Typhoid Conjugate Vaccine: A Boon for Endemic Regions

Typhoid fever has the highest disease burden in countries in low- and middle-income countries, primarily located in Asia and Sub-Saharan Africa. Previous typhoid vaccines such as the live attenuated typhoid (Ty21a) vaccine and Vi (virulence) capsular polysaccharide vaccine had the limitation that they could not be administered with other standard childhood immunizations and were ineffective in children under two years of age. To address these shortcomings of the previous vaccines, typhoid conjugate vaccines (TCVs) were developed and prequalified by the World Health Organization. Cross-reacting material and tetanus toxoid are widely used as carrier proteins in TCVs. According to various studies, TCV has higher efficacy, has a more extended protection period, and is safe and immunogenic in infants as young as six months. This review article aims to comprehensively appraise the data available on TCVs' efficacy, duration of protection, safety, and immunogenicity in endemic regions.

The dog as a sentinel and animal model for coccidioidomycosis

Coccidioidomycosis is a potentially fatal fungal disease of humans and animals that follows inhalation of Coccidioides spp. arthroconidia in the environment. The disease in dogs resembles that in people, and because dogs may be at increased risk of exposure due to their proximity to the ground and digging behavior, they are valuable models for the disease in humans. Dogs have been sentinels for identification of new regions of endemicity in Washington and Texas. Canine serosurveillance has also been used to predict variables associated with environmental presence of Coccidioides spp. Expansion of the endemic region of coccidioidomycosis with climate change-along with predicted population increases and increased development in the southwest United States-may result in 45.4 million additional people at risk of infection by 2090. Here we provide an overview of the value of dogs as sentinels for the disease and encourage the routine reporting of coccidioidomycosis cases in dogs to public health agencies. We also highlight the value of dogs as naturally occurring models for studying novel treatment options and preventatives, such as a novel live avirulent coccidioidomycosis vaccine.

Dengue Incidence Trends and Its Burden in Major Endemic Regions from 1990 to 2019

BACKGROUND

Dengue has become one of the major vector-borne diseases, which has been an important public health concern. We aimed to estimate the disease burden of dengue in major endemic regions from 1990 to 2019, and explore the impact pattern of the socioeconomic factors on the burden of dengue based on the global burden of diseases, injuries, and risk factors study 2019 (GBD 2019).

METHODS

Using the analytical strategies and data from the GBD 2019, we described the incidence and disability-adjusted life years (DALYs) of dengue in major endemic regions from 1990 to 2019. Furthermore, we estimated the correlation between dengue burden and socioeconomic factors, and then established an autoregressive integrated moving average (ARIMA) model to predict the epidemic trends of dengue in endemic regions. All estimates were proposed as numbers and age-standardized rates (ASR) per 100,000 population, with uncertainty intervals (UIs). The ASRs of dengue incidence were compared geographically and five regions were stratified by a sociodemographic index (SDI).

RESULTS

A significant rise was observed on a global scale between 1990 and 2019, with the overall age-standardized rate (ASR) increasing from 557.15 (95% UI 243.32-1212.53) per 100,000 in 1990 to 740.4 (95% UI 478.2-1323.1) per 100,000 in 2019. In 2019, the Oceania region had the highest age-standardized incidence rates per 100,000 population (3173.48 (95% UI 762.33-6161.18)), followed by the South Asia region (1740.79 (95% UI 660.93-4287.12)), and then the Southeast Asia region (1153.57 (95% UI 1049.49-1281.59)). In Oceania, South Asia, and Southeast Asia, increase trends were found in the burden of dengue fever measured by ASRs of DALY which were consistent with ASRs of dengue incidence at the national level. Most of the countries with the heaviest burden of dengue fever occurred in areas with low and medium SDI regions. However, the burden in high-middle and high-SDI countries is relatively low, especially the Solomon Islands and Tonga in Oceania, the Maldives in South Asia and Indonesia in Southeast Asia. The age distribution results of the incidence rate and disease burden of dengue fever of major endemic regions showed that the higher risk and disease burden are mainly concentrated in people under 14 or over 70 years old. The prediction by ARIMA showed that the risk of dengue fever in South and Southeast Asia is on the rise, and further prevention and control is warranted.

CONCLUSIONS

In view of the rapid population growth and urbanization in many dengue-endemic countries, our research results are of great significance for presenting the future trend in dengue fever. It is recommended to policy makers that specific attention needs to be paid to the negative impact of urbanization on dengue incidence and allocate more resources to the low-SDI areas and people under 14 or over 70 years old to reduce the burden of dengue fever.

Amoebic Liver Abscess: Rare Entity in Recent Times

Intestinal amoebiasis and sequelae such as amoebic liver abscess are rarely reported in the era of modern medicine. Atypical presentation of amoebic liver abscess with high false-positive results on serology in endemic regions poses major diagnostic issues in the developing nations of the world. We report a case of amoebic liver abscess and describe the imaging appearances in a 59-year-old female. A detailed medical history was elicited to determine the etiology of amoebic liver abscess. Furthermore, the diagnosis was confirmed based on serological tests. Percutaneous aspiration of the amoebic liver abscess was performed, and treatment was initiated with intravenous metronidazole followed by diloxanide furoate. The patient has been on follow-up since three months with a negative stool examination and with no complaints of recurrence.

A qualitative exploratory study using One Health approach for developing an intervention package for elimination of human anthrax in an endemic district of Odisha, India

Background & objectives:

Anthrax is a zoonotic disease of public health concern in India. One of the key predisposing factors is linked to the behaviour of the community. This study was nested within a baseline survey to understand the risk perception, attitude, socio-cultural and behavioural practices among different communities in an anthrax endemic tribal district of Odisha, India. It was aimed to explore the systemic gaps from the officials of different departments while addressing the animal and human anthrax cases and the knowledge, attitude, and behavioural practices among the tribal communities with regards to both animal and human anthrax signs, symptoms, and transmission from animal to human.

Methods:

A qualitative exploratory study was carried out in the district of Koraput, Odisha. Insights from eight focus group discussions (FGDs) and 42 in-depth-interviews (IDIs) with the stakeholders from health, veterinary, forest, general administrative departments and community were collected and analyzed thematically.

Results:

Major themes that emerged were inter-departmental coordination, livestock vaccination, surveillance network, laboratory facilities, prevention and control strategies with regards to the animal and human anthrax cases. The study also emphasized setting up the surveillance system as per the standard guidelines, and strengthening the diagnostic facilities for timely detection of confirmed cases. It also highlighted the current needs and the gaps among inter-sectoral coordination, collaboration, and sensitization among Health, Veterinary, Forest, Education, Nutrition, and Tribal Welfare Departments at various levels to reduce the prevalence and control the outbreaks of anthrax in the district and State.

Interpretation & conclusions:

The coordination gaps, financial burden, insufficient relevant knowledge and information among the concerned stakeholders were the issues found in this study in addition to non-availability of proper diagnostic facility. The coordination among different departments adapting One Health approach may be one of the best possible ways for the elimination of anthrax cases in an endemic region.