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Diseases related to water, sanitation and hygiene (WASH). Contents. Public Health in Emergencies: Indicators Relevance of water, sanitation and hygiene to health Diseases related to water and excreta, and transmission mechanisms. 1. Health indicators in emergencies.
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Contents Public Health in Emergencies: Indicators Relevance of water, sanitation and hygiene to health Diseases related to water and excreta, and transmission mechanisms.
Causes of Death in Emergencies (Worldwide) • Diarrhoeal Diseases • Trauma (Injury) • Measles • Malnutrition • Malaria • Acute Respiratory Infections (ARI)
Health Indicators in Emergencies • Daily Crude Mortality Rate (CMR) • Definition: The rate of death in the entire population, including both sexes and all ages. • Formula most commonly used during disaster: Total number of deaths during time period x 10.000 persons Total population No.days in time period = deaths/10.000 persons/day • Under 5 Mortality Rate (U5MR) • Definition : The rate of death among children below 5 years of age in population. • Formula most commonly used during disaster: • Total number of deaths in children • <5 years during time periodx 10.000 persons Total number of children < 5 years No.days in time period = deaths/10.000 children/day
Mortality Rates in Emergencies Fuente: UNICEF State of the World’s Children 2003
Benchmark for CMR and U5MR (worldwide) • Benchmark for CMR (world): • Baseline 0.5 • Serious 1.0-2.0 • Crisis >2.0 • Benchmark for U5MR (world): • Baseline 0.8-1.2 • Serious >2.0-4.0 • For a specific area, when baseline is unknown agencies should aim to maintain the CMR at below 1/10.000/ day.
...To minimise health risks of the population The most important aim of a water and sanitation programme…
The main objective of water supply, sanitation and hygiene programmes in disasters is to reduce the transmission of faecal-oral diseases and exposure to disease-bearing vectors that transmit diseases with epidemic potential, allowing people living with good health, dignity, comfort and security.
WATER / SANITATION / HYGIENE HEALTH
To supply sufficient safe water To supply the means for an adequate excreta disposal and other types of waste To implement hygiene measures To train people regarding hygiene and the proper use of water The crucial aims of water and sanitation programmes are…..
Hygiene Water quantity Sanitation Water Water quality Most common routes for the transmission of Diarrhoea germs DIAGRAM F Adapted from Winblad U & Dudley E, 1997. Source: WHO PHAST
HEALTH CARE LATRINE Faecal-oral transmission: 1.- Water 2.- Food 3.- Objects SPRING SAFE WATER DOMESTIC AND PERSONAL HYGIENE
3. Diseases associated with water and excreta, and spreading mechanisms
THE MOST IMPORTANTS TRANSMITTED by VECTORS DIARRHOEA FAECAL-ORAL route
E. coli Shigella BACTERIA 10.000/g V. cholera 10.000.000/g 10.000.000/g Giardia Poliovirus VIRUS Virus de Hepatitis Rotavirus Entomoeba PROTOZOAN 10.000/g 10.000/g 10.000/g Cryptosporidium
Water-borne or water-washed diseases Transmission mechanisms Cholera, shigellosis, diarrhoea, salmonellosis. Typhoid, paratyphoid, etc. Amoebic dysentery, giardiasis Hepatitis A, poliomyelitis, rotavirus diarrhoea • FAECAL-ORAL • Water contamination • Poor sanitation • Poor personal hygiene • Crop contamination
DIARRHOEA DISEASES According to Curtis and Cairncross (2003), hand washing with soap and water after contact with faecal material can reduce diarrhoeal diseases by 42% or more. Curtis, V. and Cairncross, S. (2003). Effect of washing hands with soap on diarrhoea risk in the community: a systematic review. Lancet Infectious Diseases 3: 275-281.
Acute watery diarrhoea: Watery stools without visible blood, vomit and fever. Dehydration Cholera Bacillary Dysentery (shigellosis): Acute bloody diarrhoea with fever, abdominal cramps and rectal pain. Complications include sepsis, rectal prolapse, haemolytic uraemic syndrome and seizures. Giardiasis: Watery stools, flatulence, greasy stools, stomach cramps, nausea, weight loss and dehydration. Amebiasis or Amebic Dysentery: Bloody stools or loose stools, stomach pain, stomach cramping and fever. DIARRHOEA DISEASES
Caused by the Vibrio Cholerae (bacteria) Endemic or with epidemic potential (Africa,South America,Asia...) Watery diarrhoea classically rice-water stools, with or without vomiting, dehydration, shock IMPORTANT!! faecal-oral route -Faecal material and vomit mist be properly disinfected and disposed of -Adequate water supply -Clean water whenever food is being handled -Hand washing promotion Cause outbreaks with case-fatality rates CHOLERA
TYPHOID FEVER • Caused bySalmonella Typhi (bacteria) • Low grade fever, malaise and dry cough, abdominal discomfort, diarrhoea or constipation, altered mental status and multiples complications. • FAECAL-ORAL • - Waste water with human and animal faeces • - Faeces contaminated food • PREVENTION • - Health education • - Safe food and water, proper food handling • - Adequate excreta disposal • - Personal hygiene • - Safe water collection points
Safe drinking water (Extraction, transport and storage) Controlled excreta disposal Safe food and proper food handling Hand washing with soap Breastfeeding Education KEY FACTORS FOR PREVENTING DIARRHOEA DISEASES
HEPATITIS • Virus A and E.(exist B,C,Δ) • Clinical: fever, tiredness, nauseas, digestive problems and later jaudince (yellow skin and mucous) with dark urine and whitish stools. • Usually complete cure. No chronic, no carrier. • Attention the A and E transmission FAECAL-ORAL route • Risk factors • Food and water contaminated • Poor sanitation infrastructure • Crowding • Waste water with human and animal faeces
POLIOMYELITIS • Virus polio virus (serotypes 1,2,3) • In endemics areas epidemics usually affect children < 5 years of age. In non endemic areas where vaccination coverage is low, young adults are most commonly affected • 90% a symptomatic • 10% disease • Non paralytic form: fever, muscle pain,tiredness, headache, intestinal problems (nausea ,vomits ,diarrhoea), backache, non neurological involvement • Paralytic form: after the non specific signs,the patient develops rapid onset acute flaccid paralysis flaccid and meningeal symptoms . • There is no cure. Prevention vaccination • FAECAL-ORAL • Point of contagious:Food and water contaminated by infected faeces, nose and mouth infected secretion.
Hygiene Water quantity Sanitation Water Water quality Most common routes for the transmission of Diarrhoea germs DIAGRAM F Adapted from Winblad U & Dudley E, 1997. Source: WHO PHAST
Water washed or water scarce diseases Transmission mechanisms • Inadequate water • Poor personal hygiene Skin and eye infections. Louse borne typhus or louse-borne relapsing fever.
Scabies: Sarcoptes scabiei hominis (parasite) Larvae dig tunnels in the external skin layers. - Rash, scab skin. - Wrinkles, between fingers, elbows, writs, penis, nipples. Impetigo: Streptococcus and staphylococcus Contagious superficial skin infection. - Blisters with pus-scab - Face, nasal cavity, mouth, neck, groin. SKIN DISEASES
Conjunctivitis: Acute inflammation of the conjunctiva due to bacterial or viral infection. * Irritation, teardrop, secretion. * Contagious : contact with infected conjunctivitis secretions,hands and clothes contaminated,fly…. Trachoma: Keratoconjunctivitis due to Chlamydia trachomatis * Progressive conjunctivitis and most common cause of blindness in endemic areas. * Contagious : contact with infected conjunctivitis secretions,hands and clothes contaminated,fly…. EYE DISEASES
TYPHUS • Caused of the genus Rickettsia pathogen R.prowasekii (bacteria) • Clinical: • Sudden onset of fever (temp of over 39 Cº), headache, myalgias. • Exanthema maculopapular • TRANSMISSION: Body louse due to lack of personal hygiene, crowding. • RELAPSING FEVER • Caused of the genus Borrelia pathogen B.recurrentis, B.hispanica, B.persica.... (spirochetes) • Clinical: • High fever, artralgia, shivering, jaundice, bleeding. • A febrile interval • TRANSMISSION: Body louse and tick due to lack of personal hygiene, crowding..
Non contaminated water for hygiene Hand washing with soap Laundry with soap Fly vector control Louse vector control No crowding KEY FACTORS FOR PREVENTING WATER-WASHED AND WATER-SCARCE DISEASES
Excreta-related helminths(Parasite worms in human intestine) Transmission mechanisms • Soil transmitted Helminths • Open defecation • Ground contamination Roundworm, hookworm, whipworm
ASCARIDIASIS • Nematodiasis due to Ascaris lumbricoides (Parasite) • Clinical • Phase of larva migration: pulmonary and allergic signs (non productive cough, mild fever) • Established infection: non specifics digestive signs nausea, vomits, diarrhoea, intestinal irritation, • TRANSMISSION: Faecal -Oral
Controlled excreta disposal Hand washing with soap Non contaminated food KEY FACTORS FOR PREVENTING HELMINTHS
Water-based diseases Transmission mechanisms • Long stay in infected waters • Water contamination Schistosomiasis, Guinea worm (Dracunculosis), clonorchiasis .
SHISTOSOMIASES • Infections bySchistosomahaematobium, S. mansoni are frequently, by S. japonicum y S. intercalatum lowness.(Parásitos) • Clinical: • Each species give rise to specific clinical form,it depends the parasite load • Shistosomiases urinaryS.haematobium signs : haematuria, frequent and painful micturation evolution to fibrosis urethral. • Shistosomiases intestinal:S. mansoni signs : bloody diarrhoea , abdominal pain, nauseas, vomit and it evolution liver fibrosis • TRANSMISSION: By contact with the parasite when bathing or swimming in contaminated water.
Safe drinking water supply Adequate drainage of stagnant waters KEY FACTORS FOR PREVENTING WATER-BASED DISEASES
Water-related insect vectors Excreta-related insect vectors Transmission mechanisms • Bitting by mosquitoes, flies. Transmited by flies, cockroaches • Bite near water • Breed in water • Dirty environment Malaria, dengue, sleeping sickness, filariasis, yellow fever. Diarrhoea and dysentery
Mosquitoes Flies Louse (Typhus, Relapsing Fever) Fleas (Plague) Ticks VECTORS RELATED TO DISEASES
MALARIA • Pathogen: Plasmodium falciparum, vivax and ovale (Parasite) • Vector: Mosquito Anopheles female • Clinical: • Painful muscles and joints,high fever with chills, headache, possybly diarrhoea and vomiting • Stagnant waters are the breeding place.
DENGUE • Pathogen: Virus (Flaviviridiae) • Vector: Aedes aegypti • Clinical: • High fever, headaches, pain in muscles and joints, red spots on skin. Classic dengue, hemorrhagic dengue . • Larva growth in water containers (tyres, vases, barrels) or other natural places (lagoons, pools). Epidemic dengue (red)
YELLOW FEVER • Pathogen: Virus (Flaviviridiae) • Vector: Aedes aegypti • Clinical: • Fever, headache, myalgia, nausea, red eyes, jaundice. • Stagnant waters. Only bites during daylight. • Vector Control
Adequate drainage of stagnant water Disposal of waste water Excreta controlled disposal Safe storage of drinking water Vector control KEY FACTORS FOR PREVENTING WATER-RELATED INSECT VECTOR AND EXCRETA-RELATED INSECT VECTOR DISEASES