Study On Epidemic Characteristics And Disease Burden Of Diarrhea

BackgroudDiarrhoeal diseases represent a major health problem in developing countries. Conservative estimates place the global death toll from diarrhoeal diseases at about two million deaths per year (1.7-2.5 million deaths), ranking third among all causes of infectious disease deaths worldwide. Most of these deaths occur in children under five years of age. An average morbidity attack rate of 3.2 episodes of diarrhoea per year per child has been reported, but in some settings in developing countries, this number can be as high as 12 episodes per year per child. In recent years, the incidence of intestinal infectious diseases reported by Zhejiang Province has been ranking first. However, this data only reflect the situation of legal infectious diseases diagnosed and reported by the doctor. We lack complete information about epidemic characteristics and economic burden of diarrheal diseases in the whole population. Most in-country and overseas studies about burden of diarrheal diseases aim at particular people and specific pathogen, or carry out in a small geographical area, so we can not consult it.Objectives To investigate the incidence rate of diarrhea disease in Zhejiang Province and explore its epidemiologic characteristics and related influencing factors, and focus on the rate of medical treatment seeking and behavioral traits due to diarrhea disease and its corresponding direct medical and non-medical expenses, grounding for health policy making for diarrhea disease prevention and control and reasonable arrangement of health resources.MethodsTwelve communities and eighteen villages in Hangzhou, Taizhou and Lishui of Zhejiang Province were included in this study, and Multi-stage sampling, stratified sampling, cluster sampling, and random sampling were employed. This study was carried out from July 2007 to June 2008. Information regarding disease onset, medical treatment seeking, and medical expense, relevant influencing factors of diarrhea disease and other related data were collected by door-to-door survey among constant residents in above places on first month of each quarter (Jul, Oct, Jan and Apr). Descriptive analyses were conducted to explore current epidemiological characteristics, medical treatment seeking and medical expense. Un-conditional logistic regression was applied to analyze influencing factors of incidence rate and rate of visiting doctors' office,1:2 matched case-control study was conducted to explore main risk factors for diarrheal disease, and Multiple Linear Regression was carried out to analyze influencing factors of economic burden of diarrheal disease.Results1. This study included 124644 person-times (PTs) in four investigations. Average two-week incidence rate of diarrheal disease was 0.99% with 1234 PTs diarrhea disease occurred in two weeks before investigation, and the rate in rural area was significantly higher than rate in city (1.13% vs.0.85%,x2= 25.15, P=0.000). Average one-year rate of diarrhea disease in the whole province was 25.74%, which meant that each person had 0.26 times for suffering from diarrhea disease in every year. Incidence rate of rural people was 0.29/person-year (PY), while rate of residents'in cities was 0.22/PY. Two-week incidence rate in July (1.52%) was highest, followed by rate in October (1.01%), and rate in January (0.70%) was lowest. Different populations with different occupations showed diverse rates for diarrhea disease, with highest rate among sporadic children (2.33%), followed by jobless people, and rate among students and medical staff is relatively low. The two-week incidence rate of diarrhea in 0-1 age group (17.24%) was highest, followed by 1-3 age group (9.53%), in other words, its average incidence rate per year-person was 4.5, higher than 1-3 age group (2.5). Two-week incidence rates of diarrhea disease among all other age groups were lower than 2%, and rate of 3-45 age group was lower than 1%. The incidence rate increased with age becoming older among young people while it showed opposite trend among older people.2. Clinical symptoms of diarrhea diseaseThe clinical onset symptom of diarrhea disease was mainly diarrhea, with 49.11% cases having this symptom, followed by other symptoms such as abdominal pain (40.37%), fever (3.60%), vomit (3.54%), nausea (2.66%). About 9.5% patients were with fever. Most patients suffered from diarrhea for 3-5 times one day, accounting for 83.5% of all cases, while 4.2% cases were much severer, with more than 10 times diarrhea one day. About 57.3 percent patients had loose stool, which was the leading excrement characteristic, followed by watery stool (51.4%), mucous stool (4.3%), rice water stool (1.2%), bloody purulent stool and others (both less than 0.5%). Courses of diarrhea among 83.1 percent patients were no longer than 3 days, while those of 9.4% cases were more than 7 days. Only 0.3 percent cases had complications, such as enterorrhagia.3. Medical treatment seekingAbout 66.13 percent diarrhea patients didn't visit doctors' office, and the rates of outpatient and hospital admission were 33.26% and 0.61% respectively. There was no significant difference between rates of medical treatment seeking of rural residents and people in city (35.46% vs.31.50%, x2= 3.05, P= 0.08). Among those who visited doctors' office for diarrhea disease,92.1 percent patients in city and 94.5 percent patients in rural area went for treatment in 2 days after the onset of disease. Level 2 and 3 general hospitals were the choices of 59.8 percent patients in city, while 78.5 percent rural residents went for treatment in village health clinic. Anti-bacteria were wildly used in diarrhea patients, and up to 45.7% patients were treated by them. Anti-diarrhea, traditional Chinese medicine or Chinese patent drugs were prescribed to 40.3% and 26.1% patients. Anti-virus drug and febricide were not used among those patients.4. Reasons for no medical treatment seekingAmong diarrhea patients who didn't go for treatment,78 percent of them thought it was unnecessary to go for a doctor because of no severe symptoms, and 40% cases considered it could be dealt with by themselves, no need to visit a doctor. Only 2.61% patients viewed medication as a high expense item, but up to 14.92% cases in rural area held the same opinion. Nearly 39.6% patients took some drug self-provided at home, and 28.0% cases went to drugstore for diarrhea disease. Less than 5 percent patients chose folk therapy. There were 27.2% patients recovering from diarrhea disease without any treatment among those who didn't go for a doctor.5. Medical expenseDirect economic loss caused by diarrhea disease in Zhejiang Province was approximately 1.011 billion Yuan, including medical expense 886 million Yuan and non-medical expense 124 million Yuan, accounting for 87.7% and 12.3% respectively. Medical expense was composed by outpatient fee 614 million Yuan (69.30%), cost of hospitalization 180 million Yuan (37.47%) and self-medication fee 92 million Yuan (10.38%). Medical expense of residents in city was lower than rural residents'(332 million Yuan vs.554 million Yuan), accounting for 37.47% and 62.53% respectively. Expense in per time paid by health assurance in Zhejiang was 9.57 Yuan. Average expense paid by health assurance was 114 million Yuan each year, which was 12.82 percent of total direct medical expense.Un-medical expense was comprised by outpatient expense 102 million Yuan (82.27%), cost of hospitalization 3 million Yuan (2.13%) and self-medication fee 19 million Yuan (15.60%). Medical expense of residents in city was lower than rural residents'(16 million Yuan vs.107 million Yuan), accounting for 12.90% and 87.10% respectively.6. Influencing factors for diarrhea diseaseResults by un-conditional logistic regression (Method:Forward) indicated that influencing factors for incidence rate of diarrhea were age, education level, living area, season and occupation. It also indicated that influencing factors for rate of seeking medical treatment were health assurance, fever, season, maximum times of diarrhea in one day, diarrhea time (measured by day), occupation and age. Results by Multiple Linear Regression indicated that influencing factors for economic burden of diarrhea were age, state of illness, education level, health assurance and living area. The 1:2 matched case-control study identified two risk factors for diarrhea disease by conditional logistic regression (Method:Forward):eating un-fresh food, cutting cooked and un-cooked food by one kitchen knife, and their odd ratios were 3.9 (97%CI:1.9～7.8) and 4.5 (95%CI:2.4～8.3) respectively.ConclusionsIncidence rate of diarrhea in rural area was significantly higher than rate in city, so disease control and prevention for diarrhea in countries should be strengthened. Infants and sporadic children were risk populations for diarrhea, and more work is needed to target for them. Anti-bacteria abuse among diarrhea cases is prevalent in rural area, so health education and relevant measures were needed to decrease improper use of anti-bacteria. Taking un-fresh food and cutting cooked and un-cooked food by one kitchen knife are main risk factors for diarrhea disease, and targeted health education should be wildly launched. The economic burden caused by diarrheal disease for Zhejiang province is enormous, so it is important to reduce the incidence rate of diarrhea among risk populations immediately and to guide the diarrhea cases' medical treatment seeking behavior accurately.