Seasonal Hyperacute Panuveitis (SHAPU)

Dr. Ranju Kharel (Sitaula)
Published Online: April 2nd, 2021 | Read Time: 15 minutes, 19 seconds


Seasonal Hyperacute Panuveitis (SHAPU) is a mysterious eye disease with grave prognosis, reported only from Nepal. Though it was reported for the first time in 1975,1-3 no definite etiopathogenesis has been established to date. It occurs as an outbreak in certain regions of Nepal in a cyclical pattern during the autumn season and peaks during the winter season (August–December) only in odd years. Thus, after the first outbreak of 1975, the next outbreaks occurred in 1977,1979, 1981, and so on and the last outbreak was reported in 2019. SHAPU predominately occurs among children4 and the youngest reported case is a 38- day-male baby.5 No gender predilection has been identified in SHAPU.4 All cases are mainly immunocompetent with no prior history of systemic or ocular illness/trauma.4, 6

SHAPU is very devastating and generally leads to the loss of sight within a week, followed by cosmetic disfigurement due to phthisis bulbi, which can have a significant emotional impact on the patient. The disease is so rare and less explored that there are only 12 articles upon it in the PUBMED to date. According to the SHAPU factsheet, >15,000 cases have been affected over the last 45 years.7

SHAPU Outbreak Period:

SHAPU occurs cyclically during the autumn season soon after the monsoon (August-November) and usually ends with the peaking of winter in December or January of the odd years.4

Presenting Visual Acuity:

Sudden onset of profound loss or drastic diminution of vision is a common presenting symptom of this disease. Usually, they present with vision of 3/60 or less but as the affected cases are predominately children, the accurate visual acuity assessment is often difficult.4

Ocular Manifestations In SHAPU:

SHAPU has characteristics symptoms and signs which makes it peculiar from the other uveitic condition. The clinical features are listed below-


Unilateral eye

Sudden onset of red-eye with no/minimal pain but no discharge

Profound loss of vision in a week

The whitish glow from the center of the eye

Affected eye getting smaller in a few weeks

No prior history of surgery or trauma

Figure 1: Unilateral red-eye with whitish pupillary light reflex


Severe decrease in the visual acuity

Marked conjunctival congestion (circumcorneal and diffuse)

Dense fibrinous reaction/exudates in the anterior chamber

Mobile hypopyon in the anterior chamber

Significant posterior synechia with difficult to dilate the pupil


Dense vitreous exudation with difficulty to visualize the fundus

IOP generally low to normal

Figure 2: Dense fibrinous reaction with hypopyon in the anterior chamber of a SHAPU case

Uncommon Manifestations:

Iris muddy

Greenish pupillary reflex

Loss of corneal sensation

Greenish pupillary reflex

Hair like particles in ocular tissue

Laboratory Investigations:

Since the etiology of SHAPU is not well understood, there are no definite investigations to establish SHAPU rather clinical pattern recognition is more important.

Laboratory tests performed at the treating hospitals have identified a variable and confusing array of bacteria and viruses isolated from the aqueous and vitreous fluid samples from the eyes of affected patients.4 In some cases, Streptococcus pneumoniae and Acinetobacter, have been grown.8 However, viruses such as human Anelloviruses and Varicella zoster have also been reported in the vitreous fluid, but with no clear clinical significance,9, 10 while in many cases no organisms could be identified. Thus, various organisms have been reported by different workers,6, 9, 10 but lack of consistency in organisms reported makes it difficult for final attribution.

Newer molecular techniques including genomic sequencing to confirm or rule out microbes in the ocular fluid samples is underway to identify the definite microbes. Similarly, identification of immunological biomarkers and HLA typing from the blood and ocular specimen are also being planned to confirm its immunological association.

There are two arms of investigations for SHAPU as it could have an infective etiology or immunological etiology or a mixture of both. Thus, to establish it, there is a need for both microbial tests and immunological tests.

Figure 4: Flowchart for the microbiological processing and immunological analysis in SHAPU

Ocular Imaging Tests:

Ocular ultrasound (USG) is a very useful investigation tool in SHAPU because the fundus in such patients is difficult to visualize due to dense vitritis. USG shows hyperechoic shadows in the vitreous and retina, thickening of the ciliary body, and retinochoriodal complex with or without retinal detachment depending upon the stage of presentation.

Figure 5: USG (A+B) scan showing dense hyperechoic shadows in the vitreous with thickened choroid

Optical Coherence tomography (OCT) is also an important tool to early detect the change in choroid and macula of SHAPU cases. But usually, it is difficult to perform in an early stage in the presence of hazy ocular media. The anterior segment OCT has been able to detect the hair particle in the cornea of a SHAPU case.11


Swinging between noninfective to infective etiology, there is no established protocol for the management of SHAPU cases.

In early reports, cases were treated with either singly or a combination of antibiotics, antiviral, immunosuppressive with uniformly poor results.4

Report from 200312 had shown better outcomes in 50% of the cases with early vitrectomy and then a report of 201013 reported regain of vision in 33.3% patients with topical, subconjunctival, oral, or intravitreal antibiotics and/or steroids but no surgical intervention.

With our experiences in various SHAPU outbreaks, we have developed a recent treatment protocol of immediate/urgent treatment with intravitreal antibiotics (Vancomycin (1 mg/0.1 ml) + Ceftazidime (2.25mg/0.1ml) ± steroid (Dexamethasone injection (0.4mg/0.1ml). Along with subconjunctival Vancomycin and Dexamethasone. If there is no sign of improvement by the 3rd day, pars plana vitrectomy ± lensectomy for diagnostic and therapeutic purposes is performed.

Figure 6: Undergoing Pars plana vitrectomy in a SHAPU case

Risk Factors of SHAPU:

In the 1980s, exposure to Tussock moths was reported as the primary risk factor for the disease.14 But later, other studies reported Gazalina moths as the suspect.8, 15 Tiny hairs of the moths have been identified in ocular structures in few patients including the cornea and anterior chamber. 6, 11

A multi-center, national case-control Epidemiological study conducted in SHAPU 2017 Outbreak has confirmed the white moths are the potential risk factors of SHAPU.16 SHAPU cases were 6.89 times more likely to report the history of direct contact with these white moths, making it the most important factor found in this study.

The moths might serve as vectors, carrying plant material acquired during their feeding time and this material may be the responsible agent that can induce infective and or immunological reactions within hours of contact with eye leading to hyperacute uveitis. Similarly, the spines and hairs of female moths bear toxic materials (histamine, acetylcholine, venom, pro-inflammatory products of cyclo-oxygenase, vaso-degenerative and fibrinolytic effects, serine proteases and pro-coagulant toxins) for natural protection of their eggs.17 These toxic materials may be capable of causing immediate hypersensitivity reactions in susceptible individuals. Additional research needed in this area, including the need for toxins & immune biomarkers analysis of the moth particles and its comparison with the ocular fluid samples of SHAPU.

Future studies also need to identify the genus of white moth, its lifecycle, and toxicology.

Figure 8: The female white moth with black striation and brownish spines and setae at the end to protect the eggs

Differential Diagnosis:

Conjunctivitis: It is often underlooked as unilateral viral conjunctivitis. But SHAPU is discharge less with circumcorneal congestion, intraocular reaction, and decreased vision, unlike conjunctivitis.

Endogenous Endophthalmitis: SHAPU cases are immunocompetent with no systemic foci of infection. All the blood parameters are normal.

Exogenous Endophthalmitis: SHAPU cases give no prior history of intraocular surgery or trauma to the eye.

HLA B 27 Uveitis: SHAPU is always unilateral with no recurrence in a ping pong manner.

Behcet’s disease: The hypopyon in SHAPU is fibrinous and not associated with the mouth/genital ulcer. SHAPU is always unilateral with no recurrence


The serious gravity of SHAPU is associated with various complications if not treated on time.

Retinal detachment

Retinal necrosis



Phthisis bulbi


SHAPU continues to be a mysterious blinding disease in the absence of its known etiology. A multi-disciplinary, multi-centric team (national +international) consisting of epidemiologists, ophthalmologists, microbiologists, entomologists, health educationist should be constituted to undertake a comprehensive investigation and intervention so as to prevent the future outbreaks and timely management of the outbreaks with the standard treatment protocol.


SHAPU Definition"Unilateral dischargeless red eye with severe intraocular reaction associated with significant vision impairment (in verbal children and adults) occurring soon after monsoon in the odd years, with contact history of white moths but no prior history of surgery or trauma”


  • Odd years since 1975
  • Seasonality (Post Monsoon season Aug-Dec)
  • Predominantly children with no gender predilection
  • Unilateral eye involved, No recurrences
  • Sudden onset of Redness without discharge
  • A dramatic loss of vision within 48 hours
  • White Pupil with Red Eye
  • No history of trauma or surgery
  • Exact cause not known till date


1. Upadhyay M, Rai N, Ogg J and Shrestha B. Seasonal hyperacute panuveitis of unknown etiology. Annals of ophthalmology. 1984; 16: 38-44.
2. Nussenblatt RB. Seasonal Hyperacute Panuveitis (SHAPU). In: Whitcup RBNSM, (ed.). Uveitis Fundamentals and Clinical Practice. Fourth ed. USA: Mosby Elsevier, 2010, p. 237-8.
3. Mozhgan Rezaeikanavi MS. Diagnosis and Treatment of Uveitis. In: Vitale CSFaAT, (ed.). Other Vector-Borne Parasitic Infections. 2nd ed. India: Jaypee Brothers Medical Publishers, 2013, p. 576.
4. Upadhyay M, Kharel Sitaula R, Shrestha B, et al. Seasonal Hyperacute Panuveitis in Nepal: A Review over 40 Years of Surveillance. Ocular immunology and inflammation. 2018: 1-9.
5. Kharel R, Karki P, Joshi SN, Sharma AK and Upadhyay MP. Youngest reported Seasonal Hyperacute Panuveitis case. American Journal of Ophthalmology Case Reports. 2019: 100523.
6. Manandhar A. Seasonal hyperacute panuveitis: an update. Current opinion in ophthalmology. 2011; 22: 496-501.
7. Madan Prasad Upadhyay RKS, Anu Manandhar, Emily W Gower, Pratap Karki, Harimaya Gurung, Indraman Maharjan, Reuben Samuel and Sagun Narayan Joshi The Risk Factors of Seasonal Hyperacute Panuveitis (SHAPU). Under Review 2020.
8. Manandhar A, Margolis TP and Khanal B. New Clinical and Laboratory Findings of SHAPU. Nepalese Journal of Ophthalmology. 2018; 10: 23-31.
9. Kathil P, Biswas J and Gopal L. Demonstration of varicella zoster virus in a case of presumed seasonal hyperacute panuveitis. Indian J Ophthalmol. 2005; 53: 270-2.
10. Smits SL, Manandhar A, van Loenen FB, et al. High prevalence of anelloviruses in vitreous fluid of children with seasonal hyperacute panuveitis. The Journal of infectious diseases. 2012; 205: 1877-84.
11. Kharel R, Karki P, Joshi SN, Sharma AK and Upadhyay MP. Moth hair in cornea in a case of seasonal hyperacute panuveitis. Indian Journal of Ophthalmology. 2020; 68: 930.
12. Byanju R, Pradhan E, Rai S and Sapkota Y. Visual outcome of vitrectomy in seasonal hyperacute pan uveitis. Kathmandu University medical journal (KUMJ). 2003; 1: 121-3.
13. Shrestha E. A profile and treatment outcome of seasonal hyper-acute panuveitis. Nepalese Journal of Ophthalmology. 2010; 2: 35-8.
14. Malla O. Endophthalmitis probably caused by Tussock moth. Report of the Proceedings of the first National Seminar on Prevention of Blindness. 1978, p. 44.
15. Manandhar A, Paudel G, Rai C, Rai S, Gurung R and Ruit S. Seasonal hyper acute pan uveitis--recent scenario in Nepal. 2008.
16. Upadhyay M MA, Kharel Sitaula R, Joshi N S. Risk Factors of Seasonal Hyperacute Panuveitis. A research conducted under the support of World Health Organisation Countryside office Nepal, 2017-2018.
17. Zaspel JM, Weller S and Branham M. A comparative survey of proboscis morphology and associated structures in fruit-piercing, tear-feeding, and blood-feeding moths in Calpinae (Lepidoptera: Erebidae). Zoomorphology. 2011; 130: 203.

Dr. Ranju Kharel (Sitaula)
Assistant Professor and Uveitis Specialist, B.P Koirala Lions Centre for Ophthalmic Studies, Institute of Medicine, Nepal.
Dr. Ranju Kharel (Sitaula) is an Assistant Professor and uveitis specialist working at B.P Koirala Lions Centre for Ophthalmic Studies, Institute of Medicine in Nepal. She graduated in 2010 and underwent uveitis fellowship at Sankara Nethralaya in 2016 and training of International Uveitis Study Group in Italy. She became the1st Nepalese Ophthalmologist to obtain Fellow of All India Collegium of Ophthalmology (FAICO) degree in uvea. Due to her interest in research, she has published >50 articles in peer reviewed journals, 4 book chapters and is the reviewer of 7 journals. She has presented many oral and poster presentations in various national and international platforms. She is the receiver of many national and international prestigious awards including Women in Eye and Vision Research (WEAVR) Developing Country Eye Researcher Award, Global Ophthalmology Awards Program (GOAP), XOVA research program by Novartis and Japanese Ophthalmological Society International Young Investigator Award.
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