3.INTESTINAL INFECTIONS.pptx

GASTROINTESTINAL INFECTIONS

Question 1 Raj, a 10 year old boy came to your PHC with complaints of vomiting , mild fever and yellowish discoloration of urine for past 5 days. His father told that few more children from his locality has the same symptoms and went for native treatment. What would be the incubation period of the infection? 15-50 days 45-60 days 14-180 days 15-64 days

Question 2 Washerman hands are seen in Typhoid Cholera Shigellosis amoebiasis

Question 3 The Ty2a Oral vaccine (TYPHORAL Vaccine) is a Subcutaneously administered live attenuated vaccine Orally administered live attenuated vaccine Orally administered killed vaccine Intramuscularly injected killed vaccine

Question 4 Vaccine associated paralytic polio (VAPP) commonly occurs with Type 3 followed by type 1 Type 2 Type 1 followed by type 3 Type 1 alone

Question 5 A 7 year old child presented at casualty with history of multiple episodes of diarrhea vomiting, not able to drink any liquid, sunken eyes, dry mouth, lethargic and floppy. What would be first line of management? Antibiotics Ringer lactate Oral rehydration therapy with appropriate antibiotics Normal saline

Question 6 The guinea worm larvae develop best between the temperature of? 17.5 – 22 ⁰C 19 – 25 ⁰C 23.5 – 29 ⁰C 12 – 18 ⁰C

Question 7 Mode of transmission of Ascariasis Eating partially cooked pork Through mosquito bite Drinking water containing eggs Tsetse fly

Question 8 Chandlers index measures No of hookworms present in 1g of faeces Ratio of number of worm infestation cases in an area No. of worms present in the drinking water No. of mosquito bites in one hour

Question 9 Which of the following is false about AFP? Every case of AFP in any child under 6 years should be reported. The number of AFP cases reported each year is used as an indicator of a country’s ability to detect polio Two stool specimens taken 24-48 hours apart are required. Specimens should be transported in reverse cold chain

Question 10 Main components of reduced osmolarity ORS. Sodium, potassium and calcium Sodium, zinc and glucose Sodium, glucose and chloride Sodium citrate and calcium

Viral hepatitis

Hepatitis viruses

Global health sector strategy on viral hepatitis – 2016-2021 TARGETS Global target of reducing new cases of chronic HBV & HCV by 90% Reducing deaths due to viral hepatitis by 65% by 2030 Key interventions of GLOBAL HEALTH SECTOR STRATEGY for viral hepatitis: Prevention interventions Three dose hep B vaccine for infants Prevention of HBV perinatally using Hepatitis B vaccines Blood safety and injection safety Harm reduction of persons who use drugs Treatment interventions Diagnosis of HBV and HCV Treatment of HBV and HCV & treatment interventions

National viral hepatitis control programme (2017) Central sector scheme launched during 12 th Five year plan. OBJECTIVES: Establish laboratory network & provide lab support. To ascertain the prevalence of different zones. Develop technical material for generating awareness.

Cholera

Cholera It is an acute diarrhoeal disease Caused by Vibrio cholerae O1 and O139 Agent Vibrio Cholerae is comma shaped gram negative bacteria Its antigenic structure consist of H and O antigen Within O group1, two subtypes-Classical and El Tor Host Cholera affects all the age groups mostly in the lower socioeconomic class

Environment : Contaminated food and water are the main source of infection Pollution and poor personal hygiene favours the infection Mode of transmission: Faecally Contaminated water and food Direct contact from person to person through contaminated fingers

Epidemiology Number of cholera cases reported to WHO going to rise In 2016 alone, a total of 132,121 cases were notified from 38 countries including 2420 deaths Cholera remains a global threat In India the introduction of cholera El tor subtype in 1964 During 2017 about 494 cases were reported with 3 deaths in India

Pathogenesis

Clinical features Stage of evacuation : Profuse painless watery diarrhoea followed by vomiting Stage of collapse : It is due to dehydration. The classical signs are sunken eyes, hollow cheeks, scaphoid abdomen, washerman hands and feet, shallow and quick respiration Stage of recovery : Here the patient shows the clinical improvement

Laboratory Diagnosis Collection of specimen Stool sample directly into VR medium Rectal swab Culture methods Culture in bile salt agar medium TCBS It appears as translucent moist raised colonies Motility Darting motility seen by hanging drop method

Control of cholera Verification of diagnosis Notification Early case finding Establishment of treatment cases Rehydration therapy Adjuncts to therapy Epidemological investigations Sanitation measures Chemoprophylaxis Vaccination Health education

Vaccination Three types of oral vaccine Dukoral (WC- rBS ) Sanchol and mORCVAX Euvichol

Programmes Diarrhoeal disease Control Progamme During the year 1980-82 , strategy of the National Cholera Control Progamme undergone changes now termed as Diarrhoeal disease control Progamme Oral Rehydration Control Progamme The main objective is to prevent dehydration

Typhoid

Typhoid fever is the result of systemic infection mainly by S.typhi found only in man. The term enteric fever include both typhoid fever(caused by S.typhi ) and paratyphoid fever (caused by S.paratyphi ‘A’,’B’ and ‘C’). Reservoir : Man is the only reservoir. carriers are more important than cases.

Age: Highest incidence occurs in the 5-19 years of age group. Sex: Males > Females. More clinical cases of typhoid are reported among males than females; But carrier rate is more common in females. Males carriers, probably, are more dangerous because they can spread the bacilli more because of work culture of country(males working predominant) Incubation period:10-14 days

Carriers There are following types of carriers:
1) Convalescent carriers : Shed bacilli for 3 weeks to 3 months after clinical cure.
2) Temporary carriers : Shed bacilli for 3 months to 1year after clinical cure.
3) Chronic carriers (includes permanent carriers): Shed bacilli for more than 1 year after

Treatment • Cases : For empirical therapy , ceftriaxone (a cephalosporine ) is the drug of choice. For susceptible organisms ciprofloxacin is the drug of choice. Carrier : ampicillin or Amoxicillin is given for 6 weeks , with or without cholecystectomy .

Antityphoid vaccines Two safe and effective vaccines are licensed and available: 1)The Vi polysaccharide vaccine (TYPHIM Vi Vaccine)
• It contains purified Vi capsular polysaccharide from Ty2 strain.
• It is given as single dose by subcutaneous or intramuscular route.

• Its confers protection 7 days after the infection.

The Ty2a Oral vaccine (TYPHORAL Vaccine)
• It is an orally administered live attenuated vaccine.
• It contains >109viable organisms of live attenuated Ty21a strain which lacks enzyme UDP-galactose-4-epimerase(gal E mutant).
• Vaccine is administered on 1,3 and 5th day,i.e . a 3-dose regimen.
• Vaccine confers the protection 7 days after the last dose.
• The recommendation is to repeat the series (3 doses) every 3 years for people living in endemic areas and every year for individuals travelling from non- endemic to endemic countries.

• Maximum cases of typhoid fever in 2017 were reported from Bihar followed by Andhra Pradesh. Other states with large number of cases are UP, MP, Maharashtra and Odisha.

POLIO

POLIO Acute viral infection caused by an RNA virus Infects the human alimentary tract May infect the central nervous system, about 1%, causing paralysis and death

Type 1( P1): It is most common type and causes more epidemics. It is most difficult to eradicate. Type-2(P2): It is most antigenic and most easily eradicable. Type-3(P3): It is associated with vaccine associated paralytic polio (VAPP) and most commonly associated with paralysis caused by wild poliovirus. Period of communicability is 7-10 days before and after onset of symptoms. Main age group affected : 6 months to 3 years, slight male preponderance

Clinical features Subclinical (inapparent) infections (95%): Most common and play a predominant role in the spread of infection. Minor (abortive) illness (4.8%) : Present with fever, sore throat, headache and malaise. Aseptic meningitis/ non-paralytic polio (1%): There are signs and symptoms of meningitis. Paralytic polio (<1%): There is flaccid paralysis with absent reflexes. Respiratory paralysis is the common cause of death

Risk of paralytic polio is increased by : Tonsillectomy, tooth extraction, adenoidectomy, strenuous physical exercise, fatigue, intramuscular infection and cortisone administration.

Laboratory diagnosis Viral culture of stool specimens collected from both AFP cases and their contacts is the most sensitive and effective way to rule out transmission of either polio virus or vaccine derived virus. Laboratory diagnosis is based on viral isolation from faecal samples 24-48 hours apart.

Types of specimen Stool CSF Throat Blood If probable case dies, a definite diagnosis of polio can be made or rejected by autopsy examination of spinal cord.

Adequate specimen for polio 2 specimens Within 14 days of onset of AFP Atleast 24 hours apart Adequate volume (8-10gm/adult thumb size)

Problem statement India has not reported any polio cases since 13 January 2011 25th Feb 2012 India was removed from the list of polio endemic countries by WHO. On 27th March 2014 , India was certified as polio free countries, Now there are three endemic countries : Nigeria, Pakistan and Afghanistan. No serotype- 2 (type 2) wild polio virus (P2) has been detected in the world since 1999, type 1 and type 3 has been detected.

Polio vaccines Two types of vaccines are used throughout the world : Inactivated Polio Vaccine Oral polio vaccine

Polio surveillance It is the most important part of whole polio eradication ACUTE FLACCID PARALYSIS SURVEILLANCE AFP is defined as acute onset(<4 weeks) of flaccid paralysis(reduced tone) without other obvious cause in children<15 years of age. Poliomyelitis is the most important etiology of AFP; other causes are GB syndrome, transverse myelitis and traumatic neuritis. WHO recommends the immediate reporting and investigation of every case of AFP in children less than 15 years

Polio surveillance Cases of AFP are classified as POLIO if: Wild polio virus is isolated from any stool specimen. Cases of AFP without isolation of wild polio virus may be classified as polio compatible if: Stool specimens were inadequate and Residual weakness was present 60 days after onset of paralysis or 60 day follow- up was not done.

Polio surveillance Four steps of AFP surveillance: Finding and reporting children with AFP Every case of AFP in any child under 15 years should be reported. The number of AFP cases reported each year is used as an indicator of a country’s ability to detect polio, even in countries where the disease no longer occurs.

Polio surveillance Transporting stool sample for analysis All children (<15 years )with AFP should be reported and tested for wild poliovirus within 48 hours of onset. Two stool specimens taken 24-48 hours apart are required. Specimens are transported in cold box at4-8 deg.C . Specimen should arrive at laboratory within 72 hours of collection.

Polio surveillance Isolating polio virus Polio virus should be isolated and should be distinguished between wild and vaccine-derived virus. Mapping the virus Tests are carried out to determine where the strain may have originated.

Mop up activity Mop-up activity is a house-to-house activity where two rounds of polio immunization,4-6 weeks apart are conducted to limit transmission of wild poliovirus. Under the mop-up activity, children below 5 years of age are covered in affected and neighbouring districts around every detected positive poli

Polio eradication and end game strategic plan(2013-2018) The plan has 4 objectives: Detect and interrupt all poliovirus transmission :by the end of 2014. Strengthen immunization system and withdraw OPV. Containment and certification of eradication: of all WHO regions by end of 2018. Legacy planning.

Rationale and timelines for OPV withdrawal Why replace trivalent OPV with bivalent OPV? Until April 2016, tOPV was an important component of routine immunization programmes . tOPV contains all three poliovirus serotypes (1, 2 and 3), and the use of this vaccine has led to the eradication of wild poliovirus type 2 (WPV2), with the last case occurring in 1999. The last detected case of WPV3 was in 2012 Even as the remaining strains of wild poliovirus are being eradicated, the switch from tOPV to bOPV was a major step to combat cVDPV and VAPP. Over 90% of cVDPV cases, and approximately 40% of VAPP cases, are due to the type 2 component of tOPV . The type 2 component of tOPV also interferes with the immune response to poliovirus types 1 and 3

Given the risk the type 2 component of tOPV poses to a world free of WPV2, tOPV was replaced with bOPV in routine programmes and supplementary immunization activities (SIAs). bOPV contains type 1 and 3 serotypes only, and can help stop transmission of WPV1 and 3 and reduce the risk of VAPP and cVDPVs . The introduction of IPV will help to reduce risks associated with the withdrawal of OPV type 2, facilitate interruption of transmission with the use of monovalent OPV type 2 in the case of outbreaks, and hasten eradication by boosting immunity to poliovirus types 1 and 3.

Key dates around the switch May 2015 The World Health Assembly endorsed the process and tentative timelines. September 2015 Target date for national operational plans to be finalized, based on the guidelines available. October 2015 As part of a readiness review, SAGE assessed the epidemiology of persistent type 2 cVDPVs .

April 2016 Two week window for the switch from tOPV to bOPV , followed by a two-week validation phase. May 2016 tOPV is no longer used globally in routine immunization, nor in SIAs. NATIONAL SWITCH DAY: 25 TH APRIL 2016 NATIONAL VALIDATION DAY: 9 TH MAY 2016

ACUTE DIARRHOEAL DISEASES

Oral rehydration solution The fluid recommended for replacement by oral route is reduced osmolarity ORS(Low Na ORS) ORS therapy is based on the observation that glucose given orally enhances the absorption of salt and water. The solution should be made fresh daily and used within 24 hours.

Condition Well alert Restless iritable Lethargic or unconscious; Floppy Eyes Normal Sunken Very sunken and dry Tears Present Absent Absent Mouth and tongue Moist Dry Very dry Thirst Drinks normally, not thirsty Thirsty,drinks eagerly Drinks poorly,or not able to drink Skin pinch Goes back quickly Goes back Slowly Goes back very Slowly Decide The patient has No signs of dehydration If the patient has Two or more Signs,including at least one sign,there is Some dehydration If the patient has two or More signs,including at Least one signs,there is Severe dehydration Treat Use treatment Plan A Weight the Patient,treatment Plan B Weight the patient and use Treatment Plan C

TREATMENT PLAN A TREATMENT PLAN B TREATMENT PLAN C No signs of Dehydration Some physical signs Of dehydration Severe dehydration Mothers educated to use increased amounts of home available fluids. ORS packets given for use at home. Breast feeding should be continued. Rehydration therapy: Correction of existing water and electrolyte deficit. 75 ml/kg ORS in first 4 hours. Maintenance therapy: Replacement of ongoing losses due to continuing diarrhoea . Begins when signs of dehydration disappear usually in first 4 hours 10-20ml/kg ORS for each liquid stool. Best IV fluid solution is Ringer lactate Normal saline can be used Dextrose is not effective 100ml/kg is to be given as : AGE FIRST (30ml/kg) THEN (70 ml/kg) < 12 months 1 hour 5 hour 12 months to 5 years 30 minutes 2 ½ hours

Worm Infestation

Dracunculiasis Vector borne parasitic disease caused by infestation of Dracunculus medinensis (guinea worm). Man is the definite host and cyclops is the intermediate host. Infection is acquired by drinking of cyclops contaminated water( water based disease). Man is the only reservoir (no animal reservoir). Cycle in cyclops is cyclo-developmental. The larvae develop best between 25-30 deg c and will not develop below 19 degree c.

Therefore, the disease is limited to tropical and sub tropical regions. In India, the last report case was in July 1996. On completion of zero incidence for 3 years, India was declared free of guineaworm disease. India certified for elimination of Guineaworm by WHO in Feb 2000 and India certified Guineaworm disease free in Feb 2001.

Eradication strategy Provision of safe drinking water Control of Cyclops Health education of public: Boiling or Sieving of drinking water Surveillance Guinea worm eradication programme

Ascariasis Most common helminthic infection and worm infestation in India Causative agent: Ascaris lumbricoides . Reservoir: Man Infective form : embryonated egg containing rhabditiform larva . Mode of transmission: faeco -oral route by ingestion of embryonated egg Incubation period : 2 months.

Ascariasis Clinical features : Loss of appetite, abdominal pain, malnutrition, obstruction, appendicitis, perforation, allergic reaction. Due to migrating larva: Loefflers syndrome ( eosinophilia pneumonia). Diagnosis : demonstration of eggs in feces. Treatment : Mebendazole or Albendazole . Pyrantel palmoate is the choice in pregnancy.

Hookworm infestation Ancyiostoma duodenale (old world hookworm ) Necator americanus (new world hookworm). Reservoir : Man The habitat is small intestine (jejunum > duodenum >ileum). Infective form : filarial form larvae Mode of transmission :through penetration of skin

Hookworm infestation Plasma forms the main source of nourishment for hookworm, the RBCs pass out from the hookworm practically unchanged into the lumen of host intestine. Average blood loss by hookworm infection is 0.03ml/day (by Necator americanus) to 0.2ml/day(by Ancylostoma duodenale). There is iron deficiency anemia and hypoalbuminemia .

Hookworm infestation Morbidity and mortality from hookworm infection depends on the worm load. Chandler worked out an index, Chandler’s index , on the basis of average number of hookworm eggs per gram of feces for the entire community.

Chandler’s index (endemic index) Average no. of eggs per gram of stool Below 200 -- Hookworm infection is not significant 200-250 --- Potential danger 250-300 --- Minor public health problem Above 300 --- Important public health problem

Taeniasis Zoonotic cestode : Taenia saginata (beef tapeworm) Taenia solium (pork tapeworm). Habitat : small intestine (jejunum) Definite host: Man (for both) intermediate host :Pig ( T.solium ) cattle ( T.saginata )

Taeniasis Mode of transmission of tapeworm : Undercooked beef or pork containing cysticercus bovis . Human cysticercosis: can occur in any organ Neurocysticercosis - increased intracranial pressure, hyrocephalous & death

Question 1 Raj, a 10 year old boy came to your PHC with complaints of vomiting, mild fever and yellowish discoloration of urine for past 5 days. His father told that few more children from his locality has the same symptoms and went for native treatment. What would be the incubation period od the infection? 15-50 days 45-60 days 14-180 days 15-64 days