Trop. Med. Infect. Dis., Volume 7, Issue 4 (April 2022) – 11 articles

Coronavirus disease 2019 (COVID-19) is the most dramatic pandemic of the new millennium. To counter it, specific vaccines have been launched in record time under emergency use authorization or conditional marketing authorization and have been subjected to additional monitoring. The European Medicines Agency recommend reporting any suspected adverse reactions during this additional monitoring phase. For the first time in the available medical literature, we report a left cubital tunnel syndrome in a 28-year-old right-handed healthy male after seven days from the first dose of Spikevax^® (formerly Moderna COVID-19 Vaccine). Histochemistry for Alcian Blue performed on the tissue harvested from the cubital site reveals myxoid degeneration of the small nerve collaterals, a clear sign of nerve injury. It still remains unclear why the syndrome occurs in a localized and not generalized form to all osteofibrous tunnels. Today, modified messenger ribonucleic acid vaccines as Spikevax^® represent an avantgarde technological platform with a lot of potential, but one which needs careful monitoring in order to identify in advance those patients who may experience adverse events after their administration. Full article

Delayed diagnosis of tuberculosis (TB) increases mortality and extends the duration of disease transmission. This study aimed to identify significant ICD-10 admission diagnoses preceding TB. All hospital electronic medical records from fiscal year 2015 to 2020 in the Songkhla Province, Thailand were retrieved. After excluding diabetes and HIV patients, a case-control analysis was performed. Exposures of interest were ICD-10 diagnoses on admissions 1–12 months prior to the visit during which TB was detected. Incident cases of respiratory tuberculosis (A15.0–A16.9) that had been admitted with at least one such exposure were chosen. For every case, controls were retrieved from weekly concurrent OPD patients who had the same 10-year interval of age, sex, and preceding admission and discharge week as the case. The 10 most common comorbidities during hospitalization preceding TB with their relative odds ratios (RORs) and 95% confidence intervals were identified. These included five significant exposures related to lower respiratory infection without adequate TB investigation. Significant RORs ranged from 3.10 (unspecified pneumonia) to 34.69 (hemoptysis). Full TB investigation was not performed due to problems with health insurance. In conclusion, the physicians should be informed about this pitfall, and the insurance system should be revised accordingly. Full article

(1) Background: vaccine hesitancy can put the public’s health at risk from vaccine-preventable diseases. This study aimed to address vaccine hesitancy in Saudi Arabia and understand the problem’s magnitude and causes. (2) Methods: this was a descriptive observational study using quantitative and qualitative evaluation methods conducted in Saudi Arabia between December 2020 and February 2021. Public survey forms, exit interviews, and healthcare professional survey forms were used. (3) Results: our study involved 2030 public survey participants, 119 exit interviews of caregivers, and 500 healthcare professionals, demonstrating that vaccine hesitancy was relatively low. Ninety percent of the participants agreed that it was essential for everyone to receive the recommended vaccines with their children (p < 0.001), 92% believed that vaccines are safe for their children (p < 0.001), 91% of the participants agreed to give their new children all the recommended doses (p < 0.001), 86% welcomed mass/school vaccination campaigns (p < 0.001), and 81% were willing to pay for additional vaccines for themselves and their children (p < 0.001). (4) Conclusions: vaccine hesitancy is low in Saudi Arabia, and a positive attitude toward vaccination was detected among most of the participants. Vaccination decision-making is complex and includes emotional, cultural, social, spiritual, and political aspects. Full article

Malaria is well-known as one of the most common causes of fever among travelers returning from endemic areas such as tropical African countries. However, afebrile Plasmodium falciparum malaria has rarely been reported in a returning traveler with no prior history of malaria infection. Here, we report an imported case of afebrile P. falciparum malaria infection from Tanzania in a returning traveler to the Republic of Korea, following an earlier COVID-19 infection without previous history of malaria infection. Our case suggests the hypothesis that severe symptoms of P. falciparum malaria infection might be prevented by cross- immunity from previous COVID-19 infection. Full article

Drug discovery for malaria has traditionally focused on orally available drugs that kill the abundant, parasitic blood stage. Recently, there has also been an interest in injectable medicines, in the form of monoclonal antibodies (mAbs) with long-lasting plasma half-lives or long-lasting depot formulations of small molecules. These could act as prophylactic drugs, targeting the sporozoites and other earlier parasitic stages in the liver, when the parasites are less numerous, or as another intervention strategy targeting the formation of infectious gametocytes. Generally speaking, the development of mAbs is less risky (costly) than small-molecule drugs, and they have an excellent safety profile with few or no off-target effects. Therefore, populations who are the most vulnerable to malaria, i.e., pregnant women and young children would have access to such new treatments much faster than is presently the case for new antimalarials. An analysis of mAbs that were successfully developed for oncology illustrates some of the feasibility aspects, and their potential as affordable drugs in low- and middle-income countries. Full article

Trichinellosis and cysticercosis remain challenges to human health and animal productivity worldwide, especially in developing countries. While information on the occurrence of both diseases is infrequent, they are endemic in parts of Vietnam and mainly related to indigenous pigs kept by ethnic minorities. This study aimed to determine the seroprevalence and risk factors of both diseases in indigenous pigs and explore the perception and awareness of both human and pig trichinellosis and cysticercosis of pig farmers. A total of 352 pig sera samples from 131 holdings were collected and analyzed using ELISA antibody tests in six communes in the Da Bac districts of Hoa Binh province, Vietnam. A survey was conducted with representatives from these households to understand the knowledge and perspective on food-borne parasitic diseases. Overall, the seroprevalence of trichinellosis and T. solium cysticercosis was 13.6% (95% CI 10.2–17.7) and 1.7% (95% CI 0.6–3.7), respectively. The seroprevalence of trichinellosis was significantly higher in female and older pigs. Risk perception and knowledge of interviewed people on both human and pig trichinellosis and cysticercosis of pig farmers was poor. Risky practices, including free roaming of pigs and eating undercooked or fermented pork, were observed. Educational and awareness campaigns aligned with further research on feasible practice changes are critical to addressing these issues. Full article

Nipah virus (NiV) disease (NVD) remains a re-emerging public health threat in India. We assessed the knowledge, attitudes, and risk perception of NVD and future vaccine intent among a convenience sample of health care providers (HCP). The primary outcome measures were the knowledge, attitudes, and risk perception scores. Of 261 participants surveyed, 203 (77.8%) had heard of NiV and associated symptoms. The majority (248, 95%) identified the fruit bat as a primary NiV reservoir and 205 (79.8%) were aware of human-to-human transmission via droplets. Only 101 (38.7%) participants were aware that drinking date palm sap is a risk factor for transmission. Most HCP either agreed (117 (44.8%)) or strongly agreed (131 (50.2%)) that NiV is a serious illness. Less than half (121 (46.4%)) were aware of any institutional protocol for NiV; 235 (90.7%) of HCP stated that they need more information about prevention and treatment options. Knowledge scores were significantly higher among physicians compared to nurses whereas nurses and academic providers were more likely to have higher attitudes scores. A majority of respondents (20,779.9%) were willing to be vaccinated and willing to recommend the NiV vaccine to their patients (21,682.8%). Future strategies include education of HCP to bridge the knowledge gaps and enhance preparedness through disease-specific training for NiV infection. Full article

While chronic schistosomiasis is pathologically well defined, the acute form of the disease is less well understood. It is generally agreed that early lesions, such as lung nodules and bladder polyps, are reversible, which impedes identification of the time elapsed since exposure. The intermediate stage between the acute and the chronic forms of schistosomiasis requires further investigation, as does the clinical stage due to lesions remaining after treatment. With current schistosomiasis control efforts gradually progressing to elimination, there is a need to focus on post-transmission schistosomiasis, which not only refers to remaining lesions from previous infections, but also accounts for the potential presence of surviving worms after treatment. This issue is particularly salient for migrants from endemic to non-endemic countries and should be kept in mind for returning expatriates from schistosomiasis-endemic countries. Negative stool examination or urine filtration are generally taken as indicative of cure since rectoscopy for Schistosoma mansoni infection, or cystoscopy for S. haematobium infection, are rarely performed. However, pathology of affected organs may persist indefinitely, while potentially remaining live worms could produce additional pathology. Hence, post-transmission schistosomiasis can prevail for years after elimination of the disease, and thus, warrant further attention. Full article

Leishmaniasis is a parasitic, widespread, and neglected disease that affects more than 90 countries in the world. More than 20 Leishmania species cause different forms of leishmaniasis that range in severity from cutaneous lesions to systemic infection. The diversity of leishmaniasis forms is due to the species of parasite, vector, environmental and social factors, genetic background, nutritional status, as well as immunocompetence of the host. Here, we discuss the role of the immune system, its molecules, and responses in the establishment, development, and outcome of Leishmaniasis, focusing on innate immune cells and Leishmania major interactions. Full article

Community transmission of SARS-CoV-2 in densely populated countries has been a topic of concern from the beginning of the pandemic. Evidence of community transmission of SARS-CoV-2 according to population density gradient and socio-economic status (SES) is limited. In June–September 2020, we conducted a descriptive longitudinal study to determine the community transmission of SARS-CoV-2 in high- and low-density areas in Dhaka city. The Secondary Attack Rate (SAR) was 10% in high-density areas compared to 20% in low-density areas. People with high SES had a significantly higher level of SARS-CoV-2-specific Immunoglobulin G (IgG) antibodies on study days 1 (p = 0.01) and 28 (p = 0.03) compared to those with low SES in high-density areas. In contrast, the levels of seropositivity of SARS-CoV-2-specific Immunoglobulin M (IgM) were comparable (p > 0.05) in people with high and low SES on both study days 1 and 28 in both high- and low-density areas. Due to the similar household size, no differences in the seropositivity rates depending on the population gradient were observed. However, people with high SES showed higher seroconversion rates compared to people with low SES. As no difference was observed based on population density, the SES might play a role in SARS-CoV-2 transmission, an issue that calls for further in-depth studies to better understand the community transmission of SARS-CoV-2. Full article

Background: Adherence to antiretroviral therapy (ART) is a strong determinant of virological suppression. We aimed to determine the magnitude of adherence as measured by medication possession ratio (MPR) and virological suppression with its predictors among adolescents and young adults (AYA) living with HIV on ART in Tanzania. Methods: This retrospective cohort study was conducted using archived data from HIV care and treatment centers in Dar es Salaam, Tanzania between 2015 and 2019. The logistic regression model assessed predictors for adherence and virological suppression. Results: Data of 5750 AYA living with HIV were analysed. The majority were females: 4748 (82.6%). About 63% had good adherence with MPR ≥ 85% at one year post ART initiation. Independent predictors of ART adherence were male sex (aOR = 1.3, 95% CI 1.1–1.5), CD4 > 500 cells/mm³ (aOR = 0.7, 95% CI: 0.6–0.9), WHO stage III (aOR = 1.6, 95% CI 1.3–1.9), enrollment in 2019 (aOR = 1.5, 95% CI 1.2–1.9), and virological suppression (aOR = 2.0, 95% CI 1.6–2.9). Using an Efavirenz- and a Nevirapine-based combination was associated with reduced odds of ART adherence (aOR = 0.3, 95% CI 0.1–0.8) and (aOR = 0.2, 95% CI 0.1–0.6), respectively. Predictors of virological suppression were MPR ≥ 85% (aOR = 2.0, 95% CI 1.6–2.4); CD4 > 500 cells/mm³ (aOR = 2.4, 95% CI 1.7–3.4), and once-daily dosing (aOR = 2.0, 95% CI 1.3–2.5). Conclusion: Adherence to ART among AYA living with HIV is suboptimal. Sex, year of enrollment, ART drug combination used, and immunological status at ART initiation are important predictors of adherence to ART and virological suppression. Full article