Importance of Balanced Attention Toward Coronavirus Disease 2019 and Neglected Tropical Diseases

Coronavirus disease 2019 (COVID-19), caused by SARS-CoV-2, has been spreading since 2019, causing a worldwide pandemic. Amid the COVID-19 pandemic, tuberculosis, AIDS, and malaria have adversely affected the quality of life of patients and killed millions of people. In addition, COVID-19 continues to impede the delivery of health services, including those for the control of neglected tropical diseases (NTDs). Furthermore, NTDs have been reported as possible co-pathogens among patients infected with COVID-19. However, studies regarding parasitic co-infection among these patients have been limited. This review aimed to explore and describe the cases and reports of parasitic infections in the backdrop of COVID-19 to provide comprehensive knowledge regarding this aspect. We reviewed seven cases of patients who had parasitic co-infection and tested positive for COVID-19, and summarized the literature on the importance of controlling parasitic diseases. In addition, we identified recommendations for the control of parasitic diseases under possible difficulties, such as declining funding for parasitic diseases in 2020. This review highlights the growing burden of NTDs under COVID-19 that may be caused by the deficiency of healthcare infrastructure and human resources as the main reasons. Clinicians should remain vigilant for possible co-infections with parasites in COVID-19 patients, while policymakers are urged to reinforce a balanced and long-term health strategy that addresses both NTDs and COVID-19.

Microbiome of Haemaphysalis longicornis Tick in Korea

Ticks can transmit pathogenic bacteria, protozoa, and viruses to humans and animals. In this study, we investigated the microbiomes of Haemaphysalis longicornis according to sex and life stages. The Shannon index was significantly higher for nymphs than adult ticks. Principal coordinates analysis showed that the microbiome composition of female adult and male adult ticks were different. Notably, Coxiella-like bacterium (AB001519), known as a tick symbiont, was found in all nymphs and female adult ticks, but only one out of 4 male adult ticks had Coxiella-like bacterium (AB001519). In addition, Rickettsia rickettsii, Coxiella burnetii, and Anaplasma bovis were detected in this study.

Geographical Distribution and Epidemiologic Factors of Chigger Mites on Apodemus agrarius during Autumn in Korea

A nationwide survey of chigger mites causing scrub typhus and an investigation of epidemiologic factors for chigger mites was conducted at 16 localities in 8 provinces in Korea during autumn 2009, 2012, and 2013. A total of 233 Apodemus agrarius were captured, and all were infested with chigger mites. The chigger index was highest in Chungcheongbuk-do in 2009 (358.3) and 2012 (290.1) and Chungcheongnam-do in 2013 (294.4). The predominant chigger mite species was Leptotrombidium pallidum in the northern and central parts and L. scutellare in the southern and western parts, Korea. L. pallidum was not found in Jellanam-do and Gyeongsangnam-do and the distribution of L. scutellare had been expanded in the northern parts of Korea. The chigger index of L. pallidum was positively correlated with temperature and negatively correlated with humidity. The incidence of scrub typhus is dependent on L. scutellare index. These findings could be helpful to monitor the distribution of chigger mites and to develop a preventive measures for scrub typhus in Korea.

Association between Sociodemographic Factors and Diarrhea in Children Under 5 Years in Rwanda

Diarrheal disease is the second leading cause of mortality and morbidity in children under 5 years old worldwide, and is the most common cause of malnutrition in sub-Saharan Africa. In Rwanda, diarrhea is the third leading cause of death in children under 5 years old. This study examined the association between sociodemographic factors and diarrhea in children under 5 years using the data of 7,474 households in the 2014-2015 Rwanda Demographic and Health Survey. Overall prevalence of diarrhea in this study was 12.7% in children. An increased risk for diarrhea was found for children aged 12-23 months (odds ratio (OR)=4.514), those with a low economic status (OR=1.64), those from the Western province (OR=1.439), those with poorly-educated mothers (OR=5.163), and those with families engaged in agricultural activities (OR=1.624). In conclusion, sociodemographic factors significantly affect the risk of developing diarrhea in children under 5 years in Rwanda. Designing and implementing health education promoting awareness of early interventions and rotavirus vaccination are essential to reduce diarrheal diseases for the Rwandan community.

Review of Successful Control of Parasitic Infections in Korea / 감염과화학요법

Korea had been one of hyperendemic countries of human parasitic infections until 1970s.In 1966, the Law for the Prevention of Parasitic Diseases was enacted, and the nationwide anti-parasitic control program began in 1969. The initiation of the national program was supported financially by Japan. The program included screening of whole students in Korea and treatment of all egg positive cases twice a year, and ended in 1995. In addition to student program, deworming campaign was run in the community, and 8 national status surveys were implemented from 1971 to 2012. Whole helminth egg positive rate was 84.3% in 1971 and decreased to 2.6% in 2012. Ascaris and other intestinal nematodes, Paragonimus, Taenia, and intestinal protozoa had decreased significantly throughout the country, but Clonorchis sinensis and intestinal trematodes are still prevalent locally in endemic areas. Lymphatic filariasis had been endemic in Jeju-do and other southern islands but elimination was endorsed in 2008. The control of parasitic infection in Korea was successful with statistical prevalence data, which can be a benchmarking model. In conclusion, the successful control in Korea could be achieved by social agreement of the priority, professional guidelines and systematic approach with good anthelminthics supply, and simultaneous economic growth.

Phylogenetic Characteristics of Echinococcus granulosus Sensu Lato in Uzbekistan

Echinococcosis occurs mainly in areas with heavy livestock farming, such as Central Asia, America, and Australia. Echinococcus granulosus sensu lato (s.l.) infection causes echinococcosis in intermediate hosts, such as sheep, cattle, goats, camels, and horses. Numerous cases of echinococcosis occur in Uzbekistan as stock farming is a primary industry. Epidemiological and genetic studies of E. granulosus s.l. are very important for mitigating its impact on public health and the economy; however, there are no such studies on E. granulosus s.l. in Uzbekistan. In the present study, to determine which genotypes exist and are transmitted, we isolated Echinococcus sp. from definitive hosts (one isolate each from jackal and dog) and intermediate hosts (52 isolates from humans and 6 isolates from sheep) in Uzbekistan and analyzed the isolates by sequencing 2 mitochondrial DNA components (cox1 and nad1). The results showed that all of isolates except one belonged to the E. granulosus sensu stricto (s.s.) G1 and G3 genotypes. Phylogenetic analysis based on cox1 sequences showed that 42 isolates from humans, 6 isolates from sheep, and one isolate from jackal were the G1 genotype, whereas the remaining 8 isolates from human and the one isolate from dog were the G3 genotype. These results suggest that the G1 and G3 genotypes of E. granulosus s.s. are predominant in Uzbekistan, and both wild animals and domestic animals are important for maintaining their life cycle. Only one isolate from human sample was confirmed to be E. eqiinus (G4 genotype), which is known to be for the first time.

Effectiveness of Mass Drug Administration on Neglected Tropical Diseases in Schoolchildren in Zanzibar, Tanzania

Soil-transmitted helminths and Schistosoma haematobium affect more than 3 billion people globally and mainly occur in sub-Saharan Africa. The present study assessed the overall infection status of a 1716-student cohort of school-children in Zanzibar and applied mass drug administration (MDA) to the cohort from 2007 to 2009. Schools in Pemba, Zanzibar, had a much higher prevalence of soil-transmitted helminth infections than those in Unguja, and the Chaani, Ghana, and Machui schools of Unguja exhibited high S. haematobium infection rates. The MDA program only partially controlled parasite infections, owing to high rates of re-infection. The infection rate of S. haematobium across all 10 schools, for example, was only reduced by 1.8%, and even this change not significant, even though the S. haematobiuminfection rates of the Chaani and Mzambarauni schools were significantly reduced from 64.4 and 23.4%, respectively, at the first screening, to 7.3 and 2.3% at the last screening. The overall infection rate of Ascaris lumbricoides was reduced from 36.0% at the first screening to 22.6% at the last screening. However, the infection rates for both Trichuris trichiuraand hookworm were generally unaffected by MDA. In the future, parasite control programs should involve strategically designed MDA schedules and holistic intervention (e.g., sanitation improvement, hygiene behavior changes, and control of intermediated hosts).

Echinostoma aegyptica (Trematoda: Echinostomatidae) Infection in Five Riparian People in Savannakhet Province, Lao PDR

Human infection with Echinostoma aegyptica Khalil and Abaza, 1924 (Trematoda: Echinostomatidae) is extremely rare. In this study, we confirmed E. aegyptica infection in 5 riparian residents living along the Mekong River in Savannakhet Province, Lao PDR. The patients revealed eggs of Opisthorchis viverrini/minute intestinal flukes, echinostomes, and other parasites in fecal examinations using the Kato-Katz technique. Following treatment with praziquantel 30-40 mg/kg and pyrantel pamoate 10-15 mg/kg in a single dose and purging with magnesium salts, adult specimens of various helminth species were collected. Among the trematodes, echinostome flukes of 4.5-7.6 mm in length (n = 134; av. 22.3 specimens per case) were of taxonomic interest and subjected in this study. The flukes were morphologically characterized by having total 43-45 collar spines arranged in 2 alternating rows (corner spines usually 5 on each side) and compatible with previous descriptions of E. aegyptica. The patients were mixed-infected with other helminths, so specific clinical manifestations due to this echinostome fluke were difficult to determine. The present paper describes for the first time human E. aegyptica infections in Lao PDR. This is the second report of human infection (2nd-6th cases) with E. aegyptica in the world following the first one from China.

Molecular Detection of Toxoplasma Gondii in Haemaphysalis Ticks in Korea

Toxoplasma gondii are intracellular protozoa that can cause neurological disease or death in fetuses and even in immunocompromised human adults. Ticks are recognized as vectors of many microorganisms including viruses, bacteria, and protozoa. Recent studies detected T. gondii in various tick species in many countries. In this study, we performed PCR detection of the T. gondii B1 gene from Haemaphysalis ticks collected from vegetation in 4 localities, Wonju, Gunsan, Miryang, and Yangsan, in Korea. We analyzed DNA from 314 ticks (268 Haemaphysalis longicornis and 46 Haemaphysalis flava) and the B1 gene of T. gondii was detected in 13 of these. The detection of T. gondii in ticks differed significantly by region (P=0.021). T. gondii was detected in the following percentages of collected ticks: 3.7% (7 of 189) in Gunsan, 10% (5 of 50) in Wonju, 16.7% (1 of 6) in Yangsan, and 0% (0 of 69) in Miryang. The detection of T. gondii in ticks was not associated with tick species or development stage. This is the first report of T. gondii detection in ticks in Korea. Our results provide important information necessary to understand toxoplasmosis transmission.

Comparative Microbiome Analysis of Three Species of Laboratory-Reared Periplaneta Cockroaches

Cockroaches inhabit various habitats, which will influence their microbiome. Although the microbiome can be influenced by the diet and environmental factors, it can also differ between species. Therefore, we conducted 16S rDNAtargeted high-throughput sequencing to evaluate the overall bacterial composition of the microbiomes of 3 cockroach species, Periplaneta americana, P. japonica, and P. fuliginosa, raised in laboratory for several generations under the same conditions. The experiments were conducted using male adult cockroaches. The number of operational taxonomic units (OTUs) was not significantly different among the 3 species. With regard to the Shannon and Pielou indexes, higher microbiome values were noted in P. americana than in P. japonica and P. fuliginosa. Microbiome composition was also evaluated, with endosymbionts accounting for over half of all OTUs in P. japonica and P. fuliginosa. Beta diversity analysis further showed that P. japonica and P. fuliginosa had similar microbiome composition, which differed from that of P. americana. However, we also identified that P. japonica and P. fuliginosa host distinct OTUs. Thus, although microbiome compositions may vary based on multiple conditions, it is possible to identify distinct microbiome compositions among different Periplaneta cockroach species, even when the individuals are reared under the same conditions.