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A STUDY OF EPIDEMIOLOGY WHICH INVOLVES MONITORING INFORMATION REGARDING EMERGING & REEMERGING COMMUNICABLE DISEASES IN GOVERNMENT HOSPITAL

 

Clinical courses

ABOUT AUTHORS:
Mr. R. Krishnaswamy, Dr.R.Sampathkumar, Mr.N.Venkateswara Murthy, Mr. Anton Vinoth.T
Department of Pharmacy Practice J.K.K.Naatraja College of Pharmacy,
Komarapalayam, Tamilnadu.
*krishnasamy1993@gmail.com

ABSTRACT
To make decisions regarding the control of communicable diseases and to reduce the epidemic situations, this article has been presented in the way of studying about the epidemiology which involves monitoring information regarding emerging & reemerging diseases, its causative agents, treatment etc., This article also relates studying about mode of transmission(through vector (or) through contact) which helps in making decisions regarding its prevention and to prevent its spreading.

REFERENCE ID: PHARMATUTOR-ART-1843

INTRODUCTION
Communicable diseases occur due to infectious agents or its toxic products which is transmitted either directly or through an intermediate host, vector or an inanimate environment.


Communicable diseases includes both “infectious” and “contagious diseases”.

Infectious Diseases:-
It is a disease resulting from infections.


Contagious Diseases:-
It is a disease which is transmitted from one individual to the other by direct contact.

MODE OF TRANSMISSION
Communicable diseases are transmitted through,

  • Contact
  • Air
  • Water
  • Insects
  • Animals(zoonotic)
  • Placenta

These, mode of transmission of communicable disease have various sub-divided routes.

They are,

ROUTE:

CONTACT TRANSMISSION:
The agents which produce the disease can be transmitted by,

  • Direct Contact
  • Indirect Contact

Direct Contact:
It is directly transmitted from the infected patients.
Eg:Venereal diseases & skin infections

Indirect Contact:
It is through contaminated objects like clothes, towels, utensils & other articles.

Eg: tuberculosis, measles, mumps  and chicken pox.

AIR BORNE TRANSMISSION:
Air borne diseases are classified based on the methods by which they are transmitted as,

  • Droplet Infection
  • Droplet Nuclei
  • Infected Dust

Droplet Infection:-
It occurs due to droplets containing infectious organisms expelled during coughs, sneezing, or taking loudly.

Eg : tuberculosis, diphtheria, meningitis, whooping cough, measles, chicken pox, mumps, influenza.

Droplet Nuclei:-
It occurs due to formation of small residues of nuclei which are formed due to evaporation of droplets. These nuclei being very small and light may remain in air for a long time.

Eg: tuberculosis, influenza, chicken pox, and measles.

Infected Dust:-
It occurs due to settling down of droplets on the floor, cloths or bedding and forms the part of the dust.

Eg:tuberculosis, pneumonia, psittacosis, Q fever.

WATER BORNE TRANSMISSION

  • Water gets contaminated with minerals and micro organisms.  All these are likely to produce a variety of diseases.
  • It is due to the presence of infectious agents in water.

Bacterial Diseases:- Cholera, dysentery, typhoid fever, gastroenteritis.

Viral Diseases:- Hepatitis, poliomyelitis.

Protozoal Diseases:- Amoebiasis , giardiasis.

Worm Infestations:- Round worm, thread worm, tape worm and guinea worm.

INSECT BORNE TRANSMISSION

  • Insect like arthropods transmit diseases by biting or by depositing the infected materials on skin.
  • The infective agents can be carried mechanically by insect or may be developed and multiplied in insect itself before transmission.

Diseases transmitted by insects are,
Mosquito:- Malaria , filarial and encephalitis.

House Fly: Cholera, typhoid, diarrhoea, dysentery and poliomyelitis.

Sand Fly:- Kala-azar , sand fly fever and oriental sore.

Rat Flea:- Bubonic plague and epidemic typhus

Itch Mite:- Scabies

ANIMAL BORNE TRANSMISSION (Zoonotic):
Zoonotic diseases are those which are transmitted by animals. The zoonotic diseases  can be classified as,

Viral Diseases:-
Rabies (transmitted through dogs).

Bacterial Diseases:-
Tuberculosis, brucellosis (transmitted through cattle).

Fungal Diseases:-
Dermatophytosis (transmitted through cats & dogs).

Protozoal Diseases:-
Amoebiasis (transmitted through dogs).

Rickettsial Diseases:-
Q fever (transmitted through cattle).

PLACENTAL TRANSMISSION
Some diseases are transmitted from the mother to the foetus through placenta.

Eg: measles, rubella and syphilis.

EPIDEMIOLOGY

RESPIRATORY  INFECTION

DISEASE

CAUSATIVE AGENTS

CHARACTERIZATION

TRANSMISSION

INCUBATION PERIOD

PREVENTION   TREATMENT

Small pox

Variola virus

Sudden onset of fever, head ache, back ache, vomiting, convulsions in children

On third day of  fever a typical rash appears which is centrifugal in distribution and passes through Successive stages of macule, papule, vesicle, pustle and scab.

Droplet inflection
Droplet nuclei
Secretions of lesions of skin

About 12 days

Vaccination and revaccination every 3-5 years.

Chicken  pox

Herpes virus Varicella  zoster

 

Vesicular rash accompanied by fever and malaise

Droplet inflection

Droplet nuclei

Fomites

About 14-16 Days

 

Varicella Zoster Immunoglobulin [VZIG]

 

Measles [rubeola]

Measles virus [myxo viruses family]

Fever, Catarrhal symptoms of upper respiratory tract [coryza, Cough]. Typical rash

  Droplet inflection

  Droplet nuclei

  Direct contact

10-14 days

 

 

  Measles vaccination

Rubella  [German Measles]

Rubella virus [RNA Virus] Togavirus  family

Low grade fever, lymphadenopathy, maculopapular rash.

 

Droplet nuclei

2-3 weak (or) 18 Days

 

Rubella Vaccine

Mumps

 Myxovirus Parotiditis [RNA Virus]

Genus àRubella   Virus

Family àpara-myxoviridae

Non-Suppurative enlargement and tenderness of one  or both the parotid grand

Droplet  infection Fomites

Varies from 2-3 weeks (or) 18 Days.

Live attenuated mumps vaccine

 

Influenza

 Influenza Virus

Familyàorthomyxoviridae

 

    Sudden onset of chills, malaise, fever, muscular pain and cough

 

Droplet infection

Droplet nuclei

18-72 hours

Prophylactic Immunization with influenza vaccine.

 

Diphtheria

 

 

 

 Toxigenic stains of corynebacterium diphtheriae

Skin, conjunctiva, vulva and other parts of the body were affected.
The bacilli multiply locally in the throat and elaborate powerful exotoxin which is responsible for,
(i) Formation of grayish members over the tonsils, pharynx.
(ii) Marked congestion, oedema and local tissue destruction.
(iii) Enlargement of regional lymph nodes.
(iv) Symptoms of toxaemia.

Air-Borne Transmission
Droplet infection
Droplet nuclei
Infected dust

2-6 Days

1. Treatment with diphtheria antitoxin.

2. Immunization by administering diphtheria vaccines or DPT(Triple antigen).

 

Whooping-Cough [Pertussis]

 

  

    Bordetella pertussis

 

 

Insidious onset with mild fever and an irritating cough, whooping synosis and vomiting

  
Droplet infection

Droplet  contact

7-1 4 Days

1. Treatment with choramphenicol (or) Tetracycline.
2. Immunization with pertussis vaccine / DPT.

Meningococcal meningitis

 [cerebrospinal fever]

 

N. Meningitidis

 

Intense head-ache, vomiting, stiff-neck and progresses to coma

 

    Droplet infection

 3-4 Days

1. Treatment with rifampicin(antibiotics).
2. Meningococcal vaccine.

Acute respiratory infections

Bacteria:-
Bordetella pertussis corynebacterium diphtheriae haemophilus influenza, klebsiella pneumoniae, ligionella pneumophilia, staphylococcus pyrogens, streptococcus pneumoniae, streptococcus pyrogens.

Virus:-
Adenoviruses
Entero viruses   
Influenza A, B, C
Measles
Para influenza   1, 2, 3
Respiratory
Syncytial virus
Rhino viruses
Corona viruses

Other Agents:-
Chlamydia B
Coxiella burntti

Running nose, cough, sore throat, Difficult breathing, ear problems, fever pneumonia.

Air-Borne route by direct contact

 -----------

1.measles vaccine
2.HIB vaccine
3.pneumococcal pneumonia vaccine  ppv 23 , pcv 7

Severe acute respiratory syndrome [SARS]

 

New stains of corona virus

Fever, malaise, chills, head ache, myalgia, dizziness, cough, sore throat, running nose.

Rapid determination of low oxygen saturation.

Droplet infection

Direct contact

3-5 Days

Antiviral agent ribavirin given intravenously in combination with high dose of corticosteroids

 

Tuberculosis

 

Mycobacterium tuberculosis

Prolonged cough, rise of temperature in evening, loss of weight, loss of appetite, opacity of lungs, affects the tissues of intestine, meninges, bones, joints, lymph glands etc.,

By droplet infection

Droplet nuclei

3-6 Weeks

1.rifampicin, isaniazid & pyrazimamide.
2.immunisation with BCG vaccination.

 

Poliomyelitis

Poliovirus(RNAvirus)

Infects the human alimentary tract and also infects the CNS causing paralysis.

Faecal oral route.

Droplet infections

 7-14 Days

1.inactivated polio vaccine[IPV]

2.oral polio vaccine[OPV]

 

 

Viral hepatitis

Hepatitis A,B,C,D,E,G virus

Cytomegalo virus,

Epstein bar virus,

Yellow fever virus & rubella virus.

 

 

  Loss of appetite, nausea, jaundice, hepatic coma &death.

 

Faecal oral route, Sexual transmission.

Hepatitis A 10-50 Days,

Hepatitis B 50-180 Days.

Personal cleanliness, safe disposal of excreta,

Hepatitis vaccination.

 

    

 

 

 

   Acute diarrhoeal diseases

Virus:-

Rota virus.

Bacteria:-

Enterotoxigenic E.coli

Shigella,

Salmonella,

Vibrio cholerae 01.

Campylobacter jejuni

Protozoans:-

cryptosporidium

 

Frequent passage of loose, liquid or watery stools.

Faecal oral route

------------

Oral rehydration therapy

 

   Cholera

 

   vibrio cholera 01.

Sudden onset of profuse, effortless, watery diarrhoea, vomiting, rapid dehydration, muscular cramps & suppression of urine (anuria)

Faecally contaminated water.

Direct Contact

1-2 Days

Oral cholera vaccine

 

  Typhoid fever

 

   Salmonella typhi

Increase in body temperature to the extent of 1 degree every day.

Severe head ache, back pain, dry &coated tongue.

 

    Faecal Oral Route.

    Urine Oral Route.

10-14 Days

Immunization by typhoid vaccine.

 

 

 

    Food   poisoning

Salmonella typhimurium,

Salmonella cholera-suis,

Staphylococcus aureus,

Clostridium botulinum,

Bacillus cereus.

 

 

 

               History of ingestion of common food.

               Toxic & allergic reactions in the body.

 

 

 

     Faecal Oral Route

 

 

 

6-14 Hours

 

 

 

Food sanitation.

 

  Amoebiasis

 

Entamoeba histolytica

Intestinal amoebiasis:-

              Dysentery, amoeboma, diarrhoea.

Extra intestinal amoebiasis:-

              Affects liver, lungs or brain.

 

Faecal Oral Route.

Sexual Transmission.

 

 

2-4 Weeks

1.Food Hygiene.

2.Oral Treatment with Metronidazole.

 

Ascariasis

 

Ascaris lumbricoides.

 

       Nausea, abdominal pain & cough

 

   Faecal oral Route

 

2 Months

Treatment with Piperazine, Mebendazole, Levamisole, Pyrantel.

 

Hook worm infection

Ancylostoma duodenale,

Necator americanus.

 

       Loss of appetite, lassitude, weakness & anemia.

Larva of the worm enters through skin of the leg.

 

7 Weeks

Treatment with anthelmintic drugs.

 

 

Dracunculiasis

 

Dracunculus medinensis [nematode parasite]

 

Penetrates into dermis &
induces an inflammatory reactions & subsequent blister formation.

Water borne disease transmitted entirely through consumption of water containing Cyclops harbouring the infective stages of parasite.

 

 

-------------

1.Treatment with Niridazole, Mebendazole & Metronidazole.

2.Provision of safe drinking water.

ARTHROPOD BORNE INFECTIONS:

Dengue syndrome

aedes aegypti & aedes albopictus which acts as the vector.

 Dengue haemorrhagic fever without or with shock.

 Thrombocytopenia.

 Transmitted through mosquitoes.

 

 Direct contact

 

  

   -------------

 

 

1. no immunization therapy.

2.treatment with leaf juice of papaya.

 Malaria

Genus- plasmodium

 

 Periodic chills, fever, enlargement of spleen. Secondary anaemia.

Transmitted by bite of female anopheles mosquito.

Direct contact.

 

 10 Days

 

Treatment with antimalarial drugs like quinine & chloroquine.

Lymphatic filariasis

W.bancrofti,

B.malayi,

B.timori.

Lymphangitis, lymphadenitis, elephantiasis of genitals,legs & arms.

Tropical pulmonary eosinophilia, filarial arthritis, suffering, deformity, disability.

Transmitted by the bite of cluex mosquito & monsonia mosquitos which acts as vector.

Prepatent Period.

Treatment with antifilarial drugs like diethyl carbamazine [hetrazan].

Rabies

Lyssa virus type 1.

Family-rhabdo viridae.

 

Hydrophobia, highly fatal viral disease of central nervous system.

 

Transmitted by bite of rabid animals like dogs & cats.

3-8 Weeks

1.post-exposure prophylaxis.
2.pre-exposure prophylaxis.
3.human antirabies vaccination.

 

Yellow fever

Flavivirus fibricus [arbo-virus]

Jaundice with haemorrhagic manifestations like black vomit, epistaxis, melena & albuminuria, anuria, shock, agitation, stupor & coma.

Transmitted by sylvan cycle(monkey to  person)

& urban cycle (person to person)

Through mosquitos & direct contact.

 

   

 

 

 

      3-6 Days

 

 

 

17D vaccine.

KFD [Kyasanur forest Disease]

Flavivirus [Togaviruses]

Febrile disease associated with Haemorrhages.

Transmitted by bite of infective ticks.

 

  

     3-8 Days

 

Immunized with killed KFD vaccine.

 

Chikungunya Fever

Chikungunya virus (Group A- virus)

High fever, severe articular pain in limbs and spinal column, Chills, Cephalalgia, anorexia, lum bago and Conjunctivities, adenopathy, coffee-colored vomiting, epistaxis, petechiae.

Transmitted by  aedes, culex, mansonia mosquitoes which acts as vector.

 4-7 Days

 

Treatment with analgesics, antipyretics like paracetamol, diclofenac sodium and chloroquine.

 

 

 ZOONOSES (BACTERIAL)

 

 

 

  Leptospirosis

Stains of leptospira interrogans

   Infects liver and Kidney

 Direct Contact

 Indirect Contact

 Droplet Infection

4-20 Days

Antibiotics like Tetra-cycline, Doxy-cycline.

Brucellosis

Brucella abortus,  B.Suis, B.Canis, B.Melitensis.

Undulent fever, malta fever, profuse sweating, arthritis, enlarged spleen.

 Transmitted by contact with animals(Contact infection)

1-3 Weeks

Human live vaccine of          B. abortus strain 19-BA.

Plague

Yersinia Pestis

Fever, prostration, inflammation, swelling of lymph nodes.

 

Transmitted by bite of infected rat-fleas.

Bubonic plague 2-7 days

 

Pneumonic plague 1-3 days

Septicaemic plague 2-7 days.

 

 

Immunization with plague vaccine

Human salmonellosis

Salmonellae Typhi

S.paratyphi A and B

Leads to Complete food poisoning, enteric fever, gastro enteritis, septicemia

    Faecal-Oral Route

   Direct Contact

 

   

   6-72 Hours

 

1. immunization of form animals against salmonellosis.

2. food sanitation.

 

 

ZOONOSES(RICKETTSIAL DISEASE)

 

 

 

Rickettsial Zoonoses

Rickettsial Prowazekii

Rochalimae a quintana

 

Q fever, fever, headache, malaise, prostration, skin rash, enlargement of spleen and liver.

Transmitted through arthropod vectors.

 

     -------------

Treatment with Tetracycline drugs.

 

Q fever

Coxiella burnetii

Acute onset  of fever, chills, malaise, headache, pneumonia, hepatitis, encephalitis and endocarditic.

Faucal oral route

 2-3 weeks

Treatment with

Oral Tetracycline drugs.

Scrub Typhus

Rickettsia tsutsugamushi

Chills, fever(104-1050 F), head ache, malaria, prostration, macular rash, lymphadenopathy, lymphocytosis.

Transmitted by bite of infected larval mites

10-12 Days

Treatment with tetra-cycline.

Murine Typhus

Rickettsia Typhi

Rickettsia mooseri

Louse-borne typhus, weil felix reaction with proteus OX-19 and becomes positive.

Transmitted by bite of rat-flea

12 Days

Treatment  with Tetra-cycline.

Tick Typhus

Rickettsia Conorii

Onset of fever for 2-3 weeks,malaria, head ache, maculopapular rash.

Transmitted by bite of infected tick.

3-7 Days

Treatment with
Broad Spectrum antibiotics.

 

 

ZOONOSES(PARASITIC)

 

 

 

 

 

  Taeniasis

Taenia Saginata

 

And

 

Taenia solium

Occasional abdominal discomfort,

Anorexia and chronic indigestion

 

Faecal-Oral Route

 

  8-14 Weeks

Treatment with praziquantel and niclosamide

 

 

 Hydatid Disease

Echinococcus granulosus and

 

E.multilocularis

 

E.Vogeli

Growth of larvae in the lobes of liver, lungs, brain, peritoneum, kidney and long bones.

Faecal-Oral Route

 

From Months to Years.