rural population higher than the urban, which justify many houses not having electrical energy and, consequently, the advantages brought by this resource. This reality of the interior of the Amazon differs sharply from that experienced in the Center-South of Brazil, in which even small towns far from urban centers present an urban population greater than the rural and largest coverage of electrical energy services 1 .
Regarding social aid, the increase of families benefited by the Family Allowance Program was substantial, especially in the rural area of the city, increment factor for the acquisition of consumer goods or improving food quality.
We verified a change in the structure of houses, with increased use of processed wood for construction and floor, as well as on the number of rooms of the houses. This scenario shows improvement in the purchasing power of the population in this city and may indicate better infrastructure conditions of families with children under five, which certainly contribute to reducing exposures to diseases, including diarrhea.
As a way to evaluate the access to health services, we chose the variable of place of birth.
The increase of home childbirth can be assigned to the fact that the population of the city is predominantly rural and, after the implantation of PSF, to increased prenatal care, training of midwives, and encouraging natural childbirth.
The introduction of cow's milk on infant feeding is an important variable to evaluate the care and knowledge of the mother about the importance of breastfeeding. We observed late introduction of cow's milk on infant feeding, decreasing the risk of diarrhea. These data indicate the importance of complementary feeding and breastfeeding practices for prevention of health problems in the early years of life. Cow's milk is responsible for 20.0% of food allergies 7 ; in addition, the digestion of the protein of cow's milk is difficult in children, increasing the risk of diarrhea. The increase of the mother's education level and PSF actions may have contributed to late introduction of cow's milk on infant feeding.
A significant portion of the children still had no toilet in their homes, even with the construction of home health facilities in partnership with the Fundação Nacional de Saúde (FUNASA -National Health Foundation), which promoted the replacement of latrines for ceramic toilets in the houses between 2005 and 2012. There is a predominance of toilets outside the houses, which is typical of the rural area. This variable was only evaluable in 2012, since in 2005 it was not part of the questionnaire applied. In African countries, the use of latrine or outhouse is universalized 13 : approximately 92.4% in Uganda, 95.0% in Kenya, and 99.5% in Tanzania. The latrines in the urban area are built of permanent materials and, in rural areas, of mud and branches, to prevent fecal material from reaching the domestic environment 13 .
We observe the importance of the program for distribution of sodium hypochlorite in the city, since more than 50.0% of respondents rely on this resource for the treatment of drinking water. Regarding the destination of trash, there was no improvement in collection and proper disposal in landfill between 2005 and 2012, a condition that contributes to the presence and proliferation of insects and rodents, which is sustained by the high presence of insects in the houses. In fact, the presence of flies is associated with infant diarrhea 11 .
Concerning the destination of sewage, in 2005, open pit and cesspit predominated, situations that favor the contamination of the environment near the houses and interfere in health conditions of children 10 . The lack of sewage disposal system interferes directly in children health for polluting the environment and allowing the transmission of excreta-related diseases, mainly parasitic ones. The disposal of excreta in open land or street is a risk for helminthiasis and, consequently, for other waterborne diseases, as diarrhea i .
We verified the care with the hygiene of hands before food preparation, but a small portion did not perform such care, contributing to the risk of contamination during food preparation. Regarding fruits and vegetables consumed raw, an expressive portion washed them, but with untreated water. As the water came predominantly from rivers, this practice can offer risk of disease transmission, especially diarrhea. The water used for consumption in rural and urban areas, in this study, came from well or river, representing a 38.0 and 60.0% higher risk (in 2005 and 2012) for diarrhea than the consumption of water from the public network. However, the risks found for diarrhea were lower than those found by Teixeira and Heller 11 in areas of subnormal settlement in the city of Juiz de Fora. Washing hands with water and soap can reduce 48.0% of the risk of diarrhea; improving water quality, 17.0% of risk; and proper sewage collection, 36.0% of risk 4 .
The sanitation conditions in the city presented an expressive improvement, with increase in the number of bathrooms with toilets, implementation of water treatment in the urban area of the city, increased maternal education, and access to health services. The multivariate regression model identified a statistically significant association between use of water from the public network, type of house, late introduction of cow' s milk, and access to health service with occurrence of diarrhea. Although the sanitary transformations that took place in Jordão were important on the occurrence of diarrhea, water supply and sewage systems remain not universalized. Expansion must be prioritized, since this service has not yet achieved a large portion of the population living in rural areas.