fadzilatul ahya idris, leelavathi muthupalaniappen, petrick periyasamy.  (2023).  parental hesitancy and perception of the covid-19 vaccine for children below five years in kuala lumpur.  - journal of health science and medical research.  95. 

nurin zainal, aznida firzah abdul aziz, chai eng tan, rahmah kamaluddin, petrick periyasamy, noorul amilin binti sulaiman.  (2023).  pause©: the case for developing a premarital hiv testing aid for primary care settings in malaysia.  - malaysian journal of public health medicine.  190-200. 

fadzilatul ahya idris, leelavathi muthupalaniappen, petrick periyasamy.  (2023).  parental hesitancy and perception of the covid-19 vaccine for children below 5 years in cheras district, kuala lumpur.  - medical journal of malaysia.  177-183. 

wahab, a.a, nurazizah, s.m.a, ding, c.h, muttaqillah, n.a.s, nordashima, a.s, kori, n, periyasamy, p.  (2023).  non-bacteremia liver abscess caused by burkholderia pseudomallei from a tertiary teaching hospital in malaysia: a case report and literature review.  - tropical biomedicine.  290-294. 

u. salamah faisal, u.a. zainulabid, n. kori, p. periyasamy, t.m.n. khaithir.  (2023).  vibrio cholera o1 ogawa bacteremia with extraintestinal manifestation.  - international journal of infectious diseases.  S7. 

petrick periyasamy, tan li fen, najma kori, ummu afeera zainulabid.  (2023).  rebound covid-19 after paxlovid in 2 related family members.  - international journal of infectious diseases.  S129. 

u.a. zainulabid, a. aslam, m. hussain, i. ibrahim, p. periyasamy, n. kamarudin, h.f. ahmad.  (2023).  whole genome sequence of sars-cov-2 from covid-19 acquired hemophilia patient.  - international journal of infectious diseases.  S14. 

nur syazana mad tahir, aniza ismail, aznida firzah abdul aziz, syed mohamed aljunid, petrick periyasamy, hazlina mahadzir, fauzi md anshar, mohd faudzi abdullah, wong ping foo, ho bee kiau, mohd fairuz ali, rizah mazzuin razali.  (2022).  clinical pathway for influenza in the elderly: a comprehensive management protocol of malaysia.  - asia-pacific journal of health management.  1-14. 

nurul amirah mohamad farook, silvia argimón, muttaqillah najihan abdul samat, sharifah azura salleh, sunita sulaiman, toh leong tan, petrick periyasamy, chee lan lau, zalina ismail, nor azila muhammad azami, mia yang ang, hui-min neoh.  (2022).  diversity and dissemination of methicillin-resistant staphylococcus aureus (mrsa) genotypes in southeast asia.  - tropical medicine and infectious disease.  1-32. 

nazrul anuar nayan, choon jie yi, mohd zubir suboh, nur-fadhilah mazlan, petrick periyasamy, muhammad yusuf zawir abdul rahim and shamsul azhar shah.  (2022).  covid-19 prediction with machine learning technique from extracted features of photoplethysmogram morphology.  - frontiers in public health.  1-11. 

ly sia loong, pauline siew mei lai, nurul adilla hayat jamaluddin, isa naina-mohamed, petrick periyasamy, chee lan lau, karin thursky, rodney james, sasheela ponnampalavanar.  (2022).  comparing the appropriateness of antimicrobial prescribing among medical patients in two tertiary hospitals in malaysia.  - journal of infection in developing countries.  1877-1886. 

wan rahiza wan mat, cheah saw kian, aliza mohamad yusof, lau chee lan, michelle tan hwee peng, petrick periyasamy.  (2022).  pharmacotherapeutics in the critically ill covid-19 patients.  - malaysian journal of medicine and health sciences.  316-323. 

najma kori, farida islahudin, muhammad yusuf zawir abd rahim, petrick periyasamy, noraida mohamed shah, ernieda md hatah, lau chee lan.  (2022).  corticosteroid effectiveness among hospitalised covid-19 patients in malaysia.  - journal of infection in developing countries.  1390-1397. 

sy hwan ang, petrick periyasamy, shamsul azhar shah, ramliza ramli, najma kori, chee lan lau.  (2022).  the risk factors for complications and survival outcomes of klebsiella pneumoniae bacteraemia in hospital canselor tuanku muhriz universiti kebangsaan malaysia.  - medical journal malaysia.  409-414. 

alex y. c. sim, ainal a. naffi, tang s. fai, najma kori, wan a. w. zaidi, petrick periyasamy, norshamsiah md din, mushawiahti mustapha, ayesha mohd zain.  (2022).  bilateral intermediate uveitis in a healthy teenager with the multisystem inflammatory syndrome in children secondary to covid-19 infection.  - journal of medical virology.  1269-1271. 

syarifah syahirah syed abas,noralisa abdul karim,petrick periyasamy,nurasyikin yusof,shamsul azhar shah,tan toh leong,saiful safuan md sani,hanita othman,sharifah azura salleh,nurul nadiah mohd zaidi,s fadilah abdul wahid,wan fariza wan jamaludin.  (2022).  correlation of dengue warning signs during febrile phase with rotational thromboelastometry, cortisol and feritin.  - international journal of environmental research and public health.  1-15. 

emelia osman, nur azma amin, thieeraporn phraseart ma noon, siti nuratiqah hanani lahat, mohamad syairazi rosli, shazia farhana sham, petrick ramesh periyasamy, nuraffini ghazali,siti nor azreen abd manap, and rahmah noordin.  (2022).  comparison of two serological assays in detecting strongyloides infection in immunocompromised patients.  - american journal of tropical medicine and hygiene.  636-639. 

tuang wei xuan, palaniapan sivakumar, periyasamy petrick.  (2022).  first reported case of cladosporium liver abscess in immunocompromised host.  - medical mycology.  194. 

chee ll, petrick p, muhd nordin s, sarah anne r, lay yg, suet yc, kiew bp, shue hk, farah waheeda t, mei ky, sheah lg, nur jannah a, xin yc, poy kl, stephanie wyt, dexter vd, ramliza r, toh lt, aliza my, saw kc, wan rahiza wm, isa naina-mohamed.  (2022).  plethora of antibiotics usage and evaluation of carbapenem prescribing pattern in intensive care units: a single-center experience of malaysian academic hospital.  - antibiotics.  1-19. 

nor azila ma, nor azian am, azmawati mn, sharifah azura s, petrick p, najma k, mohd rohaizat h, norfazilah a, anita s, hanita o, tuti ningseh md, nurul syakima am, ezanee azlina, siti aishah, nurul syeefa', abdul rashid, abdul halim, hanafiah hr, rahman j.  (2021).  covid-19 in malaysia: exposure assessment and prevention practices among healthcare workers at a teaching hospital.  - journal of infection in developing countries.  1816-1824. 

shamira shahar, ruslinda mustafar, lydia kamaruzaman, petrick periyasamy, kiew bing pau, ramliza ramli.  (2021).  catheter-related bloodstream infections and catheter colonization among haemodialysis patients: prevalence, risk factors and outcomes.  - international journal of nephrology.  1-9. 

norfazilah ahmad, norzehan fatimah mohd ali, azmawati mohammed nawi, mohd rohaizat hassan, azimatun noor aizuddin, rozita hod, faiz daud, sharifah azura salleh, petrick periyasamy, abdul halim abdul gafor, najma kori.  (2021).  clinical characteristics of patients with coronavirus disease 2019 (covid-19) in a teaching hospital in malaysia.  - journal of infection in developing countries.  1059-1065. 

petrick periyasamy, ng boon hau, umi kalsom satariah ali, zetti zainol rashid, najma kori.  (2021).  aerosolized sars-cov-2 transmission risk: surgical or n95 masks?.  - infection control & hospital epidemiology.  1150-1152. 

azlina ibrahim, isa naina mohamed, lau chee lan, ramliza ramli, najma kori, petrick periyasamy.  (2021).  an observational prospective study on the appropriateness of ceftriaxone use in medical wards of ppukm.  - international journal of infectious diseases (ijid).  104. 

petrick periyasamy, navaneedha lingam mahalingam, najma kori, andrea ban yu lin, ramliza ramli, isa naina mohamed, lau chee lan.  (2021).  time to clinical stability in hcap in a tertiary center hospital in kuala lumpur.  - international journal of infectious diseases.  106. 

ahmad izuddin mustaffa, petrick periyasamy, lau chee lan, ramliza ramli, najma kori,.  (2021).  the overly attached bacteria.  - international journal of infectious disease.  167-168. 

d. muhamad, p. periyasamy, r. ramli, l. chee lan, r. abdul rahman.  (2021).  impact of infectious diseases specialists in intensive care unit on antimicrobial utilization and patient outcomes.  - international journal of infectious diseases.  113. 

wan asyraf wan zaidi, muhamad danial zulkifli, najma kori, petrick k. periyasamy, wan nur nafisah wan yahya.  (2021).  ischaemic stroke in covid-19 patients in hospital canselor tuanku muhriz, national university of malaysia medical centre.  - international journal of stroke.  159. 

juen kiem tan, dalleen leong, hemalatha munusamy, nor hazwani zenol ariffin, najma kori, rozita hod, petrick periyasamy.  (2021).  the prevalence and clinical significance of presymptomatic covid-19 patients: how we can be one step ahead in mitigating a deadly pandemic.  - bmc infectious diseases.  1-10. 

nurnabila syafiqah muhamad rizal, hui-min neoh, ramliza ramli, petrick @ ramesh a/l k periyasamy, alfizah hanafiah ,muttaqillah najihan abdul samat, toh leong tan, kon ken wong, sheila nathan, sylvia chieng, seow hoon saw, bee yin khor.  (2021).  16s rrna gene next-generation sequencing (16sngs) for bacterial pathogen identification: pilot study in a malaysian teaching hospital.  - international journal of infectious diseases.  180-203. 

boon hau ng, hsueh jing low, nik nuratiqah nik abeed, mohamed faisal abdul hamid, chun ian soo, petrick periyasamy, andrea ban yu-lin.  (2021).  understanding of coronavirus disease 2019 (covid-19) and the practice of preventive measures among doctors and nurses in a university teaching hospital- a cross-sectional study.  - medical journal of malaysia.  454-460. 

nurul adilla hayat jamaluddin, petrick periyasamy, chee lan lau, sasheela ponnampalavanar, pauline siew mei lai, ramliza ramli, toh leong tan, najma kori, mei kuen yin, nur jannah azman, rodney james, karin thursky and isa naina mohamed.  (2021).  point prevalence survey of antimicrobial use in a malaysian tertiary care university hospital.  - antibiotics.  1-13. 

azmawati mohammed nawi, azimatun noor aizuddin, rozita hod, norfazilah ahmad, faiz daud, sharifah azura salleh, najma kori, petrick periyasamy, mohd rohaizat hassan, hanafiah harunarashid, kamaruzaman jusoff & mohd afiq arifin.  (2021).  managing covid-19 pandemic in teaching hospitals: an early preparedness setting (pengurusan pandemik covid-19 di hospital pengajar: suatu penetapan persediaan awal).  - sains malaysiana.  1165-1173. 

yusuf abu shamsi, xiong khee cheong, rozita mohd, petrick periyasamy, ruslinda mustafar.  (2021).  a case of lupus nephritis flare-up in severe covid-19 infection.  - medical journal of malaysia.  757-761. 

afifah aqilah abdul malik, petrick periyasamy, najma kori, asrul abdul wahab, chuan hun ding.  (2021).  a spuriously negative cryptococcal antigen assay result in disseminated cryptococcosis: the deception of the postzone phenomenon.  - annals of clinical & laboratory science.  430-433. 

nurnabila syafiqah muhamad rizal, hui-min neoh, ramliza ramli, petrick @ ramesh a/l k periyasamy, alfizah hanafiah, muttaqillah najihan abdul samat, toh leong tan, kon ken wong, sheila nathan, sylvia chieng, seow hoon saw, bee yin khor.  (2020).  advantages and limitations of 16s rrna next-generation sequencing for pathogen identification in the diagnostic microbiology laboratory: perspectives from a middle-income country.  - diagnostics.  1-19. 

boon hau ng, nik nuratiqah nik abeed, andrea ban yu-lin, mohamed faisal abdul hamid, chun ian soo, najma kori, shahizon azura mohamed mukari, isa azzaki zainal, lydia kamaruzaman, muhammad yusuf abu shamsi, halim gafor, norlaila mustafa, wan nur nafisah w.  (2020).  lung computed tomography patterns of a cluster of asymptomatic young males with covid-19 admitted to a teaching hospital in kuala lumpur.  - medical journal of malaysia.  368-371. 

min h. cheah, eon t. gan, nur j. azman, najma kori, petrick periyasamy, siti-azdiah abdul-aziz.  (2020).  factors affecting modification of initial antiretroviral therapy regimen in hiv positive patients.  - journal of pharmaceutical policy and practice.  10. 

ng boon hau, nik nuratiqah nik abeed, mohamed faisal abdul hamid, soo chun ian, low hsueh jing, najma kori, petrick periyasamy, norlaila mustafa, andrea ban yu-lin.  (2020).  a descriptive study of the psychological experience of health care workers in close contact with a person with covid-19.  - medical journal of malaysia.  485-489. 

chien-chang leea, andrea lay hoon kwaa, anucha apisarnthanarak, jia-yih feng,eric howard gluck, akihiro ito, anis karuniawati, petrick periyasamy, busadee pratumvinit,jeetendra sharma, rontgene solante, subramanian swaminathan, niraj tyagi, dien minh v....  (2020).  procalcitonin (pct)-guided antibiotic stewardship in asia-pacific countries: adaptation based on an expert consensus meeting.  - clinical chemistry and laboratory medicine (cclm).  1983-1991. 

ng boon hau, andrea ban yu-lin, nik nuratiqah nik abeed, mohamed faisal abdul hamid, soo chun ian, najma kori, petrick periyasamy.  (2020).  covid-19 detected from targeted contact tracing, attempting to see the pattern in random happenings: early lessons in malaysia.  - medical journal of malaysia.  582-584. 

nurul azmawati mohamed, nizam baharom, wan sw sulaiman, zetti z rashid, wong kon ken, umi k ali, siti n othman, muttaqillah n samat, najma kori, petrick periyasamy, nor a zakaria, agni n kumar sugurmar, cheong xiong khee, siti m saniman, ilina isahak.  (2020).  early viral clearance among covid-19 patients when gargling with povidone-iodine and essential oils: a clinical trial.  - international medical journal.  651-654. 

syahrul sazliyana shaharir, ruslinda mustafar, lydia kamaruzaman, andrea ban yu lin, petrick periyasamy.  (2020).  tuberculosis (tb) infection among the multiethnic systemic lupus erythematosus (sle) cohort in universiti kebangsaan malaysia medical centre.  - international journal of rheumatic diseases.  313. 

elengoe s, jamil a, goh sw, arumugam m, ismail r, periyasamy p.  (2019).  levetiracetam induced drug reaction with eosinophilia and systemic symptoms (dress).  - brunei international medical journal.  140-144. 

cl lau, j azman, n shaharuddin, c bacha lal, ma rosli, petrick periyasamy.  (2019).  observational study of iv to oral switch practice in malaysian teaching hospital.  - infection & chemotherapy.  173. 

nurnabila syafiqah muhamad rizal, hui-min neoh, ramliza ramli, petrick @ ramesh a/l k periyasamy, alfizah hanafiah, muttaqillah najihan abdul samat, toh leong tan, kon ken wong, sheila nathan, sylvia chieng, seow hoon saw, bee yin khor.  (2019).  culture and biochemical testing versus 16s rrna gene sequencing for pathogen identification in the clinical microbiology laboratory: preliminary findings on cost comparison and breaking the bioinforma.  - infection & chemotherapy.  S94-S95. 

najma kori, razman jarmin, petrick periyasamy, lau chee lan.  (2019).  new perspective of antimicrobial stewardship: changing surgeon's paradigm.  - antimicrobial resistance and infection control.  144-145. 

azlina ibrahim, isa naina mohamed, chee lan lau, ramliza ramli, najma kori, petrick periyasamy.  (2019).  appropriateness of ceftriaxone use in medical wards of ukmmc - how compliant are we?.  - antimicrobial resistance and infection control.  148. 

marsilla mariaty marzukie, khairunisa ahmad affandi, azyani yahaya, petrick periyasamy.  (2019).  disseminated histoplasmosis mimicking an acute appendicitis.  - malaysian journal of pathology.  223-227. 

petrick periyasamy.  (2018).  dengue: vaccine preventable diseases.  - malaysian journal of public health medicine.  . 

syahrul sazliyana shaharir, narisa sulaiman sahari, zeena mohamed fuad, wan zul haikal wan zukiman, nurul hafizah mohd yusof, anita sulong, petrick periasamy.  (2018).  non-tuberculous mycobacterium bacteraemia in a pregnant systemic lupus erythematosus (sle) patient: a case review and pooled case analysis.  - clinical rheumatology.  837-847. 

chuan hun ding, hamidah yusoff, najihan abdul samat muttaqillah, yee loong tang, toh leong tan, petrick periyasamy, andrea yu-lin ban.  (2018).  the crucial role of molecular testing to facilitate the diagnosis of pneumocystis pneumonia during pregnancy.  - malaysian journal of pathology.  . 

nasheeda saeed, ching soong khoo, rabani remli, zhe kang law, petrick periyasamy, syazarina sharis osman and hui jan tan.  (2018).  first reported case of neuroleptospirosis complicated with anton's syndrome.  - frontiers in neurology.  1-5. 

n.a. mohd fauzi, c.s. khoo, h.j. tan, a.m.m. shahizon, c.h. ding, m.n. tzar, m.p. suria hayati, k. nurul akmal, t. jegan, w.a. wan zaidi, p. petrick.  (2017).  the first case report of thoracic extradural mucormycosis in a diabetic patient.  - journal of the neurological sciences.  1004-1005. 

mohamed faisal abdul hamid, petrick periyasamy, andrea ban, roslina abdul manap.  (2017).  detection rate of pneumococcal pneumonia using the urine antigen kit binaxnow streptococcus pneumoniae test: a prospective cohort study in a tertiary hospital in malaysia.  - international medical journal malaysia.  29-36. 

zainudin, n.s.,nasarudin, s.n.s.,periyasamy, p.,moktar, n.,noordin, r.,osman, e..  (2016).  diagnosis of disseminated microsporidiosis: detection of circulating enterocytozoon bieneusi dna in blood of hiv/aids patients.  - tropical biomedicine.  761-770. 

ng c.s., isa h.m., periyasamy p., mohamad s., raja ali r.a..  (2015).  an ocular diploid fungus: a case of an overlook systemic mycosis.  - brunei international medical journal.  103-105. 

choon seong ng, shahrul azmin, zhe kang law, ramesh sahathevan, wan nur nafisah wan yahya, rabani remli, petrick periyasamy, norlinah mohd ibrahim and hui jan tan.  (2015).  an unusual neurological complication from a garden-variety organism: post-melioidosis parkinsonism.  - the medical journal of australia.  333-334. 

mohamed faisal abdul hamid, petrick periyasamy, andrea ban yu-lin, roslina abdul manap.  (2015).  a prospective cohort study comparing between pneumococcal and non-pneumococcal community-acquired pneumonia (cap) and health-care associated pneumonia (hcap) in ukmmc.  - respirology.  127. 

wan fariza wan jamaludin,petrick periyasamy, wan rahiza wan mat , s. fadilah abdul wahid.  (2015).  dengue infection associated hemophagocytic syndrome: therapeutic interventions and outcome.  - journal of clinical virology.  91-95. 

law zk, henry lj, alias nf, kumar s, sahathevan r, htwe o, naicker as.  (2015).  do stroke patients load on both lower limbs differently from what they perceive?.  - cerebrovascular diseases.  58. 

abdul halim abdul gafor, pau cheong ping, anis farahanum zainal abidin, muhammad zulhilmie saruddin, ng kah yan, siti qania`ah adam, ramliza ramli, anita sulong, and petrick periyasamy.  (2014).  antibiogram for haemodialysis catheter-related bloodstream infections.  - international journal of nephrology.  1-6. 

chuan hun ding, mohd nizam tzar, md mostafizur rahman, najihan abdul samat muttaqillah, shazatul reza mohd redzuan, petrick periyasamy.  (2014).  paecilomyces lilacinus fungaemia in an aids patient: the importance of mycological diagnosis.  - pakistan journal of medical sciences.  30(4):914-6. 

abdul aziz marwan, chai soon ngiu, petrick periyasamy.  (2013).  an interesting finding in a patient with chronic diarrhoea.  - annals academy of medicine singapore.  42(2):97-98. 

mohamed faisal, petrick periyasamy, andrea ban yu-lin, roslina abdul manap.  (2013).  detection rate of pneumococcal pneumonia using binaxnow streptococcus pneumoniae test, a prospective cohort study in a tertiary hospital in malaysia.  - respirology.  18(suppl 4) : 106. 

arif m shahar, chai soon ngiu, hasnur zaman hashim, hui jang tan, petrick periyasamy.  (2011).  no coma, but expressive dysphasia with cerebellar signs: an unique presentation of cerebral malaria.  - annals of academy of medicine singapore.  40(8):383-383. 

petrick periyasamy, siva rao subramaniam, sakthiswary rajalingham.  (2011).  an increasingly notorious mimicker of testicular tumours;crossing borders.  - bmj case reports.  2011. 

deborah je marriott, petrick periyasamy.  (2011).  anticonvulsant hypersensitivity syndrome secondary to lamotrigine mimicking a septic episode.  - annals of the academy of medicine, singapore.  40(9):422-423. 

azlina abu bakar, cs ngiu, ms mohamad said, petrick periyasamy.  (2011).  salmonella related mycotic aneurysm with psoas and paraortic abscess treated.  - annals academy of medicine singapore.  40(10):467-468. 

sakthiswary rajalingham, mohd shahrir mohd said, syahrul sazliyana shaharir, aini abaziz, petrick periyasamy, fauzi md anshar.  (2011).  dermatomyositis masquerading musculoskeletal tuberculosis.  - bmj case reports.  2011. 

periyasamy, p; kadir, aa; nyiu, cs.  (2011).  cotrimoxazole resistant burkholderia pseudomallei in neurological melioidosis.  - international journal of infectious diseases.  15(1):S49. 

c s ngiu, m s mohamed said, p periyasamy, s f low.  (2010).  nocardiosis in a patient with rheumatoid athritis treated with rituximab and a summary of reported cases.  - bmj case reports.  2010:1-3. 

n mustafa, p periyasamy, n kamaruddin.  (2009).  steven johnson syndrome in a patient with cushing`s disease.  - medical journal of malaysia.  64(3):238-239. 

p. petrick, n.c.t. kong, a.j. nordiah, c. izham, m.a. tamil.  (2007).  outcome of bacteraemia in patients admitted to the adult medical wards of the ukm hospital.  - medical journal of malaysia.  62(4):329-334.