Am. J. Trop. Med. Hyg., 76(1), 2007, pp. 182–183 Copyright © 2007 by The American Society of Tropical Medicine and Hygiene

SHORT REPORT: HUMAN IN CHILDREN WITH -LIKE ILLNESS IN YUCATAN, MEXICO

GUADALUPE AYORA TALAVERA* AND NELSON E. DORANTES MÉZQUITA Centro de Investigaciones Regionales Dr. Hideyo Noguchi, Departamento de Biomedicina de Enfermedades Infecciosas, Universidad Autónoma de Yucatán, Mérida, México; School of Biological Sciences, Microbiology Department, The Reading University, Whiteknights, United Kingdom

Abstract. The present study suggests that human metapneumovirus (hMPV) is an important cause of community acquired respiratory in children. We report the detection of hMPV in a pediatric population with influenza- like illness in the subtropical area of Yucatan in Mexico. Our data also shows that hMPV circulates in the community with other respiratory pathogens.

Human metapneumovirus (hMPV) was described by van acquired respiratory tract infections in the pediatric popula- den Hoogen and others who isolated the from young tion. In addition to the recent report of hMPV in San Luis children with respiratory infections in The Netherlands.1 Re- Potosi Mexico,2 our data are not surprising because the cently, hMPV was reported in Mexico as a cause of respira- Yucatan region has been reported to have the highest rates of tory tract infections in hospitalized young children.2 acute respiratory tract infections in Mexico.5 Conversely, The Yucatan region of Mexico has a subtropical climate Noyola and others2 studied hospitalized children with well- and the epidemiology of common pathogens can differ from defined respiratory conditions, who showed a different pat- that seen in other regions of Mexico with different locations, tern of respiratory pathogens when compared with our study. climates, and epidemic patterns. In this study, we were inter- The hMPV-positive patients ranged in age from 13 to 60 -months), and the virus was de 32.6 ס ested to know the frequency of hMPV in children Յ 5 years months (mean age of age in the context of two factors that have been poorly tected more frequently in children between 13 and 36 months analyzed, the role of hMPV in community-acquired acute re- of age (13%) and in infants more than three years of age spiratory infections and its prevalence in the tropics. (5%). The most common symptoms in hMPV-positive pa- From December 1999 through December 2002, a total of 98 tients included (100%), (95%), Յ throat swabs from children 5 years of age were submitted to (75%), (54%), and general (33%). There the respiratory virus laboratory in Merida, Yucatan, Mexico. was no statistically significant difference in clinical symptoms All samples were negative for influenza A or B by between patients positive or negative for hMPV. Nine (50%) indirect immunofluorescence assay at the time of collection. of 18 patients were treated with antibiotics at the time that Ninety throat swabs were analyzed. Original samples were they were seen by a clinician. Another important observation thawed and used for extraction of viral RNA using the was that 13 (72%) of 18 positive samples were obtained from QIAamp viral RNA mini kit (Qiagen, Valencia, CA). cDNA patients with an onset of symptoms Յ 24 hours after sample was amplified as described by Ellis and others.3 To amplify a collection. Thus, collection of specimens early in the illness fragment of the hMPV F gene, we used a nested reverse increases the likelihood of detecting hMPV. transcription–polymerase chain reaction (RT-PCR) with spe- Human metapneumovirus was detected from 1999 through cific primers to obtain a PCR product of 311 basepairs (Zam- 2002. Fifty percent of the positive samples were detected in bon MC, unpublished data) (primer sequences available upon the summer of 2001 (September) and 2002 (May, June, and request). The remaining cDNA was frozen at −80°C until sub- sequent analysis by multiplex RT-PCR to detect other respi- August) when the peak of ILI was recorded and also when ratory viruses.4 Yucatan has its greatest rainfall, temperature, and relative False-negative results were ruled out by using a positive humidity. The remaining samples were detected in December control for hMPV, which in the nested PCR produced a 1999, February 2000, and January and March 2001. The pat- tern of hMPV circulation is similar to what we previously unique and clear band of the appropriate size. False-positive 6 2 results were ruled out by including water as a negative control reported for influenza virus. In contrast, Noyola and others every sixth clinical sample. Both positive and negative con- reported hMPV only during the winter months, which sug- trols were tested with clinical samples in all experiments. gests that differences in location and climate between Negative samples for hMPV were ruled out either because of Yucatan and San Luis Potosi alter the epidemic pattern of the presence of a band of unexpected size or the absence of hMPV. Our data are consistent with those of a study in Hong Kong that reported the presence of hMPV in the late spring bands. 7 Human metapneumovirus was detected in 18 (20%) of 90 and summer. clinical samples from children Յ 5 years of age with influenza- The fact that samples were collected from children with ILI like illness (ILI). Our investigation showed that hMPV in suggests possible circulation of several other respiratory vi- Yucatan, Mexico is an important cause of community- ruses at the same time. Although all samples were negative for influenza A and B viruses at the time of collection, we analyze these samples retrospectively by multiplex RT-PCR. We detected mixed infections with hMPV and influenza and * Address correspondence to Guadalupe Ayora Talavera, School of Biological Sciences, Animal and Microbial Sciences Building, Micro- other respiratory viruses. Overall, 44 (48%) of 90 samples biology Department, The Reading University, Whiteknights, RG6 were positive for one or more respiratory viruses. Coinfec- 6AJ, United Kingdom. E-mail: [email protected] tions with hMPV and other viruses were detected in seven 182 HUMAN METAPNEUMOVIRUS IN YUCATAN, MEXICO 183

TABLE 1 Financial support: Nelson E. Dorantes-Mézquita was supported by Positive samples for human metapneumovirus (hMPV) and the PRIORI- Universidad Autónoma de Yucatán Program. ס other respiratory viruses in children 5 years old from Authors’ addresses: Guadalupe Ayora Talavera, Centro de Investi- Yucatan, Mexico* gaciones Regionales Dr. Hideyo Noguchi, Departamento de Biome- dicina de Enfermedades Infecciosas, Universidad Autónoma de Virus No. (%) positive Yucatán, Av. Itzáes #490 × 59, Colonia Centro, CP 97000. Mérida, hMPV 11 (12) Yucatán, México, Telephone: 51-999-924-6412 extension 122 or 137, hMPV + Influenza H3 5 (5) Fax: 52-999-923-6120, E-mail: [email protected] and School of HMPV + RSV 2 (2) Biological Sciences, Animal and Microbial Sciences Building, Micro- Influenza A H3 18 (20) biology Department, The Reading University, Whiteknights, RG6 RSV A 3 (3) 6AJ, United Kingdom, Telephone: 44-118-973-7894, E-mail: Influenza H3 + RSV 5 (5) [email protected]. Nelson E. Dorantes-Mézquita, Cen- Total 44/90 (48) tro de Investigaciones Regionales Dr. Hideyo Noguchi, Departa- mento de Biomedicina de Enfermedades Infecciosas, Universidad ס * RSV respiratory syncytial virus. Autónoma de Yucatán, Av. Itzáes #490 × 59, Colonia Centro, CP 97000. Mérida, Yucatán, México. patients (Table 1). Coinfections with hMPV and other respi- REFERENCES ratory viruses have previously been detected at low rates of 1. van den Hoogen BG, de Jong JC, Groen J, Kuiken T, De Groot 1–3%.8,9 Our study reports a higher rate of 8%. However, this R, Fouchier RA, Osterhaus AD, 2001. A newly discovered is not surprising because we used a sensitive PCR assay to human pneumovirus isolated from young children with respi- 4 ratory tract disease. Nature 7: 719–724. detect other respiratory viruses. 2. Noyola DE, Alpuche SA, Herrera DA, Soria GR, Sanchez AJ, Our results show that hMPV cocirculates in the Yucatan López RR, 2005. Human metapneumovirus infections in region of Mexico with other respiratory pathogens and is as Mexico: epidemiological and clinical characteristics. J Med Mi- prevalent as influenza virus. The low frequency at which re- crobiol 54: 969–974. 3. Ellis JS, Fleming DM, Zambon MC, 1997. Multiplex reverse tran- spiratory syncytial virus (RSV) was detected may be ex- scription-PCR for surveillance of influenza A and B viruses in plained by the type of clinical sample (throat swabs are not England and Wales in 1995 and 1996. J Clin Microbiol 35: optimal for RSV isolation) and the case definition used to 2076–2082. recruit patients. Coinfections were all detected in children 4. Stockton J, Ellis JS, Clewley JP, Zambon MC, 1998. Multiplex more than 30 months of age, except in one infant who was PCR for typing and subtyping influenza and respiratory syn- cytial viruses. J Clin Microbiol 36: 2990–2995. only six months of age. 5. Incidencia de Infecciones Respiratorias agudas por Grupos de In conclusion, hMPV showed an incidence rate of 20% in Edad. Estados Unidos Mexicanos. Anuarios de Morbilidad. children with ILI in the subtropical region of Yucatan, Mexico City: Epidemiologica/Direccion General de Epidemio- Mexico. There is a clear peak of circulation of hMPV and logia/SSA. 6. Ayora-Talavera G, Gongora-Biachi BR, Lopez-Martinez I, Mo- other respiratory viruses during the summer months. A more guel-Rodriguez W, Perez-Carrillo H, Vazquez-Vapata V, Bas- carefully designed survey will give us a better epidemiologic tarrachea-Vazquez D, Canto-Cab A, 2002. Detection of hu- picture of hMPV circulating in this region. man influenza virus in Yucatan, Mexico. Rev Invest Clin 54: 410–414. Received March 1, 2006. Accepted for publication September 24, 7. Peiris JSM, Hong TW, Chan KH, Khong PL, Guan Y, Lau YL, 2006. Chiu SS, 2003. Children with respiratory disease associated with metapneumovirus in Hong Kong. Emerg Infect Dis 9: Acknowledgments: We thank Dr. Maria Zambon (Health Protection 628–633. Agency, Colindale, London, United Kingdom) for providing the RT- 8. Sockton J, Stephenson I, Fleming D, Zambon M, 2002. Human PCR method and positive controls for influenza virus (A/Taiwan/1/ metapneumovirus as a cause of community-acquired respira- 68-H1N1; GS10-H3N2); Dr. Guy Bovin (Center de Recherche en tory illness. Emerg Infect Dis 8: 897–901. Infectiologie, Sainte-Foy, Quebec, Canada) for providing the hMPV 9. Vicente D, Cilla G, Montes M, Pérez TM, 2003. Human metap- positive control (hMPV 75-1998/CAN 98-75), and Dr. Wendy Barclay neumovirus and community acquired respiratory illness in chil- for reviewing the manuscript. dren. Emerg Infect Dis 9: 602–603.