All cases should be verified and investigated within 48 hours of notification by the SMO.  

Verification:  Once an AFP case is reported from a physician/health unit or any othersource, the SMO must personally see this case to ascertain if the case meets the AFP case definition.   If AFP is NOT present, the SMO may discuss his findings with the reporting physician/health worker and discard the case as not AFP on the Case Investigation Form.

Investigation:  Upon verification, the SMO determines the case is AFP.  He must then commence the investigation.  The necessary steps in the investigation of all AFP cases are outlined below:

1. If case is reported from a remote area or a Phase III area, the SMO should coordinate the investigation with the District office and concerned health staff.
2. Once case is verified as AFP, collect all available demographic and clinical information on the case.
3. Fill out AFP case investigation form and assign EPID number.  Copies of case investigation forms should be sent by the SMO to the WHO-IPD central office in Lalitpur.
4. Collect two stool specimens from the case at a minimum interval of 24 hours. Even if you are in doubt as to whether it is AFP or not it is better to collect stool specimens.  Each specimen should be 8 grams (each approximately the size of an adult thumb).  Stool cultures have the maximum chance of yielding a positive result if the specimen is collected within 2 weeks (14 days) of paralysis onset.  If collected after 14 days, the specimen will be considered inadequate.  Therefore, all efforts must be taken to collect stool specimens within 2 weeks of paralysis onset. If stool cannot be collected from the case, the SMO should be diligent in collecting detailed epidemiological and clinical case information because the case may be presented to the Expert Review Committee for classification.
5. Establish a time and place for the 60-day follow-up examination of the case in order to assess presence of residual paralysis or weakness.

If the onset of paralysis occurred at some time within the previous 12 months, enroll the case in IFA database and initiate community investigation to identify additional cases.

The SMO should visit the home of each AFP case to obtain further epidemiological information.  A line listing of all AFP cases should be maintained by the field offices.  Inquiries should be made to determine whether other AFP cases have appeared in places the case had visited during the month prior to paralysis.

ORI is limited in its potential to stop wild poliovirus transmission.  It is an effective tool in raising awareness of the importance of immunization coverage in that particular area among the district officers as well as among the public.  It also allows for the opportunity to motivate health staff as well as conduct active search of AFP.

It is important that all stool specimens are collected prior to the start of outbreak response immunization (ORI); otherwise, vaccine virus may interfere with attempts to isolate the wild virus from AFP cases and contacts. The house-to-house campaign approach is the most effective method for outbreak response.

When it is decided that ORI is necessary, certain information should be gathered and a plan of required actions developed by the DHO.  It is important to note the DHO and designated district team will conduct ORI.  The SMO will assist and provide necessary materials.  The following points should be considered in managing an outbreak.
-     Population data - obtain most recent population size and distribution.
-     What is the level of EPI coverage? - Coverage rate using existing data; conduct a quick assessment to assess immunization coverage in the area at that time.

1. Where are the cases? - Spot map to mark the location of case(s) and areas targeted for immunization on a map.
2. Has an NID or SNID been conducted recently?
3. Look for additional cases of AFP in the area

Target Group: Children aged less than 5 years should receive one dose of OPV, regardless of OPV immunization history. 

Each case of paralytic poliomyelitis probably represents 100 to 1,000 asymptomatic infected persons.  As a result, the spread of the virus may be wider than the local area where the case resides.  The number of children to be vaccinated will depend upon the population density.  For example, in the Terai, and entire village of perhaps 300-500 children may be targeted, whereas in the mountains, where the population is more scattered, only 50-200 children may be targeted. 

Resources:  It is important to determine what resources are available at all levels (transportation, vaccine, cold chain materials, etc.). 

Coordination:  Keep the appropriate health/community authorities informed regarding when and where the team will be arriving, and ask that local health staff/community representatives be present.

Supplies:  The necessary supplies to take to the outbreak area include:
-     Adequate quantities of OPV, based on estimated target population.
-     Cold chain equipment: ice packs, cold boxes, vaccine carriers, and vaccine monitor thermometers.  .
-     Adequate supply of forms: case investigation, laboratory, and line list forms.

Outbreak Monitoring: Information on cases, immunization coverage monitored during an outbreak.

Additional Case Finding during a quick assessment and/or ORI: All attempts should be made to find additional cases during an AFP investigation.  In conjunction, community leaders should be contacted and their assistance obtained.  Door-to-door searches are an effective way to find additional cases, particularly in areas where patients are not likely to seek medical care. Each temple, preschool center, school, hospital, clinic, drugstore, and rehabilitation center in the affected area must be identified and listed.

In larger population centers, contacts may also include selected medical professionals, such as pediatricians and neurologists.  Efforts to identify additional cases should extend well beyond the neighborhood or community in which the AFP case lives.

The quality of surveillance may be assessed in several ways.  The two most important surveillance performance indicators are 1) the rate of non-polio AFP cases per 100,000 children <15 years of age and 2) the percentage of AFP cases from which two adequate stool specimens are collected.  In addition, evaluation of the completeness of weekly "zero" reporting is very important to ensure that regular AFP surveillance is functioning in every geopolitical unit of the country.  These and other performance indicators for both integrated surveillance in general and AFP in particular are discussed in Chapter 5.

An important aspect of a successful polio eradication program is a well-developed information system one that provides program managers and health workers with the necessary information to take appropriate actions.

AFP cases should be plotted on a map according to their place of residence and the plot compared with coverage data and surveillance reporting sites.  These maps can be useful for coordinating activities (such as vaccination points, etc.).  This information will also help determine whether improvements in surveillance contacts are needed.

Terai: SMOs should maintain spot maps for wild polio cases in India bordering their districts.  This will help in targeting areas of surveillance and immunization coverage rates. Accurate information on the vaccination history of persons with poliomyelitis is essential for evaluating vaccine efficacy and possible cold chain problems. Monitoring techniques for performance of program strategies are outlined in Chapter 5.

The quality of surveillance may be assessed in several ways.  The two most important surveillance performance indicators are 1) the rate of non-polio AFP cases per 100,000 children <15 years of age and 2) the percentage of AFP cases from which two adequate stool specimens are collected.  In addition, evaluation of the completeness of weekly "zero" reporting is very important to ensure that regular AFP surveillance is functioning in every geopolitical unit of the country.  These and other performance indicators for both integrated surveillance in general and AFP in particular are discussed in Chapter 5.

Major Signs and Symptoms of Paralytic Poliomyelitis In the Acute Phase Acute onset Fever just prior to paralysis – hallmark finding. Muscle pain. Asymmetrical paralysis. Absent or diminished DTRs. No sensory loss.

A hallmark of paralytic poliomyelitis is fever just prior to the onset of paralysis. Other associated symptoms may include malaise, anorexia, nausea, vomiting, headache, sore throat, constipation, and abdominal pain. Signs of meningeal irritation may be present, i.e. stiffness of neck and back muscles. The tripod sign may be present; i.e. the child finds difficulty in sitting and sits by supporting hands at the back and by partially flexing the hips and knees.

Progression of the paralysis to reach its maximum in the majority of cases occurs within 4 days; however; a few may take 4 – 7 days. The paralysis is usually descending, i.e. starting from the trunk at the shoulder or hip and moving distally down the extremity. The paralysis tends to be asymmetrical, and muscle strength may vary in the muscle groups of different limbs. However, proximal muscle groups are more involved as compared to distal ones. DTRs are diminished before the onset of paralysis. Cranial nerve involvement is seen in the bulbar and bulbospinal forms of paralytic poliomyelitis, but is not common. Facial asymmetry may be present, with difficulty in swallowing, weakness, or loss of voice. Respiratory insufficiency can be life–threatening and may lead to death.
Diagnosis is confirmed by isolation of wild poliovirus from the stool specimen. In polio, the spinal fluid is inflammatory and it may or may not be under pressure. The fluid may be transparent or slightly turbid. Protein is increased moderately to 40 – 65 mg. From 20 – 300 cells per mm3 are present with polymorphonuclear leukocytosis initially, but later a shift toward lymphocytosis occurs.

Guillain – Barré Syndrome (GBS):
GBS is another common cause of AFP. GBS is an acquired demyelinating disease of the peripheral nervous system with major features of weakness and areflexia. Fever occurs about 2 – 3 weeks prior to onset of paralysis. The paralysis in GBS is flaccid and tends to be symmetrical, with absent or diminished deep tendon reflexes (DTRs). In general, the paralysis of GBS occurs in an ascending fashi1on, affecting lower limbs first, followed by trunk, then upper limbs. Bilateral cranial nerve involvement is common, especially involving the facial nerve. Ninth and tenth cranial nerve involvement causing difficulty in swallowing is the second most commonly observed cranial nerve abnormality. Pain and muscle tenderness is prominent at the onset of paralysis. Sensory deficit is frequently present but is difficult to elicit in children.

The reported annual incidence rate of GBS in Latin America is highest in the age group 1 – 4 years with a mean of 0.9/100,000 population aged 1 – 4 years. GBS also occurs in adults. The clinician should be aware that some age overlap exists between case of paralytic poliomyelitis and GBS.
Persons with GBS often complain of hypesthesia or anesthesia in a glove–stocking distribution. Tingling and burning sensations in the soles and palms are also frequent, as well as cramps in the peroneal muscles; however, the child with GBS is not disturbed by handling or changes in position, as is the child with polio.

Electrophysiologic study is preferably performed 3 weeks after onset of flaccid paralysis. Electromyography in GBS remains normal or minimally abnormal in severe cases. In GBS the demyelination of the peripheral nerves greatly reduces impulse conduction velocity but does not stop the conduction altogether. In GBS sensory nerve conduction time is also slow.
The most important feature of GBS is an increase in protein (up to 200 mg), with a cell count usually 10 or fewer monocytes per mm3 of cerebrospinal fluid (CSF). A CSF white count of 50 or more is strong evidence against the diagnosis of GBS.
            The prognosis of GBS is good, with complete recovery in the majority of cases. However, sequel in children with GBS may be present at 3 months after onset of paralysis, characterized by bilateral foot drop, weakness of grip, wrist drop, symmetrical atrophy of peroneal and anterior tibial muscles in legs, and atrophy of the thenar and hypothenar eminence in palms.

Features differentiating GBS from paralytic poliomyelitis are:

*     Age: The maximum number of cases of polio occurs in children aged below 3 years, while GBS is more likely to occur in individuals aged more than 2 years. There is age overlap at 3–4 years for both diseases. GBS is very rare in children < 1 year of age.
*     Fever: In polio fever is typically present just prior to the onset of paralysis, while in GBS it is 2–3 week's prior.
*     Paralysis: In polio paralysis is asymmetrical and initially involves large proximal muscles. In GBS, paralysis is symmetrical and usually involves distal smaller muscles. In GBS, the paralysis is ascending from the feet, while in polio it is descending from the shoulder or hip muscles.
*     CSF findings: In polio CSF shows 20 – 300 WBCs and protein is normal or minimally elevated, while in GBS, WBCs usually < 10 and proteins are up to 200 mg.
*     Although not routinely done, electrophysiologic diagnostic testing is occasionally performed. The usual findings are
       –     Nerve: Nerve conduction velocity may be normal in polio, but is reduced in GBS.
       –     EMG: Electromyography is highly abnormal in polio with signs of denervation and giant action potential, while in GBS its is normal or slightly abnormal. However, a normal EMG does not rule out polio.

           
Transverse Myelitis (TM):

Transverse myelitis may occur in persons aged 4 years and above. Fever may be present before the onset of AFP, but rarely during onset. Paralysis is usually symmetrical in the lower limbs and is accompanied by profound anesthesia to all forms of sensation. The site of involvement is usually the thoracic cord, but can be lumbar, thoracic, or cervical. Arms may also be partially paralyzed, but this occurrence is infrequent. Hypotonia is present and DTRs are absent in TM. The most common sequence of symptoms is flaccidity of legs, followed by loss of control of rectal and bladder sphincters. Recovery is related to onset when onset is fulminate or rapid (within hours), recovery usually begins several weeks to months later, and neurologic deficits remain. In contrast, children whose paralysis took several days to develop to completion usually begin to recover 1 to 5 days after symptoms peak and may recover completely. Flaccidity gradually may change to spasticity after several weeks and areflexia may be replaced by hyperreflexia.

Features differentiating transverse myelitis from polio are:
*     Age: Polio tends to affect children aged less than 3 years, while TM occurs mainly in persons aged more than 4 years.
*     Paralysis: The paralysis of polio tends to be asymmetrical and mostly involves the large proximal muscles, while the paralysis of TM is more often symmetrical and may involve trunk and both lower limbs.
*     Sensory: In polio there is no sensory loss, while in TM there is marked sensory loss.
*     Autonomic: In polio bladder retention my occasionally occur, while in TM there is marked dysfunction of the bladder and bowel sphincters.
*     CSF: In polio abnormal, while in TM normal.

 
Traumatic Neuritis:

Traumatic neuritis caused by injections may lead to AFP of the lower extremity. The onset of AFP in the affected lower limb occurs from 1 hour to 5 days after injection in the gluteal region. Fever is usually present before the onset of paralysis because often the injection has been given for a preexisting febrile illness. The sequence may be difficult to establish when several injections are applied in both gluteus muscles. AFP is usually accompanied by pain in the gluteal region or along the affected leg. Atrophy may appear 40 to 60 days later. Knee jerk is present. Ankle jerk is absent or diminished. Hip and knee strength is normal. The child walks with a foot drop. However, atrophy caused by a traumatic injection never reaches the degree seen in polio. Differences in calf circumference usually do not exceed 0.5 to 1.5 cm. Rarely; children are affected in both lower limbs because injections were given in both sides. Sequel is rarely severe and children gradually recover with physiotherapy within 3 to 9 months.
           
Differentiating features of traumatic neuritis (TN) from polio are:
*     Age: Polio occurs mainly below 3 years of age, while in TN there is no specific age distribution.
*     Paralysis: In polio the large proximal muscle groups are involved although any group of muscles may be affected and the DTRs are diminished. In TN only one leg is involved below the knee, and the knee jerk is normal while the ankle jerk is diminished.

Non–polio Enteroviruses (NPEV):

A number of other non-–polio enteroviruses are known to cause AFP. Many of the Coxsackie A viruses, most of the Coxsackie B and Echoviruses, Enterovirus types 70 and 71, as well as the mumps virus, have been temporally associated with both mild and severe neurolytic disease. Although most cases show a course of improvement with complete recovery, in some cases sequel may mimic paralysis caused by wild poliovirus. Because healthy children excrete other non-–polio enteroviruses, the isolation of non-–polio enteroviruses from patients with AFP may not be proof of causal relationship.

Other Conditions:

Other peripheral neuropathies that present as flaccid paralysis are caused by metabolic defects (diabetic), toxins (including lipid solvents and fish toxins), organophosphate pesticides, raw metals (lead), several pharmacological products, hereditary disease (Charcot – Marie – Tooth), diphtheria toxin and tick bite. The clinical picture of post – diphtheritic paralysis is similar to GBS. However, prior history of sore throat, nasal twang, and nasal regurgitation of fluids about 2 may differentiate it – 7 weeks before onset of paralysis.
            The paralytic sequel of polio is generally more severe and permanent, and atrophy of muscles and shortening of one lower limb may be present. AFP due to causes other than polio tends to resolve or improve within 60 days of onset.

Tumors may lead to acute flaccid paralysis that is asymmetrical. Progression is usually slow and generally there is no fever associated with paralysis onset. Distribution of nerve involvement is dependent upon the anatomic location of the space-occupying lesion.

Diagnostic dilemmas:

The differential diagnosis of AFP may at times be quite confusing, even in the best of hands. Difficulties arise particularly with 2–5 year–old children, who present with paralysis of both lower limbs. In this example, the history of fever is not definite. There may have been a mild upper respiratory tract infection or gastrointestinal disturbance before the onset of paralysis. The paralysis is of sudden onset and parents are unable to define whether it is ascending or descending. Slight asymmetry may be seen in GBS, also. Sensory loss, though specific for GBS, is not always possible to elicit in children. In this example, the CSF exam is useful, but if traumatic further delays diagnosis. Stool specimens will be helpful, but results are not available for 2–3 weeks. The clinician should re–evaluate confusing cases at more frequent intervals, perhaps after 2–3 days or after a week, and not hesitate to obtain second opinions. Electrophysiologic studies can help, but may not always be possible to obtain.

Other dilemmas occur when children present with generalized paralysis, which is rapid in onset and progression and has cranial nerve involvement. Unilateral facial nerve involvement favors the diagnosis of paralytic poliomyelitis, rather than GBS. Sensory loss will favor GBS. Children  < 1 year of age should be checked for hypokalemia. In general, in children < 1 year of age with AFP the clinician should be keenly aware of other treatable causes of paralysis and "pseudo" paralysis, such as scurvy, congenital syphilis, and low potassium (hypokalemia).

In a child with unilateral lower limb involvement, diagnosis may be confused with traumatic neuritis. Although not as common, paralytic poliomyelitis may present with weakness of the anterior tibialis leading to foot drop. Involvement of the gluteal and quadriceps muscles may be minimal. If the child in the supine position keeps the affected hypotonic limb in external rotation at the hip, paralytic poliomyelitis should be considered. A diminished knee jerk also supports the diagnosis of paralytic poliomyelitis. However, if the child is irritable, then reflexes may be difficult to elicit. A history of intramuscular injection in the gluteal area will favor the diagnosis of TN. In TN the knee jerk should be normal and the ankle jerk diminished. In general, residual paralysis of the lower limb, which does not involve the gluteus maximus, quadriceps, or anterior tibialis muscles, is unlikely to paralytic poliomyelitis.

In summary, the examination of the sick child is by nature difficult. A difficult history from parents can make the less common, atypical presentations even more confusing. Second opinions should be obtained when the diagnosis in not clear. Other measures that can be taken to increase accuracy of diagnosis include: (1) obtaining stools specimens for culture on all patients with AFP; (2) completing the 60 day follow–up examination; and (3) establishing expert review boards to evaluate case records of difficult patients.

           
"Pseudo" paralysis:

Certain conditions present with "pseudo" paralysis, which may be confused with AFP. These conditions are not AFP and should not be reported as AFP. Unrecognized trauma from contusions, sprains, or fractures is common sources of confusion.

Children with hypokalemia are toxic, irritable, and present with generalized acute flaccid paralysis of all 4 limbs and neck flop, caused by diminished serum potassium levels especially due to diarrhea and vomiting. Weakness is noticed first in limb muscles, followed by weakness in trunk and respiratory muscles. Parents often bring their children in when the child becomes floppy and sudden neck flop is noted. Areflexia, paralysis, death from respiratory muscle failure and cardiac arrest can occur. Intravenous potassium drip save lives when the alert clinician recognizes this condition.

Children with non–specific toxic synovitis present with unilateral limp. Hip or knee joints are commonly affected. There is usually swelling of the joint and movements are painful. Low-grade fever may persist for several days. X–rays may show fluid in the joint space. 
Acute osteomyelitis shows localized signs of inflammation of the affected bone. There is polymorphonuclear leukocytosis. X–rays are diagnostically helpful.

Vitamin C deficiency (Scurvy) may occur at any age, but the majority of cases occurs between 6 months to 2 years of age (like polio). The onset of symptoms is gradual. There is a history of irritability, digestive disorders, and loss of appetite. There is generalized tenderness and child resents handling. Pain leads to pseudo paralysis and the legs are kept in the "frog" position. In some cases subperiosteal hemorrhage may be palpated at distal end of femur. Gums show bluish–purple spongy swelling of mucous membranes, especially when teeth have erupted. X–ray of the knees is diagnostic. In early cases a white line is visible at the distal end of the femur and the proximal end of tibia and fibula. In advanced cases a zone of destruction on the medial side of the distal end of the femur and proximal end of the tibia is seen.

In acute rheumatic fever the clinical pattern is usually diagnostic. The arthritis is migratory and affects different joints, i.e. elbows, knees, ankles, and wrists. The affected joints are red, warm and swollen.

Congenital syphilitic osteomyelitis is found only in early infancy. X–rays are diagnostic and include osteochondritis at wrists, elbows, ankles, knees, and periostitis of the long bones. Osteochondritis is painful and refusal to move the limb leads to pseudoparalysis.

Other conditions such as meningitis or meningoencephalitis can initially be confused with paralytic poliomyelitis; however, their etiologies are clarified after diagnostic procedures, such as lumbar puncture and biochemistry’s.

Post polio syndrome (also called postpolio residual paralysis and postpolio muscular atrophy) refers to a group of disorders experienced by many poliomyelitis sufferers, typically starting 25–35 years after initial onset. Symptoms include renewed, usually gradual progression of muscle weakness, increased fatigability, joint pain, muscle cramps, intolerance to cold, and sometimes increased difficulty in breathing (when respiratory muscles are involved or severe scoliosis is present). Postpolio syndrome appears to be more frequent and severe in persons who had a more severe initial poliomyelitis illness. No single examination, procedure, or laboratory test can definitely diagnose this condition. There is no evidence to suggest that these patients be re-infected or have chronic infection; rather, they may be experiencing the consequences of long–term overuse or disuse to compensate for the original destruction of nerve cells.

Management of paralytic poliomyelitis in the acute phase is symptomatic. The child needs rest and care to ensure that there is no stress on the affected muscles. Care is also required to see that the child does not get secondary infections. Massage and injections during this period are contraindicated.

Uncomplicated cases of single lower limb or both lower limbs and trunk involvement can be treated at home. However, if poliomyelitis is suspected, such children should be examined by a physician as early as possible, to confirm diagnosis, rule out "high–risk" factors, such as early respiratory involvement, and for proper advice to parents on the care of the child at home.

Complete bed rest is essential during the acute phase. There should not be any stress on the muscles involved. The mother or other persons caring for the child should frequently change the posture of the child in bed every two to three hours. The child should be placed on the stomach for short periods each day, to avoid the risk of pneumonia.

The limb should be place in the optimum position for relaxation of the paralyzed muscles. The affected limbs can be positioned with pillows or rolled towels. The recommended positions are hip–slight flexion; knee – 5 degrees flexion; foot – 90 degrees (support against the sole of the foot). Both legs should be supported from the lateral sides with pillows or rolled towels to prevent external rotation. Rolled towels should also be place under the knee for positioning of hips and knees.

Joints of paralyzed muscles should be moved passively gently through full range of motion to prevent contracture. Such movements should be done for 10 minutes 2 to 3 times a day. The movements should involve all joints of the affected limb. The movement should be within the range of pain.
Warm water compress using hot packs with soaked towels wrapped around the affected parts for 10 minutes 2 to 3 times daily should be started as soon as possible and continued up to 6 weeks after onset of paralysis.

There is no restriction on diet and normal food may be given to the child. Children may be constipated during this period. Transient urine retention may be noted which alternate hot may relieve and cold compressed over the suprapubic region. However, if constipation lasts for 3 days or if there is no unit for 24 hours, such children should be immediately taken to a hospital.

As the acute phase of illness subsides and recovery of strength begins, the emphasis shifts to active rather than passive movements and a vigorous program of physical therapy is initiated to regain muscle power. Management of the recovery phase begins with a careful assessment and recording of muscle power of the weak muscle groups to serve as a baseline. The degree of recovery ranges from minimal to complete. Maximum recovery of the affected muscles takes place in the first six months, but slow recovery continues up to two years. Physical therapy is necessary to prevent deformities and contracture due to muscle imbalance or improper posture. Physical therapy under a qualified physiotherapist is important for regaining muscle power and rehabilitation of the child.

Braces are used to compensate for weak muscle groups, e.g. foot drop or more severe leg weakness. Children are fitted with braces (calipers) depending upon the age and degree of involvement of the limbs. Unilateral brace is given in case of a single lower limb paralysis by the age of one and a half years, when the child begins to start walking. Bilateral leg braces are prescribed for both leg paralysis by the age of 2 1/2 to 3 years of age. Children with bilateral braces need crutches. Bracing above or below the knee depends on the extent of paralysis. It can be extended up to the trunk in the case of trunk muscle weakness. Infants and younger children are also given abdominal support and jackets to help in sitting in case of trunk weakness.

Although further clinical recovery is not expected after two years, continued physiotherapy is required to prevent deformities. Contracture, denervation, or imbalance of muscle tension can lead to progressive skeletal deformities. Reduced growth of a denervated extremity is commonly seen. Tendon shortening can be largely prevented by active physical therapy in the weeks following acute poliomyelitis, but some cases will require orthopedic procedures. Tendon transplants may be considered to improve function of the hand or foot. Surgical interventions may be indicated for various forms of deformities. Orthotic appliances also need to be changed as the child grows.

Except for physical handicap of residual paralysis, children are otherwise normal and should be treated as such. They should be encouraged to take part in childhood activities and attend normal schools. The guidance of a pediatric physiatrist, occupational therapist, social worker, and a vocational counselor are helpful in promoting a positive approach and adjustment.