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Serologic Evidence dilution) was designated as 1:1,000 Medicine, Nagasaki University. No ELISA units. ELISA titers of sample specimens of C. sphinx bats were of Nipah serum specimens were obtained at positive by NT; however, 2 specimens Infection in Bats, a single dilution (1,000×) by using a from R. leschenaulti bats, both positive Vietnam standard curve of positive serum with with low titers, were confi rmed to be high titers. A sample titer >3,000 was positive by NT (50% cytopathic effect To the Editor: Bats are potential considered positive for IgG against after NT, titers of 33.6 and 14.1). reservoir for highly pathogenic NiV. However, the latter specimen was , such as (NiV) Positive results were detected negative by WB analysis. and , which can cross from only 2 fruit bat species, R. Seroepidemiologic studies in species barriers (1). However, leschenaulti (31 bats [49.1%]) and other countries have indicated that only limited surveillance has been Cynopterus sphinx (3 bats [2.8%]) Pteropus spp. bats (fruit-eating bats) conducted to assess risk for infection (Table). Of the 34 samples positive are the main reservoirs for NiV (3–6). by these deadly emerging viruses. We by ELISA, only 22 (20 from the Pteropid bats are usually found only in conducted a study in Vietnam from former and 2 from the latter bat southern Vietnam. We could not obtain 2007 to 2008 to assess the prevalence species), which had enough volume these bats for our study. However, a of these pathogens in bats. left, were further analyzed by Western relatively high prevalence (49.1%) of Different species of live bats blot (WB) with E. coli–expressed was found in R. were obtained from hunters or were recombinant N protein of NiV (Table; leschenaulti specimens from Hoa Binh captured in caves, pepper fi elds, online Technical Appendix Figure Province. Rousettus spp. bats are the and residential areas by using mist 2). Twenty of the 22 specimens were only that use echolocation. nets or harp traps (online Technical confi rmed as positive by WB. ELISA- These bats hang together on cave Appendix Figure 1, wwwnc.cdc.gov/ positive samples with high titers were ceilings in a tightly packed manner EID/pdfs/11-1121-Techapp.pdf). also positive by WB for both bat and in groups composed of bats of A total of 451 serum samples were species. However, only 1 sample from both sexes and of different ages. collected and subjected to IgG ELISA an R. leschenaulti bat was positive by They roost in large colonies and fl y by using an Escherichia coli–derived WB that used a baculovirus-expressed vast distances to fi nd fruit (7). This recombinant nucleocapsid (N) protein recombinant N protein. Because behavior might be related to their of NiV (NiV-N-ELISA) (2). Two of the different protein expression high rate of seropositivity for viral Leschenault’s rousette bats (Rousettus systems, the reactivity of bat antibody infections. In southern China, bats leschenaulti) were vaccinated with against NiV protein in WBs showed of the same species showed a high the same recombinant N protein to different patterns (online Technical prevalence of henipavirus antibody obtain positive serum specimens Appendix Figure 2). Neutralization (8). R. leschenaulti bats are distributed that contained against tests (NTs) in which live NiVs (strain from central to northern Vietnam and NiV-N. An optical density of 492 nm Ma-JMR-01–98) were used were southern China. C. sphinx bats are for negative control serum (1,000× performed at the Institute of Tropical common all over Vietnam, and their

Table. Results of serologic tests for Nipah virus on bats captured in Vietnam, 2007–2008* Bat species No. samples No. (%) ELISA+ No. WB+/no. ELISA+ No. micro-NT+/no. ELISA+† Megachiroptera Cynopterus sphinx 109 3 (2.8) 2/2 0/3 Rousettus leschenaulti 74 31 (41.9) 18/20 2‡/31 Total 183 34 (18.6) 20/22 2/34 Microchiroptera Chaerephon plicata 130 0 Hipposideros armiger 1 0 Hipposideros cineraceus 3 0 Hipposideros larvatus 3 0 Hipposideros pomona 5 0 Hypsugo cadornae 25 0 Megaderma spasma 3 0 Miniopterus magnater 1 0 Scotophilus kuhi 45 0 Unidentified 52 0 Total 268 0 *+, positive; WB, Western blot; NT, neutralization test. Blank cells indicate that test was not done. †Micro-NT was done only on specimens positive for Nipah virus by ELISA. ‡One of the NT-positive samples was negative by WB analysis.

536 Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 18, No. 3, March 2012 LETTERS habitat overlaps with that of pteropid Technology, Japan; Japan Initiative for 8. Li Y, Wang J, Hickey AC, Zhang Y, Li bats in southern Vietnam. Global Research Network on Infectious Y, Wu Y, et al. Antibodies to Nipah or Nipah-like viruses in bats, China. Emerg Previous studies showed that Diseases; and Yakult Honsha Co., Ltd.. Infect Dis. 2008;14:1974–6. http://dx.doi. IgG ELISA results for NiV-positive org/10.3201/eid1412.080359 fl ying foxes correlated well with NT Futoshi Hasebe, results (3,4). However, in our study, Nguyen Thi Thu Thuy, Address for correspondence: Futoshi Hasebe, discrepancies existed between NT Shingo Inoue, Fuxun Yu, Center of International Collaborative Research, results and NiV-N-ELISA and WB Yoshihiro Kaku, Nagasaki University, Nagasaki, Japan; email: results. A reason for these differences Shumpei Watanabe, [email protected] could be that Nipah-like viruses are Hiroomi Akashi, Dang Tuan Dat, circulating among bats in Vietnam, Le Thi Quynh Mai, producing antibodies that are cross- and Kouichi Morita reactive by ELISA and WB, but poorly Author affi liations: Nagasaki University, cross-reactive by NT. The cross- Nagasaki, Japan (F. Hasebe, S. Inoue, F. reactive antibodies were probably not Yu, K. Morita); National Institute of Hygiene directed against neutralizing epitopes. and Epidemiology, Hanoi, Vietnam (N.T.T. Discordance in To date, no reports have been made Thuy, L.T.Q. Mai); National Institute of of an increased number of febrile Infectious Diseases, Tokyo, Japan (Y. Mycobacterium cases among the residents Kaku); University of Tokyo, Tokyo (S. tuberculosis in Hoa Binh and Dak Lak Provinces Watanabe, H. Akashi); and Tay Nguyen Rifampin where seropositive bats were captured. Institute of Hygiene and Epidemiology, Dak The circulating viruses may lack the Lak, Vietnam (D.T. Dat) Susceptibility pathogenic potential of Hendra and Nipah viruses. DOI: http://dx.doi.org/10.3201/eid1803.111121 To the Editor: Multidrug- A survey by questionnaire was resistant tuberculosis (MDR TB), conducted among residents of Dak References i.e., TB resistant to at least the 2 most Nong and Dak Lak Provinces, where effective fi rst-line antituberculous 1. Calisher CH, Childs JE, Field HE, Holmes drugs (isoniazid [INH] and rifampin NiV-N-ELISA–positive C. sphinx KV, Schountz T. Bats: important reservoir bats were captured, to determine the hosts of emerging viruses. Clin Micro- [RIF]), is increasing globally. World frequency of contact between humans biol Rev. 2006;19:531–45. http://dx.doi. Health Organization estimations of org/10.1128/CMR.00017-06 and bats. Risk factors for infection 390,000–510,000 new MDR TB cases 2. Yu F, Khairullah NS, Inoue S, Balasub- and 150,000 related deaths in 2008 were observed in this study, such as bat ramaniam V, Berendam SJ, Teh LK, et hunting and cooking and drinking bat al. Serodiagnosis using recombinant highlight the need for timely drug blood. In such situations, persons have Nipah virus nucleocapsid protein ex- susceptibility testing and improved pressed in Escherichia coli. J Clin Mi- direct contact with bat body fl uids and therapies (1). Although novel rapid crobiol. 2006;44:3134–8. http://dx.doi. drug susceptibility testing tools are feces and might be bitten during bat org/10.1128/JCM.00693-06 hunting. Thus, long-term systematic 3. Yob JM, Field H, Rashdi AM, Morrissy increasingly available, their clinical surveillance of bats is needed to C, van der Heide B, Rota P, et al. Nipah applicability is unsettled. We report virus infection in bats (order Chiroptera) determine the ecologic relationship a patient with pulmonary TB relapse in peninsular . Emerg Infect Dis. with discordant genotypic and in vitro between bats, humans, other animals, 2001;7:439–41. and the environment. 4. Reynes JM, Counor D, Ong S, Faure C, phenotypic drug susceptibility testing Seng V, Molia S, et al. Nipah virus in results associated with a mutation Lyle’s fl ying foxes, Cambodia. Emerg In- outside the RIF resistance determining Acknowledgments fect Dis. 2005;11:1042–7. region (RRDR) of the rpoB gene. We thank Vu Dinh Thong for 5. Wacharapluesadee S, Lumlertdacha B, In August 2009, a 45-year-old identifying bat species and Corazon Boongird K, Wanghongsa S, Chanhome L, Rollin P, et al. Bat Nipah virus, Thai- homeless woman with AIDS (CD4+ Cerilla Buerano for her valuable scientifi c land. Emerg Infect Dis. 2005;11:1949–51. T-cell count 3 cells/mm3) and a history suggestions. http://dx.doi.org/10.3201/eid1112.050613 of substance abuse sought care for 6. Hsu VP, Hossain MJ, Parashar UD, Ali This work was supported by the MM, Ksiazek TG, Kuzmin I, et al. Nipah , night sweats, weight loss, Grant-in-Aid for Scientifi c Research virus encephalitis reemergence, Bangla- and cough (online Appendix Table, (KAKENHI) no. 18659131; Global desh. Emerg Infect Dis. 2004;10:2082–7. wwwnc.cdc.gov/EID/article/18/3/11- Center of Excellence program, Ministry 7. Altringham JD, McOwat T. Bats: biology 1357-TA1.htm). Pulmonary TB had and behavior. Oxford (UK): Oxford Uni- of Education, Culture, Sports, Science and versity Press; 1998. been diagnosed in June 2008. At

Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 18, No. 3, March 2012 537 Article DOI: http://dx.doi.org/10.3201/eid1803.111121 Serologic Evidence of in Bats, Vietnam

Technical Appendix

Technical Appendix Figure 1. Bat study sites in Vietnam, 2007–2008.

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Technical Appendix Figure 2. Bat specimen (from Rousettus leschenaulti and Cynopterus sphinx bats) results of WB analysis and ELISA that used Escherichia coli–expressed and baculovirus-expressed recombinant NiV N protein and virus NT, Vietnam, 2007–2008. WB, Western blot; NiV, Nipah virus; N, nucleocapsid; NT, neutralization test; P, positive control.

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