EPIDEMIOLOGY OF CHOLERA Introduction Magnitude of the Program Agent, Host and Environment Sign and symptoms Complications. Prevention and Control Program Status National Policy and Strategies References2
INTRODUCTION Cholera is an infection in the small intestine caused by the bacterium Vibrio cholerae. The word cholera is from Greek: kholera from kholē "bile". The main symptoms are watery diarrhea and vomiting. Transmission occurs primarily by drinking water or eating food that has been contaminated by the feces (waste product ).3
Contd. … Vibrio cholerae is a Gram-negative bacterium that produces cholera toxin, Vibrio cholerae, which causes cholera, has 139 serotypes, based on cell antigens. Only two of them produce an enterotoxin and are pathogens: 0:1 and 0:139 Cholera endemic and epidemic today in developing countries, some cases also found in developed countries. Cholera became one of the most widespread and deadly4 diseases.
EPIDEMIOLOGY OF CHOLERA Introduction Magnitude of the Program Agent, Host and Environment Sign and symptoms Complications. Prevention and Control Program Status National Policy and Strategies References5
OCCURRENCE: Cholera likely has its origins in the Indian Subcontinent; it has been prevalent in the Ganges delta since ancient times. The disease first spread by trade routes (land and sea) to Russia in 1817, then to the rest of Europe, and from Europe to North America. Seven cholera pandemics have occurred in the past 200 years, with the seventh originating in Indonesia in 1961.7
OCCURRENCE: The first cholera pandemic occurred in the Bengal region of India starting in 1817 through 1824. The disease dispersed from India to Southeast Asia, China, Japan, the Middle East, and southern Russia. The second pandemic lasted from 1827 to 1835 and affected the United States and Europe. It killed 150,000 Americans during the second pandemic. The third pandemic erupted in 1839, persisted until 1856, extended to North Africa, and reached South America, for8 the first time specifically infringing upon Brazil.
OCCURRENCE: In Russia alone, between 1847 and 1851, more than one million people perished of the disease. Cholera hit the sub-Saharan African region during the fourth pandemic from 1863 to 1875. The fifth pandemic raged from 1881–1896. sixth pandemics raged from 1899-1923. Between 1900 and 1920, perhaps 8 million people died of cholera in India. These epidemics were less fatal due to a greater9 understanding of the cholera bacteria.
OCCURRENCE: Egypt, the Arabian peninsula, Persia, India, and the Philippines were hit hardest during these epidemics, while other areas, like Germany in 1892 and Nepalese from 1910–1911, experienced severe outbreaks. The final pandemic originated in 1961 in Indonesia and is marked by the emergence of a new strain, nicknamed El Tor. which still persists today in developing countries. cholera became one of the most widespread and deadly diseases of the 19th century.10
SIZE OF THE PROBLEM GLOBALLY: 140 000 – 290 000 cases were reported between 1997- 1998. In 1999, global incidence was about 254 000 , and Africa alone accounted for about 81% of the global total number of cases. In 2000, multiple outbreaks were reported in populations in various islands of Oceania .11
Cholera affects an estimated 3–5 million people worldwide, & causes 100,000–130,000 deaths a year as of 2010. This occurs mainly in the developing world. In the early 1980s, death rates are believed to have been greater than 3 million a year. Cholera remains both epidemic and endemic in many areas of the world.12
Nepalese origin of cholera epidemic in Haiti. Cholera appeared in Haiti in October 2010 for the first time in recorded history. Vibrio cholerae serogroup O1, serotype Ogawa, biotype El Tor. The isolates were obtained from 30 July to 1 November 2010 from five different districts in Nepal. 24 cases of V. cholerae isolates from Nepal16
Doti cholera outbreak under control A total of 14 persons had lost their lives due to the epidemic from June 13 to July 1 in the district. District Health Office informed that it has treated more than 700 cholera patients till now. Cholera was found in people from Doti’s Dipayal Silgadi municipality along with Kalena, Bagalek, Khatiwada, Gajari, Kadamandau, Sanagaun, Basudev, Durgamandau, Barwata and Gajunda17 VDCs.
EPIDEMIOLOGY OF CHOLERA Introduction Magnitude of the Program Agent, Host and Environment Sign and symptoms Complications. Prevention and Control Program Status National Policy and Strategies References18
AGENT FACTORS Agent: Vibrio cholerae Has over 150 identified serotypes based on O-antigen Only O1 and O139 are toxigenic and cause Cholera disease (Water-borne illness) Source of infection: case of Cholera by Fecal-oral transmission Infective materials: secretion of the Intestine cases.19 .
Period of CommunicabilityDuring acute stageA few days after recoveryBy end of week, 70% of patients non-infectiousBy end of third week, 98% non-infectious 20
HOST FACTORS 1. Age: Children: 10x more susceptible than adults, And Elderly also higher susceptible. 2. Sex: Equal in both male and female. 3. Immunity: Less immune higher risk. 4. People with low gastric acid levels 5. Blood types O>> B > A > AB21
ENVIRONMENTAL FACTORS at risk areas include peri urban slums, refugee camps where clean water and sanitation are not met Consequences of a disaster Lack of education, poor quality of life22
EPIDEMIOLOGY OF CHOLERA Introduction Magnitude of the Program Agent, Host and Environment Sign and symptoms Complications. Prevention and Control Program Status National Policy and Strategies References24
SIGNS AND SYMPTOMs The primary symptoms of cholera are profuse, painless diarrhea and vomiting of clear fluid. The diarrhea is frequently described as "rice water" in nature and may have a fishy odor. An untreated person with cholera may produce 10 to 20 litres of diarrhea a day with fatal results. patients skin turning a bluish-gray hue from extreme loss of fluids.25
If the severe diarrhea is not treated with intravenous rehydration, it can result in life- threatening dehydration and electrolyte imbalances. The typical symptoms of dehydration include low blood pressure, poor skin turgor (wrinkled hands), sunken eyes, and a rapid pulse.27
A person with severe dehydration due to cholera - note the sunken eyes and decreased skin turgor28 which produces wrinkled hands and skin
MODE OF TRANSMISSION A. Primary ingestion of water (contaminated with faeces) OR B. Ingestion of food contaminated by dirty water, faeces, soiled hands or flies. OR C. The disease transmitted from one person to another person in over crowded and unhygienic conditions.29
INCUBATION PERIOD Ranges from a few hours to 5 days. Universal I/P is 5 days. Shorter incubation period: High gastric pH (from use of antacids) Consumption of high dosage of cholera30
EPIDEMIOLOGY OF CHOLERA Introduction Magnitude of the Program Agent, Host and Environment Sign and symptoms Complications Prevention and Control Program Status National Policy and Strategies References31
COMPLICATIONS The degree and duration of fluid and electrolyte loss determines the medical consequences of cholera. For example, renal failure may stem from the reduced fluid flow through the kidneys; low blood sugar (hypoglycemia) may result in seizures or coma, especially in the young; or lowered potassium levels may trigger serious cardiac complications32
EPIDEMIOLOGY OF CHOLERA Introduction Magnitude of the Program Agent, Host and Environment Sign and symptoms Complications Prevention and Control Program Status National Policy and Strategies References33
Control and prevention Sterilization: Proper disposal and treatment of infected fecal waste water produced by cholera victims and all contaminated materials (e.g. clothing, bedding, etc.) are essential. Sewage: antibacterial treatment of general sewage by chlorine, ozone, ultraviolet light or other. Source: to decontaminate the water (boiling, chlorination etc.) for possible use.34
CONT. .. Water purification: All water used for drinking, washing, or cooking should be sterilized by either boiling, chlorination, ozone water treatment, ultraviolet light sterilization. Surveillance and prompt reporting allow for containing cholera epidemics rapidly. practice of folding a sari (a long fabric garment) multiple times to create a simple filter for drinking water.35
VACCINE A number of safe and effective oral vaccine for cholera are available. Dukoral, inactivated whole cell vaccine, has an overall efficacy of about 52% during the first year after being given and 62% in the second year, with minimal side effects. It is available in over 60 countries. One injectable vaccine was found to be effective for two to three years. Work is under way to investigate the role of mass vaccination. WHO recommends immunization of high risk groups, such as37 children and people with HIV, in countries.
Treatment Continued eating speeds the recovery of normal intestinal function. The World Health Organization recommends this generally for cases of diarrhea no matter what the underlying cause. A CDC training manual specifically for cholera states: “Continue to breastfeed your baby if the baby has watery diarrhea, even when traveling to get treatment. Adults and older children should38 continue to eat frequently.”
Fluids: In most cases, cholera can be successfully treated with oral rehydration therapy (ORT), which is highly effective, safe, and simple to administer. Electrolytes: As there frequently is initially acidosis, the potassium level may be normal, even though large losses have occurred.39
Cholera 40 patient being treated by medical staff in 1992
Antibiotic treatments for one to three days shorten the course of the disease and reduce the severity of the symptoms. Doxycycline is typically used first line, Other antibiotics proven to be effective include cotrimoxazole, erythromycin, tetracycline, chloramphenicol, and furazolidone.41
EPIDEMIOLOGY OF CHOLERA Introduction Magnitude of the Program Agent, Host and Environment Sign and symptoms Complications Prevention and Control Program Status National Policy and Strategies References42
DIARRHOEA CONTROL PROGRAM IN NATIONAL CONTEXT CONTROL OF DIARRHOEAL DISEASE (CDD) the CB-IMCI programme was expanded up to community level. Although the incidence of diarrhoea has increased significantly in this fiscal year but the proportion of severe dehydration cases was decreased at the last year. Almost half of the diarrhoeal cases (50%) were treated by the Female Community Health Volunteers (FCHVs).43
STRATEGY FOR DIARRHOEA CONTROL Training to all health workers on CB‐IMCI including zinc treatment for diarrhoea; Nutritional supplementation, enrichment, nutrition education and Rehabilitation Environmental sanitation School Health Program Raise public awareness; and promote specific prevention measure through communication. increase access to the Zinc tablets through CHW44 (FCHVs, VHWs & MCHWs).
Community Based Integrated Management of Childhood Illness (CB-IMCI) Program CB-IMCI programme intensely focuses on management of Diarrhoeal diseases among the under five year’s children. Standard case management of diarrhoea with Oral Rehydration therapy and Zinc tablet has been provided in the community level. All health facilities and community health volunteers at community level will serve as the primary health care providers in the45 treatment of Diarrhoea
Prevention and control of cholera outbreaks: WHO policy and recommendations The main tools for cholera control are: proper and timely case management in cholera treatment centres; specific training for proper case management, including avoidance of nosocomial infections; sufficient pre-positioned medical supplies for case management (e.g. diarrhoeal disease kits); improved access to water, effective sanitation, proper waste management and vector control; enhanced hygiene and food safety practices;46 improved communication and public information.
EPIDEMIOLOGY OF CHOLERA Introduction Magnitude of the Program Agent, Host and Environment Sign and symptoms Complications. Prevention and Control Program Status National Policy and Strategies References47