Public Health Data Analysis and Recommendations for COVID-19 in Western Visayas as of 30 April 2020

| Posted by UP Media and Public Relations Office


Helena Marie Lagon Alvior, MD1, Mary Camille Samson, RMT1, Joseph Arbizo, RMT, MoS2, and Philip Ian Padilla, MD, PhD2

1ThinkWell Philippines, Iloilo City
2University of the Philippines Visayas, Miagao, Iloilo
*Based on the data available on 30 April 2020.



Extension of enhanced community quarantine in Bacolod City, Iloilo City, and the Province of Iloilo is imposed until May 15, 2020 while other provinces (Aklan, Antique, Guimaras, Capiz, Negros Occidental) in the region are placed under general community quarantine. Decision for the lifting of ECQ in selected provinces are supported by IATF-EID Resolution No. 30 and was announced by Presidential Spokesperson Harry Roque in a press briefing last April 30, 2020.


Figure 1. Trend of COVID Cases in Western Visayas (DOH6 and Provincial/HUC Data)


Local transmission is present in Region VI – Western Visayas and community transmission is increasing. Since April 20 when policy note 1 was shared, there have been 14 new confirmed cases in the region, bringing the total number of confirmed cases to 66. Three out of the fourteen are imported cases, two of which are repatriates. Seven of the fourteen are local and linked transmissions, while the remaining 4 are cases with no known contacts or importations. The provinces of Aklan and Capiz have no new confirmed cases while the island province of Guimaras remain COVID-free (Fig 1. and Table 1).

Local transmission is present in the provinces of Antique, Iloilo, Negros Occidental, and the highly urbanized cities (HUCs), Iloilo City and Bacolod City. Community transmission is increasing, and this is contributed to by Bacolod City, Iloilo City and the province of Iloilo (Fig. 1)


Table 1. Total number of COVID-19 cases in Western Visayas as of April 30, 2020 (DOH6 and Provincial/HUC Data)


Local incidence and daily incidence rates are low:  The incidence for COVID-19 in the different provinces and HUCs of Western Visayas has a range of 0.16 (Negros Occidental) to 2.23 (Antique). Guimaras Province has been excluded already in the data set due to its zero incidence. The daily transmission rates are also notably very low (Table 2).


Table 2. Incidence proportion and daily incidence rate for COVID-19 in Western Visayas


Asymptomatic cases are detected by active contact tracing and testing. Comprising 41% of the COVID-19 cases in the region are asymptomatic and most were tested because they are close contacts of index cases.


Figure 2. Confirmed cases by degree of infection (DOH6 Data)


The detect/trace-test-isolate/treat pathway is indicative of the health system and public health capacity of an area. Only 23 of 66 confirmed cases (35%) in the region have data on number of contacts traced. More than half of confirmed cases in the region have either no published data on contact tracing (39%) or still in initiated/ongoing status (26%). Annex A shows a detailed presentation of the data per province/HUC.

For the 66 confirmed cases, the total number of contacts traced is 840. Almost 71% of traced contacts identified in the region have no data published on their testing status. The province of Iloilo and Iloilo City continue to have no published data on the contact tracing and testing status of their confirmed cases.On the other hand, Bacolod City has started to share data for transparency on their efforts. The rest of the provinces have testing results but are not disaggregated to the cases.

RT-PCR test result turn-around time ranges from a minimum of two (2) days to a maximum of thirteen (13) days (average of 6, mode of 4).The Western Visayas Medical Center Sub-National Laboratory started testing on March 26. Prior to which, test specimens were sent to RITM and turn-around time was 6-7 days. From March 27 to April 11, test results are announced within 2-7 days, with 4 days being the most frequent count. After the Holy Week, turn-around time for the results ranged from 3-13 days, with a mode of 6 days. The data in Figure 3 is based only on the dates of specimen collection and confirmation of COVID-19 cases.Factors of delay are multi-faceted (i.e. supplies shortage, personnel/machine fatigue, invalid results) and further discussions with the SNL team may shed light on the bottlenecks that need to be addressed.


Figure 3. Testing result turn-around time by confirmed case (DOH6 and Provincial/HUC Data)


The WVMC SNL has been designated to test specimen from Region 4B and Region 6 as per DOH Memorandum 2020-0188. The facility has already conducted a total of 4,130 tests and remaining available test count is 2,640. According to the UPV Philippine Genome Center Visayas, a third PCR machine has arrived at the SNL. It can be assumed that the maximum testing capacity per day has increased from 200 tests per day to 400 tests per day. Available data shows that the highest number of tests conducted in a day is 287, while the average is about 123 tests. Given the sample calculation below (Fig. 4), testing capacity can accommodate all specimens (persons under monitoring, suspect cases, probable cases and those pending) in 6 days, provided WVMC SNL is maximizing capacity.


Figure 4. Testing result turn-around time by confirmed case (DOH6 and Provincial/HUC Data)


For Region 6 – Western Visayas, a total of 2,823 specimen have been submitted for testing. An average of 2.4% turn out positive (range: 1.2-3.1%), negative results account for 84.8%, and 12.9% are still pending.

In Western Visayas, there are 316 identified quarantine facilities with a total of 5,899 beds to accommodate COVID-19 related cases (Table 3). This statistic is inclusive of facilities intended for use by the repatriated Overseas Filipino Workers (OFWs). Most of the municipalities have identified at least 1 quarantine facility. However, considering the number of positive and COVID-related cases in the region, these facilities are not fully utilized since most probable, suspect, and asymptomatic cases are placed under home quarantine. The 41.73% bed occupancy rate of in Negros Occidental is the highest in the region but still low compared to the number of available beds. The underutilization of these facilities can strain healthcare resources.


Table 3. Distribution of COVID-19 Quarantine Facilities in Western Visayas (DOH6 Data).


There are 37 COVID-19 treatment facilities in the region where 21 (57%) facilities are government-owned and the other 16 (43%) are private facilities. Fifteen of these government facilities are classified as level 1 facilities while 3 other facilities are categorized as Level 2. Private facilities also account for the 10 other Level 2 facilities while all Level 3 facilities (3 government, 6 private) are in HUCs – Bacolod City and Iloilo City.


Figure 5. Distribution of COVID-19 Treatment Facilities in Western Visayas per Province/HUC (DOH6 Data)


Out of 744 beds in identified treatment facilities, only 21% is occupied indicating that most COVID-related cases are mild. Strict monitoring appropriate management of these mild cases should be done to prevent further infection. There are 84 mechanical ventilators for exclusive use of COVID-19 patients, 60% of which are available in private hospitals. Ventilators in Level 3 government facilities are available in Corazon Locsin Montelibano Memorial Hospital (CLMMH) and Western Visayas Medical Center (WVMC) located in Bacolod City and Iloilo City,respectively. In Western Visayas, WVMC has been identified as the main treatment center for COVID-19 patients.


Figure 6. Availability of Beds and Mechanical Ventilators in Region 6 COVID-19 Treatment Facilities (DOH COVID-19 Tracker)



From a public health perspective, the Department of Health guided by CDC’s Pandemic Interval Framework came up with an LGU Epidemic Response Framework and Classification Methodology (Fig.7) to guide LGUs in the decision-making process for in relation to ECQ implementation. Possible actions for the gradual lifting of ECQ in the provinces are dependent on the critical care utilization rate and case doubling time which will determine the pandemic phase of an area and basis for proper COVID-19 response strategies.


Figure 7. LGU Epidemic Response Framework and Classification Methodology for April 30 Decision by DOH


Reproductive number (R0):  R0 (R naught) or Reproductive number indicates how contagious a particular infectious disease is. Higher than 1 indicates more number of infections. Less than 1 means less number of infections and epidemic is now declining. R0 for the whole of WV is little less than 1 signifying the epidemic is in a decline overall in the region. Negros Occidental has the slowest viral transmission rate with Iloilo Province and City, and Antique closer to the WV R0 (Table 4). This data is further supported by the Forecast Report No. 5 by David et al showing the same decreasing R0 trend at less than 1 for the whole island of Panay (Fig. 8).

Table 4. Reproductive number (R0) for COVID-19 in Western Visayas as of May 1, 2020


Figure 8. Reproduction number and moving average interpolation for Panay from April 1. The reproduction number R for Panay has dropped below 1 based on latest trends. Care must be taken to ensure adequate testing and health measures are in place before ECQ is relaxed (Adapted from David, et al. Forecast Report No. 5. (COVID-19 FORECASTS IN THE PHILIPPINES: Sub-National Models for NCR and other Selected Areas)


Force of infection (FoI):  Fo Iindicate rate of infection among susceptible populations. WV FoI values over time had two peaks (in the middle of March and April). Aklan had the most promising pattern with zero transmissions after April 1 indicating good infection control (applicable for confirmed cases only). Capiz had the second most promising pattern with the highest peak occurring during the third week of April. The rest of the LGUs also exhibited favorable patterns with declining FoI values at the end of April. The declining rates are also reflected for the whole of WV(Fig. 9).


Figure 9. Temporal patterns of the Force of Infection (FoI) of COVID-19 in Western Visayas provinces as of May 1, 2020. Vertical grey bars indicate the presence of cases on specific date, while dashed blue lines indicate current day


Epidemic projections:  Daily projections based on an unchanged R0 for the region might hinge on cases from Antique and Iloilo City and to a lesser extent, Iloilo Province. Aklan, Capiz, and Negros Occidental projections indicate zero cases for May based on current measures. Projected rates for WV will depend on stricter measures for Antique, Iloilo Province and City (Fig. 10). Antique has high case turnouts because they are practicing active case finding, diligently doing contact tracing and testing, and recent confirmed cases are already contacts of contacts.


Figure 10. Epidemic projections of probable daily cases of COVID-19 if the R0 value is unchanged in Western Visayas provinces. The areas colored in grey indicate the predicted incidence for the next 30 days within the 95% credible interval



1. Based on the overall transmission rates data, COVID-19 infection is controlled and gradually declining. However, the recent arrival of OFWs, who are now confirmed cases, might lead to another wave of new infections if public health measures are not in place:


• Who is on top of the disease surveillance and contact tracing in the region and at each province/HUC? Who are the strong links to facilitate rapid data sharing for analysis and decision-making?

• The high proportion of asymptomatic confirmed cases is indicative that the infection is present and with the lifting of the quarantine more of these may be potential carriers.


Figure 11. A sample of a Patient Pathway by DOH


• Review contact tracing data and disaggregate per case, if possible, to ensure that all contacts or possible clusters of cases can be contained. (Refer to Annex A)

• Multisectoral collaboration is evident in helping to build the capacity of the WVMC SNL. There is a need to look into the turn-around time delays, find bottlenecks, and work together to address them.An additional SNL in the region can ramp up the testing capacity and can serve as back up.


• Who are the teams in charge at every step/level of the pathway?What are the possible supply needs at every step/level of the pathway?

• Clarity on this and when communicated well to all of the constituents is indicative of a system in place, working hard to protect the people and contain the spread even while quarantine measures are being lifted.

• Review list of quarantine facilities and determine realistic capacity (human resource and supply complement). (Refer to Annex B1)

• Build the capacity of the treatment facilities/hospitals, especially at the district/provincial levels. (Refer to Annex B3)

• Engage in dialogue for the strengthening of the referral networks.

2. If the data remains constant, Western Visayas LGUs might already transition from ECQ to GCQ with stricter measures for LGU hotspots and for HUCs, with influx of OFWs. The region may adopt the classification shown in the table below to guide the provinces/HUCs and update it accordingly:


Table 5. Provincial and regional strategic response and action points for COVID-19 based on the LGU Epidemic Response Framework of DOH.


3. Lastly, it is emphasized that the assumption here is the continuing trend of R0 reduction and other factors remaining constant. In-migration movements especially in Panay Island, including returning OFWs, and other residents (students, other workers from other regions) is a major factor and therefore, more strategies to mitigate this should be in place. There needs better coordination among the different WV LGUs, regional department agencies, and the National Government.


Download the full policy note here.


Abrigo, MRM, et al. Projected disease transmission, health system requirements, and macroeconomic impacts of the Coronavirus Disease 2019 (COVID-19) in the Philippines

Balista, JAF. COVID-19 Time-dependent reproduction number, Rt: threshold and context for Iloilo

David, G.  et al. Forecast Report No. 5. COVID-19 Forecasts in the Philippines: Sub-national models for NCR and other areas. University of the Philippines, OCTA Research

DOH.GOV.PH. DOH COVID-19 Tracker Philippines. Tableau. [Online] 2020. [Cited: May 1, 2020, 2020.]

Ferriols, Noel. Report on testing capacity of the sole Covid-19 testing center in WV. 26 April 2020. PGC-Visayas, UP Visayas

UP COVID-19 Pandemic Response Team. Modified Community Quarantine beyond April 30: Analysis and Recommendations. University of the Philippines.

World Health Organization. COVID‑19 Strategy Update 14 April 2020.