• Bordetella pertussis in children hospitalized with a respiratory infection: clinical characteristics and pathogen detection in household contacts

      del Valle-Mendoza, Juana; Silva-Caso, Wilmer; Aguilar-Luis, Miguel Angel; del Valle-Vargas, Cristina; Cieza-Mora, Erico; Martins-Luna, Johanna; Aquino-Ortega, Ronald; Silva-Vásquez, Andrea; Bazán-Mayra, Jorge; Weilg, Pablo; juana.delvalle@upc.pe; gian_will@hotmail.com; ma23aguilar@gmail.com; cristina.del.valle88@gmail.com; ericocieza@yahoo.es; johmarlu14@gmail.com; ronaldaquino.one@gmail.com; silvavasquezandrea@mail.com; jorgebazan7@gmail.com; pablo.weilg@gmail.com (BioMed Central Ltd., 2018-05)
      Objective: Describe the prevalence of Bordetella pertussis via PCR in children under 5 years old hospitalized as probable cases of pertussis and report the most common clinical features among them. Results: A positive PCR result for B. pertussis was observed in 20.5% of our samples (18/88), one-third of them were from infants between 2 and 3 months old. The most common symptoms were paroxysms of coughing (88.9%), difficulty breathing (72.2%), cyanosis (77.8%) and fever (50%). The mother was the most common symptomatic carrier (27.8%), followed by uncles/aunts (22.2%) among children with pertussis.
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    • Co-infection with Bartonella bacilliformis and Mycobacterium spp. in a coastal region of Peru

      Silva-Caso, Wilmer; Mazulis, Fernando; Weilg, Claudia; Aguilar-Luis, Miguel Angel; Sandoval, Isabel; Correa-Nuñez, German; Li, Dongmei; Song, Xiuping; Liu, Qiyong; del Valle-Mendoza, Juana (BioMed Central Ltd., 2017-12-01)
      Objective This study investigated an outbreak of Bartonellosis in a coastal region in Peru. Results A total of 70 (n = 70) samples with clinical criteria for the acute phase of Bartonellosis and a positive peripheral blood smear were included. 22.85% (n = 16) cases of the samples were positive for Bartonella bacilliformis by PCR and automatic sequencing. Of those positive samples, 62.5% (n = 10) cases were positive only for B. bacilliformis and 37.5% (n = 6) cases were positive to both Mycobacterium spp. and B. bacilliformis. The symptom frequencies were similar in patients diagnosed with Carrion’s disease and those co-infected with Mycobacterium spp. The most common symptoms were headaches, followed by malaise and arthralgia.
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    • Dengue diagnosis in an endemic area of Peru: Clinical characteristics and positive frequencies by RT-PCR and serology for NS1, IgM, and IgG

      Palomares-Reyes, Carlos; Silva-Caso, Wilmer; del Valle, Luis J.; Aguilar-Luis, Miguel Angel; Weilg, Claudia; Martins-Luna, Johanna; Viñas-Ospino, Adriana; Stimmler, Luciana; Mallqui Espinoza, Naysha; Aquino Ortega, Ronald; Espinoza Espíritu, Walter; Misaico, Erika; del Valle-Mendoza, Juana; juana.delvalle@upc.pe (Elsevier B.V., 2019-04)
      Background: Huánuco is a central eastern region of Peru whose geography includes high forest and low jungle, as well as a mountain range that constitutes the inter-Andean valleys. It is considered a region endemic for dengue due to the many favorable conditions that facilitate transmission of the virus. Methods: A total of 268 serum samples from patients in Huánuco, Peru with an acute febrile illness were assessed for the presence of dengue virus (DENV) via RT-PCR and NS1, IgM, and IgG ELISA during December 2015 and March 2016. Results: DENV was detected in 25% of samples via RT-PCR, 19% of samples by NS1 antigen ELISA, and 10.5% of samples by IgM ELISA. DENV IgG was detected in 15.7% of samples by ELISA. The most frequent symptoms associated with fever across all groups were headache, myalgia, and arthralgia, with no significant difference between the four test methods Conclusions: In this study, DENV was identified in up to 25% of the samples using the standard laboratory method. In addition, a correlation was established between the frequency of positive results and the serological tests that determine NS1, IgM, and IgG. There is an increasing need for point-of-care tests to strengthen epidemiological surveillance in Peru.
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    • Detection of Zika virus infection among asymptomatic pregnant women in the North of Peru

      Weilg, Claudia; Troyes, Lucinda; Villegas, Zoila; Silva-Caso, Wilmer; Mazulis, Fernando; Febres, Ammy; Troyes, Mario; Aguilar-Luis, Miguel Angel; del Valle-Mendoza, Juana; claudia.weilg@gmail.com (BioMed Central Ltd., 2018-05-18)
      Objective: To report an outbreak of ZIKV infection among asymptomatic pregnant women during 2016 in the city of Jaen, Cajamarca. Results: Zika virus RNA was detected in 3.2% (n = 36) of cases by RT-PCR. The mean age of patients positive for ZIKV infection was 29.6 years. 7 patients (19.4%) infected with ZIKV were in their first-trimester of gestation, 13 (36.1%) were in their second-trimester, and 16 (44%) were in their third-trimester. All of the infected pregnant women were asymptomatic. ZIKV infection remains a major public health issue that calls for constant epidemiological surveillance. It can cause the congenital Zika virus syndrome in the newborns of infected mothers. The lack of molecular diagnostic methods in isolated localities and the similarity of symptoms to other arboviral infections, lead to an under-diagnosis of this disease in endemic areas.
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    • Emerging and reemerging arboviruses: A new threat in Eastern Peru

      Alva-Urcia, Carlos; Aguilar-Luis, Miguel Angel; Palomares-Reyes, Carlos; Silva-Caso, Wilmer; Suarez-Ognio, Luis; Weilg, Pablo; Manrique, Carlos; Vasquez-Achaya, Fernando; del Valle, Luis J.; del Valle-Mendoza, Juana; jdelvall@upc.edu.pe (Public Library of Science (PLoS), 2017-11-14)
      Background Arboviral diseases are one of the most common causes of acute febrile illness (AFI) and a significant health problem in South America. In Peru, laboratory etiologic identification of these infections occurs in less than 50% of cases, leading to underdiagnoses of important emerging arboviruses. Aim To assess the prevalence of the Dengue (DENV), Oropouche (OROV), Chikungunya (CHIKV), Mayaro (MAYV) and Zika (ZIKV) viruses in patients with acute febrile illness from Puerto Maldonado (Peru). Methodology Serum samples were obtained from patients with AFI during January 2016 to March 2016. A total of 139 specimens were analyzed for the presence of DENV, OROV, CHIKV, MAYV, and ZIKV using polymerase chain reaction (PCR). Results CHIKV in 9.4% and OROV in 8.6% were the most prevalent arboviruses, followed by DENV and ZIKV, with a prevalence of 6.5% and 5%, respectively. Among all patients, the most common symptoms accompanying fever were headaches 79.9%, muscle pain 65.5% and joint pain 63.3%. Conclusions During this short 3-month period, 4 arboviruses were detected by PCR, CHIKV and OROV being the most common arboviruses in Puerto Maldonado (Peru). Thus, it is crucial to include OROV detection in the national health surveillance. Furthermore, the etiologic clinical diagnosis of arboviral infections is not possible due to the low specificity of symptoms; therefore an increase of cases confirmed by molecular diagnostic methods will enhance arboviral surveillance in Peru.
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    • Etiology, epidemiology and clinical characteristics of acute diarrhea in hospitalized children in rural Peru

      Cornejo-Tapia, Angela; Orellana- Peralta, Fiorella; Weilg, Pablo; Bazan-Mayra, Jorge; Cornejo-Pacherres, Hernán; Ulloa-Urizar, Gabriela; Aguilar-Luis, Miguel Angel; Pons, Maria Jesus; del Valle-Mendoza, Juana (2017-12-10)
      Introduction: Diarrhea remains one of the main causes of morbidity and mortality in children under five years of age especially in low-income countries. In Peru, epidemiological reports about enteropathogens related to acute diarrhea are scarce in rural areas. The aim of this study was to describe the etiology, epidemiology, and clinical characteristics of the principal causes of acute infectious diarrhea in in a northern rural region of Peru. Methodology: A prospective study was conducted from January 2011 to December 2012 to describe the main pathogens causing acute diarrhea using PCR assay. Results: A total of 117 children diagnosed with acute diarrhea were included in the study. A single etiological agent was identified in 41.03% of samples, being rotavirus followed by norovirus and Shigella. Co-infections containing virus and bacteria were found in 22.22% of samples. Vomiting was most commonly found symptoms in 58.97% cases followed by fever (54.70%). Malnutrition was detected in 14.53% of the children. Conclusions: High prevalence of rotavirus, as well as adenovirus and norovirus, was observed in the present study. Shigella was the most common bacteria found in acute diarrhea in the area. The implementation of a better surveillance system is mandatory in order to identify the principal etiologies of gastroenteritis in the rural areas of Peru and to develop of better prevention strategies and reduce diarrhea-associated mortalities.
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    • Helicobacter pylori and its relationship with variations of gut microbiota in asymptomatic children between 6 and 12 years

      Benavides-Ward, Araceli; Vasquez-Achaya, Fernando; Silva-Caso, Wilmer; Aguilar-Luis, Miguel Angel; Mazulis, Fernando; Urteaga, Numan; del Valle-Mendoza, Juana; araceli.benavides.95@gmail.com (BioMed Central Ltd., 2018-07-13)
      Objective: To determine the variations in the composition of the intestinal microbiota in asymptomatic children infected with Helicobacter pylori in comparison with children without the infection. Results: Children infected with H. pylori doubled their probability of presenting 3 of 9 genera of bacteria from the gut microbiota, including: Proteobacteria (p = 0.008), Clostridium (p = 0.040), Firmicutes (p = 0.001) and Prevotella (p = 0.006) in comparison to patients without the infection. We performed a nutritional assessment and found that growth stunting was statistically significantly higher in patients infected with H. pylori (p = 0.046).
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    • High Prevalence of Mycoplasma pneumoniae and Chlamydia pneumoniae in Children with Acute Respiratory Infections from Lima, Peru

      del Valle-Mendoza, Juana; Orellana-Peralta, Fiorella; Marcelo-Rodríguez, Alvaro; Verne, Eduardo; Esquivel-Vizcarra, Mónica; Silva-Caso, Wilmer; Aguilar-Luis, Miguel Angel; Weilg, Pablo; Casabona-Oré, Verónica; Ugarte, Claudia; del Valle, Luis J.; jdelvall@upc.edu.pe (2017-01-27)
      Background Mycoplasma pneumoniae and Chlamydia pneumoniae are atypical pathogens responsible for pneumonia and a leading cause of morbidity and mortality in low income countries. The study objective is to determine the prevalence of this pathogens in Peruvian children with acute respiratory infections. Methods A consecutive cross-sectional study was conducted in Lima, Peru from May 2009 to September 2010. A total of 675 children admitted with clinical diagnoses of acute respiratory infections were tested for Mycoplasma pneumoniae and Chlamydia pneumoniae detection by polymerase chain reaction (PCR), and clinical symptoms were registered by the attending physician. Results Mycoplasma pneumonia was detected in 25.19% (170/675) of nasopharyngeal samples and Chlamydia pneumonia in 10.52% (71/675). The most common symptoms in patients with these atypical pathogens were rhinorrhea, cough and fever. A higher prevalence of Mycoplasma pneumoniae cases were registered in summer, between December 2009 and March 2010. Conclusions Mycoplasma pneumoniae and Chlamydia pneumonia are a significant cause of morbidity in Peruvian children with acute respiratory infections (ARI). Further studies should evaluate the use of reliable techniques such as PCR in Peru in order to avoid underdiagnoses of these atypical pathogens.
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    • Identification of infection by Chikungunya, Zika, and Dengue in an area of the Peruvian coast. Molecular diagnosis and clinical characteristics

      Sánchez-Carbonel, José; Tantaléan-Yépez, Derek; Aguilar-Luis, Miguel Angel; Silva-Caso, Wilmer; Weilg, Pablo; Vásquez-Achaya, Fernando; Costa, Luis; Martins-Luna, Johanna; Sandoval, Isabel; del Valle-Mendoza, Juana (BioMed Central Ltd., 2018-03-14)
      Objective: To assess the presence of Dengue, Chikungunya, and Zika in serum samples of patients with acute febrile illness in Piura, Peru and describe the most common clinical features. Results: Dengue was the most common arbovirus detected in 170/496 (34.3%), followed by Zika in 39/496 (7.9%) and Chikungunya in 23/496 (4.6%). Among the 170 samples positive for Dengue, serotype 2 was the most predominant type present in 97/170 (57.1%) of samples, followed by the serotype 3 in 9/170 (5.3%). Headaches, muscle pain, and joint pain were the most common symptoms associated with fever in patients with Dengue and Zika. No symptoms predominance was observed in patients with Chikungunya.Dengue is considered the most frequent arbovirus in Peru and the number of cases has increased dramatically in the last 5 years. However, it is not the only arbovirus that circulates along the northern coast of Peru. It has also been determined the presence of Zika and Chikungunya in our population, which may suggest the circulation of other arboviruses that have not been detected.
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    • Immunosuppressive and angiogenic cytokine profile associated with Bartonella bacilliformis infection in post-outbreak and endemic areas of Carrion's disease in Peru

      Pons, Maria J.; Gomes, Cláudia; Aguilar, Ruth; Barrios, Diana; Aguilar-Luis, Miguel Angel; Ruiz, Joaquim; Dobaño, Carlota; del Valle-Mendoza, Juana; Moncunill, Gemma; jdelvall@upc.edu.pe (Public Library of Science, 2017-06-19)
      Analysis of immune responses in Bartonella bacilliformis carriers are needed to understand acquisition of immunity to Carrion’s disease and may allow identifying biomarkers associated with bacterial infection and disease phases. Serum samples from 144 healthy subjects from 5 villages in the North of Peru collected in 2014 were analyzed. Four villages had a Carrion’s disease outbreak in 2013, and the other is a traditionally endemic area. Thirty cytokines, chemokines and growth factors were determined in sera by fluorescent bead-based quantitative suspension array technology, and analyzed in relation to available data on bacteremia quantified by RT-PCR, and IgM and IgG levels measured by ELISA against B. bacilliformis lysates. The presence of bacteremia was associated with low concentrations of HGF (p = 0.005), IL-15 (p = 0.002), IL-6 (p = 0.05), IP-10 (p = 0.008), MIG (p = 0.03) and MIP-1α (p = 0.03). In multi-marker analysis, the same and further TH1-related and pro-inflammatory biomarkers were inversely associated with infection, whereas angiogenic chemokines and IL-10 were positively associated. Only EGF and eotaxin showed a moderate positive correlation with bacteremia. IgM seropositivity, which reflects a recent acute infection, was associated with lower levels of eotaxin (p = 0.05), IL-6 (p = 0.001), and VEGF (p = 0.03). Only GM-CSF and IL-10 concentrations were positively associated with higher levels of IgM (p = 0.01 and p = 0.007). Additionally, IgG seropositivity and levels were associated with high levels of angiogenic markers VEGF (p = 0.047) and eotaxin (p = 0.006), respectively. Our findings suggest that B. bacilliformis infection causes immunosuppression, led in part by overproduction of IL-10. This immunosuppression probably contributes to the chronicity of asymptomatic infections favoring B. bacilliformis persistence in the host, allowing the subsequent transmission to the vector. In addition, angiogenic markers associated with bacteremia and IgG levels may be related to the induction of endothelial cell proliferation in cutaneous lesions during chronic infections, being possible candidate biomarkers of asymptomatic infections.
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    • Molecular etiological profile of atypical bacterial pathogens, viruses and coinfections among infants and children with community acquired pneumonia admitted to a national hospital in Lima, Peru

      del Valle-Mendoza, Juana; Silva-Caso, Wilmer; Cornejo-Tapia, Angela; Orellana-Peralta, Fiorella; Verne, Eduardo; Ugarte, Claudia; Aguilar-Luis, Miguel Angel; De Lama-Odría, María del Carmen; Nazario-Fuertes, Ronald; Esquivel-Vizcarra, Mónica; Casabona-Ore, Verónica; Weilg, Pablo; del Valle, Luis J. (2017-12-06)
      Objective: The main objective of this study was to detect the presence of 14 respiratory viruses and atypical bacteria (Mycoplasma pneumoniae, Chlamydia pneumoniae), via polymerase chain reaction in patients under 18 years old hospitalized due to community-acquired pneumonia (CAP) from Lima, Peru. Results: Atypical pathogens were detected in 40% (58/146); viral etiologies in 36% (52/146) and coinfections in 19% (27/146). The most common etiological agent was M. pneumoniae (n = 47), followed by C. pneumoniae (n = 11). The most frequent respiratory viruses detected were: respiratory syncytial virus A (n = 35), influenza virus C (n = 21) and parainfluenza virus (n = 10). Viral-bacterial and bacterium-bacterium coinfections were found in 27 cases. In our study population, atypical bacteria (40%) were detected as frequently as respiratory viruses (36%). The presence of M. pneumoniae and C. pneumoniae should not be underestimated as they can be commonly isolated in Peruvian children with CAP.
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    • Molecular identification of Bartonella bacilliformis in ticks collected from two species of wild mammals in Madre de Dios: Peru

      del Valle-Mendoza, Juana; Rojas-Jaimes, Jesús; Vásquez-Achaya, Fernando; Aguilar-Luis, Miguel Angel; Correa-Nuñez, Germán; Silva-Caso, Wilmer; Lescano, Andrés G.; Song, Xiuping; Liu, Qiyong; Li, Dongmei; juana.delvalle@upc.pe; jesus.rojas.jaimes@gmail.com; fernando.vasquez.achaya@gmail.com; ma23aguilar@gmail.com; biologo.geo@yahoo.com; gian_will@hotmail.com (BioMed Central Ltd., 2018-06)
      Objective: To study the presence of Bartonella bacilliformis in ticks collected from two wild mammals in Madre de Dios, Peru. Results: A total of 110 ticks were collected. Among the 43 Amblyomma spp. extracted from the 3 Tapirus terrestris only 3 were positive for B. bacilliformis. In addition, 12 out of the 67 Rhipicephalus (Boophilus) microplus obtained from the 3 Pecari tajacu were positive for B. bacilliformis. For the first time B. bacilliformis have been detected in arthropods other than Lutzomyia spp. Further studies are required to elucidate the possible role of ticks in the spread of South American Bartonellosis.
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