The overall five years Malaria trend analysis of Central, North and West Gondar zones indicates that the incidence of confirmed outpatient and inpatient malaria cases were increased from 220406 (22%) in July 2013-June 2014 to 249474 (25%) in July 2015- June 2016 and decreased to 139296 (14%) in July 2017- June 2018. Average annual malaria cases of 200,589 (55 cases per 1000 population) were identified and treated with anti-malaria in Central, North and west Gondar zones which contributes 2.23% of East Africa nations malaria cases. These results shows that there were an increment of cases compared to Namibia 24,682 (12.33/1000 population) cases in 2016, Zambia 119,593 (7.7/1000 population) and highly affected regions of Botswana 794(0.36/1000 population) malaria cases 2017 WHO report [3, 8]. This variation may be due to strong commitment of malaria controlling strategies of the countries, geographical variation and accessibility of controlling materials.
The number of malaria death were also decreased from 14 (0.34/100,000 Population) in July 2013- June 2014 to three (0.07/100,000 Population) in July 2017- June 2018 in the central, North and West Gondar zones. This result shows a different report in Burundi 4,000(4/10,000 population) cases killed due to malaria and similar to five (0.23/100,000 Population) deaths in Botswana 2017 WHO report [3, 5, 8]. This significant difference may be due to outbreak conditions of the country and not timely treatment or arrival of cases to treatment centers and it requires further investigations.
A total of 1770 (0.18%) cases received inpatient malaria service within five years period. Average annual inpatient malaria cases in West Gondar zone were high 265 (83 per 100,000 population) as compared to Central Gondar 69 (three per 100,000 populations) and North Gondar 20 (two per 100,000 populations). From 1770 inpatient cases only 20 deaths were recorded in five years period in these zones. Case Fatality Rate (CFR) in West Gondar zone were 13(3/100,000 population), which is high as compared to Central Gondar zone four (0.89/100,000 population). This zonal inpatient death variation may be due to high 265 (83/100,000 population) inpatient cases in related to central Gondar Zone 69(three/100,000 Population) inpatient cases and not severely arrival of cases to the health institutions and continuous follow up cases in the inpatient service.
Within five years period ≥ 15 years of age were more affected by malaria. Out of 103,391 total confirmed and clinical malaria cases obtaining outpatient and inpatient service, ≥ 15 years of age accounts 720,029(71.76%) followed by 5–14 years of age 183,516(18.29%) in outpatient visit. Within five years period in Central, North and West Gondar zones inpatient malaria cases were 1,770 (17.64/10,000 population) with a discharge rate of 1750 (98.87%). Next to ≥ 15 years of age 1401(14/10,000 population), < 5 years of age 197(2/10,000 population) were more affected compared to 5–14 years of age 140(1.4/10,000 population) in inpatient service. This study shows slightly similar to studies conducted in other part of Ethiopia in 2015 and in North Shoa, Ethiopia between 2013 and 2017 . This may be due to geographical similarity of reported zones and woredas and similarity of study design.
Highest monthly Plasmodium falciparum transmission were observed in November with 24993(17%) cases followed by October 20873(14%) and September 16892(11%) cases respectively. Plasmodium vivax transmission were also high in November, October and September with 7365(14%), 5813(11%) and 5431(10%) cases respectively at Central, North and West Gondar zones. This result showed that a different study conducted in Sibu Sire District, East wolega zone, with a highest peak in June 18.9% followed by May, November, and July with prevalence rate, 13.3%, 13.2%, and 11.2%, respectively. The prevalence rate in October, August, and September were 9.4%, 8.7%, and 7%, respectively . This study variation may be due to amount of rain fall, climatic variation, geographical difference and year of study.
From a total of 1,002, 946 confirmed malaria cases in Central, North and West Gondar zones; Plasmodium falciparum species were 736149 (73.4%) and plasmodium vivax were 266797 (26.6%). This result shows difference in the study conducted in South Wollo zone Kombolcha health center from January to December 2016, plasmodium falciparum accounted for 1243 (60.2%) while P. vivax accounted for 734 (35.5%) cases . In this study PF in West and Central Gondar zone was the most frequently reported species. The reason for this variation is not clear; however, may be due to the previous study focus on health center and the current study cover zonal level and may need further study.
API and ABER of West Gondar zone were High 86929(273/1000 population) and 237675 (75%) respectively compared to Central Gondar zone of API 98816 (40/1000 population) and ABER 286527(12%). Annual parasite incidence were high in Mirab Armachiho, Genda wuha and Metema woreda 20796(481/1000 population), 7753 (298/1000 population) and 37553 (269/1000 population) respectively compared to central and North Gondar zones of its woredas. Annual blood examination rate of Gendawuha 35983(138%) were high compared to Mirab Armachiho 285,743 (132%) and Metema woreda 90723(65%). This result shows that rate of infection with transmission and diagnostic efforts were high in West Gondar zone of all woredas. This high risk may be due to geographical location of the woredas and increased the number of daily labors to investment area.
Annual Falciparum incidence were high in West Gondar zone 67561 (213/ 1000 population) compared to central Gondar Zone 70287 (28/1000 population) and North Gondar 9382 (11/1000 population). Tsegede 11770 (135/1000 population) and Tacharmachiho Woreda 111770 (110/1000 population) were have high annual falciparum incidence relative to other central Gondar zone Woredas. From west Gondar zone; Mirabaremachio 15222 (352/1000 population), Gendawuha 35985 (229/1000 population) and Metema 90723 (218/1000 population) were the leading woreda by Annual falciparum incidence. This result shows that a similar report to 167,079 (43.2%) cases of previous North Gondar Zone 2017 Health Bureau PHEM report . This difference may be due to study period and study design variation and it also need further investigation.
Limitations of the study
Plasmodium Falciparum and Vivax infection by pregnancy status, age categories and death of malaria with species infection were not analayzed. Distrbution of malaria by investement areas with its population at risk were not identified. Additionally, any malaria intervention activities that had been taken to control malaria were not collected from the study area.