April 2005
Acute Watery
Diarrhoea / Cholera | Crimean
Congo Haemorrhagic Fever | Dengue Fever | Diphtheria | Acute Viral Hepatitis | Human Immunodeficiency Virus (HIV)
| Influenza | Leishmaniasis Malaria | Measles | Meningococcal
Meningitis | Pertussis | Human
Plague | Poliomyelitis | Severe Acute Respiratory Syndrome
(SARS) | Neonatal Tetanus | Tuberculosis | Typhoid
Fever
Infectious diseases are those illnesses caused by micro-organisms and transmitted from an infected person or animal to another person or animal. Some of these diseases are airborne such as diphtheria, measles, whooping cough, influenza, SARS and meningococcal meningitis. Some are spread through contaminated food or water as in poliomyelitis, typhoid fever, acute watery diarrhoea/cholera and hepatitis A and E. Other diseases are introduced by insects such as in malaria, classical dengue fever and plague, or transmitted through parenteral routes as in hepatitis B and C viral infections and Human Immunodeficiency Virus (HIV) or mainly by contamination with infected blood as in Crimean Congo Haemorrhagic Fever. Sexual contact is another route for infectious diseases' transmission as is the case for HIV and hepatitis B infections. Utilization of devices contaminated with infected soil or dirt may also constitute a source of infection from tetanus. All of the above mentioned diseases are included in the Disease Early Warning System with specific case definitions in this handbook.
Outbreaks of infectious diseases render populations
vulnerable to increased morbidity and mortality. Effective control depends upon
improved detection, early recognition and warning through notification,
outbreak verification and effective response. In addition to the provincial and
national network of laboratories and reporting sites that collect information
on reported and rumoured outbreaks, the system is also linked to WHO global
surveillance network. Such national and joint efforts indeed form an effective
partnership to investigate and contain those outbreaks that could spread wide
and require concerted action. WHO is assisting several priority disease control
programmes in
Khalif Bile Mohamud, MD, PhD
WHO Representative in
This document is an integral component of the Disease Early Warning System (DEWS) tools and is published by the Epidemic Investigation Cell, Public Health Laboratories Division of National Institute of Health in order to improve the timely recognition, reporting and management of epidemic prone diseases. It is the third edition after the first 2001 edition with just definitions and the 2002 edition, which included case management and prevention strategies as well. In this version we have updated each section and have added Severe Acute Respiratory Syndrome (SARS) a new viral respiratory disease that made its global appearance in 2002.
For timely reporting of outbreaks, this booklet should be used in conjunction with the DEWS manual and the Weekly Watch Chart. According to the definitions herein, a case of disease can be suspected, probable or confirmed. When immediate laboratory confirmation is not available, it is recommended that the suspected and / or probable case definitions be used for outbreak detection and the initiation of outbreak investigation. While investigation is being carried out, laboratory confirmation should also be undertaken promptly. Depending on the type of the disease, in investigating medical officer should exercise his / her best judgment to take outbreak control measures as early as possible. We hope these guidelines will augment the good judgment of physicians and other health officials in the timely management of disease outbreaks and therefore reduce morbidity and mortality resulting from epidemic prone diseases.
Lt. Gen. (R) Prof. Dr. K. A. Karamat
Executive Director
National
Bacterium - Vibrio cholerae
Faecal-oral route, contaminated water and food.
Usually between 1 and 5 days
§ In an area where the disease is not known to be present: severe dehydration or death from acute watery diarrhoea in a patient aged 5 years or more.
§ For management of cases of acute watery diarrhoea in an area where there is a cholera epidemic, cholera should be suspected in all patients with acute watery diarrhoea.
Any suspected case confirmed by laboratory through isolation of Vibrio cholerae 01 or 0139 from stool in any patient with diarrhoea.
§ Cholera can be simply and successfully treated by immediate replacement of the fluid and salts, which are lost throughout diarrhoea period.
§ Patients can be treated with oral rehydration solution (ORS), a pre-packaged mixture of sugar and salts to be mixed with water and drunk in large amounts.
§ Even in cholera, intravenous electrolyte solutions should be used only for the initial rehydration of severely dehydrated patients, including those who are in shock. Ringer's lactate solution (Hartmann's solution for injection) is the preferred fluid for intravenous rehydration. Its composition is suitable for treating patients of all ages and with all types of diarrhoea. Plain glucose solutions are ineffective and should not be used.
§ After vomiting stops, 500 ml fluid should then be given orally every hour. Total fluid requirements can be in excess of 50 litres over a period of 2-5 days.
§ Food should be given after 3-4 hours of treatment, when rehydration is completed. Breast-feeding of infants and young children should be continued.
§
The choice of antibiotic should take into
account local patterns of resistance to antibiotics. In 2004, sensitivity
patterns in
The only sure means of protection against severe gastroenteritis including cholera epidemics is ensuring adequate safe drinking water supply and sanitation. To make water safe for drinking, when the water source has been contaminated, either boil the water or chlorinate it. Bringing water to a vigorous, rolling boil and keep it boiling for one minute will kill Vibrio choleras 01 and most other organisms that cause diarrhoea.
To make water safe by chlorination, first make a stock solution of 33 gm (3 tablespoons) of bleaching powder in one litre of water and store it in a brown bottle. Then put 3 drops (0.6 ml) of stock solution in one litre of water or 6 ml in 10 litres of water or 60 ml in 100 litres. Wait 30 minutes before drinking or using the water.
Good sanitation to avoid the contamination of clean water sources can markedly reduce the risk of transmission of intestinal pathogens, including cholera vibrios. High priority should be given to observing the basic principles of sanitary human waste disposal at appropriate distance from water source and supply. When large groups of people congregate for fairs, funerals, religious festivals, etc., particular care must be taken to ensure the safe disposal of human waste and the provision of adequate facilities for hand washing.
· Wash hands thoroughly with soap after defecating, or after contact with faecal matter, and before preparing or eating food, or feeding children.
· Handle and prepare food in a way that reduces the risk of contamination (e.g. cooked food and eating utensils should be kept separate from uncooked foods and potentially contaminated utensils and crockery).
· Avoid raw food, except those undamaged fruits and vegetables from which the peel can be removed in a hygienic manner.
· Cook food until it is hot throughout.
· Eat food while it is still hot, or reheat it thoroughly before eating.
· Wash and thoroughly dry all cooking and serving utensils after use.
Nairovirus group, Bunyaviridae family
Tick-borne (Hyalomma genus); also direct contact with blood / tissue of infected people, blood / tissue of infected domestic animals (butchering) or the grinding of infected ticks.
Incubation period is usually 1 to 3 days, with a maximum of 9 days. The incubation period following contact with infected blood or tissues is usually 5 to 6 days, with a documented maximum of 13 days.
Patient with sudden onset of illness with high-grade fever over 38.5°C for more than 72 hrs and less than 10 days, especially in CCHF endemic area and among those in contact with sheep or other livestock (shepherds, butchers, and animal handlers). Note that fever is usually associated with headache and muscle pains and does not respond to antibiotic or anti-malarial treatment.
Suspected case with acute history of febrile illness 10 days or less, AND any two of the following: Thrombocytopenia less than 50,000 /mm3, Petechial or purpuric rash, Epistaxis, Haematemesis, Haemoptysis, Blood in stools, Ecchymosis, Gum bleeding, Other haemorrhagic symptom -
AND no known predisposing host factors for haemorrhagic manifestations.
Probable case with
positive diagnosis of CCHF in blood sample, performed in specially equipped
high bio-safety level laboratories. Positive diagnosis includes any of the
following:
·
Confirmation of
presence of IgG or IgM antibodies in serum by ELISA or any method.
·
Detection of
viral nucleic acid by PCR in specimen or isolation of virus.
· A suspected case of CCHF should be managed by diagnosing and treating for other likely causes of fever. If there is no response to anti-malarial and antibiotic treatment, the patient’s platelet count should be checked and examined in view of the criteria mentioned above for “probable CCHF”. All specimens of blood or tissues taken for diagnostic purposes should be collected and handled using universal safety precautions.
· If the case meets the criteria for probable CCHF, begin isolation precautions, alert health facility staff, report the case immediately, draw blood samples for CCHF diagnostic confirmation, and start treatment protocol below without waiting for confirmation. Patients with probable or confirmed CCHF should be isolated and cared for using barrier-nursing techniques – masks, goggles, gloves, gowns and proper removal and disposal of contaminated articles. Specimens of blood or tissues of probable CCHF cases should be tested only in high-level bio-safety laboratory.
General supportive therapy is the mainstay of patient management in CCHF. Intensive monitoring to guide volume and blood component replacement is recommended. If the patient meets the case definition for probable CCHF, oral ribavirin treatment protocol needs to be initiated immediately with the consent of the patient/ relatives and strictly in consultation with the attending physician.
Oral Ribavirin: 2 gm loading dose
4 gm/day in 4 divided doses (6 hourly) for 4 days
2 gm/day in 4 divided doses for 6 days
Please note that pregnancy should be absolutely prevented (whether female or male partner) within six months of completing a course of ribavirin.
· In case of known direct contact with the blood or secretions of a probable or confirmed case such as needle stick injury or contact with mucous membranes such as eye or mouth, do baseline blood studies and start the person on the ribavirin protocol above in consultation with physician.
·
Household or other contacts of the case who may
have had the same exposure to infected ticks or animals, or who recall indirect
contact with case body fluids should be monitored for 14 days from the date of
last contact with the patient or other source of infection by taking the
temperature twice daily. If the patient
develops a temperature of 38.5° C or greater, headache and muscle pains, he/she
would be considered a probable case and should be admitted to hospital and
started on ribavirin treatment as mentioned above.
· Educate public about the mode of transmission through tick bites, handling ticks, and handling and butchering animals, and the means for personal protection.
· Tick control with acaricide (chemicals intended to kill ticks) is a realistic option for well-managed livestock production facilities. Animal dipping in an insecticide solution is recommended.
· Persons who work with livestock or other animals in the endemic areas should take practical measures to protect themselves. They include the use of repellents on the skin (e.g. DEET) and clothing (e.g. permethrin) to prevent tick bites and wearing gloves or other protective clothing to prevent skin contact with infected tissues or blood.
· In case of death of CCHF patient, family should be informed to follow safe burial practices. Please see EIC Publication: Guidelines for Management, Prevention and Control of CCHF.
·
Hospitals should maintain stock of Ribavirin; in
· Bio-safety is the key to avoiding nosocomial infection. Patients with suspected or confirmed CCHF should be isolated and cared for using barrier-nursing techniques to prevent transmission of infection to health workers. Please see EIC Publication: Guidelines for Management, Prevention and Control of CCHF.
Flavivirus group
Bite of infective mosquitoes, principally Aedes aegypti (day biting species)
From 3 to 14 days.
Any person with acute febrile illness of two to seven days duration AND two or more of the following symptoms: Headache, retro-orbital pain, myalgia, arthralgia, rash, haemorrhagic manifestations and leucopoenia.
Any suspected case, which occurs in an area where an outbreak of Dengue exists, with laboratory-confirmed cases and presence of the vector.
Any suspected case confirmed by laboratory isolation of the virus or by the IgM-ELISA test or by PCR.
A probable or confirmed case of dengue AND any two of the following: Thrombocytopenia less than 100,000 /mm3, Petechial or purpuric rash, Epistaxis, Haematemesis, Haemoptysis, Blood in stools, Ecchymosis, Gum bleeding, Other haemorrhagic symptom -
AND no known predisposing host factors for haemorrhagic manifestations.
· Supportive treatment - there is no specific therapeutic agent.
· Severe pains can be relieved by paracetamol but occasionally opiates are required.
· Prevent access of day biting mosquitoes by screening patient or using a bed net.
· Fluid replacement and corticosteroids are indicated in the haemorrhagic variety.
· Take universal safety precautions to prevent contamination with blood or secretions.
· Investigate contacts - determine place of residence of patient for 2 weeks before onset of illness