The present study describes the frequency of Foot and Mouth Disease (FMD) virus serotypes (O,A and Asia-1) in major regions (all provinces) of Pakistan using Indirect Sandwich ELISA.Also,spatial distribution of various FMD serotypes and their comparison is discussed.A total of 590 samples (Epithelial tissue) have been analyzed during a period of five years (2005-2009).Out of 590 samples,180 were found positive,giving an overall confirmation of FMDV about 33.2 ％.Of the prevalent serotypes,FMDV ‘O’ serotype caused most outbreaks (20.7 ％),followed by serotype A (6.6 ％) and serotype Asia-1 (4.6 ％) while there was no positive case oftype ‘C’.The study clearly showed that the disease was more frequent in the agro-climatic zones than in hilly areas.Based on the data of 590 samples (＞50 outbreaks),the overall prevalence of FMDV in cattle and buffaloes in Pakistan was 33.2 ％,while in cattle alone,it was 37.1％,higher than in buffalo (28.7 ％).There were eight cases of mixed serotypes infection,indicating the presence of endemic state of disease.Another significant feature was the change over time.In phase-I (2005-2007),there was an overall prevalence of 29.4 ％,while the occurrence of the serotype O,A and Asia-1 was 20.4 ％,2.9 ％ and 4.7 ％,respectively.During phase-II (2008-2009),the overall prevalence was 59.21％,while those of serotype O,A and Asia-1 were 22.4 ％,31.6 ％ and 4.0 ％,respectively.This clearly indicated a shift from serotype O to A,which may help to explain the occurrence of more severe outbreaks,despite vaccination.

OBJECTIVES: West Nile virus (WNV) is a re-emerging mosquito-borne viral infection. This study investigated the pooled prevalence pattern and risk factors of WNV infection among humans and animals in Nigeria. METHODS: A systematic review was conducted of eligible studies published in PubMed, Scopus, Google Scholar, and Web of Science from January 1, 1950 to August 30, 2020. Peer-reviewed cross-sectional studies describing WNV infections in humans and animals were systematically reviewed. Heterogeneity was assessed using the Cochrane Q statistic. RESULTS: Eighteen out of 432 available search output were eligible and included for this study. Of which 13 and 5 were WNV studies on humans and animals, respectively. Although 61.5% of the human studies had a low risk of bias, they all had high heterogeneity. The South West geopolitical zone of Nigeria had the highest pooled prevalence of anti-WNV immunoglobulin M (IgM; 7.8% in humans). The pooled seroprevalence of anti-WNV IgM and immunoglobulin G (IgG) was 7.1% (95% confidence interval [CI], 5.9 to 8.3) and 76.5% (95% CI, 74.0 to 78.8), respectively. The WNV RNA prevalence was 1.9% (95% CI, 1.4 to 2.9), while 14.3% (95% CI, 12.9 to 15.8) had WNV-neutralizing antibodies. In animals, the pooled seroprevalence of anti-WNV IgM and IgG was 90.3% (95% CI, 84.3 to 94.6) and 3.5% (95% CI, 1.9 to 5.8), respectively, while 20.0% (95% CI, 12.9 to 21.4) had WNV-neutralizing antibodies. Age (odds ratio [OR], 3.73; 95% CI, 1.87 to 7.45; p<0.001) and level of education (no formal education: OR, 4.31; 95% CI, 1.08 to 17.2; p<0.05; primary: OR, 7.29; 95% CI, 1.80 to 29.6; p<0.01) were significant risk factors for WNV IgM seropositivity in humans. CONCLUSIONS The findings of this study highlight the endemicity of WNV in animals and humans in Nigeria and underscore the need for the One Health prevention and control approach.

OBJECTIVES: West Nile virus (WNV) is a re-emerging mosquito-borne viral infection. This study investigated the pooled prevalence pattern and risk factors of WNV infection among humans and animals in Nigeria. METHODS: A systematic review was conducted of eligible studies published in PubMed, Scopus, Google Scholar, and Web of Science from January 1, 1950 to August 30, 2020. Peer-reviewed cross-sectional studies describing WNV infections in humans and animals were systematically reviewed. Heterogeneity was assessed using the Cochrane Q statistic. RESULTS: Eighteen out of 432 available search output were eligible and included for this study. Of which 13 and 5 were WNV studies on humans and animals, respectively. Although 61.5% of the human studies had a low risk of bias, they all had high heterogeneity. The South West geopolitical zone of Nigeria had the highest pooled prevalence of anti-WNV immunoglobulin M (IgM; 7.8% in humans). The pooled seroprevalence of anti-WNV IgM and immunoglobulin G (IgG) was 7.1% (95% confidence interval [CI], 5.9 to 8.3) and 76.5% (95% CI, 74.0 to 78.8), respectively. The WNV RNA prevalence was 1.9% (95% CI, 1.4 to 2.9), while 14.3% (95% CI, 12.9 to 15.8) had WNV-neutralizing antibodies. In animals, the pooled seroprevalence of anti-WNV IgM and IgG was 90.3% (95% CI, 84.3 to 94.6) and 3.5% (95% CI, 1.9 to 5.8), respectively, while 20.0% (95% CI, 12.9 to 21.4) had WNV-neutralizing antibodies. Age (odds ratio [OR], 3.73; 95% CI, 1.87 to 7.45; p<0.001) and level of education (no formal education: OR, 4.31; 95% CI, 1.08 to 17.2; p<0.05; primary: OR, 7.29; 95% CI, 1.80 to 29.6; p<0.01) were significant risk factors for WNV IgM seropositivity in humans. CONCLUSIONS The findings of this study highlight the endemicity of WNV in animals and humans in Nigeria and underscore the need for the One Health prevention and control approach.

Materials and methods: Twenty-one studies out of 2,215 available articles were eligible and included for this systematic review. Relevant articles were searched, screened and included in this study according to the Preferred Reporting Items for Systematic reviews and MetaAnalyses (PRISMA) criteria. The risk of bias in primary studies was assessed by Cochrane's method. Heterogeneity of pooled prevalence was calculated using the chi-square test on Cochrane's Q statistic, which was quantified by I-square values. The random-effects analyses of proportions were used to determine the pooled prevalence of DENV antibodies, antigen and RNA from eligible studies. Results: Of these, 3 studies reported co-circulation of all the 4 serotypes, while 2 separately reported co-circulation of DENV-1 &2 and DENV-1 to -3. All the antibody-based studies had significantly high heterogeneity (I2 >90%, P <0.05), while the NS1 and PCR-based studies had low heterogeneity (I2 <25%, P >0.05). The pooled prevalence of DENV IgM, IgG, RNA, NS1 and neutralizing antibodies were 16.8%, 34.7%, 7.7%, 7.7% and 0.7%, respectively. Southeast Nigeria had the highest pooled DENV-IgG seropositivity, 77.1%. Marital status, gender, educational level and occupation status, the proximity of residence to refuse dumpsite, frequent use of trousers and long sleeve shirts were significantly associated with DENV IgG seropositivity (P <0.05). Conclusion Based on these findings, it can be inferred that Nigeria is hyperendemic for Dengue fever and needs concerted efforts to control its spread within and outside the country.

Materials and methods: Twenty-one studies out of 2,215 available articles were eligible and included for this systematic review. Relevant articles were searched, screened and included in this study according to the Preferred Reporting Items for Systematic reviews and MetaAnalyses (PRISMA) criteria. The risk of bias in primary studies was assessed by Cochrane's method. Heterogeneity of pooled prevalence was calculated using the chi-square test on Cochrane's Q statistic, which was quantified by I-square values. The random-effects analyses of proportions were used to determine the pooled prevalence of DENV antibodies, antigen and RNA from eligible studies. Results: Of these, 3 studies reported co-circulation of all the 4 serotypes, while 2 separately reported co-circulation of DENV-1 &2 and DENV-1 to -3. All the antibody-based studies had significantly high heterogeneity (I2 >90%, P <0.05), while the NS1 and PCR-based studies had low heterogeneity (I2 <25%, P >0.05). The pooled prevalence of DENV IgM, IgG, RNA, NS1 and neutralizing antibodies were 16.8%, 34.7%, 7.7%, 7.7% and 0.7%, respectively. Southeast Nigeria had the highest pooled DENV-IgG seropositivity, 77.1%. Marital status, gender, educational level and occupation status, the proximity of residence to refuse dumpsite, frequent use of trousers and long sleeve shirts were significantly associated with DENV IgG seropositivity (P <0.05). Conclusion Based on these findings, it can be inferred that Nigeria is hyperendemic for Dengue fever and needs concerted efforts to control its spread within and outside the country.

The present study aimed at exploring whether sunlight exposure might account for the relative difference in COVID-19-related morbidity and mortality between tropical and non-tropical countries. A retrospective observational study was designed and data from the World Health Organization weekly COVID-19 epidemiological update was compiled. We examined the total number of confirmed COVID-19 cases per 100 000 population, as well as the total number of COVID-19-related mortalities per 100 000 population. Solar variables data were obtained from the Global Solar Atlas website (https://globalsolaratlas.info/). These data were analyzed to determine the association of sunlight exposure to COVID-19-related morbidity and mortality in tropical and non-tropical countries. Results revealed a statistically significant decrease in the number of confirmed COVID-19 cases per 100 000 population (P<0.001), as well as the number of COVID-19-related mortalities per 100 000 population (P<0.001) between tropical and non-tropical countries. Analyses of sunlight exposure data found that specific photovoltaic power output, global horizontal irradiation, diffuse horizontal irradiation and global tilted irradiation at optimum angle were significantly inversely correlated to COVID-19-related morbidity and mortality. This suggests that stronger sunlight exposure potentially leads to lower COVID-19-related morbidity and mortality. Findings from this study suggest that the relatively low COVID-19-related morbidity and mortality in tropical countries were possibly due to better sunlight exposure that translates into adequate vitamin D status.