Acute Flaccid Paralysis surveillance in Gaza Strip, Palestine

The incidence rate among children less than 15 years old which range from 0.58 / 100.000 in 2006 to 1.2 / 100.000 in 2012; Most of the cases 89.5 % had fully vaccinated and 10.5% had not fully vaccinated due to their ages less than one year, 65.8 “25 cases” had residual weakness, all of the cases classifi ed as discarded according to the expert committee decision; no one case dead, all of the samples sent to the Tal-Hashomir laboratory in the occupied land in 1948 for viral isolation; most of the results 81.6% revealed that no virus isolated, 11.8% isolated ECHO virus, 2.6% isolated Coxsachie virus and 4 % isolated NPEV.


Introduction
Acute Flaccid Paralysis (AFP) is a clinical syndrome characterized by rapid onset of weakness, in the respiratory muscles, swallowing and limbs; and death because of respiratory muscles failure.
Surveillance for AFP is an important as it consider as a key strategy used by the Global Polio Eradication Initiative by the World Health Organization [1].
According to WHO's strategy the countries required to survey the AFP cases in order to combat the Poliomyelitis using a standard case defi nition.  The disease considered as seasonal disease, commonly occur in summer and early autumn.

Epidemiology of poliomyelitis
In the low immunization coverage countries such as developing countries, the virus led to more signifi cant disability, illness death. As reported, fi ve to ten cases every 1000 cases will develop paralytic disease.

Transmission
The virus transmitted from person-to-person through the fecal-oral route. Through feces the virus spread after multiplying in the intestines, after infection the virus excreted for two months or more but the maximal amount excreted just before paralysis and during the fi rst fourteen days after paralysis onset. The incubation is seven to ten days with range extended from 4-35 days.

Reservoir
The unique reservoir of the virus is human only. Some studies reveled that small amount of wild poliovirus persist in very cold water for a period extended to months, in tropical climates the virus can survive for a few days only.

Communicability
The Poliovirus considered as one of the high communicable viruses, one week before and 2 weeks after onset of paralysis the infected ones can be highly infectious to all household and close contacts especially in poor sanitation areas.

Immunity
Any non-immunized person considers susceptible to infection. According to literatures any infant born to mother have antibodies against the virus the infant will be protected against paralytic polio naturally for a few weeks.
Infection with wild Poliovirus and/ or the immunization leading to obtaining of immunity against the disease, the vaccination of Oral Polio Vaccine "OPV" resulting in both local intestinal cellular and humoral responses this immunity may persist for years and lead break of chain of infection.
The immunization with inactivated Poliovirus Vaccine "IPV" confers humoral immunity with less intestinal immunity, the IPV does not provide resistance to carriage and spread of wild polio virus in the community.

Case defi nition of Acute Flaccid Paralysis & Poliomyelitis
Acute Flaccid Paralysis: Acute onset of a fl accid paralysis of one or more groups of muscles with decreased or absent tendon refl exes in the affected muscles, without other apparent cause, and without sensory or cognitive loss.
All diagnosed cases must be investigated to exclude Poliomyelitis as one of WHO requirements for Poliomyelitis eradication goal.
Poliomyelitis and AFP cases consider from group A diseases in the Palestinian surveillance system and to be immediately to the epidemiology department.

Poliomyelitis
Acute diseases caused by wild poliomyelitis viruses characterized by acute onset of a fl accid paralysis of one or more groups of muscles with decreased or absent tendon refl exes in the affected muscles, without other apparent cause and without sensory or cognitive loss; One confi rmed polio case must be considered as an outbreak.

Confi rmed case:
A case with acute paralytic illness, with or without residual paralysis, and isolation of wild poliovirus from the stools of either the case or its contacts.

Polio-compatible case:
A case in which one adequate stool specimen was not collected from a case within 2 weeks of the onset of paralysis, and there is either an acute paralytic illness with polio-compatible residual paralysis at 60 days, or death takes place within 60 days, or the case is lost to follow-up.

Vaccine-Associated Paralytic Poliomyelitis case "VAPP":
A case with acute paralytic illness in which vaccine-like poliovirus is isolated from stool samples, and the virus is

Study design
The research study conducted through cross sectional study, based on AFP investigation forms in the epidemiology department. All AFP reported cases were followed up after 60 days for clinical assessment to ascertain residual paralysis.

Results & discussion
The AFP surveillance system provides a sensitive tool for investigating AFP cases in children, with careful clinical evaluation of the differential diagnosis and expert review of cases. Accurate diagnosis requires a precise knowledge of the etiology and underlying pathophysiology. Analysis of the clinical fi ndings and diagnosis reported for the 38 cases in this study showed that the underlying causes were diverse.
During the period of this study, 38 AFP cases below age 15 years were reported to our department Table 1.
Demographic related variable showing that most of the cases were male 71.1% "27 case" & 28.9 were female. 36.8% " 14 case" of the cases were living in Gaza governorate, 26.3% "10cases" were living in North Gaza governorate, 21.1% "8cases" were living in Khanyounis and the rest of the case in Rafah & Mid-zone 3 cases for each.
In relation to age category most of the cases 73.7% "28 case" their ages in between 1-9 years, 4 cases "10.5% below one year and 15.8% "6 cases" more than 10 years up to 15 years. Table "2" showing the clinical related variables in which the primary diagnosis of the cases were 28.9 % "11" cases diagnosed as AFP, 21.1% "8 cases" diagnosed as GBS, and the rest of the cases diagnosed as Inability to walk 16%, Poly neuropathy 2.6% "one case" and Hemiparesis, Quadriparesis, Quadriplegia and paraplegia 7.9% "3 cases" for each; 94.7% "36 case" complained from rapid progression of the paralysis; 92.1 % complained from fl oppy paralysis; 52.6 % complained from fever with onset of paralysis while 47.4% did not complain.
Most of the cases 71.1 % did not complain from asymmetric paralysis; Most of the cases 81.6 % did not complain from Sensory nerve loss; More than half of the cases 57.9% "22 case" complained from both lower limb paresis & / or plegia.
The fi nal diagnosis of the cases were as follow, 71.1% "27 cases" were GBS, 10.5 % were Encephalitis, 7.9% were Neuropathy, 2.6% " one case only" for each of the following Aseptic meningitis, Transverse myelitis, Tuphus fever and Subspinal musculae atrophy.
Gullain Barre Syndrome (GBS) accounted for 71.1% "27/38 cases" of AFP cases in this study. In the absence of wild poliovirus induced poliomyelitis, GBS is the most common cause of AFP reported in many parts of the world, accounting for over 50% in many industrialized and developing countries [2].
A study of AFP surveillance in Malaysia, data from 1997 to 2001 showed that GBS was found in 30.2% of AFP cases, with an annual incidence of 0.36% [3].
The majority of GBS cases in the AFP surveillance were diagnosed based on typical clinical features, such as progressive ascending and symmetrical paralysis of the limbs with Table 3.
In this table its` clear that most of the cases 89.5 % "34 case" had fully vaccinated and 10.5% "4 cases only " had not fully vaccinated due to their ages less than one year This may not indicate the actual incidence of AFP, as many cases may not have been reported to epidemiology department for further investigation.
Since AFP notifi cation is part of the poliomyelitis eradication exercise some cases may have been omitted when a defi nite diagnosis by history, for example trauma, did not indicate the need for laboratory investigation at the time of clinical assessment [4][5][6][7][8].
In this table it appears that about half of the cases 47.4 % "18 /38" notifi ed about the cases to the epidemiology department by El-Nasser pediatric hospital Table 6.   In this table it appear that all of the cases 100% "38 case" were followed up by the epidemiology staff and the clinicians; 65.8 "25 cases" had residual weakness and 34.2 % had no residual weakness; All of the cases classifi ed as discarded according to the expert committee decision; No one case died 0.0 % " 0/38 case" during the disease and the follow up period Table 7. • Two adequate stool specimens collected from at least 80% of cases of AFP.
• All stool specimens should be processed at the Tal-Hashomir laboratory the WHO accredited laboratory in the occupied Palestinian land in 1948.    The list of underlying causes of AFP is broad and complex.

Virologic classifi cation scheme
Clinicians need to have a detailed knowledge of the differential diagnosis to ensure effective and timely management. The current surveillance program provides a sensitive tool for investigating AFP cases with careful clinical evaluation of the differential diagnosis and expert review of cases. It is therefore crucial that AFP surveillance be conducted even in the absence of wild poliovirus transmission.
All polio eradication strategies should continue to be effectively implemented if we must preserve the current status of polio eradication in Palestine.
Polio continues to be reported in a number of regions throughout the world specially Easter Mediterranean region countries.
Until polio eradication has been globally achieved polio virus could be imported into Palestine.
Currently, AFP surveillance in Gaza is inadequate (range in between "2006-2012" 0.58-1.2 /100,000 population among children < 15 years of age) which reveal improvement of the surveillance system in 2012 1.2/100.000, which meets WHO standards.
Ensuring high quality AFP surveillance and high immunization coverage rates are necessary to maintain poliofree status, to rapidly identify importation of polio cases and respond quickly in the event that polio importation does occur.

All clinicians are encouraged to
• Report all cases of AFP among children < 15 years of age.
• Submit at least two stool samples to the epidemiology department (at least 24 hours apart within 14 days of onset of paralysis).
No national laboratory for primary poliovirus isolation and identifi cation in Palestine, which consider as obstacle to the Palestinian health care system.