The global burden of neglected zoonotic diseases: Current state of evidence

The majority of emerging infectious diseases are zoonoses, most of which are classified as "neglected". By affecting both humans and animals, zoonoses pose a dual burden. The disability-adjusted life year (DALY) metric quantifies human health burden since it combines mortality and morbidity. This review aims to describe and analyze the current state of evidence on neglected zoonotic diseases (NZDs) burden and start a discussion on the current understanding of the global burden of NZDs. We identified 26 priority NZDs through consulting three international repositories for national prioritization exercises. A systematic review of global and national burden of disease (BoD) studies was conducted using pre-selected databases. Data on diseases, location and DALYs were extracted for each eligible study. A total of 1887 records were screened, resulting in 74 eligible studies. The highest number of BoD was found for non-typhoidal salmonellosis (23), whereas no estimates were found for West Nile, Marburg and Lassa fever. Geographically, the highest number of studies was performed in the Netherlands (11), China (5) and Iran (4). The number of BoD retrieved mismatched the perceived importance in national prioritization exercises. For example, anthrax was considered a priority NZD in 65 countries; however, only one national study estimating BoD was retrieved. By summing the available global estimates, the selected NZDs caused at least 21 million DALYs per year, a similar order of magnitude to (but less than) the burden due to foodborne disease (included in the Foodborne Disease Burden Epidemiology Reference Group). The global burden of disease landscape of NZDs remains scattered. There are several priority NZDs for which no burden estimates exist, and the number of BoD studies does not reflect national disease priorities. To have complete and consistent estimates of the global burden of NZDs, these diseases should be integrated in larger global burden of disease initiatives.

Rift Valley fever and Brucella spp. in ruminants, Somalia

Background

Fourteen-years after the last Rift Valley fever (RVF) virus (RVFV) outbreak, Somalia still suffers from preventable transboundary diseases. The tradition of unheated milk consumption and handling of aborted materials poses a public health risk for zoonotic diseases. Limited data are available on RVF and Brucella spp. in Somali people and their animals. Hence, this study has evaluated the occurrence of RVFV and Brucella spp. antibodies in cattle, goats and sheep sera from Afgoye and Jowhar districts of Somalia.

Methods

Serum samples from 609 ruminants (201 cattle, 203 goats and 205 sheep), were serologically screened for RVF by a commercial cELISA, and Brucella species by modified Rose Bengal Plate Test (mRBPT) and a commercial iELISA.

Results

Two out of 609 (0.3 %; 95 %CI: 0.04–1.2 %) ruminants were RVF seropositive, both were female cattle from both districts. Anti-Brucella spp. antibodies were detected in 64/609 (10.5 %; 95 %CI: 8.2–13.2 %) ruminants by mRBPT, which were 39/201 (19.4 %) cattle, 16/203 (7.9 %) goats and 9/205 (4.4 %) sheep. Cattle were 5.2 and 2.8 times more likely to be Brucella-seropositive than sheep (p = 0.000003) and goats (p = 0.001), respectively. When mRBPT-positive samples were tested by iELISA, 29/64 (45.3 %; 95 %CI: 32.8–58.3 %) ruminant sera were positive for Brucella spp. Only 23/39 (58.9 %) cattle sera and 6/16 (37.5 %) goat sera were positive to Brucella spp. by iELISA.

Conclusions

The present study showed the serological evidence of RVF and brucellosis in ruminants from Afgoye and Jowhar districts of Somalia. Considering the negligence of the zoonotic diseases at the human-animal interface in Somali communities, a One Health approach is needed to protect public health.

A path to cooperation between China and Mongolia towards the control of echinococcosis under the Belt and Road Initiative

Health is the core of development. Health cooperation between countries plays a pivotal role under the Belt and Road Initiative (B&R). In 2013, China launched its B&R to improve the international cooperation of which health was an important component. As one of the neglected zoonotic diseases, echinococcosis has become a public health concern and is on top of the government agenda among neglected zoonosis in Mongolia. The transmission of the disease involves animal husbandry, and its characteristics determine the prevention and control of such diseases which requires cross-sector collaboration and comprehensive prevention and control strategies. Taking echinococcosis as an entry point and adopting a 'Mongolia-led, China-supported, and results-sharing' approach to public health cooperation will not only contribute to the advancement of Mongolia's national health coverage, but also promoting China's capacity to engage in global health. In this way, it contributes to meeting the sustainable development goals, especially goal 3, target 3.3: by 2030, end the epidemics of AIDS, tuberculosis, malaria and neglected tropical diseases and combat hepatitis, water-borne diseases and other communicable diseases. This paper provides an overview on how the cooperation between China and Mongolia under the context of B&R was initiated, planned and moved forward to implementation. The experience may provide a good model and inform policy and practice for other bilateral cooperations.

Controlling Taenia solium and soil transmitted helminths in a northern Lao PDR village: Impact of a triple dose albendazole regime

Taenia solium taeniasis-cysticercosis and soil-transmitted helminths (STHs) are parasitic Neglected Tropical Diseases endemic throughout Southeast Asia. Within Lao PDR, a remote northern hill tribe village had previously been identified as a hyper endemic focus for T. solium. To reduce this observed prevalence, a One Health intervention covering both pigs and humans was implemented, which included two Mass drug administrations (MDA1 and MDA2) for village residents using a triple dose albendazole 400mg treatment regime. In addition to the effect on T. solium levels, the dual impact of this anthelmintic regime on STHs within the community was also monitored. Faecal samples were collected pre and post MDA1 and MDA2 and analysed for the presence of Taenia species and the STHs Ascaris lumbricoides, Trichuris trichiura and hookworm species. The McMaster technique was used to measure the changes in both prevalence and intensity of infection. Molecular characterisation of Taenia and hookworm species was conducted to detect zoonotic species. The level of taeniasis within the sampled population decreased by 79.4% after MDA1, remained steady during the five month inter-treatment interval and decreased again by 100% after MDA2. The prevalence of STHs decreased by 65.5% and 62.8% after MDA1 and MDA2 respectively; however an increase to 62.1% of pre MDA1 levels was detected during the inter-treatment interval. Individually, hookworm prevalence decreased by 83.4% (MDA1) and 84.5% (MDA2), A. lumbricoides by 95.6% and 93.5% and T. trichiura by 69.2% and 61%. The intensity of infection within the sampled population also decreased, with egg reduction rates of 94.4% and 97.8% for hookworm, 99.4% and 99.3% for A. lumbricoides and 77.2% and 88.5% for T. trichiura. Molecular characterisation identified a T. solium tapeworm carrier from 21.6% (13/60) of households in the village. T. saginata was identified in 5% (3/60) of households. The zoonotic hookworm A. ceylanicum was detected in the resident dog population. These results suggest that the triple dose albendazole 400mg treatment regime achieved a significant reduction in the level of taeniasis whilst simultaneously reducing the STH burden within the village. The increased STH prevalence detected between MDAs reflects the need for behavioural changes and a sustained chemotherapy programme, which may also need to include the resident dog population.