Clinico-molecular diagnosis and phylogenetic investigation of foot-and-mouth disease in small ruminant population of India

Spatial-temporal distribution and risk factors of foot and mouth disease outbreaks in Java Island, Indonesia from 2022 to 2023

BACKGROUND

Indonesia faced new outbreaks of foot and mouth disease in 2022 after being officially free from the disease for several decades. The outbreaks were first reported in East Java in April 2022 and subsequently spread to many regions in Indonesia. This study investigated the epidemiology and risk factors of foot and mouth disease outbreaks in Java, Indonesia, from 2022 to 2023. Descriptive, spatial, spatiotemporal, and risk factor analyses were conducted to investigate the patterns and risk factors associated with the outbreaks in Java.

RESULTS

Results showed that the outbreaks were distributed across the island. East Java was the most affected region. The outbreaks peaked in June 2022, followed by a downward trend until 2023. Positive spatial autocorrelations were found in both years, indicating that the outbreaks clustered in several areas. The spatiotemporal analysis found a total of 16 clusters in both years, with 11 clusters in 2022 and 5 clusters in 2023. The temporal distribution of clusters indicated a peak period from May to July, with 12 out of 16 clusters occurring during this time. Risk factor analysis found that environmental and agricultural-related factors, including annual precipitation, the presence of livestock markets, the presence of slaughterhouses, the presence of animal health centres, cattle population, and goat population, are significant risk factors for the occurrence of outbreaks in Java. Probability risk mapping found higher risk areas primarily distributed in the eastern and central parts of Java.

CONCLUSIONS

The outbreaks predominantly clustered in eastern and central parts of Java. The outbreaks peaked in June 2022, followed by a downward trend until the end of 2023. Environmental and agricultural-related factors significantly increased the risk of outbreak occurrence.

Ovarian activity in crossbred Thai native does during naturally occurring foot-and-mouth disease (FMD) virus infection

This study aimed to compare the follicular dynamics in goats during naturally infected with foot-and-mouth disease virus (FMD) subjected to induced ovulations, and after disease recovery, crossbred Thai native does were synchronized with CIDR for 14 days, and then PGF_2α and PMSG were administered on the day following CIDR removal. The ovarian activity was determined by transrectal ultrasonography. Clinical signs (fever, anorexia, lameness, and foot lesion) were observed on day 12 post-estrus (day 0, day of expected estrus). The study was carried out for 2 periods: FMD outbreak (day 0-day 21) and FMD recovery (day 63-day 84). Infected does were classified into two groups: (I) does without (n = 5) and (II) does with clinical signs (n = 5). The results showed that during FMD outbreak, the number of follicles/waves and number of follicles > 5 mm in ovulatory follicle wave of group II were lower than those of group I and those of its own group after FMD recovery (P<0.05). Higher in follicular regression rate were found in group II compared to group I in the does with 3 follicular waves during FMD outbreak (P<0.05). Moreover, during FMD outbreak, the does had lower number of follicles > 5 mm and longer day of emergence and day of largest follicles in ovulatory follicle wave than of those after FMD recovery. This observation demonstrated that FMD impaired folliculogenesis in goats, and the ovarian activity could be restored about 1 month after disease recovery.

Beneficial effects of antioxidants in improving health conditions of sheep infected with foot-and-mouth disease

The effect of multinutrient antioxidant treatment on sheep naturally infected with FMD virus was investigated in terms of general health conditions, serum proteins profile, and antioxidant/oxidant parameters. Twenty diseased sheep were divided into 4 equal groups (n = 5) and underwent certain therapeutic protocols for 8 weeks as follows: GI, infected not treated group; GII, infected and treated with the ideal and usual line of treatment against FMD virus infection; GIII, infected animals supplemented orally zinc methionine at a dose of 5 g/head/day and vitamin E with selenium-enriched yeast at the same dose level; GIV, infected animals received both the ideal treatment and antioxidants. The animals under experiment were clinically evaluated. Blood samples were obtained for the comet assay and biochemical examination at zero time and at the 8th week after treatment. Results revealed that DNA damage reduced in both GIII and GIV groups which received antioxidants. In the GI group, the activity of SOD and GPx and the level of total antioxidant capacity (TAC) markedly decreased. However, in both GIII and GIV groups treated with multinutrient antioxidants, GPx and TAC values significantly increased after treatment in comparison with the values of the same groups before treatment. After treatment with multinutrient antioxidants, α1-, β-, and γ-globulins levels markedly increased in GII and GIII groups while α2-globulin level decreased. The improvement in healing of clinical signs and general health conditions was clear in the GIV group. Finally, FMD infection in sheep was found to be associated with oxidative stress. The use of antioxidants as therapeutic approaches recovers and improves general health conditions and performance of affected animals.

Emergence of an exotic strain of serotype O foot-and-mouth disease virus O/ME-SA/Ind-2001d in South-East Asia in 2015

The O/Middle East-South Asia (ME-SA)/Ind-2001 lineage of foot-and-mouth disease virus (FMDV) is endemic in the Indian subcontinent and has been reported in the Middle East and North Africa, but it had not been detected in South-East Asia (SEA) before 2015. This study reports the recent incursions of this viral lineage into SEA, which caused outbreaks in Vientiane Capital of Lao People's Democratic Republic (PDR) in April 2015, in Dak Nong, Dak Lak and Ninh Thuan Provinces of Vietnam from May to October 2015, and in Rakhine State of Myanmar in October 2015. Disease investigations were conducted during the outbreaks and followed up after laboratory results confirmed the involvement of FMDV O/ME-SA/Ind-2001 sublineage d (O/ME-SA/Ind-2001d). Affected host species included cattle, buffalo and pig, and all the outbreaks resolved within 2 months. Animals with clinical signs were separated, and affected premises were disinfected. However, strict movement restrictions were not enforced, and emergency vaccinations were only implemented in Vientiane Capital of Lao PDR and Dak Nong and Ninh Thuan Provinces of Vietnam. Clinical samples were collected from each outbreak and examined by nucleotide sequencing of the FMDV viral protein 1 coding region. Sequence analysis revealed that the O/ME-SA/Ind-2001d isolates from Lao PDR and Vietnam were closely related to each other and similar to viruses previously circulating in India in 2013. Viruses collected from Myanmar were divergent from viruses of the same sublineage recovered from Lao PDR and Vietnam but were closely related to viruses present in Bangladesh in 2015. These findings imply that at least two independent introductions of O/ME-SA/Ind-2001d into SEA have occurred. Our study highlights the transboundary nature of foot-and-mouth disease (FMD) and reinforces the importance of improved FMD surveillance and promotion of safer cross-border trade in SEA to control the risk of introduction and spread of exotic FMDV strains.