The American Journal of Tropical Medicine and Hygiene - Online First

Studies on the early introduction of SARS-CoV-2 in a naive population have important epidemic control implications. We report findings from the epidemiological investigation of the initial 135 COVID-19 cases in Brunei and describe the impact of control measures and travel restrictions. Epidemiological and clinical information was obtained for all confirmed COVID-19 cases, whose symptom onset was from March 9 to April 5, 2020. The basic reproduction number (R0), incubation period, and serial interval (SI) were calculated. Time-varying R was estimated to assess the effectiveness of control measures. Of the 135 cases detected, 53 (39.3%) were imported. The median age was 36 (range = 0.5–72) years. Forty-one (30.4%) and 13 (9.6%) were presymptomatic and asymptomatic cases, respectively. The median incubation period was 5 days (interquartile range [IQR] = 5, range = 1–11), and the mean SI was 5.4 days (SD = 4.5; 95% CI: 4.3, 6.5). The reproduction number was between 3.9 and 6.0, and the doubling time was 1.3 days. The time-varying reproduction number (Rt) was below one (Rt = 0.91; 95% credible interval: 0.62, 1.32) by the 13th day of the epidemic. Epidemic control was achieved through a combination of public health measures, with emphasis on a test–isolate–trace approach supplemented by travel restrictions and moderate physical distancing measures but no actual lockdown. Regular and ongoing testing of high-risk groups to supplement the existing surveillance program and a phased easing of physical distancing measures has helped maintain suppression of the COVID-19 outbreak in Brunei, as evidenced by the identification of only six additional cases from April 5 to August 5, 2020.

Nurses at the Front Line of COVID-19: Roles, Responsibilities, Risks, and Rights

Japanese encephalitis (JE) virus is a mosquito-borne flavivirus endemic throughout Asia. Incidence in non-endemic countries is rare, with an estimate of less than one case per one million travelers. Most human JE infections are asymptomatic or cause a mild, nonspecific febrile illness. Neurological involvement, if present, is usually severe and associated with high mortality or ongoing neurological sequelae in survivors. Ocular manifestations are rare with JE, but uveitis has been described to be associated with other flavivirus infections, including West Nile virus. We report the first probable case of JE chorioretinitis acquired by a 45-year-old Australian traveler to Bali. This case highlights the importance of a detailed ocular examination when there is clinical suspicion of JE.

Diagnosis of tuberculosis with GeneXpert and same-day initiation of tuberculosis treatment (SITT) has important public health and clinical benefits. GeneXpert allows for rapid diagnosis, hence presenting an opportunity for SITT. We determined the association between GeneXpert diagnosis and SITT, and the effect of SITT on the treatment success rate among adult persons with bacteriologically confirmed pulmonary tuberculosis (BC-PTB) in rural eastern Uganda. We conducted a retrospective cohort study using routinely collected data at 10 health facilities, used modified Poisson regression analysis to determine the association between GeneXpert and SITT, and expressed the results as RR. We used propensity score-matched analysis to match SITT participants to delayed initiation of treatment (DIT) participants and then performed logistic regression analysis to determine the independent effect of SITT on the treatment success rate, expressed as odds ratio (OR). Of 1,045 participants, 764 (73.1%) had SITT. The use of GeneXpert for diagnosis of tuberculosis was associated with higher likelihood of SITT (adjusted RR [aRR], 1.28; 95% CI: 1.19–1.37) and for persons with new BC-PTB diagnosis (aRR, 1.16; 95% CI: 1.02–1.32). We successfully matched 530 participants (265 in SITT and 265 in DIT) through 1:1 nearest neighbor caliper matching. Before propensity score-matched analysis, SITT was not significantly associated with the treatment success rate (adjusted OR, 0.97; 95% CI: 0.70–1.33). After propensity score-matched analysis, SITT remained nonsignificantly associated with the treatment success rate (OR, 0.96; 95% CI: 0.67–1.40). GeneXpert thus increases the likelihood of SITT, but SITT has no significant effect on the treatment success rate.

The prevalence of malaria in India is decreasing, but it remains a major concern for public health administration. The role of submicroscopic malaria and asymptomatic malaria parasitemia and their persistence is being explored. A cross-sectional survey was conducted in the Kandhamal district of Odisha (India) during May–June 2017. Blood samples were collected from 1897 individuals for screening of asymptomatic parasitemia. Samples were screened using rapid diagnostic tests (RDTs) and examined microscopically for Plasmodium species. Approximately 30% of randomly selected samples (n = 586) were analyzed using real-time PCR (qPCR), and the genetic diversity of Plasmodium falciparum was analyzed. The prevalence of Plasmodium species among asymptomatic individuals detected using qPCR was 18%, which was significantly higher than that detected by microscopy examination (5.5%) or RDT (7.3%). Of these, 37% had submicroscopic malaria. The species-specific prevalence among asymptomatic malaria-positive cases for P. falciparum, Plasmodium vivax, and mixed infection (P. falciparum and P. vivax) by qPCR was 57%, 29%, and 14%, respectively. The multiplicity of infection was 1.6 and 1.2 for the merozoite surface protein-1 gene (msp1) and (msp2), respectively. Expected heterozygosity was 0.64 and 0.47 for msp1 and msp2, respectively. A significant proportion of the study population, 105/586 (18%), was found to be a reservoir for malaria infection, and identification of this group will help in the development of elimination strategies.

Adult T-cell leukemia/lymphoma (ATLL) is a peripheral T-cell neoplasm caused by the human T-cell leukemia virus type 1 (HTLV-1). It is characterized by a short survival time and lack of response to chemotherapy. We report a case of a 56-year-old woman, from the Brazilian northeast state of Bahia, who presented with a 2-month history of infiltrated papular and nodular skin lesions, especially on her forehead and also on her lower and upper limbs. Laboratory tests revealed positive serology for HTLV-1. Histopathological findings and the immunohistochemical profile confirmed the diagnosis of adult T-cell lymphoma/leukemia. A month after the diagnosis, the patient presented acute fatigue and pronounced paleness of the skin, dying of septic shock after her first chemotherapy cycle. The aim of this case report was to emphasize the importance of maintaining high clinical suspicion for ATLL, considering the epidemiological profile of the disease, especially for patients whose only early symptoms are cutaneous lesions.

Globally, healthcare systems are facing the enormous challenge of the COVID-19 pandemic. Ethiopia is currently implementing different preventive measures to interrupt the transmission of SARS-CoV-2. The early effect of these preventive measures on essential healthcare service delivery is unknown. In this study, we looked at the number of essential healthcare visits over 8 weeks, 4 weeks before and 4 weeks after the implementation of preventive measures. During the implementation of these measures, patient flow decreased in all elements of essential healthcare service. The decline was dramatic for family planning (98%), emergency surgery (77%), and follow-up of chronic surgical conditions (70%). An understanding of the reasons behind the decrease in patient flow is urgently needed to design ways of sustaining essential care.

The SARS-CoV-2 pandemic is now expanding into the developing world with devastating consequences. Departing from a population-based study in rural Ecuador where all adult individuals (aged 40 years or older) were tested for SARS-CoV-2 IgG and IgM antibodies, we expanded it to include a house-based case–control component assessing in-house clustering and other variables potentially associated with infection. We selected houses where exactly two study participants lived and were both seropositive (case-houses), and matched 1:1 to control-houses where both were seronegative. Younger household members had an antibody test performed. Infected household members were found in 33 (92%) case-houses and in only six (17%) control-houses. In 28/29 discordant house pairs, the case-house had seropositive household members and the control-house did not (odds ratio: 28; 95% CI: 4.6–1,144). Our data demonstrate strong in-house clustering of infection in community settings, stressing the importance of early case ascertainment and isolation for SARS-CoV-2 control.

Molecular data are required to improve our understanding of the epidemiology of leptospirosis in Africa and to identify sources of human infection. We applied molecular methods to identify the infecting Leptospira species and genotypes among patients hospitalized with fever in Tanzania and compared these with Leptospira genotypes detected among animals in Tanzania to infer potential sources of human infection. We performed lipL32 real-time PCR to detect the presence of pathogenic Leptospira in acute-phase plasma, serum, and urine samples obtained from study participants with serologically confirmed leptospirosis and participants who had died with febrile illness. Leptospira blood culture was also performed. In positive specimens, we performed species-specific PCR and compared participant Leptospira secY sequences with Leptospira reference sequences and sequences previously obtained from animals in Tanzania. We detected Leptospira DNA in four (3.6%) of 111 participant blood samples. We detected Leptospira borgpetersenii (one participant, 25.0%), Leptospira interrogans (one participant, 25.0%), and Leptospira kirschneri (one participant, 25.0%) (one [25%] undetermined). Phylogenetic comparison of secY sequence from the L. borgpetersenii and L. kirschneri genotypes detected from participants was closely related to but distinct from genotypes detected among local livestock species. Our results indicate that a diverse range of Leptospira species is causing human infection. Although our analysis suggests a close relationship between Leptospira genotypes found in people and livestock, continued efforts are needed to obtain more Leptospira genetic material from human leptospirosis cases to help prioritize Leptospira species and genotypes for control.

Gene drive technologies represent powerful tools to develop vector control strategies that will complement the current approaches to mitigate arthropod-borne infectious diseases. The characteristics of gene drive technologies have raised additional concerns to those for standard genetically engineered organisms. This generates a need for adaptive governance that has not been met yet because of the rapid rate of progress in gene drive research. For the eventual release of gene drive insects into wild populations, an international governance network would be helpful in guiding scientists, stakeholders, public opinion, and affected communities in its use. We examined the current institutions and governing bodies among various continents that could have an impact on gene drive governance or the potential to adapt to its future use. Possible governance strategies also are proposed that seek to bridge gaps and promote an ethically sound policy framework. Ideally, governance strategies should be developed before or at the same pace as gene drive research to anticipate field releases and maximize their impact as a public health tool. However, this is not likely to happen as it takes years to develop global accords, and some countries may choose to move ahead independently on the new technology.