The American Journal of Tropical Medicine and Hygiene - Current Issue

The aim of this study was to evaluate the occurrence of pulmonary embolism in returning travelers with hypoxemic pneumonia due to COVID-19. All returning travelers to Reunion Island with hypoxemic pneumonia due to COVID-19 underwent computed tomography pulmonary angiography (CTPA) and were included in the cohort. Thirty-five patients were returning travelers with hypoxemic pneumonia due to COVID-19 and had recently returned from one of the countries most affected by the COVID-19 outbreak (mainly from France and Comoros archipelago). Five patients (14.3%) were found to have pulmonary embolism and two (5.9%) were incidentally found to have deep vein thrombosis on CTPA. Patients with pulmonary embolism or deep vein thrombosis had higher D-dimer levels than those without pulmonary embolism or deep vein thrombosis (P = 0.04). Returning travelers with hypoxemic pneumonia due to COVID-19 should be systematically screened for pulmonary embolism.

The news was reported from the Wuhan region of China about a novel corona virus in the end of 2019. After spreading around the world, a pandemic was declared by the WHO. Depending on the different involvement of the disease, the most common symptoms are fever, cough, and dyspnea. However, some indeterminate symptoms that make diagnosis difficult, such as myalgia and fatigue, can also be seen alone, without the typical clinical picture. We describe a patient with COVID-19 pneumonia, the only complaint of which is myalgia, and the first diagnosis is mild rhabdomyolysis. The patient had no evidence or history other than viral infection that could explain muscle pain and also increased level of muscle enzymes. When mild rhabdomyolysis lack of myoglobinuria and complications was diagnosed, treatment-related rhabdomyolysis was also avoided as no treatment related to COVID-19 was initiated yet. Apart from the typical symptoms leading to the typical diagnosis of COVID-19 at the first admission, SARS-CoV-2 related with rhabdomyolysis should also be kept in mind.

Dengue fever continues to be an important cause of morbidity and mortality in tropical and subtropical countries. A wide range of neurological manifestations including dengue encephalopathy, Guillain–Barre syndrome, acute disseminated encephalomyelitis, transverse myelitis, cranial nerve palsies, and myositis have been reported following dengue infection. But parkinsonism secondary to dengue virus infection is uncommon, with only three published case reports in adults and one in children. We describe a 13-year-old pre-morbidly normal boy, who presented with bradykinesia, bradyphonia, mask-like facies, and cogwheel rigidity while recovering from uncomplicated DF. He responded favorably to levodopa/carbidopa supplementation and had resolution of symptoms over the next 2 weeks. We also did a comparative review of all published cases of dengue-induced parkinsonism. Post-dengue, parkinsonism is uncommon, and treating clinicians should be aware of this uncommon but treatable neurological complication of a common arboviral infection.

New dengue vaccines are needed to prevent this globally expanding vector-borne disease. The V180 vaccine candidate consists of four recombinant, soluble, dengue virus envelope glycoproteins and has been previously evaluated in two clinical trials for safety and immunogenicity in Flavivirus-naive participants (NCT01477580 and NCT0093642). Here, we report on a randomized, placebo-controlled, double-blind study of the safety and immunogenicity of the V180 vaccine in subjects who have previously received the live attenuated tetravalent vaccine (LATV) developed by the National Institute of Allergy and Infectious Diseases (protocol #V180-002 [CIR-301]). The study was designed to evaluate whether this recombinant subunit vaccine could boost the neutralizing antibody responses induced by dengue LATV. Twenty participants who had previously received one or two doses of dengue LATV were randomized and received a single dose of V180 nonadjuvanted (N = 8), V180 adjuvanted with Alhydrogel™ (aluminum hydroxide gel, Brenntag Biosector, Frederikssund, Denmark) (N = 8), or placebo (N = 4). Immunogenicity was measured using a plaque reduction neutralization test at days 1, 15, 28, and 180 after vaccination. In addition, vaccine safety (solicited and unsolicited adverse events) was assessed using a vaccination report card for 28 days following vaccination, and serious adverse events were captured from the time of informed consent through the final study visit at 6 months after vaccination. The results of the study demonstrate that the V180 vaccine is generally well tolerated and immunogenic in these dengue-seropositive volunteers.

Japanese encephalitis (JE) is endemic in Malaysia. Although JE vaccination is practiced in the neighboring state of Sarawak for a long time, little is known about JE in Sabah state in Borneo. As a result, informed policy formulation for JE in Sabah has not been accomplished. In the present study, we have analyzed JE cases that have been reported to the Sabah State Health Department from 2000 to 2018. A total of 92 JE cases were reported during 19 years, and three-fourths of the cases were attributed to children. The estimated mean incidence for JE cases is 0.161/100,000 population. Japanese encephalitis was predominant in Sabah during June, July, and August, peaking in July. In most cases, pigs were absent within a 400-m radius of the place of residence. We could not establish any relationship between the mapping of JE cases and the number of piggeries in each district. We could not establish a relationship between average rainfall and JE cases, either. We propose the cases reported are possibly showing the tip of an iceberg and continuous surveillance is needed, as JE is a public health challenge in Sabah.

Chikungunya virus (CHIKV) and Zika virus (ZIKV) are arthropod-borne viruses transmitted mainly by Aedes aegypti mosquitoes. These viruses have become endemic in large parts of North, Central, and South America. Arboviruses persistently infect mosquitoes throughout their life span and become infectious (i.e., expectorate infectious virus in saliva) after a period of time called the extrinsic incubation period (EIP). The duration of this infectiousness, however, is not well characterized. This is an important shortcoming because many epidemiological models assume that mosquitoes continue to be infectious for the duration of their life span. To define the duration of infectiousness for CHIKV and ZIKV, mosquitoes were infected orally with these viruses. Every 2 days, legs/wings, midguts, salivary glands, and saliva were collected from 30 to 60 mosquitoes and viral load measured. In CHIKV-infected mosquitoes, infectious virus in saliva peaked early (2–4 dpi), and then decreased rapidly and was rarely observed after 10 dpi. Viral RNA in infected tissues also decreased after the initial peak (4–8 dpi) but did so much less drastically. In ZIKV-infected mosquitoes, the infectious virus in saliva peaked at 12–14 dpi and dropped off only slightly after 14 dpi. In infected tissues, viral RNA increased early during infection, and then plateaued after 6–10 days. Our findings suggest that significant variation exists in the duration of the infectious period for arboviruses that is in part influenced by virus clearance from expectorated saliva.

Vertical transmission, or pathogen transfer from female to offspring, can facilitate the persistence of emerging arboviruses, such as Zika virus (ZIKV), through periods of low horizontal transmission or adverse environmental conditions. We aimed at determining the rate of vertical transmission for ZIKV in its principal vector, Aedes aegypti, and the vector competence of vertically infected progeny. Aedes aegypti females that consumed a blood meal provisioned with ZIKV were maintained under three temperature conditions (27°C, 30°C, and 33°C) following the infectious blood meal and allowed to complete three reproductive cycles. The overall vertical transmission rate was 6.5% (95% CI = 3.9–9.9). Vertical transmission of ZIKV was observed across all temperature conditions and virus detected in adult progeny up to 2 weeks postemergence. In total, 3.4% (95% CI = 1.6–6.2) of adult progeny produced saliva with ZIKV, indicating their vector competence. These results suggest the virus may be maintained in Ae. aegypti populations without a vertebrate host for short periods.

We developed and evaluated the Global Health Wizard Hepatitis B Best Practice Alert (BPA) to increase primary care provider adherence to evidence-based guidelines for hepatitis B virus (HBV) infection screening in non–U.S.-born patients. We conducted a pilot study using nine clinics to test BPA effectiveness. Eligible patients were aged ≥ 12 years, from a country of origin with ≥ 2% HBV prevalence, had no electronic health record documentation of HBV screening, and were seen for primary care during July 2012–March 2013. The BPA triggered for > 4,500 patients and identified six previously unrecognized HBV-infected patients. The pilot project demonstrated BPA effectiveness and continued to be used at pilot clinics until 2018 and was expanded to additional clinics in 2019; 29 additional HBV-infected patients were identified. Although successful, BPA usage steadily decreased over time. Poor BPA usage limits the power to achieve the goal of improved population-based HBV screening.

Increasing access to rapid diagnostic tests for malaria (mRDTs) has raised awareness of the challenges healthcare workers face in managing non-malarial febrile illnesses (NMFIs). We examined NMFI prevalence, clinical diagnoses, and prescribing practices in outpatient clinics across different malaria transmission settings in Malawi. Standardized facility-based malaria surveillance was conducted at three facilities one of every 4 weeks over 2 years. Information on demographics, presenting symptoms, temperature, clinical diagnosis, and treatment were collected from outpatients presenting with malaria-like symptoms. Of the 25,486 patients with fever, 69% had NMFI. Non-malarial febrile illness prevalence was lower in 5- to 15-year-old patients (55%) than in children < 5 years (72%) and adults > 15 years of age (77%). The most common clinical diagnoses among febrile patients with negative mRDTs in all age-groups and settings were respiratory infections (46%), sepsis (29%), gastroenteritis (13%), musculoskeletal pain (9%), and malaria (5%). Antibiotic prescribing was high in all age-groups and settings. Trimethoprim–sulfamethoxazole (40%) and amoxicillin (29%) were the most commonly prescribed antibiotics and were used for nearly all clinical diagnoses. In these settings with minimal access to diagnostic tools, patients with fever and a negative mRDT received a limited number of clinical diagnoses. Many were likely to be inaccurate and were associated with the inappropriate use of the limited range of available antibiotics. Prescription and diagnostic practices for NMFIs in the facilities require research and policy input. Resource-limited malaria-endemic countries urgently need more point-of-care diagnostic tools and evidence-based diagnosis and treatment algorithms to provide effective and cost-efficient care.

Falsified and substandard medicines may undermine the progress toward the Sustainable Development Goals. The present study investigated the quality of 13 essential medicines in Cameroon and the Democratic Republic of Congo (DR Congo). Five hundred six medicine samples were collected from the government and faith-based health facilities, private pharmacies, and informal vendors (total 60 facilities). Collected samples were analyzed according to the U.S. Pharmacopeia (USP) for identity, content, and dissolution of their active pharmaceutical ingredients (APIs) and for uniformity of dosage units. Three samples (0.6%) were identified as falsified. Overall, 8.5% of the samples failed USP specifications for the content of the API and 11.7% failed dissolution testing. Medicines from informal vendors showed a higher out-of-specification rate (28.2%) than other types of drug outlets (12.3%; P < 0.0001). All three falsified medicines had been sold by informal vendors. The failure rate of medicines stated to be produced in Europe (5.1%) was lower than that for medicines from Asia (17.7%; P = 0.0049) and Africa (22.2%; P = 0.0042). Medicines against noncommunicable diseases showed a higher failure rate than antibiotics (25.3% versus 12.1%; P = 0.0004). Four hundred fifty-one of the samples were analyzed in Cameroon and the DR Congo with the Global Pharma Health Fund Minilab (thin-layer chromatography and disintegration testing). The three falsified medicines were readily detected in Minilab analysis. However, substandard samples were detected with low sensitivity. A well-enforced ban of medicine sales by informal vendors and increased attention to supplier qualification in the procurement process may reduce the prevalence of substandard and falsified medicines.

The aims of this study were to describe a smartphone app aimed at healthcare professionals who work in areas endemic for visceral and tegumentary leishmaniases, and to report the user’s perception of the app in these areas. The software, called LeishCare®, has the following features: data registration, image filter to record the evolution of skin lesions using photos, calculation of a score set to identify the risk of death from visceral leishmaniasis, and guides to the diseases. LeishCare® was made available to healthcare professionals in endemic municipalities in Brazil, and the perception of potential users was evaluated at baseline and after 6 and 12 months. In the first meeting, 96 (94.1%) of the 102 professionals who knew the app reported positive expectations for its use. The installation of LeishCare® on the individual device and the evaluation of user perception were completed at 6 months with 16 users and at 12 months with 20 users. More than 90% of the professionals evaluated in both assessments found the information of the app useful. The features related to the calculation of visceral leishmaniasis severity score, and the guides to leishmaniases were the most frequently accessed. Users reported competence gain attributed to the app for all items evaluated. In conclusion, LeishCare® was found to be a promising tool to help healthcare professionals in endemic areas with leishmaniasis management.