Slaying little dragons: the impact of the Guinea Worm Eradication Program on dracunculiasis disability averted from 1990 to 2016

Guinea Worm Disease: A Neglected Diseases on the Verge of Eradication

Background: Dracunculiasis, also known as Guinea worm disease (GWD), is a neglected tropical disease (NTD) caused by a parasite (Dracunculus medinensis). In the past, dracunculiasis was known as “the disease of the empty granary” because of the difficulties patients had in going to work in fields or to school when affected by this disease. In tropical areas, the condition has been widespread in economically disadvantaged communities, and has been associated with reduced economic status and low levels of education. Methods: we searched PubMed, Scopus, Google Scholar, EMBASE, Cochrane Library, and WHO websites for literature addressing dracunculiasis published in the last 50 years. Results: by development and optimization of multi-layered control measures, transmission by the vector has been interrupted, but there are foci in several African countries with a high risk of compromising the results obtained in the control of this neglected disease. Conclusion: this review features state-of-the-art data on the infection prevalence, geographical distribution, diagnostics, parasite–host interactions, and the pathology of dracunculiasis. Also described are the current state and future perspectives for vector control and elimination strategies.

Global burden and trends of neglected tropical diseases from 1990 to 2019

BACKGROUND

An updated analysis of neglected tropical diseases (NTDs) from a global perspective is missing from the literature. We aimed to assess the global burden and trends of NTDs from 1990 to 2019.

METHODS

Yearly incident case, mortality and disability-adjusted life years (DALYs) data for NTDs were extracted from the Global Burden of Disease Study 2019 (GBD 2019) based on global, regional, country, social development index (SDI), age and sex categories. The age-standardized rate (ASR) and number of incident cases, mortality and DALYs were computed from 1990 to 2019. The estimated annual percentage change (EAPC) in the ASR was calculated to quantify the changing trend.

RESULTS

Globally, the age-standardized incidence rate (ASIR) and the number of incident cases of total NTDs increased between 1990 and 2019, whereas the age-standardized mortality rate (ASMR), mortality, age-standardized DALY rate and DALYs of total NTDs decreased. Although tropical Latin America, South Asia, Southeast Asia and Oceania had the highest ASIR for total NTDs in 2019, tropical Latin America was the only region to experience a decreasing trend in ASIR from 1673.5 per 100 000 in 2010 to 1059.2 per 100 000 in 2019. The middle, high-middle and high SDI regions experienced increasing ASIR trends between 1990 and 2019, whereas the low-middle SDI region remained stable, and the low SDI region presented a decreasing trend. Children and older adults were vulnerable to dengue, rabies and leishmaniasis (cutaneous and mucocutaneous). Females had a higher ASIR but a lower ASMR and age-standardized DALY rate than males.

CONCLUSIONS

NTDs still represent a serious problem for public health, and the increasing ASIR and incident cases globally may require more targeted strategies for prevention, control and surveillance, especially among specific populations and endemic areas.

Infectious disease: Dog diets may drive transmission cycles in human Guinea worm disease

Domestic dogs have an important role in the ecology of transmission of the Guinea worm, a debilitating human parasite. A new study documents how fish content in dogs' diets can predict Guinea worm infection status, suggesting additional avenues for control.

Early warning signals of malaria resurgence in Kericho, Kenya

Campaigns to eliminate infectious diseases could be greatly aided by methods for providing early warning signals of resurgence. Theory predicts that as a disease transmission system undergoes a transition from stability at the disease-free equilibrium to sustained transmission, it will exhibit characteristic behaviours known as critical slowing down, referring to the speed at which fluctuations in the number of cases are dampened, for instance the extinction of a local transmission chain after infection from an imported case. These phenomena include increases in several summary statistics, including lag-1 autocorrelation, variance and the first difference of variance. Here, we report the first empirical test of this prediction during the resurgence of malaria in Kericho, Kenya. For 10 summary statistics, we measured the approach to criticality in a rolling window to quantify the size of effect and directions. Nine of the statistics increased as predicted and variance, the first difference of variance, autocovariance, lag-1 autocorrelation and decay time returned early warning signals of critical slowing down based on permutation tests. These results show that time series of disease incidence collected through ordinary surveillance activities may exhibit characteristic signatures prior to an outbreak, a phenomenon that may be quite general among infectious disease systems.