Dengue virus infection in Australia following occupational exposure: A reflection of increasing numbers of imported cases

Journal of Clinical Virology 54 (2012) 376–377

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Letter to the Editor Dengue virus infection in Australia following occupational exposure: A reflection of increasing numbers of imported cases To the Editor, Nosocomial transmission of dengue virus has been reported infrequently previously, and never in an Australian health care

worker (HCW). During a period when higher than normal numbers of individuals returned to Western Australia with dengue virus infection, particularly from Bali, such a case occurred. In January 2011, a 27-year-old junior doctor presented to a Western Australian Infectious Diseases department with a three day history of fever, myalgia, and retro-orbital headache. She had not left the Perth region for over three months. Temperature

D3/AUS/316Z/2011 Recipient D3/AUS/764T/2011 Donor AB219138 Indonesia 2005 AY858046 Indonesia 2004 DQ518678 Indonesia 2005 AY858045 Indonesia 2004 AB189125 Indonesia 1998 AY265856 Indonesia 1998 DQ518676 Indonesia 1998 EU448437 Indonesia 2003 83

EU448434 Indonesia 2007 EU448435 Indonesia 2006 AB219130 East Timor 2005

Genotype I (Southeast Asia, Pacific)

DQ518675 Indonesia 1999 AB219137 Indonesia 2005 FM986662 Sarawak 1997 L11428 Indonesia 1985 AY145714 Thailand 1988 71

DQ518674 Indonesia 1991 DQ518673 Philippines 2005 EU448433 Philippines 2006 L11432 Philippines 1983 L11426 Indonesia 1978

67

L11429 Malaysia 1974 L11422 Fiji 1992 L11619 Tahiti 1989 L11425 Indonesia 1973 L11427 Malaysia 1981 L11423 Philippines 1956

Genotype V (East and SE Asia)

AB111085 Japan 1973 L11442 Thailand 1987 AY496874 Bangladesh 2002 55

L11620 Thailand 1973 L11440 Thailand 1962

Genotype II (Indian sub-continent, Southeast Asia)

L11435 Samoa 1986 L11424 India 1984

98

L11431 Sri Lanka 1981 83

L11430 Mozambique 1985 L11437 Sri Lanka 1989 DQ118869 Brazil 2002

Genotype III (Africa, Americas, Pacific islands, Indian sub-continent)

DQ341207 Mexico 2000 L11434 Puerto Rico 1977

100

L11433 Puerto Rico 1963 L11439 Tahiti 1965

Genotype IV (Americas, Pacific Islands)

0.02

Fig. 1. Phylogenetic tree showing the relationship of the donor/recipient strain of dengue virus type 3 (DENV-3) with 42 reference sequences. Each of the 5 recognised genotypes are indicated (G1–G5) along with the geographic origins of their constituent strains. The DENV-3 sequences from this study are indicated by closed circles. The tree was constructed using MEGA57 by the neighbour-joining method and is unrooted. Nucleotide distances were calculated using the Maximum Composite Likelihood method from a 358 nt sequence of the envelope gene (position 2056–2413 of the DENV-3 H87 prototype strain genome [M93130]). Percentage bootstrap values from 1000 replicates are indicated for major nodes with a cut-off value of 50%. Scale bar represents nucleotide substitutions per site. 1386-6532/$ – see front matter © 2012 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.jcv.2012.04.012

Letter to the Editor / Journal of Clinical Virology 54 (2012) 376–377

was 38.1 ◦ C, with an erythematous rash over the trunk. Leukocyte count was 3.66 × 109 /L (4.0–11.0), lymphocyte count 0.83 × 109 /L (1.2–4.0), platelet count 193 × 109 /L (150–400), alanine aminotransferase 56 U/L (<35) and C-reactive protein 5.4 mg/L (<5). Peripheral blood cultures and malaria film were negative. Serology was negative for Epstein-Barr virus, cytomegalovirus and HIV. Five days prior to symptom onset she sustained a penetrating needlestick injury to her index finger whilst taking blood. The donor patient had been admitted with a febrile illness following travel to Bali. Dengue virus immunoglobulin M (IgM) and NS1 antigen (ELISA) were positive, and dengue virus type 3 (DENV-3) RNA was identified by an in-house real-time RT-PCR. The doctor’s serology also subsequently revealed positive dengue IgM, NS1 antigen, and DENV-3 nested RT-PCR.1 She made a full recovery. RT-PCR amplification and sequencing of a 358 bp region of the DENV-3 envelope gene (Genbank accession numbers JN021289 and JN021290) was performed on samples from both the doctor and the patient. Viral sequences were identical, confirming nosocomial transmission. Phylogenetic analysis using reference genomic sequences, representing each of the recognised genotypes of DENV3, demonstrated that this strain clustered within genotype 1 (Fig. 1). It was most closely related to Indonesian strains isolated between 1998 and 2007 (97.2–97.8% nucleotide identity), consistent with the location where the donor patient is thought to have become infected. This is the first described case of dengue virus infection occurring in a health care worker in Australia following occupational exposure. Currently, Australian dengue virus infection occurs only sporadically in far northern Queensland. Dengue virus can be detected within a patient’s blood during the entire febrile period and can be transmitted to a susceptible recipient via parenteral or mucosal exposure to viraemic blood. Transmission without a mosquito vector has been reported following needlestick injuries, bone marrow transplantation, blood transfusion, mucocutaneous exposure, intrapartum and vertical transmission.2–4 In 2010, dengue fever notifications in Western Australia increased by 250%, with about 2/3 acquired in Bali, Indonesia.5 Bali received about 2.3 million foreign visitors in 2010, approximately 25% from Australia. As well as an increasing number of visitors, there is increasing dengue incidence in Bali. In Indonesia 33,443 cases were reported in 2000, increasing to 156,052 cases in 2009.6 Though common concerns are the transmission of HIV, hepatitis B virus, and hepatitis C virus, HCWs should be aware that nosocomial transmission of other viruses can occur following

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occupational exposure, and must be vigilant when caring for patients with illnesses following overseas travel. References 1. Lanciotti RS, Calisher CH, Gubler DJ, Chang GJ, Vorndam AV. Rapid detection and typing of dengue viruses from clinical samples by using reverse transcriptasepolymerase chain reaction. J Clin Microbiol 1992;30(March (3)):545–51. 2. Chen LH, Wilson ME. Transmission of dengue virus without a mosquito vector: nosocomial mucocutaneous transmission and other routes of transmission. Clin Infect Dis 2004;39(6):e56–60. September 15. 3. de Wazieres B, Gil H, Vuitton DA, Dupond JL. Nosocomial transmission of dengue from a needlestick injury. Lancet 1998;351(9101):498. February 14. 4. Wagner D, de With K, Huzly D, Hufert F, Weidmann M, Breisinger S, et al. Nosocomial acquisition of dengue. Emerg Infect Dis 2004;10(October (10)): 1872–3. 5. Giele CSD. Dramatic increase in Bali-acquired dengue fever among Western Australians, 2001–2010. In: Communicable disease control conference 2011. 2011. 6. WHO. Situation update of dengue in the SEA Region, 2010, ; 2010. 7. Tamura K, Peterson D, Peterson N, Stecher G, Nei M, Kumar S. MEGA5: molecular evolutionary genetics analysis using maximum likelihood, evolutionary distance, and maximum parsimony methods. Mol Biol Evol 2011;28(October (10)):2731–9.

Benjamin M. Clark ∗ James S. Molton Tariq Habib Department of Infectious Diseases, Fremantle Hospital, Alma Street, Fremantle, WA 6160, Australia David T. Williams Leader Diagnostic Virology, Australian Animal Health Laboratory, Diagnosis, Surveillance & Response, CSIRO Livestock Industries, Private Bag 24, Geelong, VIC 3220, Australia Emma L. Weston a David W. Smith a,b a Division of Microbiology and Infectious Diseases, PathWest Laboratory Medicine WA, Nedlands, WA, Australia b School of Biomedical Sciences, Curtin University, Bentley, WA, Australia ∗ Corresponding

author. Tel.: +61 8 9431 2149; fax: +61 8 9431 2035. E-mail address: [email protected] (B.M. Clark) 10 April 2012