Asian Pacific Journal of Tropical Medicine

97-98

Authors: Folorunso Oludayo Fasina

The year 2020 was welcomed and characterized with a report of pneumonia of unknown etiology, which occurred primarily in Wuhan City of Hubei Province of China. Between 31 December 2019 and 3 January 2020, a total of 44 cases in human was reported to the World Health Organization (WHO) by the Chinese Health Authorities [1] . By 3 February 2020, a total of 17 391 cases have been confirmed globally with 2 838 new cases (China: 17 238; 2 831 new cases and 361 deaths; Outside China: 153 with 7 new cases and 1 death from 23 countries) [1] . Wuhan City of Hubei Province has accounted for approximately 64.8% of all cases from China. Globally, the risk of infection and spread remains high. The pathogen causing the infection has been classified as 2019 novel coronavirus (2019-nCoV). Due to a surge in numbers of cases from the third week of January 2020, and after intense consultations and deliberations by the International Health Regulations (2005)Emergency Committee, the WHO, on 30 January 2020 declared the outbreak of 2019-nCoV a Public Health Emergency of International Concern (PHEIC) [2,3] . Since the date of this declaration, global attention has been focused on 2019-nCoV [4,5] .Preliminary clinical features indicated that most of the infected patients were men with underlying diseases (comorbidities)including diabetes, hypertension, cardiovascular disease, chronic obstructive pulmonary disease, malignancy and chronic liver disease [6] . Patient presented with fever, cough, myalgia, sputum production, headache, haemoptysis, diarrhea and dyspnea [6] . Person-to-person transmission and familiar association have also beenconfirmed [7] . To date, a diagnostic kit has been developed for 2019-nCoV [8] , and efforts are ongoing to develop other protocols. Whilst several important aspects of 2019-nCoV epidemiology, virology, mode of transmission, pathogenesis, diagnosis, clinical features, have been defined, there remain many unanswered questions, including source, transmission and epidemic potential. The Wuhan outbreak is a stark reminder of the continuing threat of zoonotic diseases.Detailed clinical, laboratory and epidemiological findings are available in several studies [3,6,7] , and further works are ongoing to solve the several unknown about the virus (more details on the source, epidemiology, virology, mode of transmission, pathogenesis,diagnosis, clinical features and epidemic potential). These information will be needed to solve many unanswered questions. Specifically, it has been confirmed that many of the patients with ongoing outbreak in humans have linkages with a large seafood and live animal market in Wuhan, Hubei Province [3] . Evidence also suggests that the 2019-nCoV is closely related to coronavirus from bats [9] , a strong indication that the virus may have an animal source(with bats acting as the primary source and the animals available in the seafood market serving as intermediate hosts between human and bats). However, while it is known that humans are the terminal hosts for 2019-nCoV, it still needs further investigations whether this is similar to the situation in Severe Acute Respiratory Syndrome coronavirus (SARS-CoV), where masked palm civet is the intermediate host, and MERS-CoV where dromedary camels have been identified as intermediate hosts [9] . The yet-to-be-identified wild animal(s) may be the intermediate host for the ongoing 2019-nCoV. It therefore becomes important to utilize one health approach in the implementation of investigation and control of the ongoing 2019-nCoV. Recent models have suggested that a lot more cases than those confirmed and reported to the WHO may have occurred [10]. It was also suggested that human-to-human transmissibility is highly likely and the epidemic may spiral out of control without the implementation of effective control measures [11] . In Germany, an asymptomatic contact served as a source of 2019-nCoV transmission to other patients and this has introduced another dimension to the transmission dynamics in the current outbreaks [12] . The health authorities have quarantined several cities in Hubei Province in an unprecedented public health response, yet outbreak continues to be reported in several locations in China, as well as in the Western Pacific, South East Asia, North America, Europe and Middle East where intense import control measures have been implemented. It is important for the infectious disease community globally to draw from the lessons of SARS-CoV, Asian highly pathogenic avian influenza H5N1 (HPAI H5N1), MERS-CoV and other public health emergencies, particularly those that have originated from the South East Asia axis, to combat the current situation in South East Asia and elsewhere. Finally, global efforts continue to target vaccine development, an urgently needed biological that may stem an epidemic. The world will continue to monitor the 2019-nCoV ‘zoonotic’ respiratory diseases as progress is made in global health security.

107-114

Authors: Chulwoo Rhee, Birendra Prasad Gupta, Bibek Kumar Lal, Jacqueline Kyungah Lim, T. Anh Wartel, Julia Lynch, Sushant Sahastrabuddhe

Objective: To assess the extent of existing published evidence on cholera and to characterize the epidemiologic data of cholera in Nepal. Methods: We conducted a literature scoping review by summarizing published literature reporting on cholera in Nepal from January 1946 to March 2019 in online databases: MEDLINE, Embase, Cochrane, and Global Health. Additionally, we reviewed national surveillance data on clinically diagnosed and laboratory confirmed cholera reported by the Ministry of Health and Population. Results: Most of the published studies were conducted predominantly in Kathmandu Valley during the rainy season; however, outbreaks have been reported in other parts of Nepal including Terai, Hilly and Mountain regions. Our literature review exhibited that all age groups were affected by cholera, but particularly children and young adults were at-risk age groups in Nepal. Vibrio cholerae serogroup O1, biotype El Tor, serotype Ogawa has been predominantly isolated with an emergence of resistant strains since 1996. Two mass vaccination campaigns using oral cholera vaccines were conducted: Rautahat district in 2014 and Banke district in 2017. Conclusions: Capacity building for a nation wide systematic cholera surveillance with rapid and reliable diagnosis is needed to better estimate the burden of cholera and identify geographically at-risk areas associated with the disease in Nepal. It is essential for developing an adequate policy on oral cholera vaccine introduction and effective water, sanitation and hygiene interventions.

123-130

Authors: Kawin Wongthamarin, Thanaporn Trairattanapa, Sirakit Kijanukul, Thanakrit Kritsilpe, Sarun Poobunjirdkul, Warit Chuengdee, Mathirut Mungthin, Saovanee Leelayoova, Tawee Naaglor, Paanjit Taamasri, Picha Suwannahitatorn, Toon Ruang-Areerate, Phunlerd Piyaraj

Objective: To investigate the incidence, spontaneous clearance, persistence and risk factors of Blastocystis infection in a rural community in Thailand. Methods: In February 2016, a cohort study was conducted in a rural community of Thailand. Baseline information of intestinal parasitic infections and follow-up visits were conducted. Blastocystis infection was detected in stool samples examined with short-term in vitro cultivation using Jones’ medium supplemented with 10% horse serum. Participants were tested for Blastocystis infection at every study visit. Cox proportional hazard regression analysis was used to evaluate co-variates to determine the incidence of Blastocystis infection. Results: Of 733 enrolled participants, 57 (7.78%) were positive and 676 (92.22%) were negative for Blastocystis infection. All 676 participants were followed-up for Blastocystis infection between December 2016 and January 2018. In all, 52 of 482 cases (10.79%) comprised individual Blastocystis infection. The incidence density rates of Blastocystis infection, of spontaneous clearance of the disease and of persistent infection were 8.13, 63.14 and 38.70 per 1 000 person-months of follow-up, respectively. Our multivariate analysis revealed that opened defecation in fields or bushes (HR=4.8; 95% CI=2.1-10.4, P<0.001), raising cows (HR=2.8; 95% CI=1.1-7.1, P=0.032), not washing hands after animal contact (HR=2.1; 95% CI=1.0-4.2, P=0.044) and presenting symptoms of nausea or vomiting (HR=2.3; 95% CI=1.0-5.3, P=0.047) were predictive associated risks for the incidence of Blastocystis infection. Conclusions: Our study indicates that the best way to prevent Blastocystis infection can be by maintaining good personal hygiene, hand washing after animal contact and improving sanitary facilities.

137-138

Authors: Sora Yasri, Viroj Wiwanitkit

Wuhan novel coronavirus or 2019-novel coronavirus (2019-nCoV) infection is a rapidly emerging respiratory viral disease[1]. 2019- nCoV infection is characterized as febrile illness with possible severe lung complication[1]. The disease was firstly reported in China in December 2019 and then spread to many countries (such as Thailand, Japan and Singapore)[2,3]. As a new disease, there is a limited knowledge of treatment for the infection. Lu recently proposed that some drug might be useful in treatment of 2019-nCoV infection[3]. Lu noted that “lopinavir/ritonavir, nucleoside analogues, neuraminidase inhibitors, remdesivir, peptide (EK1), abidol, RNA synthesis inhibitors (such as TDF, 3TC), anti-inflammatory drugs (such as hormones and other molecules), Chinese traditional medicine, such ShuFengJieDu capsules and LianHuaQingWen capsule might be useful[3].” Of those mentioned drugs, lopinavir/ritonavir is a widely used antiviral for management of another important virus infection, human immunodeficiency virus (HIV) infection. Since 2019-nCoV infection is an RNA virus similar to HIV, lopinavir/ritonavir is proposed for management of 2019-nCoVinfection. At present, lopinavir/ritonavir is widely used for possible treatment of 2019-nCoV infection in countries that the emerging infection exists. Here, the authors used a mathematical modelling theoretical approach to predict the expectedproper dosage of lopinavir/ritonavir for possible treatment of 2019-nCoV infection. The protocol for mathematical modeling in this work is the same as previous report by Wiwanitkit et al[4]. Briefly, the primary agreement was there had to be a specific amount of required energy for reaction between lopinavir/ritonavir and its target enzyme and this energy is a specific constant for the reaction. Based on bonding theory, the required amount of lopinavir/ritonavir was varied to the two substrates, lopinavir/ritonavir and target, protease. Here, the simple equation ‘A + B → C where A was the target enzyme, B was lopinavir/ritonavir and C was end product’ could be written. For HIV, the molecular mass of protease is equal to 21.6 kDa. For 2019-nCoV, the molecular weight was calculated from the functional motif showing protease function within the sequence of the virus. From molecular weight calculation tool (https://www. bioinformatics.org/sms/prot_mw.html; version 1 by Stothard[4]), the molecular mass of protease of 2019-nCoV is equal to 33.8 kDa. By standard comparison technique as used in the previous report[5], the required dosage of lopinavir /ritonavir for 2019-nCoV infection was about 1.56 times higher than that for HIV infection. Hence, based on the modeling study, if lopinavir/ritonaviris used for management of 2019-nCoV, a doubled dosage of the present dosage for HIV infection is recommended.